**The Materials Research Society Series**

StefanoPasserini · Linda Barelli · Manuel Baumann · JensF. Peters · MarcelWeil *Editors*

# Emerging Battery Technologies to Boost theClean Energy Transition

Cost, Sustainability, and Performance Analysis

The Materials Research Society Series

The Materials Research Society Series covers the multidisciplinary field of materials research and technology, publishing across chemistry, physics, biology, and engineering. The Series focuses on premium textbooks, professional books, monographs, references, and other works that serve the broad materials science and engineering community worldwide. Connecting the principles of structure, properties, processing, and performance and employing tools of characterization, computation, and fabrication the Series addresses established, novel, and emerging topics. Stefano Passerini • Linda Barelli Manuel Baumann • Jens F. Peters • Marcel Weil Editors

# Emerging Battery Technologies to Boost the Clean Energy Transition

Cost, Sustainability, and Performance Analysis

Editors Stefano Passerini Sapienza University of Rome Rome, Italy

Manuel Baumann Karlsruhe Institute of Technology Karlsruhe, Germany

Marcel Weil Karlsruhe Institute of Technology Karlsruhe, Germany

Linda Barelli University of Perugia Perugia, Italy

Jens F. Peters University of Alcalá Alcalá de Henares, Spain

ISSN 2730-7360 ISSN 2730-7379 (electronic) The Materials Research Society Series ISBN 978-3-031-48358-5 ISBN 978-3-031-48359-2 (eBook) https://doi.org/10.1007/978-3-031-48359-2

© The Editor(s) (if applicable) and The Author(s) 2024. This is an open access publication.

Open Access This book is licensed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license and indicate if changes were made.

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# Editors' Foreword

Batteries are a crucial element for the world's future energy systems built upon renewable energy sources of strongly intermittent nature such as solar and wind. While the market for lithium-ion batteries, the currently dominating technology, keeps growing at stunning pace and technological boundaries are being pushed further, also concerns about the corresponding demand for raw materials and associated environmental and societal impacts are becoming stronger. This has led to an increase of research activities in the field of recycling, material demand and sustainability of lithium-ion batteries, but also to the search and development of new battery technologies based on more abundant, less toxic and broadly available materials. To this regard, technologies based on materials such as sodium, magnesium or aluminium could play a crucial role since they are expected to offer advantages in terms of performance, costs and sustainability. However, these systems are still in an early stage of development, while many sustainability problems do not arise until a technology is broadly implemented and creates market forces strong enough to trigger changes in the industrial landscape, global resource and material streams and corresponding mining and waste handling activities. Here, the principal challenge is to identify promising technologies in an early research stage, extrapolate their possible future deployment at the large scale and thereby assess potential sustainability hotspots in a prospective, foresight-oriented view, anticipating recycling and circular economy challenges. This requires a combination of different perspectives including electrochemistry and material science, energy system modelling, market projections and material flow analysis, system analysis and environmental assessments, as well as societal expectations regarding technology and sustainability.

The present book analyses the most relevant technological developments in the field of batteries, taking a prospective and interdisciplinary view with a broad sustainability angle, including environmental, societal and economic aspects. By assuming a broad introduction of the considered emerging technologies in the markets, potential environmental, societal and economic implications are anticipated from a system and technology assessment perspective, providing a glimpse on the energy storage demand answered by future batteries systems. As such, the book will be relevant to all scholars working on or interested in the development or the assessment of new battery technologies or other energy storage technologies and their integration in the power system or in on-board applications.

Rome, Italy Stefano Passerini Perugia, Italy Linda Barelli Karlsruhe, Germany Manuel Baumann Alcalá de Henares, Spain Jens F. Peters Karlsruhe, Germany Marcel Weil

# Overview of the Book

Rechargeable batteries are everywhere, from our mobile phone and its wireless earphones, our cars, trucks, and buses up to large battery installations replacing conventional power plants for guaranteeing stability of the electricity grid. However, the sustainability of this booming market is repeatedly being questioned, with the energy-intensive cell manufacturing, resource demand and shortages, or limited recyclability just being some of the keywords frequently heard in this context. Moreover, also limitations of current technologies are remarked in addressing seasonal energy storage needs. New battery technologies are being developed aiming at solving at least some of these issues by using earth-abundant materials, applying design-for-recycling principles, or pushing performance and economic boundaries far beyond the current state of the art of current lithium-ion batteries. But can these expectations be ever fulfilled? This book tries to give a first answer on this critical question by combining the perspectives of technology developers with those of system analysts, presenting emerging battery technologies that could contribute to short- and long-term storage in different application areas. Moreover, prospective analyses of the potential sustainability challenges and opportunities of these emerging technologies in a future decarbonized economy are provided. In this way, the reader has the opportunity to gather knowledge not only at the technology level, but also on a systemic scale, analyzing the whole sector from both a micro- and a macro-scale perspective.

# Acknowledgments

The editors want to thank all the authors that supported this project from the very beginning with their expertise and their valuable time. In addition, the editors acknowledge the financial support from the Institute of Technology Assessment (ITAS) of the Karlsruhe Institute of Technology, in particular the Helmholtz Program Energy System Design and Materials and Technologies for the Energy Transition, the EU-Project Storage Research Infrastructure Eco-System1 and the European Energy Research Alliance Joint Programme for Energy Storage.2

1 https://www.storiesproject.eu/

2 https://www.eera-energystorage.eu/

# Contents

#### Part I Batteries for the Clean Energy Transition

# Contributors

Abdur-Rahman Ali Chair of Sustainable Manufacturing & Life Cycle Engineering, Institute of Machine Tools and Production Technology (IWF), Technische Universität Braunschweig, Braunschweig, Germany

Fraunhofer Institute for Surface Engineering and Thin Films IST, Braunschweig, Germany

Joao Avelar TES – Sustainable Technology Solutions, TES, Recklinghausen, Germany

Joris Baars Fraunhofer Institute for Surface Engineering and Thin Films IST, Braunschweig, Germany

Manuel Baumann Karlsruhe Institute of Technology – Institute for Technology Assessment and System Analyses (ITAS), Karlsruhe, Germany

Sergio Brutti Department of Chemistry, Sapienza University of Rome, Rome, Italy

Johannes Büngeler HOPPECKE Batterien GmbH & Co. KG, Brilon, Germany

Maurizio Cellura University of Palermo, Palermo, Italy

Felipe Cerdas Chair of Sustainable Manufacturing & Life Cycle Engineering, Institute of Machine Tools and Production Technology (IWF), Technische Universität Braunschweig, Braunschweig, Germany

Fraunhofer Institute for Surface Engineering and Thin Films IST, Braunschweig, Germany

Paul Christensen School of Engineering, Newcastle University, Newcastle, UK

Cristian Giovanni Colombo Department of Energy, Politecnico di Milano, Milan, Italy

Amrita Dasgupta International Energy Agency (IEA), Paris, France

Shannon Helen Davies Tyndall Centre of Climate Change Research, School of Engineering, Newcastle University, Newcastle, UK

Eduardo Sanchez Diéz Centre for Cooperative Research on Alternative Energies (CIC EnergiGUNE), Basque Research and Technology Alliance (BRTA), Alava Technology Park, Vitoria-Gasteiz, Spain

Christian Doetsch Fraunhofer Institute for Environmental, Safety and Energy Technology UMSICHT, Oberhausen, Germany

Fraunhofer UMSICHT, Oberhausen, Germany

Nicolas von Drachenfels Battery Lab Factory Braunschweig (BLB), Technische Universität Braunschweig, Braunschweig, Germany

Ulrike Ehrenstein Fraunhofer Institute for Environmental, Safety and Energy Technology UMSICHT, Oberhausen, Germany

Laura Mesa Estrada Karlsruhe Institute of Technology – Institute for Technology Assessment and System Analyses (ITAS), Karlsruhe, Germany

Marco Ferraro CNR-Istituto di Tecnologie Avanzate per L'Energia "Nicola Giordano" (ITAE), Palermo, Italy

Federica Foiadelli Department of Energy, Politecnico di Milano, Milan, Italy

Giorgia Greco Department of Chemistry, Sapienza University of Rome, Rome, Italy

Anna Grevé Fraunhofer Institute for Environmental, Safety and Energy Technology UMSICHT, Oberhausen, Germany

Martina Haase Karlsruhe Institute of Technology – Institute for Technology Assessment and System Analyses (ITAS), Karlsruhe, Germany

Oliver Heidrich Tyndall Centre of Climate Change Research, School of Engineering, Newcastle University, Newcastle, UK

Christoph Helbig University of Bayreuth, Bavarian Center for Battery Technology (BayBatt), Bayreuth, Germany

Martin Hillenbrand University of Bayreuth, Bavarian Center for Battery Technology (BayBatt), Bayreuth, Germany

Thomas Holberg TES – Sustainable Technology Solutions, TES, Recklinghausen, Germany

Nathalie Iofrida Department of Agriculture, University Mediterranea of Reggio Calabria, Reggio Calabria, Italy

Alissa Kendall University of California, Davis, CA, USA

Michela Longo Department of Energy, Politecnico di Milano, Milan, Italy

Anna Irene De Luca Department of Agriculture, University Mediterranea of Reggio Calabria, Reggio Calabria, Italy

Michael Lüken New Vision University (NVU), School of Politics and Diplomacy, Climate and Sustainability Governance Research, Tbilisi, Georgia

Christine Minke Chair of Circular Economy Systems, Clausthal University of Technology, Clausthal-Zellerfeld, Germany

Seyed Mahdi Miraftabzadeh Department of Energy, Politecnico di Milano, Milan, Italy

Marina Mistretta Department of Information, Infrastructure and Sustainable Energy, University Mediterranea of Reggio Calabria, Reggio Calabria, Italy

Tim Müller Karlsruhe Institute of Technology – Institute for Thermal Energy Technology and Safety (ITES), Karlsruhe, Germany

Maria Assunta Navarra Department of Chemistry, Sapienza University of Rome, Rome, Italy

Oladele Ogunseitan University of California, Irvine, CA, USA

Javier Olarte CIC energiGUNE, Parque Tecnológico de Álava, Albert Einstein, Vitoria-Gasteiz, Álava, Spain

Drahomíra Pavelková Faculty of Management and Economics, Tomas Bata University in Zlín, Zlín, Czech Republic

Viera Pechancová University Institute, Tomas Bata University in Zlín, Zlín, Czech Republic

Federico Poli Department of Chemistry "Giacomo Ciamician", Alma Mater Studiorum Universitá di Bologna, Bologna, Italy

ENERCube, Centro Ricerche Energia, Ambiente e Mare, Centro Interdipartimentale per la Ricerca Industriale Fonti Rinnovabili, Ambiente, Mare ed Energia (CIRI -FRAME), – Alma Mater Studiorum University of Bologna, Marina di Ravenna, RA, Italy

BETTERY Srl, Massafra, Italy

National Reference Center for Electrochemical Energy Storage (GISEL) – INSTM, Florence, Italy

Bernhard Riegel HOPPECKE Batterien GmbH & Co. KG, Brilon, Germany

Petr Sáha University Institute, Tomas Bata University in Zlín, Zlín, Czech Republic

Eva Schischke Fraunhofer Institute for Environmental, Safety and Energy Technology UMSICHT, Oberhausen, Germany

Max Schönfisch International Energy Agency (IEA), Paris, France

Francesca Soavi Department of Chemistry "Giacomo Ciamician", Alma Mater Studiorum Universitá di Bologna, Bologna, Italy

ENERCube, Centro Ricerche Energia, Ambiente e Mare, Centro Interdipartimentale per la Ricerca Industriale Fonti Rinnovabili, Ambiente, Mare ed Energia (CIRI -FRAME), – Alma Mater Studiorum University of Bologna, Marina di Ravenna, RA, Italy

BETTERY Srl, Massafra, Italy

National Reference Center for Electrochemical Energy Storage (GISEL) – INSTM, Florence, Italy

Brian Tarroja University of California, Irvine, CA, USA

Akiko Tsurumaki Department of Chemistry, Sapienza University of Rome, Rome, Italy

Giovanni Tumminia CNR-Istituto di Tecnologie Avanzate per L'Energia "Nicola Giordano" (ITAE), Palermo, Italy

Brent Wanner International Energy Agency (IEA), Paris, France

Stefan Wolf VDI/VDE Innovation + Technik GmbH, Berlin, Germany

Dario Zaninelli Department of Energy, Politecnico di Milano, Milan, Italy

# Part I Batteries for the Clean Energy Transition

#### Preface

Accelerated global warming evidences the need for a drastic change of our present society towards a world economy operating within the planetary boundaries. This implies, among others, a rapid and profound decarbonization with all activities ultimately based on renewable energies. To overcome the intrinsic variable nature of renewable energy sources, the integration of energy storage devices, particularly batteries, is considered as a key enabler, allowing to store electricity for use on demand in areas that have traditionally been run on fossil energy. These include a wide set of grid-connected and mobility services and, possibly, new fields such as drones and robotics.

This chapter prepares the ground for the subsequent chapters of the book by introducing the general concepts and challenges related with these transitions. Specifically, Chapter 1 picks the mobility sector as one of the sectors that is undergoing fundamental changes and elaborates on the specific trends to be expected in near future and the role that batteries play for these. This includes not only electrification of vehicles but also aspects of intelligent vehicles, interconnections, and charging infrastructure. Chapter 2 then takes a circular economy perspective by introducing the key challenges and opportunities related with the transition toward a closed loop economy. It tackles the limitations of the present linear economy model and introduces the "R"-imperatives of the circular economy and then applies these to the emerging battery recycling sector to highlight the most important bottlenecks for a circular battery economy.

# Chapter 1 Mobility and Future Trends

Seyed Mahdi Miraftabzadeh, Michela Longo, and Federica Foiadelli

#### Contents

#### 1.1 Introduction

The world is rapidly changing, and the transportation and mobility industry is no exception. Mobility, a paramount part of modern society, helps people to access jobs, education, healthcare, and other destinations. There has been a significant shift in thinking about mobility, with a growing emphasis on sustainability and the need to reduce the environmental consequence of transportation. Mobility is an essential aspect of modern society, encompassing everything from personal transportation to public transit, logistics, and infrastructure. With the rapid advancements in technology, mobility is undergoing a significant transformation, with new technologies and services emerging that have the potential to revolutionize the way we move [1– 3]. Mobility has seen a surge in development over the past few decades, and it is worthwhile to follow the latest trends in recent years.

S. M. Miraftabzadeh · M. Longo (✉) · F. Foiadelli

Department of Energy, Politecnico di Milano, Milan, Italy e-mail<EMAIL_ADDRESS>
© The Author(s) 2024

https://doi.org/10.1007/978-3-031-48359-2\_1 S. Passerini et al. (eds.), Emerging Battery Technologies to Boost the Clean Energy Transition, The Materials Research Society Series,

One of the most significant development and trends in mobility is the transition toward electric vehicles (EVs) from internal combustion engine vehicles. Electric vehicles are powered by batteries rather than fossil fuels, and they produce zero emissions while in operation [1, 4, 5]. Thus, EVs are more sustainable options compared to traditional fuel-powered vehicles. Additionally, the cost reduction of batteries and advancements in charging infrastructure make EVs a more reasonable choice for all people.

Furthermore, another trend in mobility is the rise of ride-sharing services like Uber and Lyft, which allow individuals to hail a ride from their smartphones and pay for it through the app, making transportation more accessible and convenient for many people, especially in urban areas where public transport may not be as welldeveloped [1, 6]. However, the convenience of ride-sharing comes with a cost, as these services have been criticized for exacerbating traffic congestion and air pollution. Also, the rise of ride-sharing has led to a decrease in public transportation and personal car ownership, which can negatively impact the environment and the economy [7]. Additionally, the employment status of ride-sharing drivers has also been a topic of debate, as some argue that they should be classified as employees rather than independent contractors. Despite these challenges, ride-sharing continues to grow in popularity and is expected to impact the future of transportation significantly.

The remainder of this chapter is organized as follows: toward the electrification of mobility is presented in Sect. 1.2. Section 1.3 presents the e-mobility and future trends. Electromobility charging infrastructure is given in Sect. 1.4. Section 1.5 discusses the importance of 5G technology in mobility and its applications. Finally, the future trends in mobility are presented in Sect. 1.6.

# 1.2 Toward the Electrification of Mobility

Electrification will play an essential role in the modification of the transportation and mobility industry and has offered major opportunities in recent years, including the environmental impacts and CO2 emission reductions of transportation [1, 4]. In general, mobility electrification refers to the use of electric power for transportation, such as electric vehicles, electric bikes, and electric scooters. The shift to e-mobility has been increasing in recent years; however, several factors, as presented in Fig. 1.1, enhance such a transition.

Several factors reinforce mobility electrification as follows [7–9]:

Government policies and incentives: Many countries have implemented policies and incentives to encourage the adoption of electric vehicles, such as tax breaks, grants, and subsidies.

Advancements in technology: The new development and improvements in battery technology have directed to cost reduction of batteries. Also, the introduction of new modules of fast and ultrafast charging has surpassed the so-called "range

Fig. 1.1 Factors driving mobility electrification

anxiety" issue of new e-mobility customers. Thus, electric vehicles are a more reasonable and affordable option for a wider range of customers.

Growing consumer demand: The transportation sector is one of the main responsible actors for climate emissions. As the concerns about climate change have grown, more people have become aware of the negative environmental impact of transportation as well. Therefore, more consumers have been choosing e-mobility, particularly electric vehicles, which are considered a sustainable alternative compared to traditional ones.

Increase in charging infrastructure: Governments and private companies are investing in the development and expansion of charging stations, both in residential and public spots, to sustain the growth of e-mobility. These investments resulted in finding more charging stations in cities and on roads in many countries.

Government and industry entities will persist in working together to promote further mobility electrifications in various areas. The availability of charging infrastructures requires to be expanded to provide more convenience for consumers to charge their EVs outside their homes as well. The improvement in the range and performance of electric vehicles reduces consumer concerns about long-distance travel with electric vehicles. The development of a thorough strategy for end-of-life battery management minimizes the environmental impact of EV batteries. Finally, customers' concerns regarding the cost, recent advances in electric vehicle performance, and sustainability of e-mobility need to be constantly updated.

#### 1.3 E-Mobility and Future Trends

E-mobility refers to any means of transportation (electric vehicles, electric bikes, electric scooters) that work by electric power. E-mobility is considered a sustainable option compared to conventional diesel and gasoline vehicles since it produces no emissions while in operation and can be powered by renewable energy sources (RESs) such as wind and solar energy, which significantly reduce the carbon footprint of transportation.

E-mobility is a promising solution for decreasing harmful pollutants and greenhouse gas emissions from transportation. However, maximizing the environmental benefits of e-mobility depends on the source of electric energy used to charge the vehicles, the manufacturing process of EVs, and the disposal of the battery at the end of its life span. Additionally, more strategies are required to achieve zero-emission transportation than only the transition to e-mobility, including sustainable urban planning, bike-sharing, and expanding public transportation systems to decrease the overall dependence on personal motorcars.

One of the main trends in e-mobility is the increasing adoption of electric vehicles since battery technology has advanced; the cost of batteries decreased from \$1000 per kWh in 2010 to \$227 per kWh in 2016, and it is predicted that it will be lower than \$100 per kWh by 2030 [10]. As a result of the reduction in battery costs, the number of electric vehicles on the roads has significantly increased. Many countries, such as European countries, have set ambitious targets for replacing traditional cars with electric versions in the coming years. Another trend in e-mobility is the development of charging infrastructure. As more electric vehicles are in operation, it becomes increasingly necessary to have a reliable and convenient charging infrastructure. Many governmental and private companies are investing in developing charging stations, both in residential and public, to satisfy future needs of charging e-mobilities ubiquitously.

Further development in e-mobility technology is expected to emerge in the near future, as it is summarized in Fig. 1.2. Currently, EVs have a limited driving range; however, since there are many advancements in battery technology and capacity, EVs are expected to have a more extended driving range. Ultrafast and wireless charging are other important predictions in e-mobility technology to provide more convenience for drivers to charge their vehicles on the go or without physical connections [11]. Smart charging technology allows scheduling the electric vehicles charging smartly, considering the electricity demands and prices or the electric grid pressure in peak hours. Another interesting aspect of the future of e-mobility is vehicle-to-everything (V2X) solutions that enable EVs to transmit their surplus

energy to electric grids, houses, buildings, or any other energy consumption destinations [12, 13]. Finally, thanks to advanced artificial intelligence, autonomous electric vehicles will not only increase the efficiency of mobility but also reduce greenhouse gas emissions.

The future of e-mobility includes using electric vehicles and steady technological advancements to support them. As the demand for electric vehicles grows, the development of charging infrastructure will become increasingly important. In the future, it is expected to see more convenient and efficient charging options such as wireless charging, ultrafast charging stations, and even faster home charging systems. Furthermore, electric vehicles will be integrated with autonomous and connected vehicle technologies, allowing for more seamless integration into smart cities and a more efficient transportation system with zero carbon emissions.

#### 1.4 Electromobility Charging Infrastructure

The charging infrastructure for e-mobility is defined as the charging stations and equipment required to charge electric vehicles, including both home charging and public charging stations. The accessibility and availability of charging infrastructure are the key factors in speeding up the transition to e-mobility. Table 1.1 presents the different current types of charging infrastructure [4, 14, 15]. Level 1 charging is the slowest and safest type of charging, usually used for overnight charging at home. Level 2 charging charges an EV in several hours and is widely operated in public charging stations. Finally, DC fast charging harnesses high power in order to recharge an electric vehicle (EV) in a few minutes. This type requires a specific protection system for monitoring and communication between EV charging equipment and the vehicle.

There are several challenges and limitations associated with the expansion of charging infrastructure:

• High costs: The installation and maintenance of charging stations can be expensive, and governments and private companies may solely be keen to invest in them if they guarantee adequate demand. Therefore, identification of best

Table 1.1 Different types of charging infrastructure

locations for charging stations and choosing the best charging infrastructure type are necessary to address this concern.

Governmental and industrial organizations have strong cooperation to overcome these challenges by developing comprehensive solutions and actions. For instance, many countries focus on standardizing charging equipment to ensure compatibility with all EVs. Also, many funds are offered to research and development divisions so as to improve charging station technology and reduce the costs of creation, installation, and maintenance.

#### 1.5 5G Application in Mobility

5G, the fifth and newest generation of mobile technology, has the potential to significantly impact various aspects of society, particularly in terms of mobility [16–20]. Some of the key applications of 5G in mobility include the following:

1 Mobility and Future Trends 9

• In-vehicle experiences: 5G networks enable faster and more dependable connectivity inside vehicles, promoting new services such as infotainment, online shopping, and streaming high-definition videos. Additionally, 5G networks can provide passengers with high-speed Internet access, allowing them to work or entertain themselves during their journey.

5G networks have the potential to revolutionize mobility by making transportation safer, more efficient, and more convenient. The technology promotes the development of new applications such as connected and automated vehicles, intelligent transportation systems, and enhanced in-vehicle experiences, which can help reduce congestion and improve traffic flow and overall mobility ventures.

#### 1.6 Future Trends

It is likely to see the continued development and expansion of electric vehicles and ride-sharing services in the future. Besides, various other trends are expected to shape the future of mobility, which are listed below.

1130 km per hour. This system includes connected mobility hubs worldwide through a network of tubes that pods can move in a vacuum at ultrahigh speeds. This concept still needs to be developed because of the limitation of nowadays technology and safety issues. Hyperloop can solve the problem of long-distance travel.

The future of mobility is likely characterized by a shift toward more sustainable and efficient forms of transportation, such as electric vehicles, and micromobility options, such as bicycles and e-scooters. Integrating autonomous vehicles and connected vehicle technologies is also expected to play a key role in shaping the future of mobility. The concept of mobility as a service (MaaS) is also gaining popularity, where transportation is seen as a service and not just a product, allowing for a more seamless, integrated, and convenient user experience. Hyperloop technology, which uses high-speed trains in vacuum-sealed tubes, is also being researched and developed as a new transportation mode. The 5G networks will also play a vital role in the future of mobility by enabling new services such as automated transportation and in-vehicle connectivity. On the other hand, as ridesharing services become more prevalent, they are likely to significantly impact the way we move around cities, reducing the need for personal car ownership and changing the way we think about transportation. These technological and transportation advancements will significantly help reduce traffic congestion and air pollution and increase accessibility.

#### References

1 Mobility and Future Trends 11

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# Chapter 2 Principles of a Circular Economy for Batteries

Christoph Helbig and Martin Hillenbrand

#### Contents

# 2.1 Definition of Circular Economy

The rapidly growing market for batteries in mobility and stationary applications leads to increasing amounts of battery material demand and returned waste batteries [45]. Battery materials like cathodes, anodes, the separator and electrolyte, connectors, casing and housing, safety equipment, and the battery management system cause environmental impacts in their supply chain, in the mining, processing, and fabrication stage [32]. These environmental impacts cause concern, not only because of the greenhouse gas (GHG) emissions related to resource extraction and processing [22] but also exposure to toxic substances, air pollution, water depletion, and land use [12]. One strategy to reduce these material-related impacts is to use products longer and use more recycled materials in their production—subsumed under the label of circular economy measures [42]. Other strategies include improving

C. Helbig (✉) · M. Hillenbrand

University of Bayreuth, Bavarian Center for Battery Technology (BayBatt), Bayreuth, Germany e-mail<EMAIL_ADDRESS>
© The Author(s) 2024

S. Passerini et al. (eds.), Emerging Battery Technologies to Boost the Clean Energy Transition, The Materials Research Society Series, https://doi.org/10.1007/978-3-031-48359-2\_2

batteries' energy and power density, extending their cycle stability, reducing fabrication waste, and reducing battery production's energy and carbon intensity. Such strategies, however, are not the focus of this chapter.

The circular economy is a concept to keep materials in the loop. It is an alternative to a conventional, linear economy in which resources are used in production and consumption to provide utility to people and society. In contrast, the circular economy generates less to no waste, minimizing the need for final disposal and raw material extraction from the lithosphere [2]. In the circular economy, materials are still used in production and consumption, but their wastes are used again for the same or different purposes. This cycling, or at least cascading, minimizes the amount of material extracted from the lithosphere. Ideally, mining and quarrying would be limited to what is required to expand in-use stocks and replace unavoidable irreversible material losses [39]. The expansion of in-use stocks has been the norm for most material systems in the past century [25], and it is likewise crucial for modern technologies, like batteries [45], that have not yet reached some level of demand saturation [44].

Cyclical ecosystems formed by the circular economy are considered more sustainable than linear ecosystems because they reduce resource consumption and environmental impacts and provide an economic benefit. The reduction of primary material requirements comes from the increased use of materials recovered from waste, replacing materials mined or quarried from the lithosphere. Recycling generally reduces energy requirements, carbon footprints, and other environmental impacts. Of course, there is a risk for a circular economy rebound, nullifying the environmental savings [47]. For very high recycling rates, high energy requirements for collection, sorting, and processing can also reduce secondary production's environmental and cost benefits [41]. Implementing a circular economy reduces the negative environmental impacts of material extraction and expansion and increases raw mYaterial supply security. Therefore, the circular economy addresses resource scarcity concerns and reduces environmental impacts. In addition, it is also expected to provide economic benefits due to the value generation of material recovery, savings from extraction reduction, and avoidance of disposal [28].

Various definitions for the circular economy exist [24]. The interdisciplinary nature of the challenge can partially explain this. Closing the material loops is not just about understanding the material flows in society or developing recycling processes and long-living products designed for recycling. It also includes policy aspects of providing the proper legislative framework to foster the use of materials recovered from waste, installing take-back schemes, and many other material efficiency measures. Sociological aspects of understanding how behavior changes contribute to the use of fewer products, the use of more sustainable products, and the most efficient use of waste management systems also play their role in establishing a circular economy. An actual circular economy can be implemented by combining the micro-, meso-, and macro-systems perspectives [24].

The overall status of the implementation of the circular economy can be measured with two simple metrics: first, a perfect circularity would be achieved if recovered end-of-life material outputs met all material demand, and second, in an ideal circular economy, this would be happening without material quality losses, meaning that no extra energy would be required to recover materials [6]. Of course, this ideal is not practically achievable because of numerous material, metallurgical, and product design challenges [39]. Every loop in the circle creates dissipation and entropy, attributed to losses in quality (mixing, downgrading) and quantity (material losses, by-products) [20], making a fully closed loop impossible. Nevertheless, for the various reasons outlined above, it is desirable to close the loop as far as possible [6]. In addition, the technical, economic, and sociological challenges to closing material cycles of different materials, like base metals, specialty metals, plastics, pulp and paper, or construction minerals, are fundamentally different.

Batteries are an exciting sector for establishing a circular economy because they represent a rapidly growing market, with significant material demand, in parts, even Critical Raw Materials [19]. The battery sector is currently subject to technological changes, and the realization of circular economy benefits within this technological change would foster the transition to low-carbon technologies.

#### 2.2 R-Imperatives of the Circular Economy

Many measures to install a circular economy are subsumed under so-called R-imperatives. Starting with short lists of just three "3Rs" like "reduce, reuse, recycle" and "recycle, remanufacture, reuse," the lists have gotten longer [24]. One list even consists of ten R-imperatives: refuse, reduce, resell/reuse, repair, refurbish, remanufacture, repurpose, recycle materials, recover energy, and re-mine [38]. Probably, talented wordsmiths will be able to extend these lists almost indefinitely. According to Walter R. Stahel, the R-imperatives in the concept of circular economy replace production with sufficiency: "reuse what you can, recycle what cannot be reused, repair what is broken, remanufacture what cannot be repaired" ([42], p. 435). In the Waste Hierarchy, a concept from the Waste Framework Directive of the European Union, waste prevention comes before preparation for reuse, recycling, recovery, and disposal [11]. Therefore, the R-imperatives can be hierarchical. Each R-imperative's potential for the circular economy depends on the maturity of a technology, its industrial sector, and inherent material properties.

Even the longer lists of R-imperatives follow three basic ideas to change the material cycles, corresponding to the three Rs of reducing, reusing, and recycling:

Distinguishing between R-imperatives at different stages of material cycles ensures that various actors are addressed. Material cycles can be narrowed, slowed, and closed by bringing together consumers, producers, legislation, and the waste management sector. Figure 2.1 shows a product's different life cycle stages, from

Fig. 2.1 Schematic visualization of the ten R-imperatives, refuse, rethink, reduce, reuse, repair, refurbish, remanufacture, repurpose, recycle, and recover, and their corresponding impact on narrowing, slowing, and closing the material cycles

extraction to waste management, and ten corresponding R-imperatives along these stages.

Narrowing material cycles means that, overall, less material is used. Refusing to use a product is the first option to use less. An example is the "flygskam" initiative to reduce the need for air transport [5]. Rethinking a product in a circular economy means providing the same service with a wholly changed product design that is much less resource intensive. An example is film photography, which has been largely replaced with digital photography, making the production of photographic films obsolete, resulting in significantly lower demand for film development, reducing silver losses [8]. Reducing material use can be achieved by making products smaller and lighter or making the production process more efficient. For example, reducing floor space in private households reduces the construction material requirements and the energy demand for heating and cooling the building [35].

Slowing material cycles is achieved by implementing measures to prevent a product from becoming end-of-life waste. Reusing products means despite the will to dispose of a product by one consumer, the product in its current state still has value for another consumer and can still be used by someone else [4]. The used clothing market is the most prominent example. Repairing products extends their usage by investing just a minimal maintenance effort, much smaller than what would be needed for a replacement. Repair is common practice for valuable, intensively used mechanical products like cars, machines, and infrastructure [40]. Refurbishing goes a bit further than repairing as you don't just want to reestablish functionality, but you might also invest in modernization. Apartments and houses are typically refurbished [37]. Remanufacturing means that parts of a product are used in a new product. The market for classic cars has a lot of experience with remanufacturing, and modular desktop PCs allow the reuse of individual components [15]. Repurposing extends the material life by changing the purpose of the product. Batteries of electric vehicles can still be used in stationary applications if their capacity is not satisfactory for mobility applications anymore [13].

If the product and its components are unsuitable for these lifetime-extending measures, its materials can still be valuable. Recycling means obtaining materials that can be used as inputs for new products. Although that is desirable, recycled materials do not necessarily have to be of the same quality. Even downcycling counts as recycling [20]. Metals are materials where quality is generally maintained, and low loss rates result in relatively high recycling rates [14]. Some materials may be hard to recycle but provide a heating value. In these cases, thermal recovery is the last option in the Waste Hierarchy. An example of recovery is mixed waste plastics replacing fuels for energy recovery [18].

#### 2.3 Battery Material Flows

Annual growth rates of the battery industry were about 30% in the past decade and are expected to be about 20% in the next two decades [36]. Until 2010, most global electrochemical storage capacity was in lead-acid batteries (LAB), with about 300 GWh of new electrochemical energy storage installed yearly, used chiefly as vehicle starter batteries [36]. LABs are positive examples of the circular economy being a mature market with established take-back schemes and recycling facilities. LABs are the main reason lead achieves relatively high circularity values compared to other base metals [21].

Since 2010, however, the focus has shifted to lithium-ion batteries (LIBs). Initially, LIBs were chiefly used in portable electronic devices; now, LIBs for electric vehicles dominate the market [36]. With this rapid market growth, concerns about resource availability and the environmental impact of LIB production have become increasingly important in recent years [19, 32].

For LIBs, the challenge of installing a functional circular economy is more prominent than for LABs. LIBs have vastly different sizes, shapes, types, and material compositions, affecting waste separability and the metallurgy of the recycling process. Battery cells for LIB consist of aluminum and copper foil current collectors, cathode and anode active materials, carbon binders, the electrolyte, and a porous separator. The cell, housing cover, and connection interface form the battery module. On the pack level, you can add a management controller, cooling system, frame and crash structure, and a battery pack housing cover [26, 33].

Technologically, there have been an extensive debate and a lot of development in terms of the cathode active materials, with the most prominent options for battery electric vehicles being nickel-cobalt-aluminum, nickel-manganese-cobalt (with various stoichiometric combinations of transition metals, from NMC111 to NMC811) [27], and iron-phosphate active materials. LIBs can also contain various critical materials, for which the establishment of material cycles is even more important and challenging [3, 26, 46].

Fig. 2.2 Minimum and maximum estimations for the material demand of Li, Ni, Co, Mn, Cu, and graphite for batteries for 2020 and 2040 in scenarios of Xu et al. [45], Marscheider-Weidemann et al. (DERA 2021), and Dunn et al. [7] in kilotons (kt). The base year for material demand in Marscheider-Weidemann et al. [30] is 2018, not 2020, as no 2020 values were provided in the source. Furthermore, only one data point is specified for 2020

In the future, new battery technologies are expected to make additional raw materials and materials necessary, for example, sodium, calcium, or aluminum [1]. Some of these developments are explicitly undertaken to reduce the dependence on Critical Raw Materials, like cobalt, or other expensive metals, like nickel. It is crucial to close material loops to meet future material demands and reduce the environmental impact of battery production, especially for expensive, scarce, or environmentally harmful materials [32].

In the meantime, material demand and end-of-life material flow for lithium, cobalt, and nickel are expected to continue to increase [45]. Figure 2.2 shows the range of estimations of current and future material demand for lithium, nickel, cobalt, manganese, copper, and graphite in recent battery material flow studies. This ever-increasing material demand causes an issue in implementing the circular economy. The International Energy Agency estimates that by 2040, recycled copper, lithium, nickel, and cobalt from spent batteries could reduce the combined primary supply requirements for these minerals by around 10% [23]. The main reason is that you can only recycle what you have used in the past because of the time lag of the product's lifetime. From a resource savings perspective, product lifetimes should be extended to reduce the demand for new batteries, but the market has grown significantly when a battery becomes waste. Therefore, even with high end-of-life recycling rates for battery materials, the recycled content in batteries will remain low until some saturation level has been achieved and the in-use stock is not multiplying anymore. Such saturation is not expected to happen before the mid-century simply because of the massive demand for electrification in mobility and stationary storage applications.

#### 2.4 Battery Design for Circularity

In the broad definition of the circular economy, more sustainable material cycles for batteries are not only a question of recycling. The goal is a holistic implementation of circular economy measures to reduce overall resource requirements and materialrelated environmental impacts. So how can the material cycles for batteries be narrowed, slowed, and closed comprehensively?

Narrowing material cycles in a rapidly growing market is a challenging task. However, significant efforts have already been made to reduce, for example, the required housing. Cell-to-pack technologies, for example, for LFP, have eliminated the module component and increased the battery's energy density, effectively reducing the amount of steel, aluminum, or plastic packaging that is not an active material in the battery. At its core, this is a "reduce" strategy, although here, it is chiefly used to increase the capacity of the vehicle battery. Circular economy strategies narrowing the material cycles are chiefly used for their Critical Raw Materials content, particularly for the partial or complete substitution of cobalt in batteries due to its high cost and conflict potential [3].

Battery material cycles can be slowed by prolonging battery life by designing cells that last for a long time and many charging cycles. Significant improvements have been made in terms of the aging stability of batteries, so it is now conceivable that an electric vehicle can drive on the same battery for 20 years and one million miles [16]. At the same time, electrolytes have been developed to allow faster charging without compromising cycle stability [29]. Batteries can also be leased to vehicle owners and afterward be used in less demanding applications, a strategy which can be identified as reuse, remanufacture, or repurpose strategy, depending on the amount of processing required and nature of the alternative use [3].

Battery material cycles can be closed by recycling the battery components [10]. Generally, one can distinguish many pyrometallurgical and hydrometallurgical processes and direct recycling routes [26]. The recoverability of contained Co, Ni, Li, Mn, Al, Cu, C, Fe, electrolytes, and plastics depends on the chosen process. Pack, module, and cell design also significantly impact battery dismantling and repair, remanufacture, and recycling options [43].

In general, the pyrometallurgical processes are more versatile regarding the battery chemistries and geometries. They have a high recycling capacity, require no sorting or pretreatment, and enable high recovery of valuable metals (Co, Ni, Cu). They are established and well-understood processes with industrial know-how [17]. On the downside, certain materials (graphite, plastics, and electrolyte) are burned and thus lost. The obtained products are often low purity and downcycled (e.g., Li and Al) or need further hydrometallurgical refinement. The pyrometallurgical process is expensive because of its high energy consumption and the need for off-gas treatment to remove toxins [17, 26].

Hydrometallurgical processes have high recovery rates, high purity of the products, low energy consumption, and low GHG emissions [17]. They have low recycling capacities. The batteries must be crushed to meet the purity and pretreatment requirements, which leads to safety problems. In addition, efficient methods for electrolyte deposition still need to be demonstrated industrially. The complex processes, the needed treatment of the final effluent (neutralization), the treatment of the contaminated wastewater, and other aspects of the process (e.g., solvents) lead to high operating costs [26].

Disassembly and pretreatments are always the first steps. In the case of the pyrometallurgical processes, the second step is directly smelting the pretreated LIBs. In addition, the alloy and the slag can be further refined by leaching, selectively precipitation, and solvent extraction. Alternatively, the disassembled and pretreated material can be converted into the so-called black mass through further mechanical treatment, which includes crushing, electrolyte separation, and mechanical separation. Afterward, the black mass can be processed through hydrometallurgical or direct recycling route. In the hydrometallurgical route, leaching, selective precipitation, and solvent extraction are used to recover the contained materials. In the direct recycling route, separating, regenerating, and producing new cathode active material are the goals [26]. While the direct recycling route provides the opportunity to obtain higher quality recyclates, it is not as mature as the pyrometallurgical or hydrometallurgical routes. Figure 2.3 shows the main process routes, advantages, and disadvantages for pyrometallurgical, hydrometallurgical, and direct recycling routes. For a more detailed description of the most important recycling processes and the corresponding efficiencies, the reader is referred to Chap. 4.3 of this book or to the work of Ekberg and Petranikova [9].

Mohr et al. [32] show that recycling could reduce the environmental impacts of lithium-ion battery production, both in the case of pyrometallurgical and hydrometallurgical processes. They highlight that the savings depend on the cell chemistry, particularly the cathode active material, and the environmental impact category, like abiotic depletion or global warming potential. Additionally, it is not always the process with maximum recycling depth that provides the most considerable environmental savings, which will become even more critical if the share of expensive materials in the battery decreases [32].

#### 2.5 Circular Economy in the EU Battery Regulation

The European Commission adopted a new Battery Regulation with severe implications for the circular economy of batteries [31]. Among other things, the regulation also addresses various issues concerning the material cycles of batteries.

The Battery Regulation is meant to narrow material cycles if successful. It enables and guides the rise of batteries in electric vehicles and stationary applications, where

Fig. 2.3 Summary of pyrometallurgical, hydrometallurgical, and direct recycling routes for battery materials and their respective main advantages and disadvantages. (Adapted from Latini et al. [26] and Harper et al. [17])

they serve as electrochemical energy storage enabling the reliable use of renewable energy and thus replacing, at least in part, fossil fuels, which are by design not circular. Several articles of the regulation are relevant to the circular economy. The previously mentioned slowing and closing of material cycles are taken up, but the narrowing of material cycles is not considered.

Articles 9 to 11, 73, and 74 have an impact on slowing the material cycles. Articles 9 and 10 describe performance and durability requirements for batteries. Article 11 mandates the removability and replaceability of portable batteries in appliances, ensuring that the appliance stays in use in case batteries have a shorter lifetime than the appliance itself. Article 73 supports the repurposing and remanufacturing of batteries. Article 74 mandates producers to provide information on the dismantling and removal of batteries to support repair, remanufacture, preparation for reuse, treatment, and recycling.

Articles 8, 59, 69, and 71 close the material cycles. Article 8 mandates that the cobalt, lead, lithium, and nickel present in new EV batteries fulfill the requirements for minimum shares of material recovered from waste for each of the metals present. As proposed, these minimum shares will be implemented in 2030 and raised in 2035. Article 59 sets targets for producers and article 69 for member states for minimum collection targets for waste of portable batteries. The proposed targets are gradually raised until 2030 when a 73% minimum collection rate shall be reached. Article 71, in combination with Annex XII, sets targets for recycling processes regarding their minimum recycling efficiencies based on the average weight of batteries, and levels of materials recovery, for cobalt, copper, lead, lithium, and nickel, respectively. By 2030, according to the proposal, an 80% recycling efficiency for lead-acid batteries and 70% for lithium-ion batteries shall be reached, enabling by 2031 a recovery of 95% for cobalt, copper, lead, and nickel and 80% for lithium.

The regulation is supported by various initiatives, such as the European Battery Alliance, and financial aid packages to support research and innovation along the entire battery value chain. But those benefits also come with risks, such as higher compliance costs, hindering innovation, technology adaptation, and competitiveness [31].

If implemented as the battery regulation proposal foresees, the contribution of recycling to meeting the raw material demand of battery production in Europe could be more than 40% for cobalt and more than 15% for lithium, nickel, and copper by 2040. Those numbers are based on a recycling volume of 150 to 300 kilotons of lithium-ion batteries and battery components per year in 2030 and 600 to 2500 kilotons in 2040 [34].

The Battery Regulation also proposes a battery passport with information on repair, disassembly, and, importantly, the carbon footprint of the battery from raw material extraction to the end-of-life phase, without the use phase. Such a mandatory carbon footprint, and in the future also carbon footprint classes and a threshold for marketing batteries in the European Union, supports the goal to reduce the overall environmental footprint of battery production. Therefore, the overall goal of the circular economy, avoiding unintended harmful environmental impact, is just as much tackled with the battery regulation proposal as the various mentioned R-imperative actions.

#### 2.6 Outlook

In a way, batteries are already a contribution to the circular economy because they allow using reversible electrochemical processes for energy storage and, thereby, replacing single-use fossil fuels. However, the circular economy of batteries will be incomplete unless batteries are recycled after their product lifetime. Linear material flows for fossil fuels would only be replaced by take-make-waste processes for lithium, nickel, cobalt, natural graphite, and other battery materials. The battery regulation proposal is a cornerstone to prevent such linear material flows.

One should never forget that recycling alone cannot meet the material demand for building up the in-use stock in a growing market. Securing Critical Raw Materials supply is equally important to allow batteries to fulfill their purpose in the required transitions in the energy sector for global net zero carbon emissions. The R-strategies and recycling technologies mentioned above are necessary to reduce the total material demand for batteries, but they will not eliminate the demand. They are necessary but not a silver bullet. Therefore, the circular economy of batteries needs to be accompanied with material research and embedded in a more general sustainability strategy.

#### References

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# Part II System Perspective for a Clean Energy Transition

#### Preface

This chapter provides an overview on the key role of batteries for the clean energy transition. First, recent projections for the development of global and European demand for battery storage out to 2050 are presented and discussed in Chapter 3, with separate insights for the power system and the mobility sector.

The impact of the projected rise in battery production is analyzed also with reference to the battery cost reduction's trend and, on the other hand, to the consequent strong increase in demand for critical minerals. Increasing the supply of these critical minerals in lockstep with demand is essential in order for battery costs to continue to decline.

Chapter 4 then provides a review of energy storage technologies, going beyond batteries. It compares and discusses the most relevant storage technologies, such as power-to-x or pumped hydro, and highlights their main features and performance characteristics, including their ecological footprint. Chapter 5 picks up on this and highlights the specific advantages of batteries, whose specific performance and technical characteristics make them a specifically promising technology for a wide set of applications. Focus is placed on applications related to both grid-connected and mobility services. For the former, this includes bulk energy services, transmission, and distribution network support and capacity firming coupled to highly variable RES plants. With regard to transport applications, electric mobility, and perspectives relative to electric vehicles (EVs), interaction with the electric infrastructure is presented and discussed.

# Chapter 3 Projected Global Demand for Energy Storage

Max Schönfisch, Amrita Dasgupta, and Brent Wanner

#### Contents

#### 3.1 Introduction

Long-term projections of the development of the global energy system foresee a dramatic increase in the relevance of battery storage for the energy system. This is driven primarily by the proliferation of electric vehicles and a growing demand for electricity storage, connected to rising shares of variable renewables in the electricity supply mix.

At the same time, electric vehicles are projected to continue to make strong inroads in the transport sector, leading to a dramatic increase in battery production geared toward the automotive sector.

Across scenarios, major outlooks published recently foresee a rapid global expansion of variable wind and solar PV-based electricity generation, as well as a rising share of electricity in total final energy consumption (see, e.g., [7, 9, 12, 26–

M. Schönfisch (✉) · A. Dasgupta · B. Wanner International Energy Agency (IEA), Paris, France e-mail<EMAIL_ADDRESS>
© The Author(s) 2024

https://doi.org/10.1007/978-3-031-48359-2\_3 S. Passerini et al. (eds.), Emerging Battery Technologies to Boost the Clean Energy Transition, The Materials Research Society Series,

28, 30]). The integration of these rising volumes of variable electricity requires key enabling technologies such as battery storage to grow as well.

This chapter provides a detailed look at recent projections for the development of global and European demand for battery storage out to 2050 and analyzes the underlying drivers. It draws primarily on the International Energy Agency (IEA)'s World Energy Outlook (WEO) 2022 [26], to which the three authors contributed.

The WEO 2022s long-term projections of the development of the global energy system foresee a dramatic increase in the relevance of battery storage for the energy system. As a result of falling costs and supportive policies, electric vehicles become the dominant technology in the light-duty vehicle segment in all scenarios in 2050, contributing to a massive increase in the demand for automotive batteries. In the electricity sector, battery energy storage systems emerge as one of the key solutions to provide flexibility to a power system that sees sharply rising flexibility needs, driven by the fast-rising share of variable renewables in the electricity mix. Batteries are also increasingly tapped to provide firm capacity as traditional generators, such as coal- or gas-fired plants, are retired.

As a result of the growing demand for batteries, the demand for critical minerals used in battery production, such as lithium, cobalt, nickel, graphite, copper, or manganese, is expected to increase substantially as well.

#### 3.2 Methodology

The projections and findings on the prospects for and drivers of growth of battery energy storage technologies presented below are primarily the results of analyses performed for the IEA WEO 2022 [26] and related IEA publications.

The IEA WEO 2022 explores the potential development of global energy demand and supply until 2050 using a scenario-based approach. It does so through three scenarios. It should be noted that these scenarios do not represent predictions but rather analyze in detail possible versions of how the energy system might develop given different policy targets and assumptions on their implementation ([26], p. 105).

The first two scenarios, the Stated Policies Scenario (STEPS) and the Announced Pledges Scenario (APS), are descriptive. The third scenario, the Net Zero Emissions by 2050 Scenario (NZE Scenario), is prescriptive:

#### 3 Projected Global Demand for Energy Storage 31

• The NZE Scenario describes a cost-effective pathway for the global energy system to reach net zero emissions by 2050, maintaining at least a 50% probability of keeping the global temperature rise below 1.5 degrees Celsius until 2050 while achieving universal access to modern energy services (primarily electricity and clean cooking) by 2030 ([15], p. 48, [26], p. 463).

The scenario projections are derived using a bottom-up, partial-optimization model of the global energy system, called the Global Energy and Climate Model (GEC-M), modeling energy demand, transformation, and supply in high detail for 26 regions (11 countries and 15 country groupings). A comprehensive description of the model, the key assumptions, and data sources used can be found in the documentation [21]. Of particular relevance to the representation of battery energy storage in the model are the power and transport sector modules of the GEC-M. The technology-rich power sector module combines an investment model with a high-resolution dispatch model to simulate the evolution of the regional power systems, ensuring that there is sufficient generating capacity to cover peak demand plus a reserve margin, as well as sufficient production to meet the annual demand of all end uses, including grid losses ([21], p. 45). The transport sector module consists of dedicated, regional bottom-up models for aviation, maritime, rail, and road transport. The road transport model projects the evolution of the regional vehicle fleets and their fuel consumption based on, among other things, activity drivers such as historical trends, GDP and population, vehicle scrappage functions, and costcompetitiveness assessments of different drivetrain technologies ([21], p. 32).

#### 3.3 Development of Demand for Battery Energy Storage

The electricity1 and transport sectors are the key users of battery energy storage systems. In both sectors, demand for battery energy storage systems surges in all three scenarios of the IEA WEO 2022. In the electricity sector, batteries play an increasingly important role as behind-the-meter and utility-scale energy storage systems that are easy to scale, site, and contribute to system reliability and flexibility. In the transport sector, the increasing electrification of road transport through plug-in hybrids and, most importantly, battery electric vehicles leads to a massive rise in battery demand.

1 In the context of this chapter, we define "electricity sector" as encompassing the production and all stationary end uses of electricity.

Fig. 3.1 Storage technologies and potential power system applications based on discharge times. Note: T and D deferral = transmission and distribution investment deferral. (Source: IEA [22], p. 64)

# 3.3.1 Electricity Sector

Energy storage, in particular battery energy storage, is projected to play an increasingly important role in the electricity sector. Storage technologies provide vital system services, ranging from short- to long-term balancing, the provision of operating reserves and ancillary services like voltage control or black start capability, to the management of congestion in the electricity grid. Currently, pumped storage hydro is the most widely deployed storage technology, accounting for 90% of total storage capacity ([22], p. 64), and there is significant additional potential in certain regions. Other emerging options include compressed air and gravity storage for the short-term and hydrogen as an option for long-term storage (IEA, [24]). An overview of several established and emerging storage technologies, as well as their typical capacities and applications, is provided in Fig. 3.1. It shows that, depending on the volume of the battery, battery energy storage systems can dispatch on timescales ranging from seconds to days, over a broad range of capacities. In contrast to other technologies with more specific use cases, batteries are able to provide a broad range of services to the electricity system. Accordingly, battery energy storage systems are the fastest growing storage technology today, and their deployment is projected to increase rapidly in all three scenarios.

Battery storage systems can be distinguished between two classes: utility-scale battery energy storage systems and behind-the-meter battery energy storage systems. Utility-scale battery energy storage systems are directly connected to the distribution or transmission systems. They typically offer much higher capacities and greater storage volumes than behind-the-meter systems. They are relatively compact and highly modular, which allows for scalable battery storage systems to be deployed rapidly in almost any location, an advantage compared to traditional large-scale electricity storage solutions such as pumped hydro. In addition to energy storage, which allows operators to engage in energy arbitrage, helping balance the power system and more cost-effectively match demand and supply, they provide important flexibility services to the system. They can be tapped to provide operating reserves and important ancillary services such as frequency control or helping with the restoration of grid operations after a blackout. Due to their scalability and modularity, they are also promising solutions for the provision of localized flexibility in distribution or transmission systems, helping to address bottlenecks and reducing the need for costly investments into new transmission and distribution infrastructure [5, 24]. Furthermore, there are more and more cases of batteries being colocated with variable renewables in order to "firm up" the latter's electricity production, for example, in Germany or India, where pairing renewables with storage is rewarded through dedicated support mechanisms. Also, where eligible, batteries are increasingly tapped to provide firm capacity in capacity markets ([25], p. 55).

Behind-the-meter battery energy storage systems are connected to the distribution grid behind the utility meter of an individual electricity consumer, typically a household or a small business. Behind-the-meter battery energy storage systems are usually paired with a distributed energy resource, in most cases rooftop solar PV. Behind-the-meter batteries enable consumers to lower electricity bills by maximizing the consumption of self-generated electricity and enabling them to engage in energy arbitrage, i.e., shifting consumption from high to low price periods. The overall magnitude of savings is highly dependent on the level and structure of electricity tariffs and the remuneration consumers receive for feeding electricity into the grid. Variable or time-of-use electricity and feed-in tariffs offer greater potentials for savings using behind-the-meter battery energy storage systems than fixed rates. Another common motivation for the installation of behind-the-meter battery energy storage systems is to improve resilience against interruptions in the power supply from the grid, where behind-the-meter battery storage systems coupled with a distributed energy resource increasingly compete with traditional solutions such as diesel generators [6].

Across all scenarios in the WEO 2022, utility-scale systems account for the majority of battery storage deployment, though the development of both utilityscale and behind-the-meter storage are heavily dependent on the prevailing regulations. In many jurisdictions, net metering2 regulations that underpin the growth of rooftop solar ([14], p. 36) are holding back investments into behind-the-meter electricity storage. Stronger growth in behind-the-meter systems can be expected should regulation change in ways that encourage self-consumption, such as time-ofuse tariffs, and introduce a time-dependent, market-based remuneration for electricity fed into the grid by small-scale generators. However, that growth would not necessarily come on top of the projected growth of utility-scale systems, since (aggregated) behind-the-meter storage can, with the right regulation and the appropriate control technology, provide some of the flexibility to the system that would otherwise be provided by utility-scale batteries.

2 Net metering is a billing mechanism that allows consumers to credit self-generated against consumed electricity irrespective of when that electricity was generated.

#### <IP_ADDRESS> Development of Stationary Battery Energy Storage

In recent years, the pace of installations of battery storage systems has picked up significantly. In 2021 alone, more than 9 GW were installed globally, a nearly 90% increase on 2020. At the end of the year 2022, total global installed stationary battery storage capacity stood at more than 27 GW ([26], p. 311). The speed of the increase has been substantial: just 10 years ago, the global installed battery energy storage was less than 1 GW in total.

Moving forward, battery storage capacity is projected to grow massively in all three scenarios (see Fig. 3.2). In the STEPS, installed global, grid-connected battery storage capacity increases tenfold until 2030, rising from 27 GW in 2021 to 270 GW. Deployments accelerate further after 2030, with the global installed capacity reaching nearly 1300 GW in 2050. Accounting for all announced pledges and policies leads battery storage capacity to grow to 425 GW in 2030 and close to 2300 GW in 2050, a near doubling compared to the STEPS. The pace of deployments is even faster in the NZE Scenario, where installed capacity reaches about 780 GW in 2030 and nearly 3900 GW by 2050, as the electricity sector is the first to be fully decarbonized, by 2035 in advanced economies and by 2040 in emerging market and developing economies.

In the European Union, total installed battery storage capacity rises from nearly 5 GW today to 14 GW in 2030 and almost 120 GW in 2050 in the STEPS, which achieves the agreed objectives, including reaching 32% of renewable energy by 2030, and fulfills all the National Energy and Climate Plans and major policies as of late 2022. In the APS, which reflects discussions on higher ambitions for renewable energy, including the goal to reach a 40% share in gross energy consumption by 2030 within the Fit for 55 package [11] and the G7 commitment to achieve predominantly decarbonized electricity by 2035 [8], battery storage capacity increases to 50 GW by 2030 and more than 200 GW in 2050. In the NZE Scenario, which requires similar emissions reductions by 2030 and 2035, higher energy efficiency and a more responsive demand side require slightly less battery capacity deployments, with installed capacity reaching 180 GW in 2050 [26].

# 3.3.2 Transport Sector

Despite the massive growth projected in all scenarios of the WEO 2022, stationary battery energy storage capacity in the electricity sector is—depending on the scenario—only equivalent to 7–10% of the combined storage capacity of electric vehicle batteries. This makes the transport sector the by far biggest user of batteries.

#### <IP_ADDRESS> Deployment of Battery Electric Vehicles

In the sector, the vast majority of batteries are used in electric and plug-in hybrid electric vehicles.

Electric vehicles are projected to make up increasing shares of newly registered vehicles across all types of road vehicles (passenger/commercial light-duty vehicles, medium and heavy-duty vehicles, buses and two-/three-wheelers) in all three scenarios.

In 2021, demand for automotive lithium-ion batteries was 340 GWh per year, doubling from 2020 ([26], p. 167), with global electric vehicle sales reaching a record-breaking 6.6 million ([20], p. 4), bringing the global electric vehicle fleet (excluding two-/three-wheelers) to 18 million ([20], p. 99). Nearly 9% of all new passenger vehicles sold were fully electric. China led the world in sales, followed by Europe and the USA [23].

In the STEPS, which considers only policies already in force as of late 2022, the global electric vehicle fleet (excluding two-/three-wheelers) grows to 200 million vehicles by 2030, representing over 20% of all road vehicle sales ([20], p. 99). In the APS, which assumes that all existing targets are met in full and on time, electric vehicle adoption is more rapid, with their share in total sales growing to over 35% in 2030 and total stock reaching 270 million vehicles in the same year ([20], p. 99). In the NZE Scenario, electric vehicle uptake proceeds even faster, and globally, 60% of all new vehicles sold in 2030 are fully electric, with the number of electric vehicles growing to 350 million ([20], p. 99).

The bulk of the growth comes from the light-duty vehicle segment, most notably passenger electric vehicles. In 2021, electric light-duty vehicles accounted for 95% of the global electric vehicle fleet (excluding two-/three-wheelers), and they continue to maintain this share through 2030 in the STEPS. Electric light-duty vehicle sales grow more rapidly in the APS, reaching a share of 35% of total light-duty vehicle sales by 2030. In the NZE Scenario, more than 60% of all light-duty vehicles sold in the same year are electric ([20], pp. 99–100). The rapid expansion of electric vehicle sales is projected to continue after 2030. In the APS, electric vehicles reach a two-thirds share in total new light-duty vehicle sales by 2040. Slow turnover in the vehicle stock means, however, that even in this scenario, the share of electric vehicles in the global light-duty vehicle fleet will exceed two-thirds only by 2050 ([26], p. 275).

Electrification is projected to proceed more slowly in the medium and heavy-duty vehicle segment. While electric trucks are well suited for roles like urban delivery, with relatively short driving distances and the possibility of overnight charging, larger batteries and a high-power charging infrastructure are required to enable longdistance electric trucking. In the STEPS, electric trucks reach a sales share of under 10% in 2030, while in the APS and NZE Scenario, they account for 10% and 25% of sales, respectively ([20], pp. 100–101).

Electric buses are the second most common type of electric vehicle in use today (excluding two-/three-wheelers). Their share in the bus stock is projected to increase to 11% by 2030 in the STEPS, 15% in the APS, and 25% in the NZE Scenario ([20], p. 100).

Although excluded from the total number of electric vehicles presented above, electric two-/three-wheelers are the most common type of electric vehicle today and are projected to remain so through 2030. In many regions, they are already costcompetitive with internal combustion engine two-/three-wheelers on a total cost of ownership basis and projected to see strong growth in Asia in particular. Electric two-/three-wheelers account for over 25% of the stock in 2030 in the STEPS, up from around 6% in 2021. In the APS, 35% of the total stock is electric, while in the NZE Scenario, that share is even higher ([20], p. 101).

The electrification of road transport is proceeding at different speeds across the world. In terms of the distribution of sales, advanced economies and China act as trailblazers, with battery electric vehicles accounting for more than 50% of the cars sold by 2030 in China, the European Union and the USA ([26], p. 274). In Europe, supportive policies ensure that it remains one of the key electric vehicle markets: in the STEPS, light-duty electric vehicles account for 35% of all light-duty vehicle sales in 2030. In the APS, assuming additional policy pledges are implemented, this share rises to over 50%. The 2030 sales shares are 50% for buses and 7% for trucks in 2030 in the STEPS and 55% for buses and 20% for trucks in the APS ([20], p. 104).

The impact on the demand for automotive batteries is substantial. In the NZE Scenario, which sees the strongest growth of electric vehicles to 2030, demand grows 16-fold, from 340 GWh per year in 2021 to more than 5500 GWh per year in 2030 ([26], p. 167).

#### 3.4 Drivers of Demand for Battery Energy Storage

As shown above, demand for batteries is projected to increase substantially until 2050 in all scenarios both in the transport and in the electricity sector.3

In the transport sector, this is driven by the rising adoption of electric vehicles, which, thanks to falling costs and supportive government policies, are becoming an increasingly attractive choice compared to conventional internal combustion engine vehicles. and supportive government policies.

In the electricity sector, the adoption of batteries is driven mainly by the rising demand for flexibility, adequacy, and energy balancing that accompanies the rise in the share of variable renewables in decarbonizing power systems.

Rising demand for batteries in both sectors can create a virtuous cycle of falling costs through technological improvements, learning, and improved economies of

3 It should be noted that the faster scale-up projected for the APS and NZE Scenario (compared to the STEPS) will require policy and regulatory frameworks to evolve in a manner that reflects the contribution that battery energy storage systems are able to make to the system.

scale, which in turn accelerates deployment, although raw materials costs are likely to play an increasingly significant role ([25], p. 55).

# 3.4.1 Electricity Sector

In the electricity sector, clean energy transitions change the nature of power systems. Maintaining capacity adequacy—the ability to match demand and supply at all times with a high degree of reliability—is central to energy security, calling for contributions without adding to overall emissions. Rising flexibility needs, linked primarily to the fast-rising share of variable renewables in the electricity mix, bolster the value of dispatchable technologies, particularly low emissions options. Growing demand for solutions that provide power system flexibility and capacity adequacy is the main driver underpinning the rapid increase in battery energy storage capacity projected in the WEO 2022, as falling costs for battery storage improve their economics compared with competing sources of flexibility and adequacy.

#### <IP_ADDRESS> Rising Electricity System Flexibility Needs

Electricity system flexibility needs are projected to increase significantly compared to today in all scenarios modeled for the WEO 2022. Rising flexibility requirements follow from the increase in variable wind and solar PV-based electricity generation in markets around the world. Furthermore, the electrification of additional end uses, such as electric heating, electric vehicles, or certain industrial processes, raises peak demand, as well as the hourly, daily, and seasonal variability of electricity demand ([26], p. 307).

At the same time, the retirement of a large part of the existing fleet of conventional coal- and gas-fired power plants will increase the demand for alternative sources of flexibility and firm capacity ([23], pp. 308). Battery energy storage systems play an increasingly important role in the provision of system flexibility (the ability of the system to respond to fluctuations in supply and demand) and capacity adequacy (maintaining available electricity supply to meet demand in all hours of the year). Additionally, battery energy storage is projected to become increasingly relevant as a component in renewables-based off-grid electricity supplies, supplanting fossil fuel-based generators.

Battery energy storage systems are highly responsive and able to charge or discharge quickly. The energy-to-power ratios of stationary battery energy storage systems, typically ranging from below 1 to 8 hours of storage at full capacity ([26], p. 312), make them well suited to providing flexibility over timescales measured from minutes and hours to a few days [24]. The change in net load from one hour to the next is thus a helpful indicator for flexibility needs that can be usefully served by batteries.

Fig. 3.3 Share of batteries in total dispatchable capacity and share of variable renewables in total electricity generation for the European Union, China, India, and the USA, 2021–2050. (Source: IEA [26], p. 311)

The rising contribution by variable wind and PV increases the variability of the net load.4 In the STEPS, the share in the global electricity mix of wind and solar PV together doubles from 10% in 2021 to 20% in 2030 and rises above 40% until 2050. In the APS, it increases to 30% by 2030 and reaches nearly 60% in 2050. In the NZE Scenario, it increases to nearly 70% by 2050. As a result, global flexibility needs5 triple until 2050 in the STEPS, rise more than 3.5-fold in the APS, and quadruple in the NZE Scenario. However, there is significant regional variation: systems which today have relatively small shares of wind and solar PV see a much stronger relative increase in flexibility demand. In India, for example, flexibility requirements rise sixfold until 2050 in the APS, whereas in the European Union—where the combined share of wind and solar PV in the electricity mix was already 18% in 2021—they double over the same time period ([26], pp. 214, 299).

The relationship between the rising share of variable renewables in the electricity mix (and thus increasing flexibility demand in the electricity system) and the increase of stationary battery energy storage capacity (as a share of total dispatchable capacity) is illustrated in Fig. 3.3. It shows that across the four regions displayed, battery capacity rises in tandem with the share of variable renewables in the electricity mix. There are, however, differences between regions and scenarios. In the APS, battery storage capacity rises faster relative to the share of renewables in the system than in the STEPS, since renewables are deployed faster and alternative sources of flexibility, such as coal-fired power plants, retired earlier. Regional

4 The net load is the load that remains after deducting the production of wind and solar PV from electricity demand.

5 In the WEO 2022, flexibility needs are measured by the hour-to-hour ramping requirements after removing hourly wind and solar PV production from hourly electricity demand, divided by the average hourly demand for the year ([26], p. 308).

differences are also the result of the relative share of solar PV and wind in the respective electricity system, as solar in particular is increasingly paired with batteries. Battery deployment thus tends to be larger in places with high proportions of solar PV compared to wind power, like the USA or India, than in regions where wind power predominates, like China or the European Union ([26], p. 312).

#### <IP_ADDRESS> Contribution to System Adequacy

In addition to providing flexibility, battery energy storage systems also play an increasingly important role in meeting the adequacy needs of the electricity system. In the APS, for example, battery storage is the primary replacement, in terms of system adequacy, for coal, which is mostly phased out globally until 2050. Battery energy storage accounts for nearly 45% of the replacement capacity, followed by dispatchable renewables, most notably hydropower (15%); solar PV and wind (slightly below 15%); nuclear, fossil fuels with carbon capture utilization and storage (CCUS), hydrogen, and ammonia (7–8% each); and new natural gas-fired capacity (4%) ([19], p. 82).

However, the speed of the shift to batteries as a system adequacy resource varies. Advanced economies, which see the rapid phasing down of their remaining coal fleets in the 2030s, see a surge in investments into battery energy storage systems for system adequacy at around the same time, with emerging market and developing economies following suit in the 2040s, coinciding with a major drop in coal capacity there ([19], p. 82).

#### <IP_ADDRESS> Falling Costs

Innovations in battery chemistry, learning effects, and economies of scale are another key driver of rising deployment, since they continue to drive down the cost of battery packs and components that comprise the balance of system of utilityscale battery energy storage systems, making them increasingly cost-competitive with alternative flexibility options. Spillover effects from the electric vehicle industry play an important role in decreasing the cost of battery packs available for stationary applications ([26], p. 311). "Second-life" electric vehicle batteries are projected to play an increasingly important role, providing an option to cheaply expand stationary battery energy storage [24].

Due to increasing economies of scale and continuous innovation along the supply chain, costs for lithium-ion batteries have already declined by nearly 90% between 2010 and 2021 ([26], p. 167). The average installed cost of battery energy storage systems designed to provide maximum power output over a 4-hour period is projected to decline further, from a global average of around USD 285/kWh in 2021 to USD 185/kWh in the STEPS and APS and USD 180/kWh in the NZE Scenario by 2030. Until 2050, costs are projected to drop to around USD 135/kWh in all scenarios ([26], p. 473), with costs in the STEPS slightly above this value and costs in the APS and NZE Scenario slightly below. This makes renewables, in particular solar PV, combined with utility-scale battery energy storage one of the most cost-competitive solutions to provide dispatchable capacity in many markets in 2050, with the levelized cost of electricity falling below that of new combined-cycle gas turbines ([26], p. 406).

It should be noted, however, that as innovation and learning make batteries cheaper and cheaper to produce, the relative contribution of mineral resource prices to the cost of battery packs increases. In 2022, sharp increases in the prices of key minerals like lithium, cobalt, nickel, graphite, copper, or manganese contributed to a 7% increase in the average price of lithium-ion battery packs, despite an ongoing shift to lower cost chemistries that require lower volumes of certain critical minerals [4]. The projected future cost declines presented above are thus contingent on prices of important minerals returning closer to their historical averages.

#### <IP_ADDRESS> Policy Frameworks and Regulation

However, while batteries are certain to continue to grow, to get on track for the high levels of deployment seen in the APS and the NZE Scenario, the two more ambitious scenarios of the World Energy Outlook 2022, policies and regulatory frameworks need to evolve.

In the electricity sector, governments should consider energy storage, alongside other flexibility options such as demand response, power plant retrofits, or smart grids, as part of their long-term strategic plans, aligned with wind and solar PV capacity as well as grid capacity expansion plans. Business cases for grid-scale storage can be complex and may not be viable under legacy market and regulatory conditions. In liberalized electricity markets, measures to increase incentives for the deployment of flexibility that is able to rapidly respond to fluctuations in supply and demand could help improve the business case for grid-scale storage. These include decreasing the settlement period and bringing market gate closure closer to real time, as well as updating market rules and specifications to make it easier for storage to provide ancillary services. The business case for storage improves greatly with value stacking, i.e., allowing it to maximize revenue by bidding into different markets. Regulatory frameworks should continue to be updated to level the playing field for different flexibility options, which would help to build a stronger economic case for energy storage in many markets. Transmission and distribution investment deferral (using storage to improve the utilization of, and manage bottlenecks in, the power grid), for example, is another potential high-value application for storage, since it can reduce the need for costly grid upgrades. To capture the greatest benefit, storage should be considered, along with other non-wire alternatives, in the transmission and distribution planning process. A key issue is ownership: in many markets, storage is considered a generation asset, and system operators (transmission as well as distribution) are not allowed to own storage assets. One solution is to allow them to procure storage services from third parties. However, regulatory frameworks need to be updated carefully to minimize the risk of storage assets receiving regulated payments and undercutting the competitive power market [24].

Behind-the-meter battery energy storage is facing challenges on its own. In many jurisdictions, legacy electricity tariff structures do not reward the deployment of behind-the-meter battery storage, which continues to fall behind grid-scale battery energy storage in the projections of the World Energy Outlook 2022. Regulatory changes, such as changes to tariff structures that reward shifting consumption with the help of batteries, could greatly enhance the prospects for behind-the-meter battery energy storage.

## 3.4.2 Transport Sector

In the transport sector, a combination of falling electric vehicle costs, government subsidies and support for the development of a charging infrastructure, as well as standards favoring electric and other zero emission vehicles is projected to lead to a massive increase in the global electric vehicle fleet.

#### <IP_ADDRESS> Improving Economics of Electric Vehicles

Falling costs, most importantly for the battery packs, driven by ongoing innovation and improving economies of scale, ensure that electric vehicles become the costeffective choice for most types of road transport after 2030 in all scenarios, especially in the light-duty vehicle segment. In many emerging market and developing economies, electric two-/three-wheelers are, depending on use, already cheaper than internal combustion engine alternatives on a total cost of ownership basis, and this is projected to become the case for most models by 2025 ([17], p. 76; [18], p. 122). The rising attractiveness of electric vehicles to consumers is reflected in the model range. In 2021, around 450 different models of electric vehicles were available on the market, 5 times more than in 2015 ([20], p. 4).

#### <IP_ADDRESS> Subsidies and Infrastructure Build-Out

Countries are increasingly looking to boost the uptake of electric vehicles to address concerns around CO2 emissions and local air pollution. Building on the improving competitiveness of electric vehicles, governments across the world are seeking to accelerate the adoption of electric vehicles through subsidies. Direct per vehicle subsidies like cash bonuses or tax rebates lower the cost of electric vehicles, making them more attractive compared to internal combustion engine vehicles.

Other ways to subsidize electric vehicles include exemptions from tolls and charges, as well as the provision of free or subsidized public charging. Increasing investments in charging infrastructure is necessary to make electric vehicle use more practical and alleviate the problem of range anxiety among current and future electric vehicle users, as well as to make electric long-distance trucking more practical ([23], pp. 275). Furthermore, initial public investments in charging infrastructure are essential to overcome the "chicken-and-egg problem" of providing enough chargers to make electric vehicles more attractive and practical to use while at the same time sustaining an infrastructure that is unlikely to be profitable initially due to the low number of users.

Total expenditures by governments in support of electric vehicles almost doubled in 2021. Some countries, including in the European Union, India, and Japan, have introduced or expanded subsidies, while some markets, such as China, Korea, and the UK, have used the opportunity provided by falling electric vehicle costs to reduce per vehicle subsidies, recognizing the narrowing cost gap between electric and conventional internal combustion engine-powered vehicles ([20], p. 59).

#### <IP_ADDRESS> Standards and Targets

Standards and targets are projected to play a major role accelerating the adoption of electric vehicles. As of mid-2022, 36 countries and several US states have committed to ending sales of internal combustion engine-powered cars and, in some cases, light trucks, by a certain year ([26], p. 273). With the "Fit for 55" package, the European Union has pledged to ensure that all new cars and vans registered in the block will have to be zero emission by 2035. In an intermediate step, new vehicles will have to comply with CO2 standards that will require emissions drop by 55% until 2030 for cars and 50% for vans (from a limit of 95 g/km for cars and 147 g/km for vans in 2021) [10]. Globally, 25% of the present light-duty vehicle market is covered by pledges or targets to bring the share of zero emission vehicles to 100% by 2035 ([20], p. 57) (Table 3.1).

Table 3.1 Selected targets to end sales of new internal combustion engine-powered vehicles, by country or state

Source: IEA ([26], p. 273)

Notes: LDVs, light-duty vehicles (passenger cars and light trucks). This table covers countries and states with legislation, a target, or stated ambition in place to phase out the sales of internal combustion engine light-duty vehicles

Major automakers are responding by turning increasingly to electric vehicles not only to respond to regulation but also to maintain or capture market share and retain or gain a competitive edge [20]. A general overview of the electrification plans of different automakers is provided in the IEA Global Electric Vehicle Outlook 2022 ([20], p. 32).

While electric vehicle sales are projected to continue to grow strongly in all scenarios, a slow turnover in the vehicle stock means that the process of electrifying significant portions of the global vehicle fleet will take time and not be completed until after 2050 in the STEPS and APS. The NZE Scenario therefore assumes an end of new internal combustion engine vehicle sales globally by no later than 2035. This will require significant efforts to step up electric vehicle and battery production ([26], p. 276).

#### 3.5 Resource Demand for Batteries

Clean energy technologies, including batteries, require far larger volumes of critical minerals than fossil fuel-based technologies. Copper is a key component of most technologies that produce or consume electricity; silver and silicon are needed for solar PV; rare earth elements are an important component of most wind turbine motors and electric motors, while lithium, nickel, cobalt, manganese, and graphite are crucial minerals for the production of lithium-ion batteries ([16], p. 5), the dominant battery chemistry for electric vehicles and utility-scale energy storage applications, both today and under the projections of the World Energy Outlook 2022 ([26], p. 217).

The energy sector is becoming a substantial consumer of critical minerals as the accelerating transition to a clean energy system is expected to significantly raise demand. For the majority of minerals, the energy industry only made up a minor portion of total demand until the middle of the 2010s.

The energy sector's share is projected to increase significantly over the next two decades: electric vehicles and stationary battery energy storage systems have already outclassed consumer electronics as the largest consumer of lithium and are projected to overtake stainless steel production as the largest consumer of nickel by 2040 ([16], p. 5).

Lithium-ion batteries have emerged as the dominant battery technology in both electric vehicles and stationary battery energy storage applications. They are far more energy dense than competing solutions such as lead acid or nickel cadmium batteries. The production of lithium-ion batteries is mineral-intensive. A battery pack is made up of modules which are composed of individual cells. Cells account for around 70–85% of the weight of the total weight of a battery pack. They contain several minerals, mainly lithium, nickel, cobalt, and manganese (in the cathode), graphite (in the anode), copper (in the current collector), as well aluminum, steel, and microelectronics (for other components of the modules and pack) ([16], p. 90).

## 3.5.1 Dominant Lithium-Ion Battery Chemistries

Lithium-ion batteries are often categorized and commonly referred to by the chemistry of their cathodes. The choice of chemistry determines a battery's energy density and longevity, which varies significantly between chemistries, and is a key determining factor for the type and amount of minerals required. The most commonly used cathode chemistries for lithium-ion batteries are lithium cobalt oxide (LCO), lithium manganese oxide (LMO), lithium iron phosphate (LFP), lithium nickel cobalt aluminum oxide (NCA), and lithium nickel manganese cobalt oxide (NMC) ([16, 32], p. 90; [29]).

Of the types mentioned above, LCO batteries have the greatest energy density and a relatively high specific energy (150–190 Wh/kg). The primary choice for consumer electronics is a mature technology, with the disadvantage, however, of a comparably short life cycle (500–1000 full cycles). This, coupled with an inherent thermal instability, means they are generally not employed in electric vehicles or as stationary electricity storage solutions ([16], p. 90).

The LMO battery has a high specific power, a longer life cycle (1000–- 1500 cycles), and much better thermal stability than LCO. Being cobalt-free is often considered as a key advantage of this chemistry. However, it has a notably lower energy density, in the range of 100–140 Wh/kg. Presently, it finds use in the production of electric bikes and some commercial vehicles ([16], p. 90).

LFP batteries offer high thermal stability and a longer life cycle (more than 2000 full cycles) ([16], pp. 90). Its lower energy density and specific energy (90–140 Wh/ kg) mean that the technology has been thus far favored for large-scale stationary energy storage applications and heavy-duty vehicles, where the size and weight of a battery are secondary considerations over safety and durability, rather than passenger electric vehicles or behind-the-meter home storage systems [24]. Nevertheless, owing to several social, geopolitical, and resource constraint concerns, LFP batteries, which do not require nickel, manganese, or cobalt, are today witnessing a massive resurgence in R&D spending to improve their energy density and make them suitable for passenger EVs. These efforts were spearheaded by automakers in China, where in the past year, both domestic and international OEMs like Tesla Motors and Volkswagen have focused on producing LFP-based entry-level EV models.

The NCA battery has the highest specific energy range (200–250 Wh/kg) in the current class of technologies as well as high specific power, combined with a lifetime of 1000 to 1500 full cycles. NCA is the technology preferred by manufacturers like Tesla and has immense potential for use in power systems in backup and load shifting applications. However, they are more expensive than other chemistries ([16], p. 91).

NMC batteries have longer life cycle (1000–2000 cycles) compared to NCA, but a lower energy density (140–200 Wh/kg). They have dominated the BEV and PHEV markets since its commercialization in the early 2000s. While NCA batteries have higher specific energy to their name, NMC batteries possess longer lifetimes, which makes them the favored choice for PHEVs. Manufacturers producing both BEVs and PHEVs, such as General Motors, are known to use NMC variants of lithium-ion batteries ([16], p. 91).

Advancement in lithium-ion battery technology involves more than just the challenge of improving energy density, durability, safety, and cost. It also includes the effort to do so while minimizing the environmental, social, and political costs of acquiring their constituent materials. Owing to price spikes and concerns over ethical mining practices in the 2010s, EV producers have been working to reduce the amount of cobalt in batteries over the past several years—this implies, in many cases, an increase in the quantity of nickel. NCA batteries transitioned to NCA+, a nickel-rich variant of NCA, and NMC 111 batteries have moved increasingly toward NMC 532, NMC 622, and NMC 811 and could move to even more nickel-rich chemistries. This trend of moving away from cobalt could therefore have major implications for the requirement for nickel, which also has a highly concentrated supply chain today ([16], p. 91).

Anodes must complement cathode chemistries. Anode materials are selected for their charge collection capability. Graphite is currently the dominant choice for the anode in most lithium-ion batteries, although certain manufacturers also use lithium titanate instead of graphite. Efforts to replace some or most atoms of carbon in the graphite anode with silicon atoms are underway (e.g., Tesla, Porsche) and are expected to drastically improve the energy density of the cells. However, silicon anodes swell during charging, causing its surface to crack and performance to drop. Another alternative to the graphite anode is pure lithium metal, which also has far greater charge collection capability than graphite. But this anode cannot be used with liquid electrolyte batteries due to undesirable chemical interactions between the electrolyte and the metal anode, which drastically reduces the lifetime of the cell. The use of a lithium metal anode may increase significantly with the advent of all-solid state batteries (ASSBs) ([16], p. 92).

The future technology mix will have a significant impact on the amount of specific mineral resources required for the production of batteries. As shown in Fig. 3.4, different battery chemistries require different minerals in varying quantities. Different assumptions about the evolution of the technology mix can thus have a substantial effect on the amounts of certain minerals consumed for battery production.

Nickel manganese cobalt oxide (NMC) batteries, for instance, usually require roughly eight times more cobalt but only half as much nickel than nickel cobalt aluminum oxide (NCA) batteries. While nickel, cobalt, and manganese are needed for lithium iron phosphate (LFP) batteries, approximately 50% more copper is required compared to NMC batteries ([16], p. 88).

Further uncertainty is introduced by the potential for disruptive leaps in battery technology. As we reach the physical limits of density and life cycle improvements with current technology and materials, notable cost reductions can only be achieved by the disruption of the current technology—for example, in the form of ASSBs with

Fig. 3.4 Critical minerals required for the production of a 75-kWh automotive lithium-ion battery using selected cathode chemistries. (Source: Adapted from Ref. [16], p. 89), based on Refs. [1–3, 13, 31]

lithium anodes or through the increased used of silicon in graphite anodes for existing liquid electrolyte chemistries, or through all together new chemistries such as sodium-ion batteries. Therefore, a continued cost decline at the pace observed during the past decade cannot be taken for granted without a further acceleration in technology innovation, and this will be accompanied by changes in mineral demand projections.

# 3.5.2 Mineral Resource Requirements for the Production of Batteries

While mineral resource requirements for battery production were not quantified for the STEPS, APS, or the NZE Scenario presented in the WEO 2022, the IEA published detailed minerals demand projections in a preceding report. They are based on the IEA Sustainable Development Scenario (SDS) which describes a global pathway for the energy system that achieves the goal of the Paris Agreement, in addition to meeting the United Nations' Sustainable Development Goals.

In the SDS, the transport sector sees battery demand from EVs grow by nearly 40 times between 2020 (160 GWh) and 2040 (6200 GWh). The base case chemistry assumptions project a shift away from cobalt-rich chemistries. This is achieved in both NCA batteries and NMC variants, where the ratio of nickel and manganese is increased in the transition from NMC 111 to NMC 532, NMC 622, and ultimately NMC 811 ([16], p. 97). While most heavy trucks are reliant on LFP batteries in the medium term, the base case also sees growth in the market share of LFP for cars due to its increasing use in China. The base case also sees ASSBs becoming commercially available by around 2030 and requiring another 5 years for manufacturing capacity to build up. Even in 2040, ASSBs remain more expensive than liquid electrolyte lithium-ion batteries and are therefore limited to premium vehicles and advanced economies. In the longer term, heavy trucks operating long haul are likely to use ASSBs as soon as they become available because of the great benefits of energy density improvement in these applications. They would enable increased payload, greater operating range, and shorter charging times ([16], p. 96).

For the anode, natural graphite is expected to continue to account for the majority of market share. Even as artificial graphite starts to replace natural graphite for reasons of improved purity and hence energy density, a small number of manufacturers choose lithium titanate (LTO) instead of graphite for heavier vehicles due to its fast-charging advantages. The dominance of graphite declines very slightly over the years to make way for nanocomposite graphite doped with silicon and for lithium metal that emerges with the advent of ASSBs ([16], p. 96).

Overall annual demand for minerals under the base case chemistry assumptions grows by 30 times between 2020 and 2040, from 400 kt to 11,800 kt. Nickel demand grows by 41 times to 3300 kt, while cobalt increases by only 21 times, as cathode chemistries shift away from NMC 111 toward lower-cobalt chemistries (NMC 622 and NMC 811). Lithium demand grows by 43 times, while copper grows 28 times. Graphite demand grows 25 times from 140 kt in 2020 to over 3500 kt in 2040. Silicon registers the largest relative growth, up over 460 times, as graphite anodes doped with silicon grow from a 1% share in 2020 to 15% in 2040 ([16], p. 97).

In the electricity sector, battery storage grows by 11 times between 2020 (37 GWh) and 2040 (420 GWh). In the base case chemistry assumptions, safe and cheap LFP batteries for utility-scale storage are expected to dominate the overall battery storage market. The remaining demand is covered by the more expensive, but energy dense, NMC 111 and NMC 532 used predominantly for home energy storage. The NMC variants transition toward NMC 622 and NMC 811 in a similar way to the market for EV batteries, albeit with a delay owing to the time needed for transfer of technology and sufficient reduction in prices. Vanadium flow batteries (VFBs) first become commercially suitable in 2030 with a small share, growing modestly to capture a wider market for storage applications in large renewables projects.

Overall demand for minerals in the base case grows by 33 times between 2020 and 2040, from 26 kt to nearly 850 kt. Overall mineral demand outpaces battery demand growth, as the market share for LFP batteries is displaced by more mineralintensive NMC chemistries. The largest relative growth is seen in nickel, which grows more than 140 times from 0.4 kt in 2020 to 57 kt in 2040. Cobalt demand increases by 70 times while manganese demand increases by 58 times.

The base case projections are founded on a set of assumptions, which, when altered due to reasons of technology advancements, could result in scenarios that produce very different results.

The base case for electric vehicle batteries, for example, assumes an ongoing shift away from cobalt toward nickel-rich cathode chemistries. Growing concerns around nickel supplies, for example, due to price spikes triggered by delays to and cost overruns at planned nickel mining projects, could conceivably slow the shift toward nickel-rich chemistries. The impact on minerals volumes could be substantial: compared to the base case, a delayed shift could result in a nearly 50% higher demand for cobalt and manganese for electric vehicle batteries by 2040. Similarly, a much more rapid shift toward ASSBs could result in higher lithium demand than in the base case but would also reduce the demand for graphite and silicon ([16], p. 99).

The base case for energy storage systems is built on the assumption that utilityscale storage forms a major proportion of the demand, wherein cost (and not space) is the primary concern for the technology selection. However, several alternative scenarios could change the base case projections. For instance, more rapid adoption of wall-mounted home energy storage would make size and thus energy density a prime concern, thereby pushing up the market share of NMC batteries such as those already used by the Tesla Powerwall. Conversely, if the technology for flow batteries, which have the advantage of virtually unlimited energy capacity and very long lifetimes, reaches a stage of widespread commercialization earlier than expected, then utility-scale storage technology could shift away from LFP batteries toward VFBs ([16], p. 105).

The mineral demand projections presented in this section show that the proliferation of batteries in the electricity and transport sectors will lead to a significant increase in the demand for various critical minerals essential for battery production. Scaling up the production of these minerals in a sustainable manner is critical to achieving the deployment rates and cost reductions projected in the scenarios presented above. Today already, raw material prices account for 50–70% of total battery costs. A doubling of lithium or nickel prices, for example, would lead to 6% increase in battery costs ([16], p. 107). It is important to note that in addition to primary production (mining), battery recycling has the potential to be a significant source of secondary supply of the critical minerals needed for future battery demand. IEA analysis suggests that the recycling and reuse of batteries from electric vehicles and stationary storage could reduce primary mineral supply requirements by more than 10% by 2040 ([16], p. 187). Targeted policies, including minimum recycled content requirements, tradable recycling credits, and virgin material taxes, all have potential to incentivize recycling and drive growth of secondary supplies. International coordination will be crucial because of the global nature of the battery and critical minerals markets [24].

#### 3.6 Conclusion

Long-term projections of the development of the global energy system foresee a dramatic increase in the relevance of battery storage for the energy system. This is driven primarily by the proliferation of electric vehicles and a growing demand for electricity storage, connected to rising share of variable renewables in the electricity supply mix.

The IEA WEO 2022 projects electric vehicles to become the dominant technology in the light-duty vehicle segment in all scenarios in 2050, contributing to a massive increase in the demand for batteries. In the electricity sector, battery energy storage systems emerge as one of the key solutions to provide flexibility to a power system that sees sharply rising flexibility needs, driven by the fast-rising share of variable renewables in the electricity mix. Batteries are also increasingly tapped to provide firm capacity as traditional generators, such as coal- or gas-fired plants, are retired.

The ongoing decline in the cost of battery packs is crucial to this. It enables electric vehicles to compete on cost with their internal combustion engine counterparts in more and more use cases. Policies and targets play an important role as well. Zero emission vehicle sales targets, such as the European Union's commitment to 100% zero emission vehicles in sales by 2035, provide guidance to carmakers, many of whom are responding by expanding the model range and setting their own fleetwide electrification targets. Direct and indirect electric vehicle subsidies, as well as investments into charging infrastructure, are boosting the competitiveness of electric vehicles and their practicality of use.

On the stationary battery energy storage side, falling costs, driven mainly by the battery pack, which benefits from spillover effects from the EV industry, but also ongoing learning and economies of scale on the rest of the balance of system, are increasingly making battery energy storage a cost-competitive choice for the provision of flexibility and secure capacity.

The projected rise in battery production leads to a strong increase in demand for critical minerals like lithium, cobalt, nickel, graphite, copper, or manganese. Increasing the supply of these critical minerals in lockstep with demand is essential in order for battery costs to continue to decline.

#### References

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# Chapter 4 Overview of Energy Storage Technologies Besides Batteries

Eva Schischke, Anna Grevé, Ulrike Ehrenstein, and Christian Doetsch

#### Contents

#### 4.1 Introduction

energy storage, and flywheel storage systems. Energy storage systems are grouped by their types of energy storage media into mechanical, electrical, electrochemical, chemical, and thermal energy storage systems. Mechanical storage systems consist mainly of pumped hydro storage, air

E. Schischke · A. Grevé · U. Ehrenstein

C. Doetsch (✉)

Fraunhofer UMSICHT, Oberhausen, Germany e-mail<EMAIL_ADDRESS>
© The Author(s) 2024

Fraunhofer Institute for Environmental, Safety and Energy Technology UMSICHT, Oberhausen, Germany

Fraunhofer Institute for Environmental, Safety and Energy Technology UMSICHT, Oberhausen, Germany

https://doi.org/10.1007/978-3-031-48359-2\_4 S. Passerini et al. (eds.), Emerging Battery Technologies to Boost the Clean Energy Transition, The Materials Research Society Series,

Electrical storage systems store electricity directly in supercapacitors and superconducting magnetic energy storages. Electrochemical storages are commonly referred to as batteries and include lead-acid, Li-Ion, Na-S, as well as redox-flow batteries. Chemical and thermal energy storage systems include, for example, hydrogen, synthetic fuels, and warm water. In addition to the other energy storage systems, they are also essential elements for the energy transition by enabling sector coupling.

The central point for establishing the concept of sector coupling and additionally the concept of power-to-X is the importance of renewably produced electricity for the energy transition and the need to integrate this electricity into the various economic sectors. Power-to-X technologies are technologies that enable this integration and include besides energy storage also material utilization paths. They can be grouped by their concepts into, e.g., power-to-power, power-to-gas, power-toliquid, or power-to-heat [5].

Regarding the energy storage technologies focused on here, Fig. 4.1 shows the different energy storage technologies sorted by energy storage capacity and storage duration. Storage systems with high capacity and high storage duration are called long-term energy storage and can be used as seasonal storage or for sector coupling with the heating and mobility sector. In contrast, technologies with lower capacity and short storage duration are called short-term storage and are generally used for short-term balancing applications.

Fig. 4.1 Overview over different types of energy storage system sorted by storage capacity and discharge time

Electric, mechanical, and electrochemical energy storage applications generally refer to power-to-power applications which remain within the power sector in their function. These can be grouped according to the corresponding segment of the energy system. Figure 4.2 shows an overview of these applications. Depending on the type of application, different storage technologies are better suited to provide the required services.

Power-to-X concepts that connect the power sector with another sector, e.g., the heat, industry, or the transport sector, are referred to as sector coupling. Sector coupling is an important element of the energy transition, as it can make decisive contributions to defossilization in the various sectors [35].

The ecological footprint of energy storage technologies includes a variety of aspects. From a cradle-to-grave perspective, there are different life cycle stages. Firstly is the production stage that includes both the production including all necessary materials and the construction including the transport processes as well as the energy and water and the resulting emissions and waste. Secondly are replacement measures and additional emissions that are caused by the energy storage system itself requiring energy during its operation. In addition, there is an energy loss associated with storing energy due to nonideal efficiencies <100 % of the storage operation. At "end-of-life," the focus is on dismantling, separating, and

Fig. 4.2 Overview of power-to-power energy storage applications sorted by the corresponding segment of the energy system

disposing of the materials and recycling, including the energy consumption and emissions required for this [14]. Especially the emissions of the respective process chains as a whole are crucially dependent on the emissions of the upstream energy system (fossil or renewable) and the round-trip efficiency of the energy storage system. With a primarily emission-free energy mix, technical aspects such as service life, capacity, and efficiency become the decisive influencing factors [22].

#### 4.2 Mechanical Energy Storage: Pumped Hydroelectric Storage

# 4.2.1 Operating Principle

Pumped hydroelectric storage (PHES) is one of the most common large-scale storage systems and uses the potential energy of water. In periods of surplus of electricity, water is pumped into a higher reservoir (upper basin). In demand times, this process is reversed, and the potential energy is transformed into electrical power by a generator within a short reaction time [20].

The energy density depends on the height difference between upper and lower reservoir and ranges between 70 and 600 meters, which corresponds to energy densities of 200–1600 Wh/m3 [21].

There are two different design principles: the tandem design and the use of pump turbines. In the tandem design, pumps and turbines are designed as independent units, whereas pump turbines can function both as pumps and turbines. Pumped storage power plants are characterized above all by high storage capacities and rapid operational readiness.

More than 96 % of installed storage capacity worldwide consists of pumped hydro storage systems. Table 4.1 shows the installed rated power and capacity of pumped hydro in the world since 1990.

With a storage duration ranging from a couple of hours up to several days and reaction times within seconds, pumped hydro storage systems are used for bulk energy services as well as ancillary services.

Table 4.1 Worldwide installed rated power and rated capacity of pumped hydro storage systems [8]

#### 4.2.2 Ecological Footprint

Of all energy storage systems, pumped hydro storage systems have the longest service life of 50–150 years [2]. Due to their design, they show neither a degradation of the high round-trip efficiency nor the capacity. Because of their low volumetric energy density, however, pumped storage power plants require large areas for storage lakes and a sufficiently high gradient between the upper and lower reservoirs. In practical terms, this means that PHES are primarily implemented in areas with natural height differences.

The main materials in the construction of PHES are concrete1 and steel. Although these materials have significant CO2 emissions during production, these are put into perspective by their long service life. The required materials are available worldwide, so they do not have any criticality worth mentioning. The operation and commissioning, which mainly consists of damming rivers or connecting existing lakes, can lead to many negative consequences for the local ecosystems. In particular, the constantly changing water levels can be negative for flora and fauna, but also for possible tourist use. Even if pumps, pipes, or turbines are hardly visible in modern designs such as cavern power plants, the intervention in nature is often viewed with skepticism or completely rejected by those affected. Therefore, "since the 1970s, especially in European countries, this has led to a continuously decreasing acceptance of these energy storage devices among the population" [1].

Decommissioning, dismantling, and recycling play a subordinate role with PHES because of the particularly long service life. At the same time, hardly any materials that are critical for disposal are installed here.

#### 4.3 Mechanical Energy Storage: Compressed Air Energy Storage

# 4.3.1 Operating Principle

Compressed air energy storage is based on the compression of air and storage in geological underground voids (e.g., salt caverns) at pressures of around 100 bar. When discharging, the compressed air is released and expanded to drive a gas turbine to generate electricity. As air cools down during expansion, it has to be heated while releasing. Here, a distinction is made between diabatic and adiabatic compressed air energy storage.

When discharging a diabatic compressed air energy storage (D-CAES), the released air is heated via combustion using natural gas or fuel. Therefore, a

1 The production of steel requires sand as raw material, which has become a scarce resource. However, it is not part of the 2020 EU Critical Raw Materials List, which has been the basis for the evaluation of critical materials in this chapter.