Lithium–sulfur system arranged in a network of nanoparticles eliminates the requirement that charge moves in and out of particles that are in direct contact with a conducting plate. Instead, the nanoparticle network allows electricity to flow throughout the liquid. This allows more energy to be extracted.
In a Semi-solid flow battery, the positive and negative electrodes are composed of particles suspended in a carrier liquid. The positive and negative suspensions are stored in separate tanks and pumped through separate pipes into a stack of adjacent reaction chambers, where they are separated by a barrier such as a thin, porous membrane. The approach combines the basic structure of aqueous-flow batteries, which use electrode material suspended in a liquid electrolyte, with the chemistry of lithium-ion batteries in both carbon-free suspensions and slurries with conductive carbon network. The carbon free semi-solid redox flow battery is also sometimes referred to as Solid Dispersion Redox Flow Battery. Dissolving a material changes its chemical behavior significantly. However, suspending bits of solid material preserves the solid's characteristics. The result is a viscous suspension that flows like molasses.
In 2022, Influit Energy announced a flow battery electrolyte consisting of a metal oxide suspended in an aqueous solution.
Flow batteries with redox-targeted solids (ROTS), also known as solid energy boosters (SEBs), is another recent development. In these batteries either posolyte or negolyte or both (a.k.a. redox fluids), come in contact with a one or more solid electroactive materials, stored in tanks outside the power stack. The redox fluids comprise one or more redox couples, with redox potentials flanking the redox potential of the solid electroactive material. Such RFBs with Solid Energy Boosters (SEBs) combine the high specific energy advantage of conventional batteries (such as lithium-ion) with the decoupled energy-power advantage of flow batteries. SEB(ROTS) RFBs have several advantages compared to semi-solid RFBs, such as no need to pump viscous slurries, no precipitation /clogging, higher area-specific power, longer durability, wider chemical design space.  However, because of double energy losses (one in the stack and another in the tank between the SEB(ROTS) and a mediator), such batteries suffer from a poor energy efficiency. On a system-level, the practical specific energy of traditional lithium-ion batteries is larger than that of SEB(ROTS)-flow versions of lithium-ion batteries.