A two-dimensional (2D) silicene–germanene alloy,
siligene
(SixGey),
a single-phase material, has attracted increased attention due to
its two-elemental low-buckled composition and unique physics and chemistry.
This 2D material has the potential to address the challenges caused
by low electrical conductivity and the environmental instability of
corresponding monolayers. Yet, the siligene structure was studied
in theory, demonstrating the material’s great electrochemical
potential for energy storage applications. The synthesis of free-standing
siligene remains challenging and therefore hinders the research and
its application. Herein we demonstrate nonaqueous electrochemical
exfoliation of a few-layer siligene from a Ca1.0Si1.0Ge1.0Zintl phase precursor. The procedure was
conducted in an oxygen-free environment applying a −3.8 V potential.
The obtained siligene exhibits a high quality, high uniformity, and
excellent crystallinity; the individual flake is within the micrometer
lateral size. The 2D SixGeywas further explored as an anode material for lithium-ion
storage. Two types of anode have been fabricated and integrated into
lithium-ion battery cells, namely, (1) siligene–graphene oxide
sponges and (2) siligene–multiwalled carbon nanotubes. The
as-fabricated batteries both with/without siligene exhibit similar
behavior; however there is an increase in the electrochemical characteristics
of SiGe-integrated batteries by 10%. The corresponding batteries exhibit
a 1145.0 mAh·g–1specific capacity at 0.1 A·g–1. The SiGe-integrated batteries demonstrate a very
low polarization, confirmed by their good stability after 50 working
cycles and a decrease in the solid electrolyte interphase level that
occurs after the first discharge/charge cycle. We anticipate the growing
potential of emerging two-component 2D materials and their great promise
for energy storage and beyond.