GaSb for High-Performance Alkali Metal-Ion Battery Anodes

Over the last decade, electric vehicles (EVs) that employ lithium-ion batteries (LIBs) have been successfully commercialized, and their market has rapidly expanded. However, EV batteries still require significant improvements in energy and power density, fast-charging capability, and high safety to be more competitive with combustion engine vehicles. It is challenging to fulfill all of these requirements using conventional LIBs. Therefore, new high-performance electrode materials for LIBs are highly required. Furthermore, sodium-ion batteries (SIBs) and potassium-ion batteries (PIBs) are promising next-generation rechargeable battery systems because Na and K are abundant (deposits of Na and K are approximately three and two times larger than that of Li, respectively) and are environmentally harmless.<br/>This study introduces a high-energy-density GaSb compound anode and optimized nanocomposite fabrication route for superior alkali metal (M)-ion batteries (M= Li, Na, K). The GaSb compound was synthesized by a simple thermal synthesis method, and its electrochemical performance for alkali M-ion battery anodes was investigated. In addition, the reaction mechanisms of GaSb with Li, Na, and K-ions were clearly investigated using state-of-the-art analytical tools. To obtain optimized GaSb anodes, two nanocomposites of the chemically modified GaSb/reduced graphene oxide (rGO) and mechanically modified GaSb/amorphous carbon (a-C) are suggested. The GaSb/a-C shows better electrochemical performance than that of GaSb/rGO nanocomposite anode. Furthermore, the GaSb/a-C nanocomposite anode exhibits higher electrochemical performance than those of conventional carbonaceous anodes. The high-performance of GaSb/a-C was attained by three-step nanoconfinement and stabilization of GaSb nanocrystallites uniformly embedded in the C matrix, which was thoroughly demonstrated. Based on the electrochemical performance, the proposed GaSb/a-C nanocomposite can be a promising alternative anode material for alkali M-ion batteries.