A Stable CaV4O9 Anode Promises Near‐Zero Volume Change and High‐Capacity Lithium Storage

Abstract Even though lithium ion batteries (LIBs) have seen extensive applications during the past 20 years, the anode materials which have realized commercialization are mainly restricted to graphite and Li 4 Ti 5 O 12 . However, because of the limited capacity of these two intercalation‐type anodes, they cannot meet the higher requirements in energy density of some applications. Very few types of high‐capacity anode materials have been successfully commercialized, mainly due to the inevitable large volume change during lithium insertion/extraction. Herein, a promising anode material, CaV 4 O 9 , which shows both high gravimetric capacity of more than 600 mAh g –1 with a safe average discharge potential of about 0.8 V, and near‐zero volume change character like Li 4 Ti 5 O 12 , is identified. The specific lithium storage mechanism and the origin of near‐zero volume change character are revealed. Considering the superior performance endowed by these unique intrinsic properties, CaV 4 O 9 shows great potential for commercialized anode material and may promote innovation in LIBs.