Enhancing the Rate Performance of a Li3VO4 Anode through Cu Doping

Li3VO4 (LVO), as an emerging anode material for lithium-ion batteries (LIBs), offers distinct advantages because of its high theoretical specific capacity (590 mAh g(-1)), high ionic conductivity, and small volume change during lithiation/delithiation. However, the low electronic conductivity of LVO severely limits its viable application in LIBs. In this work, we doped LVO with Cu2+ ions through a simple solution reaction method, aiming to improve its electronic conductivity and electrochemical performances as a LIB anode. Among various dopant concentrations, LVO doped with 10% Cu (LVO-0.10Cu) showed the highest Li-ion diffusion coefficient (2.79 x 10(-14) cm(2) s(-1)) and specific surface area (16.1 m(2) g(-1)), as well as lowest charge-transfer resistance. High reversible capacities of 440, 420, 379, and 335 mAh g(-1) were achieved at current densities of 1, 2, 4, and 8 A g(-1), respectively. In particular, the capacity of LVO-0.10Cu at 8 A g(-1) was twice as high as that of pristine LVO (335 vs. 168 mAh g(-1)). The significantly enhanced electrochemical performance of Cu-doped LVO can be attributed to lattice expansion and improved electronic conductivity afforded by Cu-doping.