Approaching the Theoretical Capacity of Li₃VO₄ via Electrochemical Reconstruction

Abstract

Li 3 VO 4 is a potential anode for Li‐ion batteries owing to its safe discharge plateau and high capacity, but the reported reversible capacity is still far from its theoretical value (592 mAh g −1 ). Here, for the first time, a Li 3 VO 4 anode is reported with reversible capacity approaching the theoretical value. Li 3 VO 4 aggregates hybridized with carbon (Li 3 VO 4 /C) are first fabricated, and then dramatically transform into well dispersed Li 3 VO 4 nanocrystals (NCs) anchoring on carbon nanoflakes (NFs) by electrochemical reconstruction. In the Li 3 VO 4 /C NC‐on‐NF structures, the small‐sized Li 3 VO 4 NCs, the flexible carbon NFs, and the good dispersity provide high Li‐ion storage, electronic conductivity and stability, respectively. Resultingly, outstanding electrochemical performance of the Li 3 VO 4 /C is achieved with discharge and charge capacities of 542 and 541 mAh g −1 after 300 cycles at a specific current of 150 mA g −1 . After 1000 cycles at a specific current of 2000 mA g −1 , the discharge and charge capacities are maintained at 422 and 421 mAh g −1 . When matching with a 4 V cathode, the specific energy density of the Li 3 VO 4 /C is 4.2 times of Li 4 Ti 5 O 12 and 1.2 times of graphite, and the volumetric energy density is 3.2 times of Li 4 Ti 5 O 12 and 1.4 times of graphite.