The Design And Electrochemical Performance Of Li₃VO₄ Anode Materials

As a new type of intercalation/deintercalation anode material,Li₃VO₄ combines the advantages of high capacity and high safety,and is expected to become a competitive commercial anode material for Li-ion batteries.However,its development and practical application has been hindered by unsatisfactory electrochemical performance caused by slow reaction kinetics.In this paper,we try to improve the comprehensive electrochemical performance of Li₃VO₄ via enhancing the electronic conductivity,designing the morphology,and combining it with other components.The main content and conclusions are as follows:Li₃VO₄/NC-MXene/N was successfully prepared by introducing conductive MXene into an intermediate precursor solution of Li₃VO₄.The contribution of the high pseudocapacitive charge storage was triggered by the N-doped MXene in the electrode,which is responsible for the excellent comprehensive electrochemical performance.The Li₃VO₄/NC-MXene/N delivers high discharge capacity of 515.2 mAh g^-1 after 500 cycles at 0.1 A g^-1.After periodic rate performance test from 0.1 to 2.0 A g^-1 for 410 cycles,the capacity of the Li₃VO₄/NC-MXene/N could be fully recovered.Followed by additional 1000 cycles at 0.5 A g^-1,the Li₃VO₄/NC-MXene/N still delivers high discharge capacity of 457.6 mAh g^-1.The robust capacitive charge storage induced by N doped MXene and the remarkable comprehensive electrochemical performance of the Li₃VO₄/NC-MXene/N are referential for the design of high performance Li₃VO₄-based anode material,and the facile approach is beneficial for mass production toward practical application.Due to its strong hydrophilia,it is a great challenge to improve the performance of Li₃VO₄via design the morphology.Hence,Li₃VO₄/C nanoflakes are firstly designed and synthesized via a concise,low-cost,and environment-friendly biomass-aided approach.The Li₃VO₄/C shows robust pseudocapacitive charge storage,rendering high capacity and excellent rate capability.After 4 periodic rate performance testing from 0.1 to 2.0 A g^-1 over 330 cycles,a high reversible capacity of 612.0 mA h g^-1 could be reverted.The excellent performance of the Li₃VO₄/C nanoflakes and the scalable fabrication approach will facilitate the practical applications of Li₃VO₄.Ga₂O₃ shows high theoretical capacity and suitable working voltage,which is a promising composite component to improve the capacity of Li₃VO₄ without scarifying its voltage.The as-prepared Li₃VO₄-Ga₂O₃/NC exhibits robust pseudocapacitive charge storage,resulting in ultra-high capacity and ultra-stable cyclability as anode for Li-ion batteries.At a specific current of0.1 A g^-1,the Li₃VO₄-Ga₂O₃/NC delivers high reversible capacity of 652.6 mAh g^-1 after 400cycles,without obvious capacity attenuation over cycling.After three periodic rate performance testing,the Li₃VO₄-Ga₂O₃/NC delivers high discharge capacity of 750.3 mAh g^-1.The Li₃VO₄-Ga₂O₃/NC also shows excellent long cycle stability at 1.0 A g^-1,delivering high discharge capacity of 450.4 mAh g^-1 after 1600 cycles.The design and synthesis of high-performance Li₃VO₄-Ga₂O₃/NC provides a new strategy for the construction of Li₃VO₄-based anodes with excellent electrochemical properties and high safety for Li-ion batteries.