Conformal and Nanoscale Poly(pyrrole) Coating on Li ₃ VO ₄ Surface Enabling High Performance Lithium‐Ion Batteries

Lithium vanadium oxide (Li 3 VO 4 ) shows great promise as an anode for high‐efficiency Li‐ion batteries (LIBs). However, its application is hindered by poor electronic conductivity and high charge transfer resistance caused by a thick and unstable solid electrolyte interface layer. A two‐step approach aimed at improving the electrochemical performance of the LVO anode for high‐rate and long‐cycle LIBs is reported. This involves the hydrothermal synthesis of crystalline LVO, followed by a conformal coating of polypyrrole (Ppy) via vapor‐phase polymerization. The conductive Ppy layer facilitates electron transport and enhances lithium‐ion diffusion, mitigating the limitations of pristine LVO. Among the tested samples, LVO@Ppy‐0.5 (0.5 indicates coating time in hours) exhibited the highest reversible capacity of 605 mAh g −1 , nearly three times that of pristine LVO with an initial Coulombic efficiency of 87% upon chemical prelithiation. The rate capability studies revealed stable performance, with 78% capacity retention over 500 cycles at 10C. Electrochemical impedance spectroscopy reveals that the LVO@Ppy‐0.5 electrode exhibits high Li‐ion diffusivity, reduced interfacial layer resistance, and enhanced charge transfer kinetics. Ex situ surface chemical analysis confirms the formation of a stable solid–electrolyte interphase layer on LVO@Ppy‐0.5. Conformal Ppy coating on LVO is a promising strategy for developing high‐performance LIB anode.