LiV₃O₈/Polydiphenylamine Composites with Significantly Improved Electrochemical Behavior as Cathode Materials for Rechargeable Lithium Batteries

Although LiV3O8 is regarded as a potential cathode candidate for rechargeable lithium batteries, it has been restricted by its weak dissolution and lattice structure change. Here, polydiphenylamine is successfully introduced to trigger the evolution of LiV3O8 material through an in situ oxidative polymerization method, significantly improving the electrochemical properties and inhibiting the adverse reaction. Expectedly, the 10 wt % LiV3O8/polydiphenylamine composite delivers a high initial specific discharge capacity of 311 mAh g–1, which decreases to 272 mAh g–1 after 50 cycles at the current density of 60 mA g–1. Even at a high current density of 2000 mA g–1, it still exhibited a reversible specific capacity of 125 mAh g–1 after 50 cycles. Quantitative kinetics analysis confirms the fundamental reasons for the enhanced rate capability. The ex situ X-ray diffraction and scanning electron microscopy results suggest that 10 wt % LiV3O8/polydiphenylamine composite possesses an ultrahigh structural stability during cycling.