LiV₃O₈/Polydiphenylamine Composites with Significantly Improved Electrochemical Behavior as Cathode Materials for...

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.