Tungsten carbide-coated LiV₃O₈ cathodes with enhanced electrochemical properties for lithium metal batteries

The electrochemical behaviors of WC-coated LiV₃O₈ cathodes were investigated with a view to enhancing their electrochemical properties, minimizing local structural damage, and inhibiting dissolution of V into the electrolyte. The WC coating was deposited using plasma-enhanced chemical vapor deposition. The WC coating layer was examined using scanning electron microscopy with energy-dispersive X-ray analyzer and transmission electron microscopy. At a rate of 0.2 C, the initial discharge capacity increased from 252.5 mAh g^-1 to 294.0 mAh g^-1 because of the effect of the coating. The capacity retentions at a high current density (7.0 C) were 113.2% for the 100th cycle and 91.2% for the 200th cycle for WC-coated LiV₃O₈. The electrochemical properties of the WC-coated cathode were evaluated based on electrochemical impedance spectroscopy, scanning electron microscopy and differential capacity curves. The properties of WC such as good electrical conductivity and high wear resistance improved the electrochemical properties of LiV₃O₈.