Tungsten Carbide-Coated LiV3O8 Cathodes with Enhanced Electrochemical Properties for Lithium Metal Batteries

Abstract

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.