Electrochemical Characteristics of a Diamond-Like-Carbon-Coated LiV3O8 Cathode When Used in a Li-Metal Battery with a Li-Powder Anode

Abstract

A diamond-like-carbon (DLC)-coated LiV3O8 cathode was synthesized for use in a rechargeable 2032-coin-type cell with a Li-powder electrode (LPE) as the anode. The LPE anode was produced using the droplet emulsion technique and was compacted by pressing. The initial discharge capacity of the LPE/DLC-coated LiV3O8 (LVO) cell was 238 mAh g(-1) at a C-rate of 0.5, while that of a LPE/bare-LVO cell was 236 mAh g(-1). After 50 cycles, the capacity retention rate of the DLC-coated-electrode-containing cell (92%) was higher than that of the uncoated-electrode-containing cell (77%). Results of electron probe microanalysis and Raman spectroscopy confirmed that the electrode had been coated with DLC. Scanning electron microscopy and energy dispersive X-ray spectroscopy were used to determine the sequence of formation of byproducts on the electrode after charging/discharging and to determine its surface composition. The voltage profile and impedance of the DLC-coated-electrode-containing cell were analyzed to determine the electrochemical characteristics of the DLC-coated cathode. (C) 2013 The Japan Society of Applied Physics