Electrochemical performance of CrOx cathode material for high energy density lithium batteries

Chromium oxides (Cr8O21 and Cr2O5) were synthesized by pyrolysis of CrO3 at different temperatures (325 °C, 350 °C and 375 °C) and employed as promising cathode materials in rechargeable lithium batteries. The material prepared at 325 °C with a heating rate of 5 °C /min in air for 2 h delivers the high specific capacity of 365 mAh/g and energy density of 1108 Wh/kg at a current density of 10 mA/g. Even at a high current density of 100 mA/g, the material shows the initial discharge capacity of 298 mAh/g and a relatively high capacity retention of 56.4% after 50 cycles. The LiCrO2 is formed during the first discharge process, and its reversibility during lithiation and delithiation process is verified by the structure and chromium valence evolution during cycling.