Optimization of Cobalt Doped Chromium Oxide as Cathode Material for Secondary Lithium Batteries

Cobalt doped chromium oxides were synthesized and characterized as cathode materials for secondary lithium batteries. A small amount of Co as dopant in the chromium oxides provides greater stability to the structure of CrO_x and helps in improving the high-rate behavior of these oxides. Optimized Co_0.2CrO_x exhibited an initial capacity of 290 mAh/g with an average discharge voltage of 3.0 V vs. Li/Li⁺. The lithiated Co_0.2CrO_x exhibited an initial capacity of 230 mAh/g. Both lithiated and non-lithated Co_0.2CrO_x were found to be reversible in the entire intercalation range (2.0 – 4.2 V vs. Li/Li⁺). Compared with pure CrO_x, Co doped CrO_x is characterized by better high-rate behavior. (> 85% capacity for Co_0.2CrO_x and > 75% capacity for LiCo_0.2CrO_x at 0.65 C discharge rate).