Cobalt doped chromium oxides as cathode materials for secondary lithium batteries

Abstract

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 CrOx and helps in improving the high-rate behavior of these oxides. Optimized Co0.2CrOx exhibited an initial capacity of 290 mA h/g with an average discharge voltage of 3.0 V vs. Li/Li+. The lithiated Co0.2CrOx exhibited an initial capacity of 230 mA h/g. Both lithiated and non-lithiated Co0.2CrOx were found to be reversible in the entire intercalation range (2.0–4.2 V vs. Li/Li+). Compared with pure CrOx, Co doped CrOx is characterized by better high-rate behavior (>85% capacity for Co0.2CrOx and >75% capacity for LiCo0.2CrOx at 0.65 C discharge rate).