Cobalt doped chromium oxides as cathode materials 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 i n the chromium oxides provides greater stability to the structure of CrOx a nd 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 discharg e 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 fo und 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 LiCo0.2C rOx at 0.65 C discharge rate). (C) 1999 Elsevier Science S.A. All rights re served.