HIGH-CAPACITY POSITIVE ELECTRODE ACTIVE MATERIAL AND LITHIUM SECONDARY BATTERY COMPRISING SAME

摘要

The present invention relates to a high-capacity lithium secondary battery which comprises layered lithium manganese oxides and spinel lithium manganese oxides that exhibit high irreversible capacity when the battery is overcharged at a high voltage, and which is activated at a high voltage of 4.45V or higher on a positive electric potential basis, thereby providing additional lithium for the utilization of a 3V region of the spinel lithium manganese oxides and enabling the lithium secondary battery to have a uniform profile over the entire SOC region. According to the present invention, the high-capacity lithium secondary battery comprises a mixture of positive electrode active materials containing the spinel lithium manganese oxides and the layered lithium manganese oxides, and is charged at a high voltage, thereby improving safety, and preventing low output caused by a sudden voltage drop in a specific SOC region, thus widening an available SOC region and improving safety.