Lithium cobalt oxide battery is composed of cobalt oxide cathode and graphite carbon anode. The LCO cathode has layered structure, during discharge, lithium ions move from anode to cathode, with the flow reversing when the battery is charging. Its high specific energy makes lithium cobalt oxide battery a popular choice for mobile phones, laptops and digital cameras.
The disadvantages of lithium cobalt oxide batteries are relatively short life, low thermal stability and limited load capacity. Like other cobalt-mixed lithium ion batteries, lithium cobalt oxide uses a graphite anode, and its cycle life is mainly limited by the solid electrolyte interface (SEI). It is mainly manifested in the gradual thickening of SEI films and the anode lithium plating during rapid charging or low temperature charging. Lithium cobalt oxide batteries should not be charged and discharged at a current higher than their capacity. This means that an 18650 battery with a 2,400mAh can only be charged and discharged at less than or equal to 2,400mA. Forced rapid charging or a load greater than 2400mA can lead to overheating and excessive stress.
Lithium cobalt oxide is being gradually replaced by lithium manganese oxide, especially NMC cathode and NCA cathode, due to the high cost of cobalt and the significant performance improvement through mixing with other cathode active materials.