Cathodes - Technological Review

摘要

Lithium cobalt oxide (LiCoO_2) was already used in the first commercialized Li-ion battery by SONY in 1990. Still, it is the most frequently used cathode material nowadays. However, LiCoO_2 is intrinsically unstable in the charged state, especially at elevated temperatures, and in the overcharged state causing volume changes and transport limitation for high power batteries. In this paper, some technological aspects with large impact on cell performance from the cathode material point of view will be reviewed. At first, it will be focused on the degradation processes and life-time mechanisms of the cathode material LiCoO_2. Electrochemical and structural results on commercial Li-ion batteries recorded during the cycling will be discussed. Thereafter, advanced nanomaterials for new cathode materials will be presented.