POSITIVE ELECTRODE MATERIALS FOR HIGH DISCHARGE CAPACITY LITHIUM ION BATTERIES

摘要

Positive electrode active materials are described that have a high tap density and high specific discharge capacity upon cycling at room temperature and at a moderate discharge rate. Some materials of interest have the formula Li1+xNialphaMnbetaCogammaO2, where x ranges from about 0.05 to about 0.25, alpha ranges from about 0.1 to about 0.4, beta ranges from about 0.4 to about 0.65, and gamma ranges from about 0.05 to about 0.3. The materials can be coated with a metal fluoride to improve the performance of the materials especially upon cycling. Also, the coated materials can exhibit a very significant decrease in the irreversible capacity lose upon the first charge and discharge of the battery.