Electrochemical properties of LiMxCo1-xO2[M = Mg, Zr] prepared by sol-gel process

• Published in: Journal of power sources 2004-11, Vol.138 (1-2), p.232-239
• Main Authors: KIM, Hyung-Sun, KO, Tae-Kon, NA, Byung-Ki, WON IL CHO, BYUNG WON CHAO
• Format: Article
• Language: English
• Subjects: Applied sciences; Direct energy conversion and energy accumulation; Electrical engineering. Electrical power engineering; Electrical power engineering; Electrochemical conversion: primary and secondary batteries, fuel cells; Energy; Energy. Thermal use of fuels; Equipments for energy generation and conversion: thermal, electrical, mechanical energy, etc; Exact sciences and technology; Fuel cells
• ISSN: 0378-7753; 1873-2755
• DOI: 10.1016/j.jpowsour.2004.06.024

LiCoO2, Mg-doped LiCoO2, and Zr doped LiCoO2, are manufactured by a sol-gel method, and are used as cathode active materials for lithium rechargeable batteries. The structural characteristics of the synthesized electrodes are analyzed by X-ray diffraction. The materials have a layered structure with the space gropu of hexagonal systems. LiCoO2 prepared by sol-gel method shows a capacity decay over 4.3V but LiCoO2 doped with Mg and Zr give an improvement in charge-discharge cycling performance. This effect may attribute to the fact that Mg2+ and Zr4+ ions have the same size as the Li+ ion and they locate at the inter-slab space. Therefore, they provide a pathway for the intercalation-deintercalation of Li+ during the charge and the discharge processes and prevent distortion of the structure. Also, the formation of a solid solution on the surface of the electrode acts as the buffer to phase transition and the structure becomes very stable.