Electrochemical performance of Li[Co sub(0.1)Ni sub(0.15)Li sub(0.2)Mn sub(0.55)]O sub(2) modified by carbons as cathode materials

To enhance specific capacity, cycle performance and rate-capability of lithium-ion battery cathode materials, the Li[Co sub(0.1)Ni sub(0.15)Li sub(0.2)Mn sub(0.55)]O sub(2) (LCMNO) is modified by coating them with amorphous carbons and by preparing nanocomposites with nanostructured carbons (carbon nanotube and graphene). The carbon-treated LCMNO powders and their cathodes are characterized by morphological observation, crystalline property analysis, galvanostatic charge-discharge, and electrochemical impedance spectroscopy. The LCMNO nanocomposite shows a superior discharge capacity of ca. 290 mAh g super(-1) at low C-rates, due to a greater number of active sites embedded by nanostructured carbon species. In contrast, the carbon-coated LCMNO shows higher discharge capacity in high rate regions due to the carbon-coated layer in the carbon-coated LCMNO, suppressing the side reactions and enhancing the electrical conductivity.