Carbon-coated high capacity layered Li[Li0.2Mn0.54Ni0.13Co0.13]O2 cathodes

Electrodes fabricated with the layered Li[Li0.2Mn0.54Ni0.13Co0.13]O2 have been coated with carbon by a thermal evaporation process and characterized. The carbon coating enhances the sample surface conductivity by 40% without degrading the layered oxide. The carbon-coated cathodes exhibit much improved rate capability and cycling performance than the bare cathode. Electrochemical impedance spectroscopy (EIS) data reveal that the improved electrochemical performances of the carbon-coated sample are due to the suppression of the solid-electrolyte interfacial (SEI) layer and faster kinetics of both the lithium-ion diffusion through surface layer and the charge transfer reaction.