Hierarchically-structured nanocrystalline lithium rich layered composites with enhanced rate performances for lithium ion battery

Li-rich layered composite cathode material: 1/2Li(2)MnO(3)center dot 1/2LiMn(1/2)Ni(1/2)O(2) with a hierarchically-structured flake morphology is firstly synthesized with a solvent-controlled organic route. X-ray diffraction evidences a pure lithium-rich layered phase of as-fabricated materials. Transmission electron microscopy investigated that each single flake possesses a highly crystalline nature and it composed by numerous hierarchically-structured plates around 20 nm. Electrochemical performances demonstrates that flake cathode delivered a significantly enhanced rate capability as compared to conventional particles prepared by regular co-precipitation method. The specific capacity of flakes cycled at 0.1 and 1 C were 210 and 155 mAh/g, respectively. Cyclic voltammetry represents distinct intercalation mechanisms between two samples, in which a higher lithium diffusivity is derived by flakes with respect to particle ones. Electrochemical impedance profiles shows that the chargetransfer resistances of flake cathodes could be effectively suppressed with respect to particles after cycled at elevated discharge rates. This study provides an alternative approach for synthesizing morphologically-tailored Li-rich layered cathode and virtually proves the ability to tolerant high current input and can preserve a good cycling retention.