Improved lithium storage performance of (Ni0.1Co0.7Mn0.2)3O4@Void@N-doped carbon via the synergistic effect between void space structure and N-doped carbon layer

The material with sufficient void space structure can buffer the volumetric expansion of active materials during charge/discharge process. Nitrogen-doped carbon (NC) layer on the surface of active materials can enhance the electronic conductivity and reactivity of active materials. Herein, we synthesize (Ni0.1Co0.7Mn0.2)(3)O-4 (NCMO)@Void@NC composite. When evaluated as anode materials for LIBs, NCMO@Void@NC composite can deliver a discharge-specific capacity of 773.7 mA h g(-1) at 0.5 A g(-1) in the 387th cycle, which corresponds to 91.16% of the 2nd discharge specific capacity. Coulombic efficiency of 99.19% can still be obtained in the 387th cycle. By contrast, bare NCMO can only deliver a discharge specific capacity of 535 mA h g(-1) at 0.5 A g(-1) in the 285th cycle. Electrochemical performances of NCMO@Void@NC composite are significantly higher than those of the bare NCMO, attributed that void space structure and NC layer in NCMO@Void@NC composite can create a strong synergistic effect.