NiCo₂N hollow sphere with interconnected nanosheets shell: A potential anode material for high performance lithium-ion batteries

Transition metal nitrides are of great interest for lithium storage application due to their high electrical conductivity and low voltage plateau. However, the relative cycling stability restricts their practical application. Herein, a stable bimetal nitride NiCo2N hollow sphere material with interconnected nanosheets shell was successfully synthesized via a facial solvothermal route. When used as anodes for lithium-ion batteries, the unique structure can effectively relieve the volume change of the electrode material, and shorten the diffusion distance of lithium ions during the repeated cycling processes. As a result, the NiCo2N electrode exhibits an excellent electrochemical performance. It delivers high discharge capacity of 1244.5 mAh g(-1) at a current density of 1 A g(-1) after 400 cycles, the capacity can maintain 529.4 mAh g(-1) at high current density of 5 A g(-1). Furthermore, the electrochemical reaction mechanism of the electrodes is revealed by ex situ XRD, ex situ EIS, and ex situ HRTEM characterization.