ZnSe embedded in N-doped carbon nanocubes as anode materials for high-performance Li-ion batteries

ZnSe is regarded as a promising anode material for reversible Li-ion batteries because of its high theoretical capacity. Herein, we report a facile chemical precipitation method to controllably synthesize ZIF-8 nanocubes and then select them as sacrificial templates to prepare ZnSe nanoparticles embedded N-doped carbon nanocubes. The as-obtained ZnSe/carbon nanocomposite at 600 °C demonstrates a high initial discharge capacity of 1170.8 mAh g−1 with the initial columbic efficiency of 68.8% at the current density of 0.1 A g−1 in the voltage range of 0.01–3 V. In addition, it displays a reversible capacity of 1166.6 mAh g−1 after 500 cycles at the current density of 0.5 A g−1, indicating the excellent cyclic stability for the designed composites. The enhanced electrochemical performance can be ascribed to its high specific surface area (493.45 m2 g−1) and unique mesoporous structure, which provides efficient Li+ transport channels and additional storage sites. Furthermore, the existence of faradaic pseudocapacitance in ZnSe/carbon nanocomposites also affords additional capacity and contributes to the increased capacity with respect to charge/discharge cycle number.