Flower-like NiS/C as high-performance anode material for sodium-ion batteries

Transition metal sulfides are the promising anode materials for high-capacity sodium-ion batteries (SIBs). However, the pitfalls of poor conductivity and large volume expansion still restrict their applications. Herein, NiS/C with a uniform flower-like structure was successfully synthesized via a glucose-assisted hydrothermal method coupled with post-annealing strategy. The petal-shaped configuration shortens the diffusion path of sodium ions in electrochemical reaction. Significantly, the formed uniform amorphous carbon is more effective in improving the electrical conductivity of electrode materials and buffering for the rapid volume change. When regarded as the anode of SIBs, the NiS/C electrode delivers a high reversible specific capacity of 1042.3 mAh g−1 at 0.1 A g−1. The excellent electrochemical performance shows that the NiS/C offers great potential for the development and research of large-scale energy storage of metal sulfide electrodes in the future.