Preparation of CuS@N, S co-doped carbon honeycomb-like composite structure for high-rate and high-stability sodium-ion storage.

Sodium ion batteries (SIBs) attract most of the attention as alterative secondary battery systems for future large-scale energy storage and power batteries due to abundance resource and low cost. However, the lack of anode materials with high-rate performance and high cycling-stability has limited the commercial application of SIBs. In this paper, CuS@N, S co-doped carbon (CuS@NSC) honeycomb-like composite structure was designed and prepared by a one-step high-temperature chemical blowing process. As an anode material for SIBs, CuS@NSC electrode exhibited an ultra-high initial Coulomb efficiency (94.9%) and an excellent electrochemical property including a high reversible capacity of 441.3 mAh g after 100 cycles at 0.2 A g, an excellent rate performance of 380.4 mAh g even at 5 A g, and a superior long-cycle stability with a capacity retention rate of approximately 100% after 700 cycles at 1A g.