Designing a ternary NiS2/CoS2@SnS2 nanocube as a secondary battery anode displaying excellent capacity and stability

Abstract

Simultaneously achieving rapid electron/ion transfer and high capacity in Na-ion batteries remains a great challenge. Here, we describe our development of a ternary composite consisting of SnS₂ grown on NiS₂/CoS₂ nanocubes, forming a NiS₂/CoS₂@SnS₂ structure that displays excellent performances as a Na-ion battery anode. The synergy of ternary sulfides improves electrical and ionic conductivities, while the hierarchical architecture enhances structural stability. In situ characterizations demonstrate good reversibility upon cycling. The NiS₂/CoS₂@SnS₂ anode displays a high capacity of 475.6 mAh g⁻¹ after 1000 cycles at 2 A g⁻¹, and of 223.4 mAh g⁻¹ after cycling 2500 times at a high rate of 5 A g⁻¹. These findings are of great importance for the development of emerging energy-storage composites and battery systems.