Heterostructured CoS2/NiS2 nanoparticles encapsulated in bamboo-like carbon nanotubes as a high performance anode for sodium ion batteries

Abstract

Sodium ion batteries (SIBs) are promising energy storage systems because sodium is a low cost and abundant resource. Appropriate electrode materials with high performance are a prerequisite to satisfy demand for efficient SIBs. Heterostructured electrodes show high specific capacity and rate capacity for SIBs owing to the synergistic effect of multiple components compared with a single component. Here, heterostructured binary metal-sulfide CoS₂/NiS₂ compounds encapsulated in bamboo-like carbon nanotubes (CoS₂/NiS₂@B-CNT), were prepared by pyrolysis and sulfidation procedures. The heterostructured anode material demonstrates a high capacity of 625.8 mA h g⁻¹ at 0.1 A g⁻¹, a distinguished rate capacity (491.6 mA h g⁻¹ at 10 A g⁻¹), and stable cyclic property (497.6 mA h g⁻¹ at 5 A g⁻¹ after 1000 cycles, 93.0% capacity retention). This design of a heterostructure offers a new avenue to develop anode materials with high performance for SIBs.