SnS Nanowall Arrays toward High-Performance Sodium Storage.

Cost-effective sodium ion batteries (SIBs) are emerging as a desirable alternative choice to lithium ion batteries in terms of application in large-scale energy storage devices. SnS is regarded as a potential anode material for SIBs because of its unique layered structure and high theoretical specific capacity. However, the development of SnS was hindered by the sluggish kinetics of the diffusion process and the inevitable volume change during repeated sodiation-desodiation processes. In this work, SnS with a unique nanowall array (NWA) structure is fabricated by one-step pulsed spray evaporation chemical vapor deposition (PSE-CVD), which could be used directly as binder-free and carbon-free anodes for SIBs. The SnS NWA electrode achieves a high reversible capacity of 576 mAh g at 500 mA g and enhanced cycling stability. Attractively, an excellent rate capability is demonstrated with ∼370 mAh g at 5 A g, corresponding to a capacity retention of 64.2% at 500 mA g. The superior sodium storage capability of the SnS NWA electrode could be attributed to outstanding electrode design and a rational growth process, which favor fast electron and Na-ion transport, as well as provide steady structure for elongated cycling.