Hierarchical SnS/SnS2 heterostructures grown on carbon cloth as binder-free anode for superior sodium-ion storage

Abstract

Sodium-ion batteries (SIBs) have attracted tremendous attention as next-generation high-performance and low-cost energy storage devices. However, achieving both high capacity and good cycling performance is still challenging. Tin sulfides are promising SIB anode materials but usually demonstrate a capacity much lower than theoretical values and suffer from large volume expansion during charge-discharge process. Herein, SnS/SnS2 heterostructures are vertically grown on carbon cloth substrates and used as a binder-free self-supporting anode, exhibiting a high Na+ storage capacity (>800 mAh g−1 at 200 mA g−1) and good cycling performance (>400 mAh g−1 after 1000 cycles at 1 A g−1). The excellent sodium-ion storage performance can be attributed to the enhanced charge-transfer kinetics by the SnS/SnS2 heterostructure, the hierarchical structure composed of uniform nanohoneycomb-like SnS/SnS2 structure and the carbon cloth as the self-supporting framework. The superior electrochemical performance by forming heterostructures may inspire the rational design of layered materials for high-performance SIB applications.