SnOxS2−x/GNS nanocomposites for reversible and high-capacity lithium-ion batteries

Abstract

SnO₂ and SnS₂ anode materials can improve the cycle stability of tin-based electrodes compared with Sn. However, they usually lead to huge initial irreversible capability and lower initial efficiency. To solve these problems, we reported SnO_xS_2−x/GNS nanocomposites with a large surface area and small particle size, which can improve the kinetics of the electrochemical reactions and realize a reversible Li⁺ storage process. The obtained SnO_xS_2−x/GNS nanocomposites (x = 0.3–1.3) have homogenously anchored on graphene nanosheets, which consists of a single phase (SnO₂ or SnS₂) nanocrystal (3–5 nm) and are surrounded by large amorphous areas. This unique structure makes the Li⁺ storage process of the obtained nanocomposites fully reversible. Specifically, the SnOS/GNS nanocomposite exhibits a good cycling performance of 1066 mA h g⁻¹ at 0.2 A g⁻¹ after 50 cycles and a rate capability of 402 mA h g⁻¹ at 2 A g⁻¹.