Carbon coated amorphous bimetallic sulfide hollow nanocubes towards advanced sodium ion battery anode

Abstract

Abstract Exploring proper anode hosts with stable and ultrafast sodium storage capability is a big challenge for commercializing sodium ion batteries. And tin-based sulfides are considered as ideal anode material for sodium ion batteries because of the high theoretical capacity, while its practical application is limited to the poor cycling stability and inferior rate capability, which are induced by the huge volume variation upon sodiation and poor conductivity of those sulfides. Herein, amorphous tin-based bimetallic sulfides hollow nanocubes encapsulated by carbon are constructed and such amorphous bimetallic sulfides show excellent rate performance (478 mAh g−1 at 10\u202fA\u202fg−1) and good cycle stability (83% capacity retention after 100 cycles at 0.1\u202fA\u202fg−1). And kinetic analysis reveals a pseudocapacitance-dominated sodium storage mechanism in the composite. Such rational nanostructure design and multicomponent synergistic interaction system can inspire further development of high performance amorphous nanomaterials for batteries and energy storage and conversion devices.