Abstract Tin sulfides are promising anode materials for sodium-ion batteries (SIBs) for their high theoretical capacity and fast kinetics for Na storage. However, the severe volume expansion and intrinsically low charge conductivity fundamentally compromise their electrochemical performance. Addressing at the issue, SnS /SnS heterostructures are decorated on three-dimensional graphene nanosheets (3D GNS) framework, which is then shielded with a nanocarbon layer. In this nanocomposite, the SnS /SnS p-n heterostructures induce an internal electric field on the heterointerfaces to promote the ch...