Figure 6. Schematic illustration of high-rate charge storage of SnS architecture.

During transfer of ions and electrons, the solvated Na⁺/electron can easily enter into the open spaces between neighbouring ultrathin nanosheets on both the outside and inner surface of the graphene foam. After de-solvation of Na⁺ on the surface of the layered SnS architecture, rapid sodiation takes place by the surface-dominated extrinsic pseudocapacitance.