Hierarchical Co-doped SnS2@Ni(OH)2 double-shell crystalline structure on carbon cloth with gradient pore distribution for superior capacitance

Hierarchical Co-doped SnS2@Ni(OH)2 double-shell nanosheets arrays are coated on the carbon cloth via two-step solvothermal method. The vertically aligned and ultrathin nanosheets arrays with gradient pore distribution and the hydrophilic nature can facilitate the electrolyte infiltration and avoid the “dead volume”, while the densely packed SnS2 array with high intrinsic electrical coductivity can bridge the carbon cloths and Ni(OH)2 to improve the electron transfer. The SnS2@Co-Ni(OH)2/CC-3 electrode can achieve a high areal capacitance (5.41 F cm-2 at 1 mA cm-2), good rate capability and cyclic stability (93.92% capacitance retention after 5000 cycles) in three-electrode system. Addtionally, an asymmetric supercapacitor (ASC) device is fabricated with the SnS2@Co-Ni(OH)2/CC composites and activated microwave-exfoliated graphene oxide, and achieves highest energy density of 57.2 W h kg-1 and maximium power density of 8.0 kW kg-1.