Hierarchical porous nickel tin sulfide nanosheets as a binder free electrode for hybrid supercapacitor

The utilization of free-standing sulfide-based hybrid nanostructures plays a paramount role in supplying the steadily increasing demand for energy storage devices. Herein, this report presents the growth of outstanding binder-free Ni-Sn sulfide thin films for high-performance supercapacitors via the revised successive ionic layer adsorption and reaction (r-SILAR) method. Molar concentration ratios between Ni/Sn have been studied, and the optimum designed mesoporous Nix-Sn1.0xS/Ni foam (NF), a single cathode electrode material, successfully achieved outstanding specific capacitance of 2890 F/g at 5 A/g, capacitance retention of 85 %, and coulombic efficiency of 100 % after 10,000 cycles. Moreover, the constructed Nix-Sn1.0xS/NF//activated carbon (AC) hybrid supercapacitor device delivers an ultrahigh power density of 53.469 KW/Kg and capacitance retention of 95 % with robust long-term cycling stability up to1000 cycles. The superior electrochemical performance of the prepared Nix-Sn1.0xS electrode could be attributed to: (i) the synergistic effect of the two binary metal sulfides (Ni/Sn) into reversible faradaic redox reaction; (ii) the growing mechanism of the ultra-thin film (1.2 nm) as a binder-free electrode, enhance the ions insertion/extraction, and (iii) the formation of hierarchically flower-like architecture with uniform mesopores provides a high surface area (62.2 m2/g) and intensifies active sites for faradaic redox reactions. These encouraging results present a novel avenue for constructing advanced freestanding electrode materials for high-performance supercapacitors.