Synergistic effect from Ni2+ ions with SnS for all solid-state type symmetric supercapacitor

Ternary compounds have attracted the attention of many in the field of energy storage owing to the synergistic effect from the material. By fine-tuning the electron structure, extremely active electrode materials can be produced. Herein, we have endeavored to synthesize ternary nickel tin sulfide (NixSn1-XS) nanocomposite using a simple and cost-effective hydrothermal technique and fabricated the lightweight, large-area paper-based electrode on conductive Ag-coated cellulose paper to explore the supercapacitor application. The effect of doping Ni2+ is explored which shows the noteworthy improvement in the electrochemical activity of pristine SnS. The Ni0.05Sn0.95S nanocomposite shows the best synergistic effects including hierarchical architectures, large specific surface area, and excellent intrinsic conductivity. Owing to these excellent properties, Ni0.05Sn0.95S displays the significant improvement in capacitive performance as high specific capacitance of 310.08 F g−1 at current density of 0.4 A g−1 and longtime cycling (7000 cycles) stability with cycling retention of 94.9 %. Furthermore, the device-specific features of Ni0.05Sn0.95S were investigated by building all-solid-state symmetric supercapacitors with two identical electrodes. The Ni0.05Sn0.95S have a high specific device capacitance with a noteworthy energy density (46.78 Wh kg−1) and the highest power density (46 KW kg−1). The energy-storage characteristics of the Ni0.05Sn0.95S are better than those of previously reported material, implying that it has enormous promise for next-generation energy-storage systems.