Solvothermally Synthesized Nickel-Doped Marigold-Like SnS₂ Microflowers for High-Performance Supercapacitor Electrode Materials

Two-dimensional transition-metal dichalcogenides (TMDs) have emerged as promising capacitive materials for supercapacitors owing to their layered structure, high specific capacity, and large surface area. Herein, Ni-doped SnS₂ microflowers were successfully synthesized via a facile one-step solvothermal approach. The obtained Ni-doped SnS₂ microflowers exhibited a high specific capacitances of 459.5 and 77.22 F g^-1 at current densities of 2 and 10 A g^-1, respectively, in NaClO₄ electrolyte, which was found to be higher than that of SnS₂-based electrodes in various electrolytes such as KOH, KCl, Na₂SO₄, NaOH, and NaNO₃. Additionally, these microflowers demonstrate a good specific energy density of up to 51.69 Wh kg^-1, at a power density of 3204 Wkg^-1. Moreover, Ni-doped SnS₂ microflowers exhibit a capacity retention of 78.4% even after 5000 cycles. Better electrochemical performance of the prepared electrode may be attributed to some important factors, including the utilization of a highly ionic conductive and less viscous NaClO₄ electrolyte, incorporation of Ni as a dopant, and the marigold flower-like morphology of the Ni-doped SnS₂. Thus, Ni-doped SnS₂ is a promising electrode material in unconventional high-energy storage technologies.