Hydrothermal synthesis of ball-like ZnS nanospheres decorated urchin-like W18O49 nanospheres as electrode for high power and stable hybrid supercapacitor

Abstract

Herein, the electrochemical performance of Urchin-like W₁₈O₄₉ nanospheres and ball-like ZnS nanospheres were synthesized by the hydrothermal route and compared with the composite of W₁₈O₄₉-ZnS performance. XRD, FESEM, and EDX analysis investigated the crystal structure and morphology. The electrochemical performance of W₁₈O₄₉, ZnS and W₁₈O₄₉-ZnS composite electrodes was examined by using 3 M KOH aqueous solution. The composite provides a high specific capacitance of 517 F/g at 1 A/g. Furthermore, we constructed asymmetric supercapacitor W₁₈O₄₉-ZnS||MnO₂-KOH, which provide the good energy and power density of 32.61 Wh/kg and 9610 W/kg respectively, maintaining excellent stability around 10,000 cycles with 98.1 % capacity retention at 12 A/g with Coulombic efficiency of 81.3 %, that make W₁₈O₄₉-ZnS composite promising electrode material for supercapacitor applications.