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

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.