Nickel doped tungsten disulfide grown on carbon cloth for flexible supercapacitors

We present the synthesis of flower-shaped nickel-doped tungsten disulfide on flexible activated carbon cloth (ACC) using a simple hydrothermal technique for flexible symmetric supercapacitors. The nickel-to-tungsten disulfide doping ratio is optimized by adjusting the mass ratio of nickel and tungsten disulfide (Ni:WS2 = 0.5:3, 1:3, and 1.5:3) to enhance charge storage capability, surface area, impedance behavior, specific capacity, and rate capability. The improved supercapacitor performance is attributed to the increased electrochemically active surface area, reduced impedance, and phase engineering from 2 H to 1 T achieved through optimal nickel doping. At a current density of 1 A g-, 1 the flexible symmetric supercapacitor device (Ni-WS2-ACC device) demonstrates a specific capacitance of 259.2 F g- 1, an energy density of 22.4 Wh kg- 1, and a power density of 803 W kg- 1. Moreover, the Ni-WS2-ACC device maintains consistent supercapacitive performance under various bending conditions. These results present a promising strategy for further enhancing tungsten disulfide-based flexible supercapacitors as energy storage devices.