Boron Nitride/Ti3C2Tx MXene Nanosheet/WS2 Nanostructure Ternary Composites for All-Solid-State Flexible Asymmetric Supercapacitors

MXene-based nanomaterials are emerging candidates for energy storage applications due to their metallic conductivity, large surface area, and facile redox activity. The sheet restacking tendency and oxidation significantly reduce their application in different industries. This study reported a facile hydrothermal synthesis of a tungsten disulfide (WS2)-decorated Ti3C2Tx/functionalized-boron nitride (BN) nanohybrid as a cathode for all-solid-state flexible asymmetric supercapacitors. The MXene/functionalized BN heterostructure showed an increased surface area by reducing the sheet restacking. On the other hand, incorporation of WS2 over the MXene/functionalized BN sheets led to the addition of redox-active centers. The loading of WS2 over MXene/functionalized BN was varied to obtain an optimum electrode that delivered a specific capacitance of 1318 F g–1 at 1 A g–1 in 1 M KOH. An all-solid-state flexible asymmetric supercapacitor was assembled using PVA–KOH–KI gel electrolyte where KI functioned as a redox additive to increase the supercapacitor's performance. The assembled device achieved an excellent specific capacitance of 140 F g–1 and a good energy density of 19.4 Wh kg–1 at 1 A g–1 with 84% capacitance retention after 10,000 cycles. Additionally, the assembled devices were able to brightly glow a light-emitting diode (LED), indicating their potential practical applicability in future portable electronics.