Laminating Layered Structures of 2D MXene and Graphene Oxide for High‐Performance All‐Solid‐State Supercapacitors

Abstract

AbstractGraphene oxide (GO)‐based all‐solid‐state supercapacitors (SCs) provide an important complement to liquid‐ and gel‐electrolyte‐based SCs in a variety of applications, including flexible electronics. Still, their mediocre capacitance and complex fabrication methods hold back the realization of their full potential. Here, a simple fabrication of all‐solid‐state SCs with layered GO as a solid electrolyte and MXene as electrodes is demonstrated. The resultant SCs show excellent energy storage capacitance comparable to other MXene‐based SCs using liquid electrolytes. The outperformance is attributed to extra interlayer spacing expansion and improved ion transport kinetics thanks to a synergistic water‐absorbing effect due to the hydrophilicity of both MXene and GO in combination, which interestingly satisfies the intrinsic surface‐dominated pseudocapacitive behavior of MXene. The application of this SC in humidity sensing has also been demonstrated to be fast responsive. The findings describe in this work provide a means of improving the capacitance performance using GO as a solid electrolyte with MXene as the electrodes and exploit the potential application as electronic elements for smart devices.