Facile synthesis of ternary MXene nanocomposites as an electrode for supercapacitive applications

Supercapacitors (SCs) are particularly appealing for building a new generation of energy storage devices considering their low cost and unique features. Thus, we present a facile and scalable approach to fabricate and engineer ternary composite electrodes composed of MXene and metal oxides (MnO2 and CuO) to develop supercapacitors with high gravimetric capacitances. Firstly, a series of CuO on FSSM (Flexible Stainless Steel Mesh) CuO@FSSM thin films were synthesized by SILAR, and subsequently, a MnO2/MXene composite (MMC) was deposited on the CuO@FSSM films by a simple cost-effective R-CBD method to synthesize CuO@MMC. The optimized CuO20@MMC ternary composite electrode showed a gravimetric capacitance of 924.16 F g(-1) at 2 mA cm(-2). Furthermore, this ternary composite electrode was employed in an asymmetric supercapacitor device (ASC) delivering 25.54 F g(-1) specific capacitance with a capacitance retention of 87.27% over 2000 cycles. Thus, this method and the results are promising to fabricate advanced electrode materials for high-performing supercapacitors combining MXene and metal oxides.