MnO1.88/R-MnO2/Ti3C2(OH/F)x composite electrodes for high-performance pseudo-supercapacitors prepared from reduced MXenes

Abstract

MnO_1.88/MnO₂/Ti₃C₂T_x composites on Ti₃C₂T_x (MXenes) were synthesized for potential applications as supercapacitor electrodes. A composite with a cotton candy-like morphology was formed on nanometer-sized Ti₃C₂T_x flakes by redox reaction using KMnO₄ at room temperature, where Ti₃C₂T_x acts both as a molecular template and as a reducing agent. MnO_1.88/MnO₂/Ti₃C₂T_x has a high specific capacity of 312 F g⁻¹ at 1 A g⁻¹, and the capacity retention was over 91% after 5000 charge–discharge cycles. As such, the facile preparation of MnO_1.88/MnO₂/Ti₃C₂T_x composites promotes the highly specific pseudo-capacitance of MXenes, which have emerged as highly promising electrode materials.