Rational design of flower-like MnO₂/Ti₃C₂T _x composite electrode for high performance supercapacitors

Abstract

Combining the new two-dimensional conductive MXene with transition metal oxide to build composite structure is a promising path to improve the conductivity of metal oxide. However, a critical challenge still remains in how to achieve a good combination of MXene and metal oxide. Herein, we develop a facile hydrothermal route to synthesize the MnO2/Ti3C2Tx composite electrode for supercapacitors by synergistically coupling MnO2 nanowires with Ti3C2Tx MXene nanoflakes. Compared with the pure MnO2 electrode, the morphology of the MnO2/Ti3C2Tx composite electrode changes from nanowires to nanoflowers. Moreover, the overall conductivity and electrochemical performance of the composite electrode are greatly improved due to an addition of Ti3C2Tx MXene. The specific capacitance of the MnO2/Ti3C2Tx composite electrode achieves 210.8 F·g-1 at a scan rate of 2 mV·s-1, while that of the pure MnO2 electrode is only 55.2 F·g-1. Furthermore, the specific capacitance of the MnO2/Ti3C2Tx composite electrode still can remain at 97.2% even after 10000 charge-discharge cycles, revealing an excellent cycle stability. The synthesis strategy of this work can pave the way for the research and practical application of the electrode materials for supercapacitors.