Rational design of flower-like MnO₂/Ti₃C₂Tcomposite electrode for high performance supercapacitors

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/Ti₃C₂Tcomposite electrode for supercapacitors by synergistically coupling MnO₂nanowires with Ti₃C₂TMXene nanoflakes. Compared with the pure MnO₂electrode, the morphology of the MnO₂/Ti₃C₂Tcomposite 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 Ti₃C₂TMXene. The specific capacitance of the MnO₂/Ti₃C₂Tcomposite electrode achieves 210.8 F·g^-1at a scan rate of 2 mV·s^-1, while that of the pure MnO₂electrode is only 55.2 F·g^-1. Furthermore, the specific capacitance of the MnO₂/Ti₃C₂Tcomposite electrode still can remain at 97.2% even after 10 000 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.