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 MnO 2 /Ti 3 C 2 T x composite electrode for supercapacitors by synergistically coupling MnO 2 nanowires with Ti 3 C 2 T x MXene nanoflakes. Compared with the pure MnO 2 electrode, the morphology of the MnO 2 /Ti 3 C 2 T x 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 Ti 3 C 2 T x MXene. The specific capacitance of the MnO 2 /Ti 3 C 2 T x composite electrode achieves 210.8 F·g −1 at a scan rate of 2 mV·s −1 , while that of the pure MnO 2 electrode is only 55.2 F·g −1 . Furthermore, the specific capacitance of the MnO 2 /Ti 3 C 2 T x composite 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.