Hierarchical binder-free MnO2/TiO2 composite nanostructure on flexible seed graphite felt for high-performance supercapacitors

Abstract Although titanium dioxide (TiO2) has excellent potential as electrode materials in supercapacitors, the low areal specific capacitance and poor conductivity have hindered further development. Herein, we describe a simple way to deposit manganese dioxide (MnO2) by a two-step hydrothermal method to improve the electrochemical properties. The hydrothermal process produces hierarchical manganese dioxide (MnO2) nanospheres and long tapered TiO2 nanorod arrays on porous seed graphite felt (SGF). The MnO2/TiO2/SGF electrode shows a high areal capacitance of 196.25 mF cm−2 at 1 mA cm−2 and after 5000 test cycles, 94.4% of the capacitance is retained indicating excellent cycle stability and good reversibility. The areal capacitance and cycle stability of MnO2/TiO2/SGF are better than TiO2/SGF and MnO2/GF, and the hierarchical nanocomposite has good prospects in high-performance supercapacitors.