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

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.