Abstract:
The MnO
2/TiO
2 composite electrodes were prepared with modifying MnO
2 onto the anodized TiO
2 nanotube arrays by the hydrothermal method. The supercapacitor was assembled with the two symmetric MnO
2/TiO
2 electrodes. The surface morphology, valence of the elements and electrochemical performance of the samples were characterized by FESEM, TEM, XPS and the electrochemical workstation. The results show that the MnO
2 nanoparticles are uniformly loaded onto the outer and inner surface of the TiO
2 nanotube array. The specific capacitance is 429.3 F/g at a charge-discharge current density of 1 A/g with 82.4% of the initial capacitance after 5 000 cycles. The MnO
2/TiO
2 symmetrical supercapacitor exhibits the charge-discharge specific capacitance of 39.9 F/g at the current density of 5 A/g with 91.5% of the initial capacitance after 5 000 cycles and the energy density of 18.98 Wh/kg at the power density of 400 W/kg. Not only the anodized TiO
2 nanotube arrays could serve as the carrier of MnO
2, but also the Ti substrate could be used for the current collector, which alleviates the weight of the supercapacitor and provides a method for preparing supercapacitors.