Design and synthesis of H-TiO2/MnO2 core–shell nanotube arrays with high capacitance and cycling stability for supercapacitors

Abstract

Constructing hybrid electrodes with pseudocapacitive materials is an efficient strategy to realize high capacitance in supercapacitors for many high-energy applications ranging from portable electronics to consumer devices. However, as a typical pseudocapacitive electrode material, MnO2 usually suffers from poor electronic and ionic conductivities, which hinders the realization of their achievable pseudocapacitances. Comparing with conventional noble metals, cost-effective and robust hydrogenated TiO2 nanotube arrays are an excellent scaffold to support pseudocapacitive materials due to enhanced ion and electron delivery. Benefit from the structural and electronic advances, the well-designed H-TiO2/MnO2 NTAs supercapacitor exhibits specific capacitance as high as ~803 F g−1 at the scan rate of 5 mV s−1, reveals ~88% of the initial capacitance after 20000 cycles (only 0.0006% loss per cycle) and shows a high-rate capability. The well-performed designer could be a promising candidate for future power sources in a wide range of applications.