Nitrogen and carbon co-doped Ni-TiO2 spindles for high performance electrochemical capacitor electrodes

Abstract Nitrogen and carbon co-doped Ni-TiO2 (nickel-titanium dioxide) spindles with hollow inner and good structural stability were facilely prepared by a direct precipitation method followed by annealing treatment. The unique composite shows a remarkably high capacitivity (223.7 F g−1 at 2 mV/s) and good rate capability (132.2 F g−1 at 100 mV s−1) when used as supercapacitor electrodes. In addition, the nitrogen and carbon co-doped Ni-TiO2 spindles also demonstrate good cycling stability (91.5% retention of the initial capacitance after 4000 cycles). The unique structure and seamlessly integration between different components generate synergistic effect to boost high performance and high electrical conductivity. The hollow inner also allows efficient diffusion of electrolyte and provides a more favorable path for charge penetration and transportation, which makes the good rate capability. The attractive performances make them potentially promising alternatives for the electrode materials of future energy storage devices.