LAUSR

Abstract In this work, NiCo2O4@TiO2 electrodes based on micro-region heterojunctions were synthesized by a simple one-step hydrothermal method. The material characteristics of resultant samples were characterized by XPS, XRD, SEM, HRTEM and BET. Compared with NiCo2O4 electrodes prepared with the same hydrothermal method, the NiCo2O4@TiO2 electrode shows higher electrochemical performance, cycling stability and lower charge transfer resistance. Specifically, the mass specific capacitances of NiCo2O4 and NiCo2O4@TiO2 electrodes are 564.3 F · g−1 and 1085.7 F · g−1 at current density of 5 A · g−1 and retained 84.4% and 95.5% after 10,000 cycles, while the Rct of NiCo2O4 and NiCo2O4@TiO2 are 1.72 Ω and 0.18 Ω, respectively. For practical applications of NiCo2O4@TiO2 electrode, a NiCo2O4@TiO2//AC two-electrode system was assembled and the performances were tested to achieve 255.9 F · g−1 at current density of 2.5 A · g−1. Additionally, the corresponding energy density and power density were recorded as 91 wh/kg and 4 kw/kg. The superior electrochemical performance and cycle stability of NiCo2O4@TiO2 electrode might be attributed to the higher specific surface and micro-region heterojunctions for enormous future applications.