Facile synthesis of CuCo2O4/N-deficient‐carbon nitride heterostructure material for high-performance asymmetric supercapacitors

Copper cobaltite is a kind of binary metal oxides that can be used as electrode material of supercapacitors, whereas its intrinsic low electric conductivity and complicated preparation process hamper further practical application. Herein, we report a facile method for preparing of CuCo2O4/N-deficient g-C3N4 (CuCo2O4/ND-C3N4) composite in 5 mins under 280 °C. The addition of g-C3N4 substrate greatly reduces the particle size of CuCo2O4 and enhances the conductivity of composites. Besides, the generated heterogeneous interface also facilitates the energy storage process. As a result, the as-obtained CuCo2O4/ND-C3N4 delivers a specific capacitance of 653 F g−1 at 1 A g−1 and the capacitance retentions can be up to 50.1 % even at 50 A g−1, which is much higher than that of pure CuCo2O4. Furthermore, using activated carbon as anode and CuCo2O4/ND-C3N4 as cathode, the assembled asymmetric supercapacitors show a high energy density of 47.6 Wh kg−1 at power density of 800 W kg−1 and extraordinary cycling life of 93.5 % capacitance retention after 5000 cycles at 5 A g−1. This work may offer valuable guidelines for the design of high-performance copper cobaltite-based electrode materials for supercapacitors.