A novel composite based on NiCo2O4@NG/MnOOH nanorods for high-performance supercapacitor electrodes

For attaining an enhanced supercapacitor performance, electrode materials enriched with high conductivity, large surface area, rational porous structure, and high capacitance are desirable. Composites based on ternary transition metal oxides enriched with nitrogen-doped graphene are considered novel materials for supercapacitor electrodes. Herein, the composite of nitrogen-doped graphene with NiCo 2 O 4 and MnOOH (abbreviated as NCO-NtG-MOOH) is synthesized through the facile three-step hydrothermal method for the first time and investigated for its chemical composition, morphology, and electrochemical properties. The as-synthesized NCO-NtG-MOOH ternary composite showed remarkable battery-type capacitive behavior owing to the multiple oxidation states, 1D rods-like morphology, inherent porosity, conductivity offered by nitrogen-doped graphene, and synergetic contribution of each component of the composite. For comparison, composite based on binary metal oxide NiCo 2 O 4 @Nitrogen-doped graphene (abbreviated as NCO-NtG) is synthesized through the same hydrothermal method. The results specified that NCO-NtG-MOOH composite-based electrode outperformed the NCO-NtG with a specific capacitance delivery of 525.72 Fg −1 at a current density of 1 Ag −1 , and cyclic stability of 94.99 % over 2000 continuous charge-discharge cycles. A symmetric coin cell supercapacitor device fabricated using the NCO-NtG-MOOH electrode delivered remarkable electrochemical performance, including a specific capacitance of 42.9 Fg −1 at 0.25 Ag −1 , working voltage window of 0–1.2 V, an energy density of 7.2 Wh kg −1 at a power density of 548.72 W kg −1 , and capacitance retention of 88 % after 2000 cycles. Thus, indicating the prospective usage of NCO-NtG-MOOH as a high-performance supercapacitor electrode material. • Rod-like porous NiCo 2 O 4 @NG/MnOOH nanocomposite material has been proposed. • The material has been synthesized by the facile hydrothermal process. • The nanocomposite NiCo 2 O 4 @NG/MnOOH delivered a high specific capacitance of 525.72 Fg −1 at 1 Ag −1 . • The symmetric supercapacitor device showed remarkable electrochemical performance.