Controllable synthesis of ZnCo2O4@NiCo2O4 heterostructures on Ni foam for hybrid supercapacitors with superior performance

• NF/ZnCo 2 O 4 @NiCo 2 O 4 heterostructures electrodes are fabricated via facile two-step methods. • The impact of all components in integrated electrode was investigated and discussed. • The integrated electrode exhibits excellent specific capacitance and cycling stability. • The hybrid supercapacitor delivers high energy and power densities. The hierarchical core-shell heterostructures ZnCo 2 O 4 @NiCo 2 O 4 on Ni foam (NF) for supercapacitors were prepared via two-step hydrothermal and electrodeposition reactions followed by two post-annealing treatments. The effect of deposition time on its morphology and electrochemical performance was investigated in detail. Combining high electric conductivity of ZnCo 2 O 4 with high stability of NiCo 2 O 4 as well as synergistic effect, the NF/ZnCo 2 O 4 @NiCo 2 O 4 -100 (NF/ZCO@NCO-100) integrated electrode exhibited high specific capacitance of 1728.1 F g −1 (240.0 mAh g −1 ) at 1 A g −1 , and excellent long-term stability with 97.8% capacitance retention after 10,000 cycles. The assembled hybrid supercapacitor (HSC) delivered the specific capacitance of 133.6 F g −1 (55.7 mAh g −1 ) at 1 A g −1 and high energy density of 40.58 Wh kg −1 at 745.62 W kg −1 as well as the outstanding long-term stability of 91.3% capacitance retention after 10,000 cycles. These results provide insights into the rational design of transition metal compound composite materials to construct integrated electrodes for high performance supercapacitors.