Dandelion-like Co3O4/Zn-Mn oxide heterostructures as high-capacity battery-type electrodes for hybrid supercapacitors

초록

Developing nanostructured electrode materials with strong interfacial integration and high redox activity remains a critical challenge in advancing hybrid supercapacitor (HSC) technology. In this study, a hierarchical dandelion-like Co3O4-ZnMn2O4/ZnMnO3 heterostructure nanocomposite was synthesized directly on nickel foam (NF) via a two-step solvothermal process followed by annealing. The synthesis strategy enables the formation of a robust, interconnected nanowire network composed of Co3O4 and Zn-Mn oxide phases, eliminating the need for binders and ensuring strong contact with the current collector. Comprehensive structural and morphological characterizations confirm the formation of a 3D nanoscale architecture with increased electroactive sites and porous channels, facilitating rapid electron transport and ion diffusion. The synergistic interaction between Co3O4 and the ZnMn2O4/ZnMnO3 phases enhances redox kinetics and electrochemical reversibility. As a battery-type electrode for HSCs, the Co3O4-ZnMn2O4/ZnMnO3 electrode delivers a high specific capacity of 1723.6 C g- 1 at 1.0 A g- 1, which is approximately four times higher than that of reported single-phase ZnMn2O4 electrodes and markedly superior to pristine Co3O4, while retaining 86 % of its capacity at a tenfold higher current density. Moreover, the electrode maintains 93 % capacity retention over 5000 cycles, demonstrating excellent long-term cycling stability. A hybrid supercapacitor (HSC) device was constructed using Co3O4-ZnMn2O4/ZnMnO3 as the cathode and activated carbon (AC) as the anode. The assembled HSC delivered a high energy density of 49.64 Wh kg- 1 at a power density of 1000 W kg- 1, demonstrating its promising energy-power characteristics. These results highlight the potential of interface-engineered heterostructure nanocomposites directly grown on conductive substrates as promising candidates for high-performance energy storage applications.

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