New energy storage option: Toward ZnCo₂O₄ nanorods/nickel foam architectures for high-performance supercapacitors

Hierarchical ZnCo₂O₄/nickel foam architectures were first fabricated from a simple scalable solution approach, exhibiting outstanding electrochemical performance in supercapacitors with high specific capacitance (∼1400 F g^-1 at 1 A g^-1), excellent rate capability (72.5% capacity retention at 20 A g^-1), and good cycling stability (only 3% loss after 1000 cycles at 6 A g^-1). All-solid-state supercapacitors were also fabricated by assembling two pieces of the ZnCo₂O₄-based electrodes, showing superior performance in terms of high specific capacitance and long cycling stability. Our work confirms that the as-prepared architectures can not only be applied in high energy density fields, but also be used in high power density applications, such as electric vehicles, flexible electronics, and energy storage devices.