Construction of hydrangea-like ZnCo₂O₄/Ni₃V₂O₈ hierarchical nanostructures for asymmetric all-solid-state supercapacitors

Reasonable design of multi-component metal oxides hierarchical nanostructures is an effective and promising way to improve electrochemical performances of electrode materials. In this work, novel hydrangea-like ZnCo₂O₄/Ni₃V₂O₈ hierarchical nanostructures are constructed by adjusting the ratio of ZnCo₂O₄ and Ni₃V₂O₈. The perfect architecture maximizes the synergistic effect between different components and provides abundant electrochemical reactive sites, promoting the diffusion and transfer of electrolyte ions in electrochemical reaction process. As a result, ZnCo₂O₄/Ni₃V₂O₈ electrodes deliver an enhanced specific capacitance of 1734 F g⁻¹ at 1 A g⁻¹ and cyclic stability (96% of initial capacitance is retained after 8000 cycles). Furthermore, the assembled ZnCo₂O₄/Ni₃V₂O₈//AC device e achieves excellent energy density of 90 Wh kg⁻¹ at power density of 812 W kg⁻¹, proving the optimized hydrangea-like ZnCo₂O₄/Ni₃V₂O₈ hierarchical nanostructures are promising electrode material for supercapacitor. In addition, this work supplies helpful insights into rational design of structure and composition of multi-component metal oxides for enhanced electrochemical performance.