Hierarchical mesoporous Co₃O₄@ZnCo₂O₄ hybrid nanowire arrays supported on Ni foam for high-performance asymmetric supercapacitors

In this paper, hierarchical mesoporous Co₃O₄@ZnCo₂O₄ hybrid nanowire arrays (NWAs) on Ni foam were prepared through a two-step hydrothermal process associated with successive annealing treatment. The Co₃O₄@ZnCo₂O₄ hybrid NWAs exhibited excellent electrochemical performances with a high specific capacity of 1240.5 C g⁻¹ at a current density of 2 mA cm⁻², with rate capability of 59.0% shifting from 2 to 30 mA cm⁻², and only a 9.1% loss of its capacity even after 3,000 cycles at a consistent current density of 10 mA cm⁻². An asymmetric supercapacitor (Co₃O₄@ZnCo₂O₄ NWAs||activated carbon) was fabricated and exhibited a high specific capacity of 168 C g⁻¹ at a current density of 1 A g⁻¹. And a preferable energy density of 37.3Wh kg⁻¹ at a power density of 800 W kg⁻¹ was obtained. The excellent electrochemical performances indicate the promising potential application of the hierarchical mesoporous Co₃O₄@ZnCo₂O₄ hybrid NWAs in energy storage field.