Leaf‐Like CuCo2O4@CuCo2O4 Core‐Shell Nanowires as Binder‐Free Electrode for High‐Performance Flexible Supercapacitors

Abstract A reasonable electrode structure is important to improve the performance of supercapacitors. In this work, Leaf‐like CuCo 2 O 4 @CuCo 2 O 4 nanowires grown erectly on Ni foam substrate were prepared by two‐step hydrothermal method to form a mutually perpendicular core–shell nanostructure. The binder‐free CuCo 2 O 4 @CuCo 2 O 4 nanowires were more likely to benefit from multidimensional synergistic effect and better conductivity, revealing a high specific capacitance of 5.86 F cm −2 at 5 mA cm −2 and good cycle stability (90.2 % after 8000 cycles). In addition, the SC based on CuCo 2 O 4 @CuCo 2 O 4 battery‐type electrodes exhibited good flexible properties. The environment friendly and low cost CuCo 2 O 4 @CuCo 2 O 4 //AC flexible SCs perform a high energy density of 0.35 mWh cm −2 at a power density of 8 mW cm −2 . The results indicated that CuCo 2 O 4 @CuCo 2 O 4 core‐shell materials have high application value, thus providing a new type of advanced electrode for flexible SCs.