Three-Dimentional Porous Nano-Ni/Co(OH)₂ Nanoflake Composite Film: A Pseudocapacitive Material with Superior Performance

Abstract

We report a novel three-dimentional (3D) porous nano-Ni/Co(OH)2 nanoflake composite film electrode for potential supercapacitor applications with both high power and energy capabilities. The 3D porous nano-Ni film with highly porous nanoramified walls functions as a scaffold to anchor Co(OH)2 nanoflakes to produce a 3D nanoporous metal/hydroxide nanoflake composite electrode. Co(OH)2 nanoflakes with thicknesses of 20 nm are directly electrodeposited on highly conductive 3D porous nano-Ni film prepared via a hydrogen bubble template. Impressively, the Co(OH)2 nanoflake in the composite film exhibits a high specific capacitance of 1920 F g–1 at 40 A g–1, with a corresponding energy density as high as 80 W h kg–1 at a power density of 11 kW kg–1. Moreover, the designed composite film exhibits excellent cycling stability, making it one of the best electrode materials for high-performance supercapacitors. This work demonstrates that the 3D porous nanometal/hydroxide nanoflake composite approach is an effective strategy toward supercapacitors with high energy and power densities.