Flexible and wire shaped supercapacitor material based on nanoflakes Co(OH)2@nanosheets Ni(OH)2/3D nickel fibers

Flexible and lightweight wire-shaped supercapacitors have recently attracted increasing interest, due to their versatility in the device design and application potentials in portable or wearable electronics. Herein, we demonstrate a wire-shaped supercapacitor by virtue of material fabrication strategy. In this article, three-dimensional (3D) porous nickel structure was fabricated via an electrochemical deposition process. The construction of the foam structure was achieved by means of a hydrogen bubble dynamic template, prepared from Ni electrodeposition at high current densities [1]. Subsequently, a Ni(OH)2@Co(OH)2 hierarchical core/shell nanostructure was grown on the 3D nickel wire using two step electrochemical process with fine control over the structure/morphology [2,3], which displays a largely improved specific capacitance, high rate capability and long cycling lifespan. When investigated as binder-free electrodes for supercapacitors, such unique Ni(OH)2@Co(OH)2 electrode exhibits ultrahigh specific capacitances, which are several times larger than the pristine Ni electrode. Because of reduced charge transfer resistance of the Ni wire, electron transfer capability is enhanced and the electrochemical performance is improved. These results suggest that the fabricated device has excellent potential as a power source for flexible, portable and wearable application as well as self-powered systems. Results showed that the proposed supercapacitor had a higher specific capacity of about 888 F g –1 at current density of 1.0 A g–1 and exhibited energy density of 27.24 Wh kg –1 and power density of up to 234.99 W kg –1.