Nano-architectured Co(OH)2electrodes constructed using an easily-manipulated electrochemical protocol for high-performance energy storage applications

Abstract

A simple, low-cost, and efficient electrochemical strategy, which includes the co-deposition of a Ni–Cu layer, selective etching of Cu from the film (leaving nano-porous Ni), and electrodeposition of Co(OH)₂ nano-whiskers on the obtained Ni substrate, is used to construct a nano-structured electrode. This process can be conducted on many conductive surfaces, which can be cheap, flexible, and wearable, and can be integrated into advanced mobile micro-power systems. Due to its unique nano-architecture, the prepared Co(OH)₂ electrode shows exceptional energy storage performance as compared to that of the conventional version of the electrode. The optimum specific capacitance obtained in this study, evaluated using cyclic voltammetry (CV), was as high as 2800 F/g. When the CV scan rate was increased from 5 to 200 mV/s, only a 4% decay in the capacitance was found, indicating excellent high-power capability. These characteristics make the nano-structured Co(OH)₂ electrode a promising candidate for supercapacitor applications.