Supercapacitive behavior of β-Ni(OH)2 nanospheres prepared by a facile electrochemical method

β-Ni(OH)2 was prepared by electrodeposition from Ni(NO3)2 bath for the electrode materials of supercapacitors. The deposition experiments were galvanostatically performed at the current density of 2 mA cm−2 on stainless steel cathode without using any surfactant or template. The structural, compositional and morphological characteristics of the obtained deposit were determined by XRD, CHN, IR and SEM techniques. Thermal behavior of the prepared deposit was also investigated by DSC–TG analysis. SEM observations revealed that β-Ni(OH)2 is composed of well-dispersed spheres with size of about 100 nm. The supercapacitive performance of β-Ni(OH)2 nanospheres was studied by means of cyclic voltammetry (CV) and galvanostatic charge–discharge tests in 1 M KOH. The prepared β-Ni(OH)2 nanospheres exhibited specific capacitance of as high as 754.5 F g−1 at the scan rate of 5 mV s−1 in the potential window of 0–0.55 V vs. Ag/AgCl. The nanospheres showed excellent capacity retention (90.1% of their initial capacity) after 1000 charge–discharge cycles at the current density of 2 A g−1. The results indicated that the β-Ni(OH)2 nanospheres can be considered as a promising candidate for the supercapacitor electrodes.