Nickel Oxide: Advanced Material for Supercapacitor Application

Chapter 3 outlines the methodology employed in synthesizing nickel oxide thin film electrodes through an aqueous route, with a focus on manipulating preparative parameters, including ingredients, concentrations, decomposition temperatures, and solution volumes. Initial thermogravimetric analysis of nickel nitrate hexahydrate indicated stable residue formation beyond 573 K. Subsequent experiments were carried out by varying the concentrations of the spraying solution from 0.2 M to 1.0 M, while keeping the deposition temperature and spray rate constant at 623 K and 2 ml/min, respectively. The next optimization was achieved by exploring various decomposition temperatures (ranging from 623 K to 723 K) while maintaining a constant spray rate of approximately 2 ml/min, using the previously identified optimal concentration (0.8 M). The optimized conditions (0.8 M and 673 K) were subsequently applied to film depositions, with the volume of the solution as the variable parameter, ranging from 30 to 110 ml. The electrochemical analysis of the optimized AV-1 electrode was carried out using different electrolytes i.e. KCl, LiCl2, Na2SO4, NaOH, and KOH.