Stoichiometry-grain size-specific capacitance interrelationships in nickel oxide.

Nickel oxide exhibits almost the highest theoretical specific capacitance ( ), which includes contributions from non-faradaic double layer charging and faradaic OH adsorption. However, the realistic and tangible is due to the faradaic process, which can be influenced by chemical ( stoichiometry) and structural ( grain size) changes. Hence, it is necessary to investigate the interrelationships among chemical and structural features and charge storage capacity.