Performance analysis, challenges and future perspectives of nickel based nanostructured electrodes for electrochemical supercapacitors

The increasing environmental problems as well as demand of energy encourage the research for safe as well as efficient energy sources. As most of the energy sources are not consistent; thus, there is a requirement for highly efficient energy storing systems. Supercapacitors emerge with great researcher interest because of their very high capacity of storing energy. The performance and efficiency of supercapacitor depends directly on the electrode materials. The oxides of transition metals are highly explored as pseudo capacitors material. Nickel based electrode materials, characterized by ultrahigh theoretical capacitance has gained significant attention. These days nickel oxide-based electrodes owing to their high chemical stability, good theoretical specific capacitance, less cost, easy availability as well as non-toxic nature makes it very popular. This review deals with the recent development in the field of nickel-based supercapacitor electrodes by grouping them on the basis different morphologies such as nanoparticles, nanowires, thin films, nanofibers, etc along with challenges as well as future research.