Recent Advancements in Microwave-Assisted Synthesis of NiO Nanostructures and their Supercapacitor Properties: A Comprehensive Review

Nanostructure based energy storage devices with high surface area and conductivity are challenging requirements, which are extensively focused in the past few years. Recently, the nanostructures synthesis by microwave energy has become an increasingly popular theme among the scientific community to fulfill the energy storage demands at commercial scale. Since, microwave heating has reduced reaction times and side reactions with increased product yields and purity as compared to conventional heating methods. The high product yield is favorable at the industrial level, which is not possible by other synthesis techniques. On the other hand, supercapacitors have wide future applications, such as replacement of Li-Ion batteries due to cost effectiveness, high shelf-life and stable cycle life. Among various types of supercapacitors NiO has shown comparable supercapacitance to RuO2. A comprehensive overview of all synthesis techniques and reported supercapacitance results in comparison with microwave-assisted synthesis of NiO nanostructures are provided in this review article.