A comprehensive review on novel quaternary metal oxide and sulphide electrode materials for supercapacitor: Origin, fundamentals, present perspectives and future aspects

In this innovative scientific world, the demand for sustainable energy is increasing due to the declining demand for fossil fuels. Efforts have been accelerated to create renewable energy storage system to produce an eco-friendly, affordable energy efficiency. Designing materials having novel electrodes with controlled structure and composition is a big challenge for energy storage applications. Hybrid supercapacitor with improved efficiency in energy density devoid of varying the efficiency in power density has been developed in latest years. Quaternary metal oxides and sulfides have attracted considerable attention in this field, where many methods have been used to improve its performance. This review presents an overview on supercapacitors, their prehistoric developments, principles, fundamentals of charge storage working mechanisms, essential components, and their respective classifications. This review also focusesan overview on high-performing supercapacitors, ongoing research activities and its examples, with specific emphasis made on the process and improvements in the novel quaternary metal oxides and sulphides as active electrodes, which itself necessary measure towards nanoscale supercapacitors preparation. Based on various recent reports on suitable materials for supercapacitor applications, novel quaternary metal oxides and sulphides as electrodes seem to hold the key in improving energy conversion and storage systems and play a pivot role in eliminating the challenges confronted with carbon materials. Basic techniques and analytical methods for distinguishing capacitive and battery like behaviours of the supercapacitor electrode materials have also been outlined. In addition, an overall guideline has been emphasized in opting a suitable selective material for the state-of-the-art of high performing supercapacitors.