A review on the electrochemical behavior of graphene-transition metal oxide nanocomposites for energy storage applications

Electrochemical energy storage devices like supercapacitors and rechargeable batteries require an improvement in their performance at the commercial level. Among them, supercapacitors are beneficial in sustainable nanotechnologies for energy conversion and storage systems and have high power rates compared to batteries. High chemical and mechanical stability, huge electrical conductivity, and high specific surface area have been beneficial for selecting graphene as a supercapacitor electrode material. The excellent properties of transition metal oxides are accountable for the application in the field of energy storage. The synergistic effects of the composites of graphene derivatives with transition metal oxides will boost the performance of the devices. Recently, several studies have been done for developing supercapacitor electrodes with these nanocomposites. This review article presents an analysis of the performance of these nanocomposites with an overview of their specific capacitance, energy density, and cycling stability for supercapacitor electrode application. A brief introduction of the theory and experimental analysis of supercapacitors is also given.