Recent advancements in metal oxides for energy storage materials: Design, classification, and electrodes configuration of supercapacitor

Among different energy storage devices, supercapacitors have garnered the attention due to their higher charge storage capacity, superior charging-discharging performance, higher power density, and long cycle life. Subsequently, introducing low-cost and highly-efficient supercapacitors is a hot topic in the industrial and scientific realms. Metal oxides are considered as the most suitable electrode materials due to their intrinsic properties, economic attractiveness, environmental friendliness, and abundant availability. However, there is still a salient need to have e comprehensive study of the significance of metal oxide nanomaterials for supercapacitors in relation to their sustainable synthesis approaches. Thus, this review delineated the different sustainable synthesis approaches for metal oxide nanomaterials following their morphological, compositional, and supercapacitive properties. Initially, the review covers designs or configurations of supercapacitors followed by the types of supercapacitors based on electrode materials. Further, metal oxides-based pseudocapacitive-/battery-type electrodes have been articulated comprehensively. Moreover, this review aims to provide sustainable fabrication of metal oxide nanomaterial-based supercapacitors with a superior interpretation of the design and functioning of the device that could serve as guidelines for new synthesis and fabrication approaches to develop sustainable supercapacitors for practical applications.