A review on perovskite oxides and their composites as electrode materials for supercapacitors

In energy storage applications, supercapacitors serve as an alternative to electrochemical batteries due to their large power density and exceptionally long cycle life. Redox-active supercapacitors are favoured for their durability and power density arising from the carbon-dominated field. However, their commercialization is questioned due to their slow reaction kinetics and low energy density limitations. Electrode materials with superior electrochemical behaviour must be developed to overcome these obstacles. The oxygen anion-intercalation mechanism leads to an interest in perovskite oxide materials with intrinsic oxygen vacancies and flexible structural characteristics. The primary objective of this review is to present an overview of the fundamental characteristics of perovskite oxides, their charge storage mechanism, and the key factors governing the electrochemical behaviour of the active material. This review was also compiled by reviewing previous research on perovskite materials for supercapacitors. This study examines the anion-intercalation mechanism and the variables affecting the electrochemical performance of electrodes. Furthermore, this review addresses the challenges and significance of previous research. Moreover, it presents the design guidelines for perovskite materials for supercapacitors, which appear beneficial for future studies on these materials.