Advances and Perspectives for the Application of Perovskite Oxides in Supercapacitors

Perovskite oxides, with the general formula of ABO3, are considered as one of the promising candidates of electroactive materials for supercapacitors (SCs) as a result of their stable structure, rich oxygen vacancies, and highly reversible redox capability. According to the oxygen ion intercalation mechanism, the concentration of oxygen vacancy in perovskite oxides is proportional to the capacitance of SCs. Meanwhile, various strategies, e.g., doping, compositing, and specific synthesis processes, are proposed to increase the capacitance for perovskite oxide electrodes. Herein, this review mainly emphasizes the relationship between the energy storage mechanism and the key role of oxygen vacancies in perovskite. In terms of structural design, preparation methods, and various approaches to improve the electrochemical performance of the latest reported perovskite-type oxides for SCs, we give a detailed discussion and summarize the characteristics of them, which is expected to have impact on the fields of perovskite oxide science. Furthermore, we pointed out the challenges and perspectives of perovskite-oxide-based SCs.