Exploring transition metal oxide-based oxygen vacancy supercapacitors: A review

Supercapacitors are increasingly recognized in the energy storage sector for their high power density, rapid charge-discharge capability, and outstanding cycling performance. A key feature of these devices is the electrochemical double-layer capacitance, which occurs at the electrode-electrolyte interface in electrochemical double-layer capacitors. To boost the energy density of supercapacitors, enhancing electrode materials and incorporating Faradaic processes are essential. However, these materials often face challenges like lower conductivity and slower ion diffusion kinetics. Oxygen vacancy supercapacitors utilize oxygen vacancies as active reaction sites in electrode materials. This review summarizes various strategies to design metallic electrode materials that harness oxygen vacancy defects to improve electrochemical properties. By exploring and utilizing oxygen vacancies, we can unlock new dimensions in electrode material science, paving the way for the development of high-performance supercapacitors. The significance of oxygen vacancies in enhancing the performance of supercapacitors by utilizing oxygen vacancy defects is emphasized.