CO₂-tolerant perovskite cathodes for enhanced solid oxide fuel cells: advancements, challenges, and strategic perspectives

The key to realizing efficient and durable operation of solid oxide fuel cells (SOFCs) lies in the development of CO₂-tolerant cathodes, a major determinant of the overall power output in the presence of contaminants. Significant strides have been made in recent years toward developing highly CO₂-tolerant perovskite cathodes, forecasting a bright future for SOFCs. This review presents an integrated and comprehensive discussion on this topic, encompassing the latest progress, underlying reaction mechanisms, various evaluation methods, and feasible coping strategies. Particular attention is devoted to cutting-edge characterization technologies, with an emphasis on in situ/operando characterization tools, together with density functional theory calculations. They are employed to provide an in-depth insight into the complex interactions between electrodes and contaminants, enabling the tailored design of cathode surfaces and interfaces to enhance performance. On this basis, by combining experimental insights with theoretical analysis, this review articulates a comprehensive roadmap for the rational design of state-of-the-art perovskite cathode materials. Ultimately, this advancement is expected to usher in a new generation of fully CO₂-tolerant cathode materials, thereby further bolstering the capability of SOFCs.