Recently, the research team led by Professor Bi Lei from the School of Resources, Environment and Safety Engineering at the University of South China has published a research paper in Energy & Environmental Science—a top-tier journal in the energy and environmental field with an impact factor of 30.8. The paper proposes a high-entropy cathode for proton-conducting solid oxide fuel cells (PC-SOFCs), which significantly improves the output power of the cells and breaks the record for the output power of cathodes with Ruddlesden–Popper (R-P) structure applied in PC-SOFCs. This study provides crucial references for the development of high-performance cathode materials for fuel cells.Owing to the novelty and significance of this research, the paper has been selected as the cover paper ofEnergy & Environmental Science.

Energy and environmental issues are major challenges hindering global development. Proton-conducting solid oxide fuel cells (PC-SOFCs) have attracted widespread attention due to their advantages such as high power generation efficiency, cleanliness, and relatively low operating temperature. However, as the operating temperature decreases, the cathode reaction kinetics of PC-SOFCs become sluggish, leading to a decline in cell performance.Cathodes with the Ruddlesden–Popper (R-P) structure are a type of traditional solid oxide fuel cell cathode material. They possess advantages like high chemical stability and good thermal expansion matching, making them promising for application in commercialized cell systems. Nevertheless, their performance in PC-SOFCs is unsatisfactory (with relatively low performance), and they undergo elemental segregation during long-term operation.

To address this challenge, Professor Bi Lei’s team developed the La₀.₄Pr₀.₄Nd₀.₄Ba₀.₄Sr₀.₄NiO₄₊ₓ cathode material, modifying the ionic coordination environment through high-entropy engineering. Both experimental and theoretical calculation studies indicate that, compared with traditional R-P structured cathodes, this material exhibits higher proton conductivity and better oxygen catalytic activity—thereby enhancing the performance of R-P-based materials.Proton-conducting solid oxide fuel cells using the La₀.₄Pr₀.₄Nd₀.₄Ba₀.₄Sr₀.₄NiO₄₊ₓ cathode demonstrate extremely high cell output power, which is the highest value reported so far for cells using R-P structured cathodes. In addition, the high-entropy structure also helps alleviate the issue of elemental segregation during long-term cell operation and improves cell stability.This work solves the problems of low performance and poor operational stability of traditional R-P cathodes, provides theoretical and practical foundations for their commercial application, and holds significant scientific importance and application prospects.