A-site entropy engineering to enhance performance of rare-earth iron perovskite cathode for solid oxide fuel cells

Solid oxide fuel cells (SOFCs) are promising energy conversion devices due to their high efficiency and low emissions. However, their commercialization is hindered by high operating temperatures, interfacial reactions, and durability issues. Here, we report a high-entropy perovskite cathode, (La0.2Pr0.2Nd0.2Ba0.2Sr0.2)FeO3-δ (HE-LSF), designed to enhance electrochemical performance and durability at intermediate temperatures for SOFCs. HE-LSF exhibits superior oxygen reduction reaction (ORR) activity, higher electrical conductivity (46–115 S cm−1), and improved thermal stability compared to LSF. Symmetrical cells with HE-LSF exhibit lower polarization resistance (Rp) and better stability over 35 h at 750 °C. A single-cell utilizing HE-LSF as cathode achieves a peak power density of 910 mW cm2 at 800 °C, with negligible performance decay observed over 90 h of continuous operation. These findings highlight the potential of high-entropy materials for developing efficient and durable SOFCs.