A-site high entropy and B-site medium entropy double perovskite structure cathode material for solid oxide fuel cells

High entropy solid oxide fuel cell (SOFC) cathode materials with a double perovskite structure have attracted considerable attention due to their unique multi-component design and the complex interactions among constituent elements, which endow them with exceptional catalytic performance. We report a double perovskite cathode material, La 0.2 Pr 0.2 Nd 0.2 Sm 0.2 Gd 0.2 BaCo 0.7 Fe 0.7 Ni 0.4 Cu 0.1 Zn 0.1 O 5+δ (LPNSGBCFNCZ), featuring a high-entropy design at the A-site and a medium-entropy design at the B-site, and systematically investigate its structure, electrochemical performance and CO 2 tolerance. The results demonstrate that LPNSGBCFNCZ exhibits excellent redox activity, with an area-specific resistance of only 0.07 Ω·cm 2 at 800 ℃. Furthermore, compared with the non-entropically designed PrBaCo 2 O 5+δ , LPNSGBCFNCZ exhibits superior thermal expansion properties and significantly enhanced tolerance to CO 2 . This performance improvement is attributed to the dual-entropy design of the A and B-sites: the high entropy at the A-site effectively suppresses the formation of BaCO 3 in CO 2 atmospheres, while the medium entropy at the B-site reduces the thermal expansion coefficient by lowering the Co content. This study indicates that LPNSGBCFNCZ is a highly promising SOFC cathode material, further validating the feasibility and effectiveness of the high-entropy strategy in the development of SOFC electrode materials.