Effective suppression of surface cation segregations on double perovskite oxides through entropy engineering

Cation segregation on cathode surfaces plays a key role in determining the activity and operational stability of solid oxide fuel cells (SOFCs). The double perovskite oxide PrBa 0.8 Ca 0.2 Co 2 O 5+ δ (PBCC) has been widely studied as an active cathode but still suffer from serious detrimental segregations. To enhance the cathode stability, a PBCC derived A-site medium-entropy Pr 0.6 La 0.1 Nd 0.1 Sm 0.1 Gd 0.1 Ba 0.8 Ca 0.2 Co 2 O 5+ δ (ME-PBCC) oxide was prepared and its segregation behaviors were investigated under different conditions. Compared with initial PBCC oxide, the segregations of BaO and Co 3 O 4 on the surface of ME-PBCC material are significantly suppressed, especially for Co 3 O 4 , which is attributed to its higher configuration entropy. Our results also confirm the improved electrochemical performance and structural stability of ME-PBCC material, enabling it as a promising cathode for SOFCs.