High-entropy design of Ruddlesden-Popper structured LNO for enhanced performance in proton solid oxide fuel cells

Protionic Ceramic Fuel Cells (PCFCs) are devices that efficiently convert chemical energy to electrical energy at low temperatures. Significant research efforts have been directed towards the development of cathodes with enhanced catalytic activity. In this work, a high-entropy approach was employed at the A site of La2NiO4+delta (LNO) with a Ruddlesden-Popper (R-P) structure, resulting in the synthesis of the LaPr 0.2 Sm 0.2 Ba 0.2 Sr 0.2 Ca 0.2 NiO 4+delta (HE-LPSBSCN) cathode. A comprehensive series of tests demonstrated that this high-entropy strategy improved the oxygen reduction reaction (ORR) activity, hydration behavior, well operational stability, and electronic conductivity of LNO. The HE-LPSBSCN cathode demonstrated record- breaking performance, achieving a maximum power density of 2004 mW cm-2 at 700 degrees C. This finding provides novel insights for the rational design and optimization of highly catalytically active cathodes for PCFCs.