Electrochemically Assisted Construction of a La2NiO4+δ@Pt Core-Shell Structure for Enhancing the Performance and Durability of La2NiO4+δ Cathodes

Ruddlesden-Popper oxide La2NiO4+& delta; (LNO) has a high ionic conductivity and good thermalmatch withthe electrolyte of solid oxide fuel cells (SOFCs); however, LNO suffersfrom performance decay owing to the La surface segregation under theoperation conditions of SOFCs. Herein, we report an in situ electrochemicaldecoration strategy to improve the electrocatalytic activity and durabilityof LNO cathodes. We show that the electrochemical polarization leadsto in situ construction of the LNO@Pt core-shell structure,significantly suppressing the detrimental effect of La surface segregationon the LNO cathode. The initial peak power density of a single cellwith the LNO cathode is 0.71 W cm(-2) at 750 & DEG;C,increasing to 1.39 W cm(-2) by the in situ constructionof the LNO@Pt core-shell structure after polarization at 0.5A cm(-2) for 20 h. The LNO@Pt core-shell structureis also highly durable without noticeable performance degradationover the duration of the test for 180 h. The findings shed light onthe design and fabrication of highly active and durable LNO-basedcathodes for SOFCs.