Surface defect engineering of perovskite oxide towards CO₂ tolerant cathode in solid oxide fuel cells

Developing CO₂-tolerant cathode materials is crucial for ensuring the optimum performance and long-term durability of solid oxide fuel cells (SOFC), particularly under realistic operating conditions. In this work, a surface engineering approach is employed to selectively produce surface defects on the La_0.6Sr_0.4Co_0.2Fe_0.8O_3−δ (LSCF) cathode with an integrated perovskite bulk structure. The surface engineering partially mitigates the Sr segregation and optimizes the local coordination environment of the active Co/Fe sites. The modified LSCF cathode exhibits enhanced electrocatalytic activity and durability with high CO₂ exposure under intermediate temperatures. The optimized LSCF cell demonstrates a ∼33 % increase in peak power density (PPD) compared to the untreated cell under the same operating conditions. The results of this work indicate surface defect engineering as an effective strategy to enhance the activity and durability of perovskite materials and offer theoretical insight for the rational design and further optimization of electrode materials for SOFCs.