Enhanced catalytic activity and stability of SOFC electrodes through plasma-driven surface modification

Abstract

The commercialization of solid oxide fuel cells (SOFCs) relies heavily on the development of active and stable oxygen electrodes that can operate at intermediate temperatures. However, the presence of an oxidizing atmosphere during the annealing process commonly used to fabricate and treat conductive perovskite oxides, which serve as oxygen electrode materials, can lead to the accumulation of Sr and formation of Sr-rich clusters on their surfaces, thereby degrading electrode performance. To suppress this segregation, a new approach that utilizes Ar plasma to amorphize the surfaces of porous oxide electrodes is proposed. The effects of said plasma treatment on the morphology, chemical composition, and crystallinity of a La_0.6Sr_0.4Co_0.2Fe_0.8O_3−δ (LSCF) electrode surface are investigated, and the resulting changes in its electrochemical properties are monitored. Remarkably, only 5 minutes of plasma exposure achieves a 43% reduction in initial LSCF electrode polarization resistance and significantly improves durability at 650 °C, compared to the bare LSCF. This study demonstrates the viability of plasma-driven surface modification for high-temperature processes, and represents the first application of an amorphization strategy to a porous electrode in the field of SOFCs.