High-performance low-temperature solid oxide fuel cell with nanostructured lanthanum strontium cobaltite/yttria-stabilized zirconia cathode via advanced co-sputtering

Recently, there has been a growing interest in developing ultra-fine nanostructured electrodes with extensive reaction areas for improved performance and low-temperature operation of solid oxide fuel cells. Recent advancements using a refined approach of co-sputtering metal alloys and oxide targets have shown the feasibility of nano-columnar structures of perovskite-based electrodes. This achievement notably expands the operating temperature range for thin film electrodes. In this study, we systematically examine the effects of chamber pressure control in the co-sputtering process using LSC perovskite oxide and YZr metal-alloy targets, targeting cathode application in all-sputtered SOFCs. We focus on variations in columnar shape, particle size, and electrochemical performance. Contrary to conventional sputtering methods, our research identifies that the relationship between sputtering pressure and the film structure is significantly complicated. Notably, the growth characteristics of metal alloys and the oxide materials diverge, leading to intricate structural changes under the process conditions. We observe substantial enhancements of performance and thermo-mechanical properties by fine-tuning columnar growth in the electrode, resulting in a high performance of 580 mW/cm² in all-sputtered SOFCs at 500 °C.