An innovative and facile synthesis route of (La,Sr) <sub>2</sub>FeO <sub>4+ <i>δ</i> </sub>–La <sub>0.4</sub>Sr <sub>0.6</sub>FeO <sub>3− <i>δ</i> </sub> composite as a highly stable air electrode for reversible solid oxide cell applications
Qihang Ren, Yang Zhang, Haoliang Tao, Ling Qin, Konrad Świerczek, Wanbing Guan, Jianxin Wang, Changrong Xia, Liangzhu Zhu
Abstract
Achieving thermal cycle stability is an imperative challenge for the successful commercialization of solid oxide cells (SOC) technology. Ruddlesden-Popper (R-P) oxides, with their thermal expansion coefficient (TEC) compatible with common electrolytes, are promising candidates for SOC applications. However, the two-dimensional conduction characteristic of R-P oxides leads to insufficient catalytic activity, which hinders their performance. Here, we proposed a win-win strategy of self-assembly decoration, employing a one-pot method to address this issue. By using the single perovskite oxide (La<sub>0.4</sub>Sr<sub>0.6</sub>FeO<sub>3</sub>) to modify the R-P oxide (La<sub>0.8</sub>Sr<sub>1.2</sub>FeO<sub>4+</sub><sub>δ</sub>), we enhance the electrochemistry performance without compromising the stability of the composite electrode. The strategic incorporation of 10 mol% perovskite phase at 800 °C resulted in a significant 49% reduction in polarization resistance, an impressive 86% increase in maximum power density under power generation mode, and a notable 33% increase in electrolysis current density under electrolysis mode. Furthermore, the perovskite-decorated R-P oxide composite also exhibit high thermal and chemical stability, with negligible performance degradation observed under both thermal cycling and charge/discharge cycling conditions. Our results demonstrate that such dual-phase composite, which is simultaneously produced by one-step process, with outstanding catalytic activity and stability can be considered an effective strategy for the advancement of solid oxide cell.