Zhao Zeyu, Zou Minda, Huang Hua, Zhai Ximei, Wofford Harrison, Tong Jianhua
Materials Science and Engineering Clemson University Clemson South Carolina USA.
J Am Ceram Soc. 2023 Jan;106(1):186-200. doi: 10.1111/jace.18643. Epub 2022 Jul 19.
One-pot synthesized twin perovskite oxide composite of BaCeFeO (BCF), comprising cubic and orthorhombic perovskite phases, shows triple-conducting properties for promising solid oxide electrochemical cells. Phase composition evolution of BCF under various conditions was systematically investigated, revealing that the cubic perovskite phase could be fully/partially reduced into the orthorhombic phase under certain conditions. The reduction happened between the two phases at the interface, leading to the microstructure change. As a result, the corresponding apparent conducting properties also changed due to the difference between predominant conduction properties for each phase. Based on the revealed phase composition, microstructure, and electrochemical properties changes, a deep understanding of BCF's application in different conditions (oxidizing atmospheres, reducing/oxidizing gradients, cathodic conditions, and anodic conditions) was achieved. Triple-conducting property (H/O/e), fast open-circuit voltage response (∼16-∼470 mV) for gradients change, and improved single-cell performance (∼31% lower polarization resistance at 600°C) were comprehensively demonstrated. Besides, the performance was analyzed under anodic conditions, which showed that the microstructure and phase change significantly affected the anodic behavior.
一锅法合成的BaCeFeO（BCF）双钙钛矿氧化物复合材料，包含立方相和正交相钙钛矿相，对有前景的固体氧化物电化学电池显示出三导电特性。系统研究了BCF在各种条件下的相组成演变，发现立方钙钛矿相在某些条件下可完全/部分还原为正交相。还原发生在两相的界面处，导致微观结构发生变化。结果，由于各相主要导电特性的差异，相应的表观导电性能也发生了变化。基于所揭示的相组成、微观结构和电化学性能变化，深入了解了BCF在不同条件（氧化气氛、还原/氧化梯度、阴极条件和阳极条件）下的应用。全面展示了三导电特性（H/O/e）、对梯度变化的快速开路电压响应（约16 - 约470 mV）以及改善的单电池性能（在600°C时极化电阻降低约31%）。此外，还分析了阳极条件下的性能，结果表明微观结构和相变显著影响阳极行为。
