Qu Gang, Akbar Muhammad, Jin Bin, Yang Weiguang, Wang Xunying, Dong Wenjing, Afzal Muhammad, Wang Hao, Xia Chen
School of Microelectronics, Hubei University, Wuhan, Hubei 430062, P. R. China.
Hubei Yangtze Memory Laboratories, Wuhan 430205, China.
ACS Appl Mater Interfaces. 2023 Oct 25;15(42):49154-49169. doi: 10.1021/acsami.3c10501. Epub 2023 Oct 11.
Semiconductor ionic electrolytes are attracting growing interest for developing low-temperature solid oxide fuel cells (LT-SOFCs). Our recent study has proposed a p-n heterostructure electrolyte based on perovskite oxide BaCoFeZrYO (BCFZY) and ZnO, achieving promising fuel cell performance. Herein, to further improve the performance of the heterostructure electrolyte, an A-site-deficiency strategy is used to solely modify BCFZY for regulating the ionic conduction and catalytic activity of the heterostructure. Two new electrolytes, BCFZY-ZnO and BCFZY-ZnO, were developed and systematically studied. The results show that the two samples gain improved ionic conductivity and auxiliary catalytic activity after A-site deficiency as a result of the increment of the surface and interface oxygen vacancies. The single cells with BCFZY-ZnO and BCFZY-ZnO exhibit enhanced peak power outputs at 450-550 °C compared to the cell based on BCFZY-ZnO (typically, 745 and 795 vs 542 mW cm at 550 °C). Particular attention is paid to the impact of A-site deficiency on the interface energy band alignment between BCFZY and ZnO, which suggests that the p-n heterojunction effect of BCFZY-ZnO for charge carrier regulation can be tuned by A-site deficiency to enable high proton transport while avoiding fuel cell current leakage. This study thus confirms the feasibility of A-site-deficiency engineering to optimize the performance of the heterostructure electrolyte for developing LT-SOFCs.
半导体离子电解质在低温固体氧化物燃料电池（LT - SOFCs）的开发中越来越受到关注。我们最近的研究提出了一种基于钙钛矿氧化物BaCoFeZrYO（BCFZY）和ZnO的p - n异质结构电解质，实现了有前景的燃料电池性能。在此，为了进一步提高异质结构电解质的性能，采用A位缺陷策略单独修饰BCFZY，以调节异质结构的离子传导和催化活性。开发并系统研究了两种新型电解质BCFZY - ZnO和BCFZY - ZnO。结果表明，由于表面和界面氧空位的增加，这两个样品在A位缺陷后获得了改善的离子电导率和辅助催化活性。与基于BCFZY - ZnO的电池相比，具有BCFZY - ZnO和BCFZY - ZnO的单电池在450 - 550°C时表现出增强的峰值功率输出（通常，在550°C时分别为745和795 mW cm²，而基于BCFZY - ZnO的电池为542 mW cm²）。特别关注A位缺陷对BCFZY和ZnO之间界面能带排列的影响，这表明BCFZY - ZnO用于电荷载流子调节的p - n异质结效应可以通过A位缺陷进行调节，以实现高质子传输，同时避免燃料电池电流泄漏。因此，本研究证实了A位缺陷工程优化异质结构电解质性能以开发LT - SOFCs 的可行性。
