AI 中文总结
本研究采用弛豫时间分布（DRT）分析，探究SDC浸润STF阴极对SOFC氧还原反应的调控，实现过程解卷积，800℃时极化电阻低至0.04 Ω·cm²，为高性能空气电极设计提供依据。
AI 中文摘要
固体氧化物燃料电池（SOFC）是极具前景的电化学能量转换装置；然而，阴极氧还原反应（ORR）的动力学迟缓仍是其中温运行的主要限制因素。通过在混合离子电子导体SrFe0.9Ti0.1O3-δ（STF）阴极上浸润离子导体Sm0.2Ce0.8O2-δ（SDC），可对ORR的各子过程进行调控。但多数情况下这些过程难以区分，且采用传统等效电路对其理解不足。弛豫时间分布（DRT）分析可区分这些过程，以识别其随温度及表面重构的动力学特性。本研究报道了该分析，揭示了活性位点增加、温度与极化电阻（RP）之间的关联。对于浸润电池，在高温下，SDC浸润优先加速氧表面交换及活化过程，而非与阴极表面相关的相对高频电荷转移过程。通过各过程的系统性重新分布，RP显著降低，在800℃时低至0.04 Ω·cm²。本研究强调将DRT作为工具对各过程进行解卷积，以及SDC浸润STF作为模型阴极体系，可为理解ORR动力学提供机理性见解，并为开发高性能SOFC空气电极提供合理设计依据。
英文摘要
Solid oxide fuel cells (SOFCs) are promising electrochemical energy conversion devices; however, the sluggish cathodic oxygen reduction reaction (ORR) remains a major limitation for intermediate-temperature operation. ORR subprocesses can be modified by infiltrating ionic Sm0.2Ce0.8O2-delta (SDC) on mixed ionic electronic SrFe0.9Ti0.1O3-delta (STF). However, the processes are indistinguishable in most cases and poorly understood using conventional equivalent circuits. Distribution of Relaxation Times (DRT) analysis distinguishes these processes to identify the dynamics with temperature and surface reconstruction. Such analysis is being reported, revealing the connection between increase of active sites, temperature, and polarization resistance (RP). SDC infiltration preferentially accelerates oxygen surface exchange and activation processes over the relatively high frequency charge transfer process related to cathode surface at elevated temperatures for the infiltrated cells. RP was reduced substantially with the systematic redistribution of each process to as low as 0.04 ohm.cm2 at 800 degC. This work underlines the deconvolution of the processes using DRT as a tool, and SDC infiltrated STF as a model cathode system to provide a mechanistic insight of understanding ORR kinetics and design a rationale for developing high-performance SOFC air electrodes
