Influence of the charge double layer on solid oxide fuel cell stack behavior

JOURNAL OF POWER SOURCES

卷:293

Article

Whiston, Michael M.¹  Bilec, Melissa M.²  Schaefer, Laura A.¹ 

[1] Univ Pittsburgh, Dept Mech Engn & Mat Sci, Pittsburgh, PA 15261 USA

[2] Univ Pittsburgh, Dept Civil & Environm Engn, Pittsburgh, PA 15261 USA

关键词: Solid oxide fuel cell;    Charge double layer;    Transient model;    Dynamic response;   

DOI  :  10.1016/j.jpowsour.2015.05.085

来源: Elsevier

【 摘 要 】

While the charge double layer effect has traditionally been characterized as a millisecond phenomenon, longer timescales may be possible under certain operating conditions. This study simulates the dynamic response of a previously developed solid oxide fuel cell (SOFC) stack model that incorporates the charge double layer via an equivalent circuit. The model is simulated under step load changes. Baseline conditions are first defined, followed by consideration of minor and major deviations from the baseline case. This study also investigates the behavior of the SOFC stack with a relatively large double layer capacitance value, as well as operation of the SOFC stack under proportional-integral (PI) control. Results indicate that the presence of the charge double layer influences the SOFC stack's settling time significantly under the following conditions: (i) activation and concentration polarizations are significantly increased, or (ii) a large value of the double layer capacitance is assumed. Under normal (baseline) operation, on the other hand, the charge double layer effect diminishes within milliseconds, as expected. It seems reasonable, then, to neglect the charge double layer under normal operation. However, careful consideration should be given to potential variations in operation or material properties that may give rise to longer electrochemical settling times. CD 2015 Elsevier B.V. All rights reserved.

【 授权许可】

Free