Investigation of three system shut-down strategies alongside optimization suggestion for proton exchange membrane fuel cells via in-situ measurements

ABSTRACT

Carbon corrosion caused by H₂/O₂ interface during the shut-down process is one of the factors that exacerbate the overall degradation of proton exchange membrane fuel cells (PEMFC) in automotive applications. Numerous studies have shown that system strategies are beneficial for reducing the duration of H₂/O₂ interface and alleviating performance degradation. In this paper, three different shut-down strategies are investigated and compared based on the internal behaviors acquired by in-situ measurements. For the three shut-down strategies, reverse current and high potential are mainly observed in a lower constant current and constant power strategy. Comparatively speaking, the internal uniformity of the cell under constant current and power load is better than that with constant voltage strategy when the shut-down time is about the same. The results suggest that adopting a higher constant power load followed by a larger voltage load during the shut-down process can effectively shorten the shut-down time and relieve carbon corrosion. These results add significant new insights into the shut-down process and will be of practical importance in directing design of combined shut-down strategy that can withstand carbon corrosion.

KEYWORDS:

• PEMFC
• Shut-down strategy
• In-situ measurement
• Current density distribution
• Temperature and RH distribution
• Uniformity

Acknowledgments

The authors would like to thank the National Key Research and Development Program of China (2017YFB0102701), Guangdong Provincial Key Laboratory of Energy Materials for Electric Power (2018B030322001), Guangdong Innovative and Entrepreneurial Research Team Program (2016ZT06N500), Development and Reform Commission of Shenzhen Municipality (2017 No.1106), Shenzhen Peacock Plan (KQTD2016022620054656), and Shenzhen Key Laboratory project (ZDSYS201603311013489) for providing financial support for this research undertaking.

Additional information

Funding

This work was supported by the National Key Research and Development Program of China under Grant [2017YFB0102701]; Guangdong Provincial Key Laboratory of Energy Materials for Electric Power under Grant [2018B030322001]; Guangdong Innovative and Entrepreneurial Research Team Program under Grant [2016ZT06N500]; Development and Reform Commission of Shenzhen Municipality under Grant [2017 No.1106]; Shenzhen Peacock Plan under Grant [KQTD2016022620054656] and Shenzhen Key Laboratory project under Grant [ZDSYS201603311013489].