Abstract

A method was developed for predicting electrolyte membrane life under mechanical degradation, by quantifying the mechanical stress generated on the fuel cell polymer electrolyte membrane and quantitatively understanding the impact on mechanical degradation. In an environment with repeated drying and wetting, mechanical degradation of the electrolyte membrane progresses at the cracks inside the catalyst layers that are bonded to the electrolyte membrane. This study focused on changes in the electrolyte membrane and catalyst layer properties in the temperature and humidity environment in which fuel cells operate as a factor that increases stress. The electrolyte membrane and catalyst layer properties were measured at the temperatures and humidity under which fuel cells operate, and the measured property values were reflected to a stress analysis model that uses the finite element method in an effort to increase the stress prediction accuracy. The cumulative fatigue damage law was applied to the relationship between the generated stress and stress frequency and the material limit line to quantify the impact of mechanical degradation on life as the life consumption rate, and it was confirmed that the life consumption rate is correlated with the thickness of the electrolyte membrane after durability tests. This enabled prediction of electrolyte membrane life according to mechanical stress. Durability tests that accelerate mechanical degradation were performed using a full-scale-size membrane electrode assembly, and the accuracy of the developed life prediction technology was verified. A high correlation was obtained, which confirmed that the developed life prediction technology can be applied to an on-board-size membrane electrode assembly.

References

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Author (organization or company)

• Masashi SUGISHITA（Automobile R&D Center）
• Suguru OHMORI（Automobile R&D Center）

Publication Information

Article of Honda R&D Technical Review Vol.28 No.1 (59 - 67)

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