Leakage characteristics of PEM fuel cell rubber seal in variable temperature environment

Abstract Hydrogen fuel cells are one of the most promising new energy sources in the future, and due to the flammable and explosive nature of hydrogen, good sealing performance is crucial for the safety and stability of PEMFC. The leakage rate is a direct index to evaluate the sealing performance of PEMFC. In this study, by establishing a sealing performance testing device for high and low temperature cycling of the fuel cell, the leakage rate of the fuel cell can be detected in real time during the temperature change process. The test results show that the rubber sealing structure has better sealing performance in the high temperature section (30-80°C), and the sealing performance remains stable as the thermal expansion tends to stabilize with the temperature change. As the ambient temperature decreases to the low-temperature section (-30 to 30°C), the resilience decreases, the elastic modulus increases sharply, and the gap caused by contraction cannot be compensated by elastic deformation, so the sealing performance is obviously weakened.