Characterization of biaxial fatigue durability for fuel cell membranes using pressure-loaded blisters
Qiang Lin, Yihao Yao, Gang Chen, Xu Chen, Shouwen Shi
Abstract
In this study, a customized pressure-loaded blister test device capable of achieving sinusoidal control of pressure was developed to investigate the biaxial fatigue durability of proton exchange membrane (PEM) for fuel cells. The effect of temperature, relative humidity and stress state on biaxial fatigue life was investigated, and the biaxial stress-strain curves under different temperature and relative humidity conditions were also compared. It is found that increasing pressure induces higher biaxial stress and exacerbates the accumulation of plastic strain in the membrane, which adversely affects biaxial fatigue lifetime of PEM. Increasing temperature and decreasing humidity reduces the biaxial yield strength, thereby reducing the fatigue life of membrane. In addition, lowering temperature can lead to a transition in the failure mode from complete rupture to leakage failure. The increase in air pressure ratio, Rp, (minimum to maximum pressure ratio) also leads to premature membrane failure.