Mechanical degradation of cross-linked sulfonated poly (ether-ether-ketone) membranes in fuel cell application

One of the key challenges facing the commercialization of fuel cell technology is the durability of proton exchange membranes, especially in automotive application. Even though proton exchange membranes (PEM) suffer from chemical degradation, mechanical degradation shouldn’t be overlooked. PEMs tend to swell in high humidity and shrink in low humidity. Additionally, temperature affects mechanical behavior of polymeric membranes for sure, thus accelerated hygrothermal cycling ends up to membrane failure and crack formation at the end. In this work sPEEK membranes were prepared, treated and characterized, i.e. sulfonation degree of 64.75 % was calculated from H-NMR spectroscopy and ion exchange capacity and a cross-linking ratio of 1.15 meq.gr-1 and 39.6 % were calculated respectively. Then combined temperature and humidity cycles were done due to putting to the test membrane’s durability in harsh fuel cell condition. It was shown membranes have a slight increment in their elastic modulus and act more brittle while water uptake increases significantly during hygrothermal cycling up to 184% which probably increases stress amplitude in cycles eventually

کلیدواژه ها:

Hygrothermal cycling ، Mechanical degradation ، sPEEK ، PEFCs