Temperature‐dependent mechanical performance of Nafion® 212 proton exchange membrane under uniaxial and biaxial loading

Abstract

AbstractThe degradation of proton exchange membranes (PEMs) can significantly affect the structural integrity and lifetime of fuel cells. This study investigates the effects of temperature, peak load, initial strain, and loading modes on the mechanical properties of Nafion® 212 PEM using an in‐situ biaxial testing system. The findings indicate that membrane creeping is positively correlated with temperature and peak loads. The stress relaxation rate increases with the increase of initial strain, and an increase in temperature also leads to an apparent decrease in the anti‐relaxation properties of Nafion® 212 membrane. Additionally, the mechanical properties of low‐cycle fatigue at various temperatures were explored under biaxial cyclic loading conditions. When the temperature is fixed, the membrane strain increases and gradually stabilizes with the rise of fatigue cycles. With an increase in temperature, the strain increases at a greater rate. The phase difference increases with temperature growth, and the “hysteresis” phenomenon of the strain becomes more pronounced, resulting in greater energy loss. These results provide valuable insights into the mechanical behavior of Nafion® 212 PEM under different conditions. And can inform the design and optimization of fuel cell systems and contribute to the development of more robust and durable PEM materials.