Repetitive hygrothermal fluctuations cause mechanical membrane degradation in fuel cells, which requires mitigation for longevity. Part 1 of this work demonstrated that gas diffusion layers (GDLs) with low surface roughness can improve lifetime by reducing harmful buckling phenomena during wet/dry cycling. As a second novel mitigation approach in the present work (Part 2), the catalyst coated membrane (CCM) is bonded with the GDLs to eliminate relative motion and further curb mechanical degradation. A custom miniaturized fuel cell fixture is used within a laboratory-based X-ray computed tomography system to visualize the membrane degradation process during wet/dry cycling. Compared to a non-bonded baseline cell, membrane buckling is shown to be completely arrested with bonding and lead to a two-fold increase in lifetime. Membrane crack development is still observed as the key failure mode, preceded by cathode catalyst layer fracture. However, the root causes are related to bonding irregularities and compressive impingement of GDL fibers rather than membrane buckling. Complementary finite element simulations of a representative fuel cell assembly are carried out to fundamentally establish the favorable effect of improved CCM-GDL adhesion on membrane durability. Overall, the improved adhesion of the bonded cell provided substantial mitigation against fatigue-driven mechanical membrane degradation and failure.

重复的湿热波动会导致燃料电池中的机械膜退化，这需要缓解以延长寿命。这项工作的第 1 部分表明，具有低表面粗糙度的气体扩散层 (GDL) 可以通过减少湿/干循环期间有害的屈曲现象来提高寿命。作为当前工作（第 2 部分）中的第二种新型缓解方法，催化剂涂层膜 (CCM) 与 GDL 结合以消除相对运动并进一步抑制机械退化。在基于实验室的 X 射线计算机断层扫描系统中使用定制的小型化燃料电池装置，以可视化湿/干循环期间的膜降解过程。与非键合基线电池相比，膜屈曲被证明完全被键合阻止并导致寿命增加两倍。在阴极催化剂层破裂之前，膜裂纹的发展仍然被观察为关键的失效模式。然而，根本原因与 GDL 纤维的粘合不规则性和压缩冲击有关，而不是膜屈曲。对具有代表性的燃料电池组件进行了互补的有限元模拟，以从根本上确定改进的 CCM-GDL 粘附对膜耐久性的有利影响。总体而言，粘合电池的粘附性提高，大大减轻了疲劳驱动的机械膜退化和失效。对具有代表性的燃料电池组件进行了互补的有限元模拟，以从根本上确定改进的 CCM-GDL 粘附对膜耐久性的有利影响。总体而言，粘合电池的粘附性提高，大大减轻了疲劳驱动的机械膜退化和失效。对具有代表性的燃料电池组件进行了互补的有限元模拟，以从根本上确定改进的 CCM-GDL 粘附对膜耐久性的有利影响。总体而言，粘合电池的粘附性提高大大减轻了疲劳驱动的机械膜退化和失效。