Hygrothermal variations that arise during dynamic fuel cell operation are known to generate mechanical stresses in the ionomer membrane. Previous research has indicated that membrane electrode assembly (MEA) interaction effects may influence membrane degradation under such loads. The present objective is therefore to evaluate novel MEA design strategies for mitigating mechanical membrane degradation in fuel cells. In this case (Part 1), a gas diffusion layer (GDL) with low surface roughness is applied to suppress buckling-driven membrane failures. Laboratory-based X-ray computed tomography is used in a customized, time-resolved workflow for non-invasive four-dimensional characterization of membrane damage evolution during accelerated stress testing. Membrane crack development is the key failure mode preceded by fracture of the cathode catalyst layer. In comparison to high surface roughness GDL, the severity of membrane buckling is substantially reduced by adoption of the smoother GDL, contributing 2x greater lifetime. Accompanying finite element simulations of the unit fuel cell assembly show plastic strain accumulation in the buckled membrane and identified a critical range of GDL void sizes that influence membrane buckling. Overall, the improvement in GDL surface demonstrates substantial mitigation effect against fatigue-driven mechanical membrane degradation and failure, which is also corroborated by the numerical simulation results.

已知在动态燃料电池操作期间出现的湿热变化会在离聚物膜中产生机械应力。先前的研究表明，膜电极组件 (MEA) 相互作用效应可能会影响这种负载下的膜降解。因此，目前的目标是评估用于减轻燃料电池中机械膜降解的新型 MEA 设计策略。在这种情况下（第 1 部分），应用具有低表面粗糙度的气体扩散层 (GDL) 来抑制屈曲驱动的膜失效。基于实验室的 X 射线计算机断层扫描用于定制的时间分辨工作流程，用于在加速应力测试期间对膜损伤演变进行非侵入性四维表征。膜裂纹发展是阴极催化剂层破裂之前的关键失效模式。与高表面粗糙度 GDL 相比，通过采用更光滑的 GDL，膜屈曲的严重程度大大降低，使用寿命延长了 2 倍。伴随单元燃料电池组件的有限元模拟显示，屈曲膜中的塑性应变积累，并确定了影响膜屈曲的 GDL 空隙尺寸的临界范围。总体而言，GDL 表面的改进表明对疲劳驱动的机械膜退化和失效具有显着的缓解作用，数值模拟结果也证实了这一点。贡献 2 倍更长的寿命。伴随单元燃料电池组件的有限元模拟显示，屈曲膜中的塑性应变积累，并确定了影响膜屈曲的 GDL 空隙尺寸的临界范围。总体而言，GDL 表面的改进表明对疲劳驱动的机械膜退化和失效具有显着的缓解作用，数值模拟结果也证实了这一点。贡献 2 倍更长的寿命。伴随单元燃料电池组件的有限元模拟显示，屈曲膜中的塑性应变积累，并确定了影响膜屈曲的 GDL 空隙尺寸的临界范围。总体而言，GDL 表面的改进表明对疲劳驱动的机械膜退化和失效具有显着的缓解作用，数值模拟结果也证实了这一点。