PEMFC边框密封结构的仿真与优化

质子交换膜燃料电池的边框一般通过黏结剂黏接在质子交换膜上,在保护质子交换膜的同时,还起到密封作用。燃料电池长期工作在复杂的环境下,边框和黏结剂的性能均会发生疲劳衰减,导致被剥离或破坏,进而影响燃料电池的气密性。因此,以边框和黏结剂的搭接试件为对象,结合内聚力模型和有限元软件设计了多种边框结构,研究了新结构对黏结性能的影响。结果表明：在低弹性模量的边框表面做三角形或梯形的凸形结构,将有效提升黏结结构的分离位移,但对于高弹性模量的边框,新结构反而会降低黏结性能;此外,优化结构的尺寸、形状对搭接模型黏结性能也有影响,当凸三角形底边长为1.5 mm时,搭接模型有最好的黏结性能。

Modeling and optimizing the frame structures of PEMFCs

The frames in PEMFCs are usually bound with membrane by the adhesive. The frames function as the rigid protecting structure for membrane and play an important role in sealing. However, due to the complex operation environment in fuel cells, the performance of the frame and adhesive could be degraded, which could endanger the gas tightness of the whole fuel cells. Therefore, with the help of finite element software and cohesive element model, series of new-type frames were designed and compared. Their effects on the frame-adhesive samples were investigated. The results show that by making convex structure (triangle or trapezoid) on the low elasticity modulus frames surface can effectively extend the separated displacement of the sample. On the contrary, these new structures can degrade the adhesive performance in high elasticity modulus frames. Moreover, the sizes and shapes of the optimized structures also have effects on the adhesive performance. Furthermore, among the optimized structures, the convex triangle structure with the 1.5 mm base shows the best adhesive performance.