고분자 전해질 연료전지의 동결이 성능 및 내부 물 분포 변화에 끼치는 영향

In this research, the effect of freezing on the performance and water distribution of PEMFC (Polymer Electrolyte Membrane Fuel cell), was analyzed. Total 40 freezing – thawing cycles were conducted and the performance was measured at some points of fixed current density. The performance of PEMFC was degraded after freezing about 35% at the high current density region. To analyze the reason of degradation, visualization and quantification of water in PEMFC was conducted using the X – ray radiography method. In situ visualization was conducted and the water thickness in PEMFC was measured based on the Beer-Lambert law. The result showed reduced water contents in MEA(Membrane Electrolyte Assembly). It was suggested that the reason of degradation. To analyze the reason of water distribution change, the structural change of GDL(Gas Diffusion Layer) was investigated by comparison of SEM(Scanning Electron Microscope) image. The image showed the crack on MPL(Micro Porous Layer) and detachment of MPL from GDL. It destroyed the effective water management in PEMFC and reduced the performance.