체결압이 고분자연료전지 기체확산층의 표면성질에 미치는 영향

Abstract

Characteristics of GDL (Gas Difusion Layer) mainly determine the gas diffusion and water removal ina cell, thereby changing the performance and affecting durability of PEFC. To optimize the water management andunderstand the two phase flow in a GDL, it is important to study the behaviors of GDL micro structure under thereal operating condition. In the clamped condition of cell, the GDL beneath the rib is more compressed than beneaththe channel. Many researches on physical, electrochemical, mechanical behaviors of gas diffusion layer has been con-ducted. However, changes in surface properties under clamped condition have rarely studied. In present study, themorphology of broken connections of carbon fibers and detachment of PTFE coatings on the fibers were shownfrom the microscopic observations. In addition, changes in wetting properties of GDL by compression were inves-tigated by using XPS and liquid uptake methods. The hydrophobic characteristics of GDL surface beneath the ribof the flow field plate are changed due to the deformation of micro structure.