Porometric Study on the Gas Diffusion Layer in PEMFCs Using Method of Standard Porosimetry

ABSTRACT:The structure of pore network of gas diffusion layers (GDLs) in PEMFCs plays a critical role in determining the transport phenomena of reaction gas as well as generated water. In addition, the interactive characteristics between water and surface of pore are no less important than the structural characteristics of pore network. In this study, porometric investigation is conducted for two kinds of GDL using method of standard porosimetry which enable to distinguish hydrophobic pores from hydrophilic pores of GDLs. The porosity of TGPH-120 decreases by 6% by adding 30 wt.% of PTFE, but the porosity of hydrophilic pores decreases by 12%. The relation of p c -S nw varies with the addition of PTFE, especially at low p c .Keywords:Fuel cell(연료전지), PEMFC(고분자전해질 연료전지), GDL(가스확산층), Porosity(공극률), Capillary pressure(모세관압력), PTFE †Corresponding author Tel.: +82-42-629-8279; fax: +82-42-629-8293 E-mail diffusionaddress: neotrin@hnu.kr 기 호 설 명 p c ：모세관압력 [Pa]r ：공극 직경 [m] 그리스 문자 θ ：접촉각 [°]σ ：표면장력 [N/m