121st General Meeting of the KCS

Type Poster Presentation
Area Environmental Energy
Room No. Event Hall
Time 4월 20일 (금요일) 11:00~12:30
Code ENVR.P-667
Subject A molecular dynamics study of Nafion and SPEEK polyelectrolyte membrane in catalyst layer
Authors Ye-Seol Ha, Hyungjun Kim1,*
EEWS, Korea Advanced Institute of Science and Technology, Korea
1Korea Advanced Institute of Science and Technology, Korea
Abstract Nafion membrane is mainly used for the polymer electrolyte membrane fuel cells (PEMFC) because of their high proton conductivity. However unlike to the bulk structure of Nafion, which has been studied by many other researchers, further studies are needed on ionomers at the catalyst layer. In this study, the internal morphology and water transport properties of Nafion polyelectrolyte at the catalyst layer were investigated using molecular dynamics (MD) simulations. We simulated the ionomer surface in contact with the gas-phase (or electrode) using slab model in addition to the bulk model. The multi-lamellar structure of Nafion proposed by several experimentalists was reproducible in our study with lamellar model. Hydrocarbon-based sulfonated poly (ether ether ketone) (SPEEK) membrane, one of the alternatives to Nafion, was also investigated and verified that there is no lamellar model for SPEEK. On the basis of these internal morphology and water dynamics in Nafion and SPEEK systems, it can be concluded that water molecules are more diffusible in more phase segregated structures. We expect that these results may contribute to improve the PEMFC performance via optimizing properties of ionomers in catalyst layer.
E-mail yeseolha@kaist.ac.kr