Flooding of gas diffusion backing in PEFCs - Physical and electrochemical characterization
2004 (English)In: Journal of the Electrochemical Society, ISSN 0013-4651, Vol. 151, no 8, A1152-A1161 p.Article in journal (Refereed) Published
In polymer electrolyte fuel cells (PEFCs) gas diffusion backings (GDBs) have a significant effect on water management and cell performance. In this study, methods for characterizing GDB performance by fuel cell testing and ex situ measurements are presented. The performance of four different commercial GDB materials was tested and significant differences were found between the materials. While the performance and behavior are almost similar in the single-phase region, the flooding behavior of different GDBs in the two-phase region varies widely. The results show that using high clamping pressures increases cell flooding, but the increase varies from material to material. Increased flooding is caused by the combination of decreased porosity and a temperature difference between GDB and current collector. Furthermore, it was observed that the decrease in porosity due to cell compression and corresponding increase in mass-transfer resistance should be studied in the single-phase region, because flooding of the GDB easily becomes the dominating source of mass-transfer resistance. In addition, a literature review on GDB studies and characterization methods was carried out. The review revealed a lack of an established GDB testing regime and the absence of a relation between physical properties of the GDB and fuel cell performance.
Place, publisher, year, edition, pages
2004. Vol. 151, no 8, A1152-A1161 p.
electrolyte fuel-cells, performance, layer, cathode, transport, pemfc
IdentifiersURN: urn:nbn:se:kth:diva-23613DOI: 10.1149/1.1763138ISI: 000222969500008ScopusID: 2-s2.0-4344683422OAI: oai:DiVA.org:kth-23613DiVA: diva2:342312
QC 20100525 QC 201111012010-08-102010-08-102011-11-01Bibliographically approved