Influence of pore-size distribution of diffusion layer on mass-transport problems of proton exchange membrane fuel cells

• Published in: Journal of power sources 2002-06, Vol.108 (1), p.185-191
• Main Authors: Kong, Chang Sun, Kim, Do-Young, Lee, Han-Kyu, Shul, Yong-Gun, Lee, Tae-Hee
• Format: Article
• Language: English
• Subjects: Applied sciences; Diffusion layer; Energy; Energy. Thermal use of fuels; Equipments for energy generation and conversion: thermal, electrical, mechanical energy, etc; Exact sciences and technology; Fuel cells; Mass-transport; Pore-size distribution; Proton exchange membrane fuel cell; Water flooding
• ISSN: 0378-7753; 1873-2755
• DOI: 10.1016/S0378-7753(02)00028-9

The influence of pore-size distribution of the diffusion layer on mass-transport problems of proton exchange membrane fuel cells (PEMFCs) is investigated using electrodes with hydrophobic diffusion layers for which the pore-size distribution is designed by pore-former and heat treatment. It is confirmed that the pore-size distribution of the diffusion layer is a more critical parameter for mass-transport processes within the electrode and for cell performance characteristics than the total porosity itself. Data obtained from mercury intrusion porosimetry, single-cell performance tests and ac impedance analyses indicate that the performance loss due to mass-transport limitations can be reduced by enlarging the macropore volume in the diffusion layer. The water flooding problem is discussed in terms of condensation phenomena which are dependent on pore-size.