TY - JOUR
T1 - Nafion membranes with a porous surface
AU - Dang, Quoc Khanh
AU - Henkensmeier, Dirk
AU - Krishnan, N. Nambi
AU - Jang, Jong Hyun
AU - Kim, Hyoung Juhn
AU - Nam, Suk Woo
AU - Lim, Tae Hoon
N1 - Funding Information:
We thank SGL Carbon for providing GDL materials. Financial support is gratefully acknowledged from the Joint Research Project funded by the Korea Research Council of Fundamental Science & Technology (KRCF), Republic of Korea , (Seed-10-2), and by the Korea CCS R&D Center (KCRC) grant funded by the Korea Government (Ministry of Science, ICT & Future Planning) (No. 2013038315 ).
PY - 2014/6/15
Y1 - 2014/6/15
N2 - Nafion membranes with a monolayer of pores on one surface (P-Nafion) were prepared by casting a Nafion SE20092 dispersion containing ortho-dichlorobenzene. The pores are not connected but provide 2μm large openings, increasing the membrane surface by one dimension. The thickness of the porous layer is typically <5μm. In catalyst coated membranes the catalyst layer penetrated the pores well. The effect on the performance of a polymer electrolyte fuel cell (PEFC) was investigated at 95°C. The porous layer formed the cathode, to enhance water back diffusion. After 24h equilibration, 30-35μm thick P-Nafion gave 10-16% higher current density, reaching 858mA/cm2 at 0.4V and 50% rh. N211 and P-Nafion equilibrated for 8min showed peak power densities of 56 and 208mW/cm2 under anhydrous conditions, respectively, indicating that drying processes are slowed down. The stability of a MEA was tested for 240h at 0.4V and 50% rh (anode/cathode), without observable degradation. Under fully humidified conditions, the electrochemical surface area (ECSA) increased 40% in comparison to a N211 based MEA. At 65°C, the ECSA more than doubled, showing 141m2/g Pt. Also influence of the pores on water transport through a membrane and stability against membrane-electrode delamination were considered.
AB - Nafion membranes with a monolayer of pores on one surface (P-Nafion) were prepared by casting a Nafion SE20092 dispersion containing ortho-dichlorobenzene. The pores are not connected but provide 2μm large openings, increasing the membrane surface by one dimension. The thickness of the porous layer is typically <5μm. In catalyst coated membranes the catalyst layer penetrated the pores well. The effect on the performance of a polymer electrolyte fuel cell (PEFC) was investigated at 95°C. The porous layer formed the cathode, to enhance water back diffusion. After 24h equilibration, 30-35μm thick P-Nafion gave 10-16% higher current density, reaching 858mA/cm2 at 0.4V and 50% rh. N211 and P-Nafion equilibrated for 8min showed peak power densities of 56 and 208mW/cm2 under anhydrous conditions, respectively, indicating that drying processes are slowed down. The stability of a MEA was tested for 240h at 0.4V and 50% rh (anode/cathode), without observable degradation. Under fully humidified conditions, the electrochemical surface area (ECSA) increased 40% in comparison to a N211 based MEA. At 65°C, the ECSA more than doubled, showing 141m2/g Pt. Also influence of the pores on water transport through a membrane and stability against membrane-electrode delamination were considered.
KW - Fuel cells
KW - Hierarchical structures
KW - Nafion membranes
KW - Porous surfaces
KW - Water management
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U2 - 10.1016/j.memsci.2014.03.003
DO - 10.1016/j.memsci.2014.03.003
M3 - Article
AN - SCOPUS:84896529465
VL - 460
SP - 199
EP - 205
JO - Jornal of Membrane Science
JF - Jornal of Membrane Science
SN - 0376-7388
ER -