TY - JOUR
T1 - Locally confined membrane modification of sulfonated membranes for fuel cell application
AU - Krishnan, N. Nambi
AU - Henkensmeier, Dirk
AU - Jang, Jong Hyun
AU - Hink, Steffen
AU - Kim, Hyoung Juhn
AU - Nam, Suk Woo
AU - Lim, Tae Hoon
N1 - Funding Information:
The work was supported by the K-GRL program of KIST and also by the Joint Research Project funded by the Korea Research Council of Fundamental Science & Technology (KRCF), Republic of Korea (Seed-10-2).
PY - 2014/3/15
Y1 - 2014/3/15
N2 - We report a method which protects sulfonated hydrocarbon based proton exchange membranes at the interface between active and non-active area and in the gas inlet/outlet areas, where stresses are maximal during fuel cell operation. The sensitive membrane regions are subjected to a locally confined heat treatment using a stainless steel frame, under which desulfonation and/or crosslinking reactions occur. While modifications in air limit the reaction temperature to 180°C, inert atmosphere allows to raise the temperature and thus to shorten the necessary reaction time from 24h to less than 30min. Membranes are prepared from a commercially available copolymer (SES0005, AquafoneTM), which has a high IEC (2.08meqg-1) and a water uptake of 64%. As expected, modified membranes show reduced IEC values, reduced water uptake, and increased dimensional stability. Catalyst coated membranes (CCMs) are assembled into single cells for fuel cell testing. A membrane modified on all edges shows a stable performance in H2/air fuel cell operation and an H2 crossover current density of 0.52mAcm-2, while a membrane modified only on two edges fails within 50h. Tensile and fuel cell tests show that the interface between modified and pristine area is not the preferred breaking point.
AB - We report a method which protects sulfonated hydrocarbon based proton exchange membranes at the interface between active and non-active area and in the gas inlet/outlet areas, where stresses are maximal during fuel cell operation. The sensitive membrane regions are subjected to a locally confined heat treatment using a stainless steel frame, under which desulfonation and/or crosslinking reactions occur. While modifications in air limit the reaction temperature to 180°C, inert atmosphere allows to raise the temperature and thus to shorten the necessary reaction time from 24h to less than 30min. Membranes are prepared from a commercially available copolymer (SES0005, AquafoneTM), which has a high IEC (2.08meqg-1) and a water uptake of 64%. As expected, modified membranes show reduced IEC values, reduced water uptake, and increased dimensional stability. Catalyst coated membranes (CCMs) are assembled into single cells for fuel cell testing. A membrane modified on all edges shows a stable performance in H2/air fuel cell operation and an H2 crossover current density of 0.52mAcm-2, while a membrane modified only on two edges fails within 50h. Tensile and fuel cell tests show that the interface between modified and pristine area is not the preferred breaking point.
KW - Crosslinking
KW - Degradation
KW - Desulfonation
KW - Life time
KW - Membrane modification
KW - Polymer electrolyte fuel cell
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U2 - 10.1016/j.memsci.2013.12.020
DO - 10.1016/j.memsci.2013.12.020
M3 - Article
AN - SCOPUS:84891437088
VL - 454
SP - 174
EP - 183
JO - Jornal of Membrane Science
JF - Jornal of Membrane Science
SN - 0376-7388
ER -