Abstract
Ionically crosslinked acid/base blend membranes of PBI-OO and a sulfonated polysulfone can be covalently crosslinked through aromatic sulfone groups, which form in a thermally induced Friedel-Crafts reaction. Here we systematically compare a series of blend membranes before and after curing. Even though the cured membranes have a lower phosphoric acid uptake even at increased doping time and temperature, they have an improved conductivity and therefore fuel cell performance than the ionically crosslinked membranes. For example, a covalently crosslinked blend membrane containing 5% of the acid component (c-BM 1) reached a conductivity of 260 mS/cm at 160 °C and a relative humidity of 5%, even though the PA uptake was just 266 wt%. In the fuel cell (H2, air, 160 °C), this membrane yielded a peak power density of 452 mW cm−2, about 100 mW cm−2 above that of the commercial meta-PBI membrane. In a long term stability test, the ionically crosslinked membrane uc-BM 1 already failed within 100 h, while the cured c-BM 1 membrane was much more stable. A cured membrane with less PA and higher amount of the acid blend component (c-BM 3) gave a stable performance for over 1000 h, proving that thermally induced sulfone crosslinking strongly increases the stability.
| Original language | English |
|---|---|
| Pages (from-to) | 416-424 |
| Number of pages | 9 |
| Journal | Journal of Membrane Science |
| Volume | 544 |
| DOIs | |
| Publication status | Published - 2017 Dec 15 |
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Keywords
- Crosslinked membranes
- Friedel-Crafts reaction
- HT PEMFC
- Phosphoric acid
- Polybenzimidazole
ASJC Scopus subject areas
- Biochemistry
- Materials Science(all)
- Physical and Theoretical Chemistry
- Filtration and Separation
Cite this
Phosphoric acid doped crosslinked polybenzimidazole (PBI-OO) blend membranes for high temperature polymer electrolyte fuel cells. / Krishnan, N. Nambi; Joseph, Dickson; Duong, Ngoc My Hanh; Konovalova, Anastasiia; Jang, Jong Hyun; Kim, Hyoung Juhn; Nam, SukWoo; Henkensmeier, Dirk.
In: Journal of Membrane Science, Vol. 544, 15.12.2017, p. 416-424.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Phosphoric acid doped crosslinked polybenzimidazole (PBI-OO) blend membranes for high temperature polymer electrolyte fuel cells
AU - Krishnan, N. Nambi
AU - Joseph, Dickson
AU - Duong, Ngoc My Hanh
AU - Konovalova, Anastasiia
AU - Jang, Jong Hyun
AU - Kim, Hyoung Juhn
AU - Nam, SukWoo
AU - Henkensmeier, Dirk
PY - 2017/12/15
Y1 - 2017/12/15
N2 - Ionically crosslinked acid/base blend membranes of PBI-OO and a sulfonated polysulfone can be covalently crosslinked through aromatic sulfone groups, which form in a thermally induced Friedel-Crafts reaction. Here we systematically compare a series of blend membranes before and after curing. Even though the cured membranes have a lower phosphoric acid uptake even at increased doping time and temperature, they have an improved conductivity and therefore fuel cell performance than the ionically crosslinked membranes. For example, a covalently crosslinked blend membrane containing 5% of the acid component (c-BM 1) reached a conductivity of 260 mS/cm at 160 °C and a relative humidity of 5%, even though the PA uptake was just 266 wt%. In the fuel cell (H2, air, 160 °C), this membrane yielded a peak power density of 452 mW cm−2, about 100 mW cm−2 above that of the commercial meta-PBI membrane. In a long term stability test, the ionically crosslinked membrane uc-BM 1 already failed within 100 h, while the cured c-BM 1 membrane was much more stable. A cured membrane with less PA and higher amount of the acid blend component (c-BM 3) gave a stable performance for over 1000 h, proving that thermally induced sulfone crosslinking strongly increases the stability.
AB - Ionically crosslinked acid/base blend membranes of PBI-OO and a sulfonated polysulfone can be covalently crosslinked through aromatic sulfone groups, which form in a thermally induced Friedel-Crafts reaction. Here we systematically compare a series of blend membranes before and after curing. Even though the cured membranes have a lower phosphoric acid uptake even at increased doping time and temperature, they have an improved conductivity and therefore fuel cell performance than the ionically crosslinked membranes. For example, a covalently crosslinked blend membrane containing 5% of the acid component (c-BM 1) reached a conductivity of 260 mS/cm at 160 °C and a relative humidity of 5%, even though the PA uptake was just 266 wt%. In the fuel cell (H2, air, 160 °C), this membrane yielded a peak power density of 452 mW cm−2, about 100 mW cm−2 above that of the commercial meta-PBI membrane. In a long term stability test, the ionically crosslinked membrane uc-BM 1 already failed within 100 h, while the cured c-BM 1 membrane was much more stable. A cured membrane with less PA and higher amount of the acid blend component (c-BM 3) gave a stable performance for over 1000 h, proving that thermally induced sulfone crosslinking strongly increases the stability.
KW - Crosslinked membranes
KW - Friedel-Crafts reaction
KW - HT PEMFC
KW - Phosphoric acid
KW - Polybenzimidazole
UR - http://www.scopus.com/inward/record.url?scp=85029722865&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85029722865&partnerID=8YFLogxK
U2 - 10.1016/j.memsci.2017.09.049
DO - 10.1016/j.memsci.2017.09.049
M3 - Article
AN - SCOPUS:85029722865
VL - 544
SP - 416
EP - 424
JO - Jornal of Membrane Science
JF - Jornal of Membrane Science
SN - 0376-7388
ER -