Thermally crosslinked sulfonated polybenzimidazole membranes and their performance in high temperature polymer electrolyte fuel cells

N. Nambi Krishnan, Anastasiia Konovalova, David Aili, Qingfeng Li, Hyun Seo Park, Jong Hyun Jang, Hyoung-Juhn Kim, Dirk Henkensmeier*

*Corresponding author for this work

Research output: Contribution to journalJournal articleResearchpeer-review

Abstract

The degradation pathway of phosphoric acid doped polybenzimidazole membranes in high temperature polymer electrolyte membrane fuel cells depends on the acid contents. If it is high, creep is discussed as the main reason. If it is low (membranes prepared by solvent evaporation and post-doping), the main cause may be loss of acid due to evaporation. The net transport of acid to the anode side at high current densities should also lead to local softening of the membrane, which could be mitigated by crosslinking the membrane. Here we show that sulfonated para-polybenzimidazole membranes can be stabilized by curing at 350 °C. In contrast to meta-polybenzimidazole and sulfonated para-polybenzimidazole, crosslinked sulfonated para-polybenzimidazole is insoluble in dimethylacetamide at room temperature and phosphoric acid at 160 °C. At 160 °C and 5% relative humidity the conductivity of crosslinked sulfonated para-polybenzimidazole and meta-polybenzimidazole is 214 mS cm−1 and 147 mS cm−1, respectively. At 600 mA cm− 2, the voltage decay rate is 16 μV h−1, much lower than published for commercial meta-polybenzimidazole (308 μV h−1). Furthermore, the average voltage at 600 mA cm− 2 is 523 mV, while a previously published cured meta-polybenzimidazole membrane only reaches 475 mV.
Original languageEnglish
Article number117218
JournalJournal of Membrane Science
Volume588
Number of pages8
ISSN0376-7388
DOIs
Publication statusPublished - 2019

Keywords

  • High temperature polymer electrolyte fuel cell
  • (HT PEMFC)
  • Sulfonated polybenzimidazole
  • Thermal crosslinking
  • Stability
  • High current density

Cite this

Nambi Krishnan, N. ; Konovalova, Anastasiia ; Aili, David ; Li, Qingfeng ; Park, Hyun Seo ; Jang, Jong Hyun ; Kim, Hyoung-Juhn ; Henkensmeier, Dirk. / Thermally crosslinked sulfonated polybenzimidazole membranes and their performance in high temperature polymer electrolyte fuel cells. In: Journal of Membrane Science. 2019 ; Vol. 588.
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title = "Thermally crosslinked sulfonated polybenzimidazole membranes and their performance in high temperature polymer electrolyte fuel cells",
abstract = "The degradation pathway of phosphoric acid doped polybenzimidazole membranes in high temperature polymer electrolyte membrane fuel cells depends on the acid contents. If it is high, creep is discussed as the main reason. If it is low (membranes prepared by solvent evaporation and post-doping), the main cause may be loss of acid due to evaporation. The net transport of acid to the anode side at high current densities should also lead to local softening of the membrane, which could be mitigated by crosslinking the membrane. Here we show that sulfonated para-polybenzimidazole membranes can be stabilized by curing at 350 °C. In contrast to meta-polybenzimidazole and sulfonated para-polybenzimidazole, crosslinked sulfonated para-polybenzimidazole is insoluble in dimethylacetamide at room temperature and phosphoric acid at 160 °C. At 160 °C and 5{\%} relative humidity the conductivity of crosslinked sulfonated para-polybenzimidazole and meta-polybenzimidazole is 214 mS cm−1 and 147 mS cm−1, respectively. At 600 mA cm− 2, the voltage decay rate is 16 μV h−1, much lower than published for commercial meta-polybenzimidazole (308 μV h−1). Furthermore, the average voltage at 600 mA cm− 2 is 523 mV, while a previously published cured meta-polybenzimidazole membrane only reaches 475 mV.",
keywords = "High temperature polymer electrolyte fuel cell, (HT PEMFC), Sulfonated polybenzimidazole, Thermal crosslinking, Stability, High current density",
author = "{Nambi Krishnan}, N. and Anastasiia Konovalova and David Aili and Qingfeng Li and Park, {Hyun Seo} and Jang, {Jong Hyun} and Hyoung-Juhn Kim and Dirk Henkensmeier",
year = "2019",
doi = "10.1016/j.memsci.2019.117218",
language = "English",
volume = "588",
journal = "Journal of Membrane Science",
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Thermally crosslinked sulfonated polybenzimidazole membranes and their performance in high temperature polymer electrolyte fuel cells. / Nambi Krishnan, N.; Konovalova, Anastasiia; Aili, David; Li, Qingfeng; Park, Hyun Seo; Jang, Jong Hyun; Kim, Hyoung-Juhn; Henkensmeier, Dirk.

In: Journal of Membrane Science, Vol. 588, 117218, 2019.

Research output: Contribution to journalJournal articleResearchpeer-review

TY - JOUR

T1 - Thermally crosslinked sulfonated polybenzimidazole membranes and their performance in high temperature polymer electrolyte fuel cells

AU - Nambi Krishnan, N.

AU - Konovalova, Anastasiia

AU - Aili, David

AU - Li, Qingfeng

AU - Park, Hyun Seo

AU - Jang, Jong Hyun

AU - Kim, Hyoung-Juhn

AU - Henkensmeier, Dirk

PY - 2019

Y1 - 2019

N2 - The degradation pathway of phosphoric acid doped polybenzimidazole membranes in high temperature polymer electrolyte membrane fuel cells depends on the acid contents. If it is high, creep is discussed as the main reason. If it is low (membranes prepared by solvent evaporation and post-doping), the main cause may be loss of acid due to evaporation. The net transport of acid to the anode side at high current densities should also lead to local softening of the membrane, which could be mitigated by crosslinking the membrane. Here we show that sulfonated para-polybenzimidazole membranes can be stabilized by curing at 350 °C. In contrast to meta-polybenzimidazole and sulfonated para-polybenzimidazole, crosslinked sulfonated para-polybenzimidazole is insoluble in dimethylacetamide at room temperature and phosphoric acid at 160 °C. At 160 °C and 5% relative humidity the conductivity of crosslinked sulfonated para-polybenzimidazole and meta-polybenzimidazole is 214 mS cm−1 and 147 mS cm−1, respectively. At 600 mA cm− 2, the voltage decay rate is 16 μV h−1, much lower than published for commercial meta-polybenzimidazole (308 μV h−1). Furthermore, the average voltage at 600 mA cm− 2 is 523 mV, while a previously published cured meta-polybenzimidazole membrane only reaches 475 mV.

AB - The degradation pathway of phosphoric acid doped polybenzimidazole membranes in high temperature polymer electrolyte membrane fuel cells depends on the acid contents. If it is high, creep is discussed as the main reason. If it is low (membranes prepared by solvent evaporation and post-doping), the main cause may be loss of acid due to evaporation. The net transport of acid to the anode side at high current densities should also lead to local softening of the membrane, which could be mitigated by crosslinking the membrane. Here we show that sulfonated para-polybenzimidazole membranes can be stabilized by curing at 350 °C. In contrast to meta-polybenzimidazole and sulfonated para-polybenzimidazole, crosslinked sulfonated para-polybenzimidazole is insoluble in dimethylacetamide at room temperature and phosphoric acid at 160 °C. At 160 °C and 5% relative humidity the conductivity of crosslinked sulfonated para-polybenzimidazole and meta-polybenzimidazole is 214 mS cm−1 and 147 mS cm−1, respectively. At 600 mA cm− 2, the voltage decay rate is 16 μV h−1, much lower than published for commercial meta-polybenzimidazole (308 μV h−1). Furthermore, the average voltage at 600 mA cm− 2 is 523 mV, while a previously published cured meta-polybenzimidazole membrane only reaches 475 mV.

KW - High temperature polymer electrolyte fuel cell

KW - (HT PEMFC)

KW - Sulfonated polybenzimidazole

KW - Thermal crosslinking

KW - Stability

KW - High current density

U2 - 10.1016/j.memsci.2019.117218

DO - 10.1016/j.memsci.2019.117218

M3 - Journal article

VL - 588

JO - Journal of Membrane Science

JF - Journal of Membrane Science

SN - 0376-7388

M1 - 117218

ER -