The stability of poly(2,2′-(m-phenylene)-5,5′-bibenzimidazole) membranes in aqueous potassium hydroxide

Publication: Research - peer-reviewJournal article – Annual report year: 2015

View graph of relations

In the form of membranes, poly(2,2′-(m-phenylene)-5,5′-bibenzimidazole) (mPBI) is known to exhibit high ionic conductivity when doped with aqueous KOH, which makes it interesting as electrolyte in e.g. alkaline fuel cells and water electrolyzers. The conductivity peaks at KOH concentrations around 25wt%. This work is devoted to a comprehensive stability study of mPBI in aqueous KOH of different concentrations for up to 200 days under conditions relevant for electrochemical energy conversion technologies. The polymer membranes were kept at 88°C in aqueous KOH with concentrations ranging from 0 to 50wt%, and the chemical and physicochemical changes were monitored. The degradation was connected to the hydrolysis of the polymer backbone and the degradation rate increased with increasing KOH concentration. In the lower concentration range mPBI proved to be stable but exhibited low ionic conductivity (10−4Scm−1). The preparation of a porous mPBI matrix was demonstrated as an effective approach to increase the ionic conductivity in the lower KOH concentration range, with great potential for further improvement through optimization of the porous structure.
Original languageEnglish
JournalJournal of Membrane Science
Volume492
Pages (from-to)422-429
Number of pages8
ISSN0376-7388
DOIs
StatePublished - 2015
CitationsWeb of Science® Times Cited: 8

    Keywords

  • Polybenzimidazole, Membrane, Alkaline, Stability, Degradation
Download as:
Download as PDF
Select render style:
APAAuthorCBE/CSEHarvardMLAStandardVancouverShortLong
PDF
Download as HTML
Select render style:
APAAuthorCBE/CSEHarvardMLAStandardVancouverShortLong
HTML
Download as Word
Select render style:
APAAuthorCBE/CSEHarvardMLAStandardVancouverShortLong
Word

ID: 113784998