Development of solid electrolytes for water electrolysis at higher temperature
- Florida Solar Energy Center, Cocoa, FL (United States)
This report describes efforts in developing new solid polymer electrolytes that will enable operation of proton exchange membrane electrolyzers at higher temperatures than are currently possible. Several ionomers have been prepared from polyetheretherketone (PEEK), polyethersulfone (PES), and polyphenylquinoxaline (PPQ) by employing various sulfonation procedures. By controlling the extent of sulfonation, a range of proton conductivities could be achieved, whose upper limit actually exceeded that of commercially available perfluoralkyl sulfonates. Thermoconductimetric analysis of samples at various degrees of sulfonation showed an inverse relationship between conductivity and maximum operating temperature. This was attributed to the dual effect of adding sulfonate groups to the polymer: more acid groups produce more protons for increased conductivity, but they also increase water uptake, which mechanically weakens the membrane. This situation was exacerbated by the limited acidity of the aromatic sulfonic acids (pK{sub A} {approx} 2-3). The possibility of using partial fluorination to raise the acid dissociation constant is discussed.
- Research Organization:
- National Renewable Energy Lab. (NREL), Golden, CO (United States)
- OSTI ID:
- 447153
- Report Number(s):
- NREL/CP-430-21968-Vol.1; CONF-9605195-Vol.1; ON: DE97000053; TRN: 97:001172-0022
- Resource Relation:
- Conference: 1996 annual hydrogen peer review for DOE, Miami, FL (United States), 1-3 May 1996; Other Information: PBD: Oct 1996; Related Information: Is Part Of Proceedings of the 1996 US DOE hydrogen program review. Volume 1; PB: 575 p.
- Country of Publication:
- United States
- Language:
- English
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