Sorption and transport properties of water in Nafion{reg_sign}/H{sub 3}PO{sub 4} polymer electrolyte at elevated temperatures
- Case Western Reserve Univ., Cleveland, OH (United States)
A major advantage of the Nafion{reg_sign}/H{sub 3}PO{sub 4} polymer electrolyte, formed by equilibrating Nafion{reg_sign} membranes with phosphoric acid, is that it retains high ionic conductivity at temperatures exceeding 100 C. Thermodynamic and transport properties of the system, including water sorption, solubility, diffusivity, permeability, electro-osmotic drag coefficient and ionic conductivity were determined as a function of water activity and temperatures up to 200 C. Results indicate that the water sorption increases with increasing water vapor activity. The electro-osmotic drag coefficient varies from 0.2 to 0.6 over the range of water vapor activity considered. Reasonably high conductivity (> 0.05 {Omega}{sup {minus}1} cm{sup {minus}1}) is observed at the elevated temperatures. Consequently, the Nafion{reg_sign}/H{sub 3}PO{sub 4} system is promising for high temperature PEM fuel cells applications.
- OSTI ID:
- 33597
- Report Number(s):
- CONF-940529--; ISBN 1-56677-080-7
- Country of Publication:
- United States
- Language:
- English
Similar Records
Water uptake by and transport through Nafion[reg sign] 117 membranes
Electro-Osmosis and Water Uptake in Polymer Electrolytes in Equilibrium with Water Vapor at Low Temperatures