Abstract
Polymer electrolytes have received considerable attention, especially for polymer electrolyte membrane fuel cells (PEMFCs) operating at temperatures above 100°C. phosphoric acid doped polybenzimidazole (PBI) and PBI composite membranes have been prepared in the present work. The PBI composites contain inorganic protonic conductors including zirconium phosphate (ZrP), (Zr(HPO4)2. nH2O); phosphotungstic acid (PWA), (H3PW12O40. nH2O); and silicotungstic acid (SiWA), (H4SiW12O40 . nH2O). The conductivity of phosphoric acid doped PBI and PBI composite membranes was found to be dependent on the acid doping level, relative humidity (RH) and temperature. A conductivity of 6.8 × 10-2 S cm-1 was observed for PBI membranes with a H3PO4 doping level of 5.6 (mole number of H3PO4 per repeat unit of PBI) at 200°C and 5% RH. A higher conductivity of 9.6 × 10-2 S cm-1 was obtained by blending 15 wt.% of ZrP in a PBI membrane at the same conditions. Homogeneous membranes with good mechanical strength were prepared by introducing PWA (20 - 30 wt.%) and SiWA (20 - 30 wt.%) into PBI, and their conductivity were found to be higher than or comparable with that of the PBI membrane up to 110°C.
| Original language | English |
|---|---|
| Title of host publication | Proceedings of the 2nd European PEFC Forum |
| Number of pages | 848 |
| Volume | volume 1 |
| Place of Publication | Switzerland |
| Publisher | European Fuel Cell Forum |
| Publication date | 2003 |
| Edition | 1 |
| Pages | 59-68 |
| ISBN (Print) | 3-905592-13-4 |
| Publication status | Published - 2003 |
| Event | 2nd European PEFC Forum - Lucerne, Switzerland Duration: 30 Jun 2003 → 4 Jul 2003 |
Conference
| Conference | 2nd European PEFC Forum |
|---|---|
| Country/Territory | Switzerland |
| City | Lucerne |
| Period | 30/06/2003 → 04/07/2003 |