Journal of Applied Electrochemistry

, Volume 31, Issue 7, pp 773–779

Phosphoric acid doped polybenzimidazole membranes: Physiochemical characterization and fuel cell applications

  • Li Qingfeng
  • H.A. Hjuler
  • N.J. Bjerrum
Article

DOI: 10.1023/A:1017558523354

Cite this article as:
Qingfeng, L., Hjuler, H. & Bjerrum, N. Journal of Applied Electrochemistry (2001) 31: 773. doi:10.1023/A:1017558523354

Abstract

A polymer electrolyte membrane fuel cell operational at temperatures around 150–200 °C is desirable for fast electrode kinetics and high tolerance to fuel impurities. For this purpose polybenzimidazole (PBI) membranes have been prepared and H3PO4-doped in a doping range from 300 to 1600 mol %. Physiochemical properties of the membrane electrolyte have been investigated by measurements of water uptake, acid doping level, electric conductivity, mechanical strength and water drag coefficient. Electrical conductivity is found to be insensitive to humidity but dependent on the acid doping level. At 160 °C a conductivity as high as 0.13 S cm−1 is obtained for membranes of high doping levels. Mechanical strength measurements show, however, that a high acid doping level results in poor mechanical properties. At operational temperatures up to 190 °C, fuel cells based on this polymer membrane have been tested with both hydrogen and hydrogen containing carbon monoxide.

electrolytefuel cellpolybenzimidazole (PBI)polymer membrane

Copyright information

© Kluwer Academic Publishers 2001

Authors and Affiliations

  • Li Qingfeng
    • 1
  • H.A. Hjuler
    • 1
  • N.J. Bjerrum
    • 1
  1. 1.Materials Science Group, Department of ChemistryTechnical University of DenmarkLyngbyDenmark