Dr. Christopher J. Cornelius
Sandia National Laboratories
Albuquerque, New Mexico

What's a PEM Material? 
A Cliff Note Overview of Fuel Cell Technology

Significant research has been involved in the development of alternative polymer electrolyte membranes (PEM) for fuel cell applications.^1,2,3  This is due to the physical property limitations of current perfluoronated PEMs such as poor mechanical properties at temperatures above 100^oC, high methanol flux in direct methanol fuel cells, loss in proton conductivity at elevated temperatures, and high material cost.  Hydrocarbon based PEM materials have demonstrated fuel cell performance characteristics that are interesting and have the potential as an alternative type of PEM.  An overview of PEM materials will be discussed with an emphasis on structure and properties of polyphenylenes as an example PEM alternative.  Polyphenylenes represent a class of thermoplastics known for their excellent thermal and chemical stability, while maintaining organic solubility making it possible to form mechanically robust films.^4,5  These materials have the potential of being developed and used as a PEM within hydrogen and methanol fuel cells.  Preliminary hydrogen fuel cell performance data of a series of sulfonated Diels-Alder polyphenylene (SDAPP) will be briefly discussed as it relates to DOE hydrogen fuel cell technical targets.^6,7,8

 

1.     Savadogo, O.  J. New Mater. Electrochem. Syst. 1998, 1, 47.

2.     Rikukawa, M.; Sanui, K. Prog. Polym. Sci. 2000, 25, 1463.

3.     Steck, A.; Stone, C. Proceedings of the Second International Symposium on New Materials for Fuel Cell and Modern Battery Systems.

4.     Stille, J. K. J. Macromol. Sci. Chem. 1969, 3, 1043.

5.     Neenan, T. X.; Kumar, U.  Macromolecules. 1995, 28, 124.

6.     Fujimoto, C.H.; Hickner, M.A.; Cornelius, C.J., and Loy, D.A., Macromolecules 2005, 38(04), 1201.

7.     Cornelius, C.J.; Grest, G.S.; Hibbs, M.R.; Fujimoto, C.H.; Hickner, M.A.; Staiger, C.L. Advanced proton-exchange materials for energy efficient fuel cells. Sandia National Laboratories SAND2005-7926

8.     Cornelius, C.J., Hybrid organic-inorganic proton-exchange membrane materials based on sulfonated polyimide block copolymers useful for direct methanol fuel cells U.S. Patent 7,022,810 B1, 2006.