Graft-type polymer electrolyte membranes consisting of poly(ether ether ketone) prepared by radiation technique

Maekawa, Yasunari; Hasegawa, Shin; Koshikawa, Hiroshi; Chen, J.

We applied the radiation-induced grafting to poly(ether ether ketone) film, which was mechanically and thermally stable aromatic hydrocarbon polymers, so-called "super engineering plastics". The developed PEEK-based polymer electrolyte membrane (PEM) with 96 m thickness exhibited 1.5 times higher conductivity and 2.3 times higher mechanical strength, compared with conventional fluorinated PEM. The single fuel cell device maintained stable operation over 1000 hours under the operation at 95C. According to the high mechanical strength of PEEK substrates, we could reduce the film thickness of PEEK-based PEM down to 10 m. The PEEK-based PEM with film thickness of 10 and 19 m showed higher cell voltages than that of Nafion at the current density in the range from 0.2 to 1.0 A/cm.