Development of Aromatic Polymer Electrolyte Membrane with High Conductivity and Durability for Fuel Cell

This report describes a design, preparation and evaluation data of a novel polymer electrolyte membrane, which have been successfully developed for the use in fuel cell vehicles (FCV). This membrane is prepared from the aromatic block copolymer, consisting of alternating stiff sulfonic acid-bearing segments and hydrophobic flexible polymeric sub-units. A bicontinuous microphase-separated morphology of the membrane has been attested, contributing to its excellent water resistance with keeping high proton conductivity. The JSR membrane exhibits actually the same chemical stability as a conventional poly(perfluorosufonic acid) one, while outperforming the latter in power output of the fuel cell, life time and temperature range. In particular, a cold start of FCV have been first demonstrated at −20 °C, using this material. A manufacturing of the JSR membrane in the semi-industrial scale is established. This technology has been officially approved for the extension through the public road examination. This SPSJ award is given for developing novel aromatic polymer electrolyte membrane with high performance for the practical use.