A proton exchange membrane is obtained which can give an excellent power generation characteristic when the membrane is applied to, in particular, a fuel cell wherein high-concentration methanol is used as a fuel. In the aromatic hydrocarbon based proton exchange membrane of the invention, the ion exchange capacity is set into the range of 0.6 to 1.3 meq/g. Moreover, the area swelling rate for a 30% by mass methanol aqueous solution at 40°C is set into the range of 2 to 30%. Preferably, a sulfonic acid group is bonded to an aromatic ring of the aromatic hydrocarbon based polymer contained in the aromatic hydrocarbon based proton exchange film. Preferably, the aromatic hydrocarbon based polymer is a polyarylene ether based polymer.
本发明获得了一种质子交换膜,当将该膜应用于燃料电池,特别是使用高浓度
甲醇作为燃料的燃料电池时,该膜可提供出色的发电特性。在本发明的
芳香烃基质子交换膜中,离子交换容量设定在 0.6 至 1.3 meq/g 的范围内。此外,在 40°C 时,质量分数为 30% 的
甲醇水溶液的面积膨胀率设定为 2% 至 30%。优选地,
磺酸基与
芳香烃基质子交换膜中所含
芳香烃基聚合物的芳香环键合。
芳香烃基聚合物最好是聚芳醚基聚合物。