Proton exchange membrane fuel cells have been investigated extensively as promising hydrogen based power generation devices due to their zero-emission and high efficiency. Although fuel cell electric vehicles and residential co-generation systems have been commercialized, their efficiency and durability need further improvement for widespread dissemination. Proton exchange membrane is one of the crucial components in the fuel cells, playing an important role to transport protons from the anode to the cathode.

In pursuit of better performing proton exchange membranes, we have found that that sulfonated polyphenylene (SPP-QP, Fig. 1) ionomer can give flexible membranes with high proton conductivity and excellent chemical stability. The SPP-QP membrane exhibited high performance and durability in operating fuel cells (Fig. 2).

By enhancing the high speed migration capability of proton and integrating it with hydrogenÅfs high densification ability, we currently intend to enhance the transport phenomena of proton in polymeric materials. This will allow us to induce the high-order functions of hydrogen by controlling proton conduction and multi-electron transfer processes inside materials and at their interfaces. We aim to design next-generation devices for energy conversion and storage.