Collagen-Based Fuel Cell and Its Proton Transfer

Abstract

We have fabricated the fuel cell based on the tissue derived biomaterial “collagen” and investigated its proton transfer. It was found that “collagen” becomes the electrolyte of fuel cell in the humidified condition. The power density of the fuel cell becomes typically 8.6 W/m2 in the 80% humidity. Further, these results indicate that collagen exhibits proton conductivity in the humidified condition. Both of proton conductivity and dielectric constant increase by the increase of humidity. From the analyses of the frequency dependence of AC conductivity, it was found that proton conductivity and the dielectric dispersion observed in the humidified condition are caused by the formation of the water bridge, which is bonded with the collagen peptide chain. Considering that hydration induces the formation of the water bridge and that increases proton conductivity and dielectric constant, it is deduced that proton transfer in the fuel cell based on collagen is caused by the breaking and rearrangement of hydrogen bond in the water bridge.