Remarkable high proton conducting P2O5-SiO2 glass as a fuel cell electrolyte working at sub-zero to 120 degrees C

Proton conductivity of the P2O5-SiO2 glasses was investigated at sub-zero t o 120 degreesC. The glasses prepared by a sol-gel method are porous, pore d iameters in which are smaller than 5 mn with an average diameter of 2.5 mn. The electrical conductivities, measured under 100%RH, follow the Arrhenius equation with the activation energy of 10 kJ/mol in the temperature betwee n 120 and -20 degreesC. Below -20 degreesC, the adsorbed-water molecules ar e frozen to increase the activation energy and decrease the proton conducti vity. We could conclude that our P2O5-SiO2 glasses, exhibiting high protoni c conductivity of similar to 30 mS/cm at 120 degreesC, have potential for t he electrolyte of the fuel cell operating at sub-zero to 120 degreesC.