PROTON CONDUCTING VISCOUS MATERIALS DERIVED FROM ZINC METAPHOSPHATE GLASS

Abstract

In the present paper, two types of proton-conducting materials with high viscosity, derived from zinc metaphosphate glass powders, are briefly reviewed. One possible material is a viscous gel prepared by the hydration of the glass powders. The conductivities of the hydrogels increased and the activation energies for the electrical conduction decreased with increasing the water content in the hydrogels. One of the possible applications is an electrolyte for electric double-layer capacitors. The other material is an organic–inorganic hybrid prepared utilizing the reaction of zinc metaphosphate glass powders with imidazole. The resulting anhydrous material showed excellent thermal stability. It showed high electrical conductivities at 110 – 180 °C. The activation energy for electrical conduction (∼0.6 eV) was close to that for proton transport between basic heterocycle molecules. A hydrogen/oxygen fuel cell test using the material as the electrolyte showed the output power of 16 mW/cm² at 150 °C.