Preparation and Characterisation of Pelletised Glass Electrolytes for Fuel Cells

Abstract

This paper reports on the preparation and characterisation of pelletised glass electrolytes that were fabricated with a proton conducting glass derived from a sol–gel technique, and several kinds of binders. The electrolytes, consisting of a glass powder that had been pulverised by planetary ball milling and mixed with an orthophosphoric acid binder, gave rise to a maximum proton conductivity of 1.3 × 10–2 S cm–1 measured at 80 °C and 80% relative humidity. The pore diameter of the PGE was in this case ∼2 nm. The hydrogen gas permeability was analysed as a function of the temperature and was found to be on the order of 10–10 mol cm–1 s–1 Pa–1 at 100 °C. Current–voltage measurements were carried out at room temperature using the PGE under H2 and O2 flow. Power densities were obtained from the I–V curves during fuel cell operation at 80 °C and 100% R.H.

Functionalized mesoporous structured inorganic materials as high temperature proton exchange membranes for fuel cells

“…109 Using proton conducting H 3 PO 4 as a binder, the power density of the P 2 O 5 -SiO 2 glass membrane cell was 70.3 mW cm À2 at 80 C and 75% RH, which is signicantly higher than 28.3 mW cm À2 on the same membrane but with PTFE as the binder. 127 Nakamoto et al This journal is © The Royal Society of Chemistry 2014 obtained maximum power densities of $25 mW cm À2 at 130 C and 38 mW cm À2 at 150 C using the phosphosilicate gel/polyimide composite membrane. 128 Most recently, Ishiyama et al reported the development of tungsten phosphate glass as PEM for fuel cells.…”

“…158 For unsupported mesoporous materials, e.g., a-Fe 2 O 3 and P 2 O 5 -SiO 2 glass, high specic surface areas, high pore volume and narrow pore size distribution in the range of 2-3 nm would be required to maintain high water uptake and thus adequate conductivity. 91,127,135 In this case, water molecules within the mesopores play a major role in proton transport by forming protonic charge carriers through hydrogen bonding. On the other hand, size of nano or mesopores is related to the proton carrier or the dopant.…”