In this study, the effect of GeO2 on the thermal stability and proton mobility (μH) of proton-conducting phosphate glasses was experimentally investigated using 22HO1/2−3NaO1/2−(12−x)LaO3/2−xGeO2−63PO5/2 glasses. Increasing glass transition temperature (Tg)...

Relationship between composition and proton mobility in proton conducting phosphate glass has been obtained using a statical analysis approach.

Anhydrous silicophosphoric acid glass with an approximate composition of H5Si2P9O29 was synthesized and its thermal and proton‐conducting properties were characterized. Despite exhibiting a glass transition at 192 °C, the supercooled liquid could be handled as a solid up to 280 °C owing to its high viscosity. The glass and its melt exhibited proton conduction with a proton transport number of ∼1. Although covalent O−H bonds were weakened by relatively strong hydrogen bonding, the proton conductivity (4×10−4 S cm−1 at 276 °C) was considerably lower than that of phosphoric acid. The high viscosity of the melt was due to the tight cross‐linking of phosphate ion chains by six‐fold‐coordinated Si atoms. The low proton conductivity was attributed to the trapping of positively charged proton carriers around anionic SiO6 units (expressed as (SiO6/2)2−) to compensate for the negative charges.

This study aimed to investigate the impact of WO3 on the thermal stability of glass, as measured by the glass transition temperature (Tg), as well as the activation energy (Ea)...