Proton conductivity in a new class of H2S modified thioborate-based glasses and ceramics

Proton conducting multi-component glasses and alkali-halide (CsI)-doped ceramics based on thioboric acid have been prepared and characterized. These materials are anhydrous proton conductors and as such are based on a new type of proton bonding and motion. The structures of the precursor material (HBS2), the mixed glass forming ternary system (H2S+B2S3+SiS2) and the alkali-halide-doped system (H2S+B2S3+CsI) and their proton conductivities are reported. Good improvement in the thermal stability and proton conductivity is obtained in the ternary multi-component system. The results illustrate the potential for the development of novel fast proton conductors in anhydrous form in the intermediate temperature range of 100–300 °C.