New type of composite proton electrolytes based on CsH2PO4 synthesized by mechanical activation

Conductivity, structural and thermal properties of the (1–x)CsH₂PO₄-xSnP₂O₇ composite electrolytes (x = 0.01–0.8) were investigated. The addition of dispersed tin pyrophosphate to CsH₂PO₄ and their mechanical mixing results in an increase in low temperature conductivity by 1–3 orders of magnitude depending on the composition. According to X-ray diffraction data there is no chemical interaction between the components and no new compounds are formed. X-ray diffraction and differential scanning calorimetry data show a significant change in structural and thermodynamic properties of CsH₂PO₄ in composites due to salt amorphization. The increase in conductivity is caused by salt disordering due to the interface interaction.