Lithium ion conducting glasses in the system LiClLi 2OP 2O 5SiO 2

Abstract

Glasses with good ionic conductivity of lithium ions have been prepared in the LiClLi 2OSiO 2P 2O 5 system. The SiO 2/P 2O 5 ratio was kept at 1 5 and it was found that below 1200°C, this leads to a Li 2O/P 2O 5 ratio of about two for the glasses formed. The structure of the glasses appears to be composed of linear chains of phosphate polymers. The highest ionic conductivity is observed in the composition 0.25LiCl0.48Li 2O0.03SiO 20.24P 2O 5 with σ = 2.5 × 10 −3 (Ω-cm) −1 and E a = 0.54 eV (52 kJ/mol) at 235°C. The conductivity increases, the activation energy and the glass transition temperature decrease with increasing LiCl content. Results of the ionic conductivity, FTIR, and DSC measurements are discussed in terms of composition and structural properties of the chloride glasses, and are compared with those of the corresponding oxide glasses.