LiClZnOSiO2 xerogels synthesized by the sol-gel method are shown by powder X-ray diffraction, Fourier transform infrared and 7Li and 29Si NMR spectra to be composites of microcrystalline LiCl and ZnOSiO2 xerogel. Ionic conductivity measurements of the xerogels show extrinsic and intrinsic behavior. Below 280°C, Li+ motion is dominated by a space charge mechanism (significant for 0.40LiCl-0.12ZnO-0.48SiO2), which is indicative of composite character. Above 280°C the conductivity is attributed to the intrinsic conductivity of LiCl in the pores of the xerogel. The increased ionic conductivity with increasing Zn/Si ratio (up to 1 4) in the high temperature regime (> 280°C) is ascribed to the decrease of activation energy due to the dissolution of LiCl in the xerogel. The highest Li+ ion conductivity is found to be ∼ 10-3 S/cm at 450°C in the composition 0.40LiCl-0.12ZnO-0.48SiO2, which is half an order of magnitude higher than that of the same composition melt-quenched glass.
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Ceramics and Composites
- Condensed Matter Physics
- Materials Chemistry