Space-Charge-Mediated Superionic Transport in Lithium Ion Conducting Glass–Ceramics

This paper describes an investigation of the properties of superionic glass-ceramic specimens synthesized from the lithium-aluminum-germanium-phosphate system. The specimens were characterized using differential scanning calorimetry, X-ray diffraction, scanning electron microscopy, and impedance spectroscopy. The concentration of lithium oxide in the glass-ceramic formulations was the primary variable investigated. It is shown that the ionic conductivity of the specimens was dependent on the lithium oxide concentration. An optimized composition exhibited a conductivity approaching 10 ―2 S cm ―1 at around room temperature. The superionic conductivity in these specimens is attributed to the space-charge-mediated effect resulting from the presence of the dielectric Li 2 O phase. The specimens also displayed different conductivities during heating and cooling scans, referred to in this paper as hysteresis effect.

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