Superionic Conductivity in a Lithium Aluminum Germanium Phosphate Glass–Ceramic

In this paper, processing and characterization of sheet, pellet, and membrane specimens based on the lithium aluminum germanium phosphate (LAGP) glass–ceramic system is reported. X-ray diffraction patterns exhibited the presence of as the primary phase. Increasing heat-treatment temperature from led to the precipitation of an impurity phase, , and a large increase in LAGP grain size. The highest total conductivity of the LAGP glass–ceramic material at was obtained by crystallizing the glass sheet at for . The total conductivity of the specimen was in the range of in the temperature range. The pelletized specimen prepared from the glass–ceramic powder and sintered at for exhibited a slightly lower conductivity at . The membrane conductivity was above in the temperature range. High grain boundary conductivity is apparent in the LAGP glass-ceramic materials. The impurity phases and were attributed to a characteristic nonlinearity in the Arrhenius plots and mediated the transport of the lithium ion, which is associated with a higher activation energy.