Crystallization kinetics and structural studies of Li1.25Al0.5Ge1.5P2.75Mo0.25O12 (LAGPM) glass/glass-ceramics based solid state electrolyte

The crystallization kinetics and structural behaviour of Li1.25Al0.5Ge1.5P2.75Mo0.25O12 (LAGPM) glass/glass-ceramics system have been investigated. Glass was prepared by melting the calcined initial charges at 1450 °C using conventional quenching technique. From model free crystallization kinetics, the value of activation energy obtained was 165 kJ mol−1. The nature of nucleation and the dimension of growth of the NASICON crystal were estimated from the kinetics parameters. This glass was converted to glass-ceramics using suitable heat schedule as per DTA data. X-ray diffraction analysis confirmed the formation of desired NASICON phase along with AlPO4 as minor phase. Raman spectroscopy and EXAFS studies showed that molybdenum ions moved to the desired tetrahedral sites in glass-ceramic. The dimension of the crystal growth was clearly seen in SEM image of LAGPM glass-ceramics sample. Impedance spectroscopy was carried out to evaluate the dc ionic conductivity (σdc) of LAGPM glass-ceramics based solid electrolyte. The value of σdc evaluated from the Nyquist plot was found as ∼4.64 × 10−4 S.cm−1 at room temperature. •Non-isothermal crystallization kinetics studies revealed the three dimensional bulk crystallization in LAGPM glass.•LAGPM solid state electrolyte was synthesised through glass route.•Rietveld refinement was carried out to quantify the phases.•EXAFS analysis confirmed the co-ordination number of molybdenum ions.•The d.c. ionic conductivity was measured using impedance spectroscopy.