Effect of phase abundance and grain size on ionic conductivity of solid state latpelectrolyte

Li1.3Al0.3Ti1.7(PO4)3 (LATP) electrolyte was prepared within the temperature range of 700-1050 ℃. The structure characteristics (phase abundance and grain size) were investigated by X-ray diffraction analysis using MAUD program. The electrical properties (electronic and ionic conductivity) were measured by impedance spectroscopy using equivalent circuit based on brick-layer model to fit the data (Nyquist plot). Themaximum LATPcontentof95% was obtained at a preparation temperature of 1000°C. However, the ionic conductivity of the electrolyte showed a maximum value of 6.6×〖10〗^(-4) S cm^(-1)at a temperature of 950°C where the LATP phasehas high concentration of 85% as well as the largest grain size of 750 nm. Thus, structure/properties correlation proves that the ionic conductivity of the electrolyte is affected by both the abundance of LATP phase as well as its grain size.