In this work, the correlation between density and ionic conductivity of the Na3Zr2Si2P1O12 NASICON system is investigated. To control the densities of sintered pellets, particles with sizes of about 670 nm and 360 nm were used. XRD, SEM, density measurement, and electrochemical impedance spectroscopy were used to study the properties of the samples. The relative densities (theoretical density = 3.27 g/cm3) of samples were measured at 91% and 96% for the 670 nm and 360 nm particles, respectively. Impedance spectroscopy data showed a significant increase of ionic conductivity in proportion to the density. The results indicates that the ionic conductivity of the sample not containing free zirconia from jet milling processing is higher than that of the sample containing free zirconia prepared by only ball-milled powder at the same density.

Keywords: NASICON, Solid electrolyte, Density and Ionic conductivity.