Study of the lithium solid electrolytes based on lithium nitride chloride (Li 9N 2Cl 3)

Abstract

Lithium nitride chloride (Li 9N 2Cl 3) is a fast solid lithium ion conductor. According to analytical data from X-ray diffraction, DSC, DTA and conductivities, we found that a phase transition could take place when Li 9N 2Cl 3 is at 250 °C. Lithium solid electrolytes of Li 9 − x M x N 2Cl 3 (M = Na +, K +, Rb +, Cs +) were prepared. The ionic conductivities of the prepared samples were determined, from room temperature to 350 °C, using a PAR368-1 AC-impedance spectrometer, with frequency measurements varying from 4 Hz to 100 kHz. The experimental results showed that the ionic conductivities could be of the order of 10 −1S cm −1 at 350 °C, with low electronic conduction and a high thermodynamic decomposition voltage at room temperature. The conductivity of Li 9 − x M x N 2Cl 3 depends on the ionic radius of Na +, K +, Rb + and Cs + ions substituted for the Li + ion. We studied the atomic transport process of lithium ion conductors of Li 9 − x M x N 2Cl 3 using X-ray diffraction and differential thermal analysis.