Conductivity and Mechanical Properties of Lithium-Conducting Ceramic Solid Electrolytes with the NASICON Structure

The electrochemical and mechanical characteristics of ceramic solid electrolytes Li1 + xAlxTi(Ge)2 – x(PO4)3 with the high Li-ionic conductivity and the NASICON crystal structure are considered. The ionic conductivity of solid electrolytes is studied by the method of electrochemical impedance spectroscopy in the frequency interval from 10 to 2 × 106 Hz. The transfer numbers of Li+ ions and the electronic conductivity are determined by potentiostatic chronoamperometry. The elastic and mechanical properties of ceramics are studied by the contact method by means of a probe microscope-nanohardness tester Nanoskan. The microhardness data obtained by comparable sclerometry and Young’s modulus determined based on cantilever approach curves are shown. The critical stress intensity factor for stresses of the first kind KIC is determined for ceramic solid electrolytes Li1 + xAlxTi(Ge)2 – x(PO4)3.