Thermal evolution of NASICON type solid-state electrolytes with lithium at high temperature via in situ scanning electron microscopy

Abstract

We present the thermal evolution of two NASICON-type ceramics namely LATP (Li_1+xAl_xTi_2−x(PO₄)₃) and LAGP (Li_1+xAl_xGe_2−x(PO₄)₃) by monitoring the electrode–electrolyte interfaces (i.e., Li/LATP and Li/LAGP) at temperatures up to 330 °C via in situ scanning electron microscopy, post-mortem energy-dispersive spectroscopy, and X-ray diffraction. Upon melting of Li and contacting electrolytes, LAGP decomposes completely to form Li based alloys, while LATP is partially decomposed without alloying.