Reactivity evaluation of NASICON-type solid electrolyte LATP, LAGP and Olivine-type cathode LCP

The chemical reactivity and thermal stability of the NASICON-type Li1.3Al0.3Ti1.7(PO4)3 (LATP) and Li1.5Al0.5Ge1.5(PO4)3 (LAGP) solid lithium-ion conductive materials with the Olivine-type LiCoPO4 (LCP) cathode active material were evaluated. The LATP or LAGP and LCP powders were mixed, uniaxially-pressed, and heat-treated in the air at 800, 900, and 1000 degrees C for 10 h. The obtained sintered bodies were crushed into powders, then characterized by X-ray diffraction and scanning electron microscopy together with energy-dispersive X-ray spectroscopy. LAGP-LCP decomposes and melts at 800 degrees C, and produces some different phases. On the other hand, LATP-LCP produces different phases at 900 degrees C, although it does not produce a different phase at 800 degrees C, thus forming a dense microstructure. This shows that the LATP-LCP system is an excellent combination of electrolyte and cathode active material that can be sintered in air. This mixed composite can also be used as a composite electrode in bulk-type lithium-ion batteries.