Influence of Al layer thickness on Li6.6Al0.05La3Zr1.75Nb0.25O12 solid electrolyte | Li anode interface in all-solid-state batteries

Abstract The critical issue of the interface between Li anode and solid electrolyte based on Li7La3Zr2O12 can be addressed by using a buffer layer. Ceramic samples were covered with Al layers of various thickness – 10, 50 and 150 nm using vacuum deposition. It was established that the deposition of 150 nm Al reduces interface resistance between solid electrolyte and Li and leads to a faster formation of the stable interface at room and elevated temperatures. The influence of constant current flow and heating on the tight and uniform interface formation between Li6.6Al0.05La3Zr1.75Nb0.25O12 and Li was studied. Heating leads to an increase in the contact area between Li and Al, which cannot be easily achieved at low temperatures even under applied current. According to X-ray diffraction method, Raman spectroscopy and scanning electron microscopy, no visible degradation processes occurred during the storage and operation of symmetric cells. Aluminum deposition with the layer thickness of 150 nm on the ceramic surface with preheating improves the contact with Li anode and can be used to create all-solid-state lithium power sources.