Microstructure and ion conductivity of Al-LLZO solid electrolyte prepared by molten salt and cold sintering process

Li7La3Zr2O12 as a feasible solid electrolyte in all solid-state batteries owns a highly active area of research due to the high Li+ conductivity and the high stability against the metallic Li. The Li6.25Al0.25La3Zr2O12 powders were synthesized by using the molten salt method to reduce calcination temperature. And cold sintering was served to densify the powders and obtain the solid-state electrolyte, which could remedy the shortcoming of the conventional sintering. The influence of cold sintering temperature and holding time on the microstructures and electrochemical properties of Li6.25Al0.25La3Zr2O12 electrolyte were explored. The cubic block grains were observed that had a sufficient impact on the ionic conductivity. The results showed that the density and Li+ conductivity of Li6.25Al0.25La3Zr2O12 solid electrolyte were 3.31 g cm(-3) and 9.13 mu S cm(-1), respectively. This work deepens the understanding of solid electrolytes prepared by the cold sintering process and shows the potential of this technology in terms of electrolytes preparation.