Synergistic Effect of Al and Zn Co-Doping on the Structure and Ionic Conductivity of LLZO /

Abstract

In our research, we were able to successfully synthesize Li6.38La3Zr2Al0.32Zn0.3O12 using solid state synthesis. Notably we avoided high temperature solid state synthesis, which often result in problems like phase instabilities and low ionic conductivities. AL has been shown to increase the phase stability of cubic LLZO in various works. Zn has been reported to increase number of Li+1ion vacancies, since they provide Li ions with more pathways which increases ionic conduction. Our primary goal was to find out how cooping would affect the densification and ionic conductivity of parent ceramic oxide. We witnessed an overall increase in the ionic conductivity. Numerous factors can be responsible for the increase in ionic conductivity. First, greater ion transport occurred due to increased densification of ceramic material and reduced porosity. Second, stabilization of cubic garnet phase guaranteed the high ionic conductivity associated with it. Additionally, rise in Li ion vacancies also increased general mobility of ions inside the crystal lattice. Furthermore, co-doping also reduced the grain boundary resistance significantly which is a bottle neck in ceramic materials. In summary this study highlights the significant advancements made in synthesis and testing of Li6.38La3Zr2Al0.32Zn0.3O12 showing how strategic use of co-doping can effectively increase ionic conductivity and stability. This research paves the way for the future developments in solid state batteries ultimately contributing to the ongoing hunt of more efficient and suitable energy storage solutions.