Preparation of Li1.3Al0.3Ti1.7(PO4)3 solid electrolyte via a sol-gel method using various Ti sources

Abstract

In this study, LATP (Li1.3Al0.3Ti1.7(PO4)3) solid electrolyte is prepared by a sol-gel process using Ti(C2H5O)4, Ti(n-C3H7O)4 and Ti(n-C4H9O)4 as Ti sources to examine the influence of the Ti source on the electrochemical properties of produced LATP. LATP is successfully produced in all cases, however, AlPO4 impurity is formed in the Ti(n-C3H7O)4 and Ti(n-C4H9O)4 samples due to insufficient formation of Ti-O-Al network. In contrast, the AlPO4 formation is not observed in the Ti(C2H5O)4 sample. Also, the Ti(C2H5O)4 sample shows the highest sinterability and the largest grain size among the three samples. As a result, the Ti(C2H5O)4 sample shows the highest Li ion conductivity due to high grain boundary conductivity and less impurity phase. The selection of Ti source is a key to obtain high conductive LATP solid electrolyte.