Synthesis method and characterization of doped NASICON based phosphate (LATP) solid electrolyte /

Abstract

Solid-state electrolytes have emerged as a viable substitute for liquid electrolytes in lithium ion batteries, holding promise for improved safety, energy density, and cyclic performance. Solid-state electrolytes have the potential to address the challenges associated with conventional liquid electrolytes, opening the door for high-performance batteries to become commercialized. Among the various solid-state electrolytes, the NASICON-type electrolyte Li1.3Al0.3Ti1.7P3O12 (LATP) is particularly attractive due to its high ionic conductivity, excellent stability, and impressive air stability. This research project focuses on the synthesis of a co-doped LATP electrolyte through the solid-state method, with the dopants targeted at the Titanium and Phosphate sites, respectively. The study examines the impact of cobalt and silicon on the phase composition, microstructure, and ionic conductivity of the LATP solid-state electrolyte. X-ray photoelectron spectroscopy confirms the presence of silicon and cobalt dopants, with peaks indicating Co in the +2 oxidation state and Silicon in the +4 oxidation state. The X-ray diffraction analysis confirms a highly crystalline structure. The optimal cobalt and silicon dopant content leads to an ionic conductivity of 5.45 x 10-5 S cm-1 at room temperature. These findings suggest that an ideal level of cobalt doping results in better ionic conductivity than pristine LATP.