Synthesis of Li4Si(1–0.75x)MxO4 (M = Yttrium) solid electrolytes for Li-ion batteries

Abstract

The investigation of Lithium-ion conductor Li₄SiO₄ solid electrolyte doped with Yttrium as a trivalent (Y³⁺) rare earth element prepared through the mechanical synthesis of the solid-state route as a partial substitution in Silicon (Si_1-xY_x). Structural analysis and peak intensities confirm the increase in doping of Yttrium in Li₄SiO_4, showing the monoclinic structure in the XRD pattern. A pure phase of Li₄SiO₄ was obtained. The W–H plot identifies the strain and particle size of the samples, which is between 21 to 50 nm. Functional groups for the transmission peaks are noted from FT-IR analysis. TGA analysis gives the detailed weight loss for pure (21.72%) and Y³⁺ doped Li₄SiO₄ (7.52%). DSC gives the exothermic and endothermic values of the compound. Decomposition of the electrolyte through the potential of 1.175 V was found from LSV. The conductivity spectra show an increase in ionic conductivity of 5.36 × 10^–5 S cm⁻¹ at a weight ratio of 8% Yttrium doping at ambient temperature. The dielectric constant, loss, and relaxation time for the highest conducting electrolyte were characterized.