Hydroflux-assisted cold sintering: eutectic mixtures for boosting ionic conductivity in LATP solid-state electrolytes

Abstract

Superior electrical properties have been achieved for a Li_1.3Al_0.3Ti_1.7(PO₄)₃ (LATP) solid-state electrolyte (SSE) by using the novel hydroflux-assisted cold sintering process (HACSP) at 400 MPa, 200 °C and 90 minutes of sintering time. The use of the eutectic LiOH:LiNO₃ mixture, with 20 wt% content, as an hydroflux to assist the CSP has allowed to obtain a total ionic conductivity of 1.51 × 10⁻⁴ S cm⁻¹ and an activation energy of 0.366 eV. Using water to better distribute the hydroflux along the LATP structure was found to be critical to the homogeneity and properties of the sample.