Two-step sintering technique of LATP ceramic electrolyte with enhanced key parameters

Abstract

A new preparation technique of Li1.3Al0.3Ti1.7(PO4)3 (LATP) ceramics is focused on optimisation of weight fractions of LATP glass additives into green ceramic powder followed by enhanced two-step sintering to improve key parameters of relative density and ionic conductivity of LATP solid-state electrolyte (SSE) pellets. The LATP SSE has been obtained with the relative density and ionic conductivity of (96.3±0.2)% and (8.0±0.2)×10−4 S/cm, respectively, after pre-annealing at 570°C for 6 h and sintering at 900°C for 6 h of mixed glass and ceramic powders with an optimal weight ratio of 5%/95%. Notably, the Li||LATP||Li symmetric cell using such LATP SSE could maintain voltage stability for 300 h, and the Li||LATP||NCM111 full cell exhibits good cycling performance over 100 cycles with capacity above 100 mAh/g (capacity retention of 79.1%). The proposed simple technique seems to be effective to improve the relative density and ionic conductivity thus acclerating the development of all-solid-state lithium metal battery.