Study on (100-x)(70Li2S-30P2S5)-xLi2ZrO3 glass-ceramic electrolyte for all-solid-state lithium-ion batteries

A novel glass-ceramic electrolyte of (100-x)(70Li 2 S-30P 2 S 5 )-xLi 2 ZrO 3 (x = 0, 1, 2, 5) is successfully prepared by a vibratory ball-milling method and followed by a heat-treatment process. Composition of the ternary sulfide electrolyte and the heat-treatment process are optimized by physical characterizations and electrochemical measurements. The testing results show that the optimal substitution quantity of Li 2 ZrO 3 into the Li 2 S-P 2 S 5 electrolyte substrate is 1 mol %. An appropriate heat-treatment temperature of 99(70Li 2 S-30P 2 S 5 )-1Li 2 ZrO 3 glass-ceramic electrolyte is 285 °C. Among the as-prepared ternary electrolyte samples, 99(70Li 2 S-30P 2 S 5 )-1Li 2 ZrO 3 glass-ceramic electrolyte may exhibit the highest conductivity of 2.85 × 10 −3  S cm −1 at room temperature, which is much higher than that of the 70Li 2 S-30P 2 S 5 glass-ceramic electrolyte. Compared to that of the all-solid-state lithium-ion battery of LiCoO 2 /70Li 2 S-30P 2 S 5 /In-Li, discharge capacities of all-solid-state lithium-ion battery of LiCoO 2 /99(70Li 2 S-30P 2 S 5 )-1Li 2 ZrO 3 /In-Li may increase 41.0% at the 10th charge-discharge cycle and 21.9% at the 50th charge-discharge cycle, respectively. Furthermore, electrochemical impedance spectroscopy (EIS) analyses of all-solid-state lithium-ion batteries reveal that addition of Li 2 ZrO 3 into the Li 2 S-P 2 S 5 electrolyte substrate may decrease the interfacial resistance between the electrodes and solid electrolyte . The improvement of electrochemical performances of 99(70Li 2 S-30P 2 S 5 )-1Li 2 ZrO 3 glass-ceramic electrolyte is ascribed to both the stable crystal structure and a high lithium-ion diffusion coefficient of Li 2 ZrO 3 .