123rd General Meeting of the KCS

Type Oral Presentation
Area Oral Presentation for Young Physical Chemists II
Room No. Room 305+306
Time THU 10:50-10:59
Code PHYS2.O-6
Subject Theoretical Studies on the Li-ion Conductivity of Solid-State Electrolytes: Li6-xPS5-xCl1+x
Authors Byeongsun Jun, Sang Uck Lee*
Department of Bionano Engineering, Hanyang University, Korea
Abstract The safety issue of Li-ion battery (LIB) has been extremely emerged as the increase in size of LIBs for electrical cars and devices because of flammable organic electrolytes. After discovering Li superionic conductors, such as Li10GeP2S12 (LGPS) and Li7La3Zr2O12 (LLZO), huge of researches have been promoted to replace organic electrolytes with nonflammable ceramic solid electrolytes. Argyrodites Li6PS5Cl is also a candidate material for all-solid-state rechargeable LIBs with a high Li-ion conductivity of almost 0.1 to 1 mS/cm. However, it is necessary to improve the Li-ion conductivity of this material to use in commercial LIBs. In this work, we theoretically elucidated the Li-ion conductivity significantly increased as the amount of Li-ion is changed (both Li excess and shortage structures). We designed the crystal structures by controlling ratio x in Li6-xS5-xCl1+x. The calculated Li-ion conductivity at 300 K was 9.24 mS/cm, 0.02 mS/cm, 6.72 mS/cm and 35.01 mS/cm for Li6.25PS5.25Cl0.75, Li6PS5Cl, Li5.875PS4.875Cl1.125 and Li5.75PS4.75Cl1.25, respectively. We expect the increased conductivity was originated from lowered energy barriers of the concerted Li-ion diffusion. Our results provide a possibility of improving alkali-ion conductivity of superionic conductors by controlling the amount of Li-ion in the crystal structures.
E-mail bsjun@cms.hanyang.ac.kr