국립 부경대학교

Pukyong National University Research Team Discovers Anion Separation Phenomenon in All-Solid-State Batteries

-Research by Professor Jeong Seong-cheol’s Team Published in the UK Royal Society of Chemistry Journal

-Localized Anion Separation Phenomenon Causes High Ionic Conductivity

Pukyong National University (President Bae Sang-hoon) announced that Professor Jeong Seong-cheol’s (Department of Physics) research team discovered a phenomenon in which monovalent and divalent ions are locally separated in the Li6PS5Cl solid electrolyte of the argyrodite structure used in all-solid-state batteries.

The research team, led by Professor Jeong Seong-cheol, Postdoctoral Researcher Lee Se-ho (G-LAMP Project), and Ph.D. student Jeon Tae-gon (Department of Physics), revealed through first-principles calculations that the difference in lithium mobility due to the anion domain caused by the anion local separation discovered in the Li6-xPS5-xClBrx solid electrolyte is the cause of the high ion conductivity in the Li6PS5Cl series solid electrolytes.

Solid electrolytes based on the argyrodite structure have excellent ion conductivity, good cost-effectiveness of raw materials, and ease of synthesis, leading to active research in this field.

Professor Jung’s team found that in this study, lithium ions are more concentrated in the S2- divalent anion region than in the Cl- and Br- monovalent anion regions, leading to the effective stabilization of the argyrodite structure. Additionally, lithium ions in the divalent anion region showed low mobility due to their strong binding with the anions, while lithium ions in the monovalent anion region exhibited higher mobility due to weaker binding with the anions. Through this, they identified that the lithium diffusion mechanism in argyrodite solid electrolytes relies on the anion regions.

Professor Jung Seong-cheol stated, “This study reveals that the well-known disordered arrangement of anions in Li6PS5Cl-based argyrodite solid electrolytes is actually related to the local separation of anions, providing a new perspective for understanding the high conductivity of argyrodite solid electrolytes.”

Meanwhile, this research was conducted with support from the Ministry of Education’s G-LAMP project and was recently published in the prestigious international journal <Journal of Materials Chemistry A>(IF=10.8) by the UK Royal Society of Chemistry, which covers the fields of chemistry, physics, and materials science.