Effect of mold pressure on compaction and ion conductivity of all-solid-state batteries revealed by the discrete element method

JOURNAL OF POWER SOURCES

卷:508

Article

So, Magnus¹  Inoue, Gen¹  Hirate, Ryusei¹  Nunoshita, Keita¹  Ishikawa, Shota¹  Tsuge, Yoshifumi¹ 

[1] Kyushu Univ, Fac Engn, Dept Chem Engn, Nishi Ku, 744 Motooka, Fukuoka 8190395, Japan

关键词: Solid electrolyte;    Plastic deformation;    Fabrication;    Stress;    Tortuosity factor;   

DOI  :  10.1016/j.jpowsour.2021.230344

来源: Elsevier

【 摘 要 】

All-solid-state batteries (ASSBs) have enabled the development of compact and safer batteries with solid and nonflammable electrolytes. However, their practical applications are limited due to the difficulty associated with solid electrolytes (SEs) in forming a connected network for ionic transport and sufficient contact area on the active material (AM). Lithium-phosphate sulfides (LPS) are promising materials for SEs in ASSBs because they can plastically deform and form a close contact with AM. Herein, we develop and numerically implement a discrete element model for cold pressing that considers plastic deformation. Particle compaction proceeds in three steps, i.e., breakage of aggregates, particle rearrangement, and particle consolidation by plastic deformation. In addition, localized stresses easily deform the SE particles, thereby resulting in a force concentration between the AM particles. A higher mold pressure increases the relative density and contact area between the AM and SE. The relative density and ionic conductivity results agree well with the experimental results. We demonstrate a new correlation for ionic conductivity based on percolation theory from our observation of poor connectivity between SE aggregates. We believe that this research will help us understand the interactions during fabrication that can guide the development of future ASSBs.

【 授权许可】

Free