Solid-solid interface bonding of cathode active material and solid electrolyte by water vapor heating

2023 Fiscal Year Final Research Report

• Project/Area Number: 20H02451
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Review Section: Basic Section 26030:Composite materials and interfaces-related
• Research Institution: Osaka University
• Principal Investigator: Kozawa Takahiro 大阪大学, 接合科学研究所, 助教 (40734158)
• Project Period (FY): 2020-04-01 – 2024-03-31
• Keywords: 水蒸気 / 固体電解質 / ナノ粒子 / 結晶化 / 多孔質粒子 / 微構造制御 / 粒成長

Outline of Final Research Achievements

Focusing on the water vapor reaction on oxide surfaces, we aimed to realize solid-solid interface bonding between electrode active material and oxide-based solid electrolyte for lithium-ion batteries by water vapor heating. As a result, we succeeded in synthesizing a maze-like porous oxide with high-capacity anode performance by accelerating particle bonding and inserting conductive carbon nanoparticles into it to improve the cycle performance. We also found that structural changes occur on the surface of the cathode active material during heating in water vapor. Furthermore, the ultrafine particles of the oxide-based solid electrolyte were prepared, and its recrystallization was accelerated by water vapor heating. Composite electrodes were prepared by compositing the electrode active material with oxide-based solid electrolyte nanoparticles and were confirmed to work in an all-solid-state half-cell.

Free Research Field

無機材料科学

Academic Significance and Societal Importance of the Research Achievements

固体微粒子どうしの低温接合が水蒸気加熱プロセスで実現したことは、無機材料科学分野における新たな接合手法として期待され、その適用範囲の拡張が想定される。また、コンポジット電極の作製において、電極活物質と固体電解質との低温接合から界面での異相形成は抑制されると考えられる。水蒸気加熱プロセスは汎用的な技術であるため、バルク型全固体電池の実用化の加速に寄与できると考えられる。