Chemical engineering approach to control of electrode-electrolyte junction interface of all solid state lithium battery

• Project/Area Number: 20H02501
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Review Section: Basic Section 27010:Transport phenomena and unit operations-related
• Research Institution: Tokyo Institute of Technology
• Principal Investigator: Taniguchi Izumi 東京工業大学, 物質理工学院, 准教授 (00217126)
• Project Period (FY): 2020-04-01 – 2024-03-31
• Project Status: Completed (Fiscal Year 2023)
• Budget Amount: ¥17,810,000 (Direct Cost: ¥13,700,000、Indirect Cost: ¥4,110,000); Fiscal Year 2023: ¥2,080,000 (Direct Cost: ¥1,600,000、Indirect Cost: ¥480,000); Fiscal Year 2022: ¥2,860,000 (Direct Cost: ¥2,200,000、Indirect Cost: ¥660,000); Fiscal Year 2021: ¥4,680,000 (Direct Cost: ¥3,600,000、Indirect Cost: ¥1,080,000); Fiscal Year 2020: ¥8,190,000 (Direct Cost: ¥6,300,000、Indirect Cost: ¥1,890,000)
• Keywords: 噴霧熱分解法 / 球状ナノ構造粒子 / 正極材料 / リチウム二次電池 / 全固体リチウム二次電池 / 高電位正極材料 / ナノ構造界面 / LiNbO3 / コーティング技術 / 全固体リチウムイオン二次電池 / 界面制御 / 噴霧乾燥法

Outline of Research at the Start

研究目的を達成するために、まず、申請者がこれまでに開発してきたリチウム二次電池正極材料の合成技術（噴霧熱分解法）を駆使して、酸化物系高電位正極材料、および硫黄過剰不定比組成の硫化銅系電極材料の合成を行う。さらに、噴霧熱分解法、噴霧乾燥法、さらには申請者が開発した合成技術である流動層滴下熱分解法を用いて、正極材料表面にリチウムイオン導電体薄膜の付与を試みる。
これにより、電極活物質-固体電解質の界面に様々なリチウムイオン導電体膜(緩衝層)を作製する新規薄膜コーティングプロセス技術の確立を目指す。
なお、このような技術開発は、全固体リチウム二次電池の開発・実用化に大きく貢献するものと期待される。

Outline of Final Research Achievements

Using the spray pyrolysis method, we synthesized sulfur-rich nonstoichiometric copper sulfide (CuSx+1, 0≦x≦1.0). Electrochemical measurements of these materials revealed that the material with the composition CuS1.58 had excellent electrochemical properties. Furthermore, the CuS1.58@ acetylene black composite exhibited an extremely large discharge capacity. Synthesis　of spherical nanostructured LiNi1/3Co1/3Mn1/3O2 particles and coating their surfaces with LiNbO3 and Li2Si2O5 were also carried out. Furthermore, we demonstrated that spherical porous LiCoPO4 microparticles could be successfully synthesized by spray pyrolysis with citrate additives.

Academic Significance and Societal Importance of the Research Achievements

高エネルギー密度を有する正極材料（CuS1.58）を見出したことは、全固体リチウム二次電池に限らず高エネルギー密度を有する蓄電池の開発にとって重要な成果である。さらに、全固体電池の正極材料として、LiNbO3 やLi2Si2O5をその材料表面にコーティングする際に、良好な接触界面を構築できる多孔質ナノ構造正極材料の新規な合成法を見出した点は学術的にも社会的にも意義のある成果と考えられる。

Research Products

• [Journal Article] Synthesis of porous C/Fe3O4 microspheres by spray pyrolysis with NaNO3 additive for lithium-ion battery applications (2023)
  • Author(s): Adi Akylbek, Taniguchi Izumi
  • Journal Title: Journal of Solid State Electrochemistry Volume: 27 Issue: 8 Pages: 2127-2137
  • DOI: 10.1007/s10008-023-05463-4
  • Peer Reviewed / Open Access
• [Journal Article] Synthesis of an Advanced Sulfur Cathode with a Porous Graphitic C/Fe3C Electrocatalyst and Three-Dimensional Current Collector for Li2S Batteries (2023)
  • Author(s): Adi Akylbek、Taniguchi Izumi
  • Journal Title: Energy & Fuels Volume: 37 Issue: 18 Pages: 14324-14333
  • DOI: 10.1021/acs.energyfuels.3c02072
  • Peer Reviewed / Open Access
• [Journal Article] Synthesis of LiCoPO4/C nanocomposite fiber mats as free-standing cathode materials for lithium-ion batteries with improved electrochemical properties (2022)
  • Author(s): Ayaulym Belgibayeva, Takeru Nagashima, Izumi Taniguchi
  • Journal Title: Electrochim Acta Volume: 419 Pages: 140400-140400
  • DOI: 10.1016/j.electacta.2022.140400
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Free-standing SiO2/C composite nanofiber mats as multi-functional interlayers for high-performance lithium battery with S-rich CuS1+x cathodes (2021)
  • Author(s): Ayaulym Belgibayeva, Zenta. Kawate, Izumi Taniguchi
  • Journal Title: Materials Letters Volume: 291 Pages: 129595-129595
  • DOI: 10.1016/j.matlet.2021.129595
  • Peer Reviewed
• [Journal Article] Insights into the improved electrochemical performance of lithium sulfur battery with free-standing SiO2/C composite nanofiber mat interlayer (2021)
  • Author(s): Ayaulym Belgibayeva, Izumi Taniguchi
  • Journal Title: J. Power Sources Volume: 484 Pages: 229308-229308
  • DOI: 10.1016/j.jpowsour.2020.229308
  • Peer Reviewed
• [Journal Article] Sulfur-rich CuS1＋x cathode for lithium batteries (2021)
  • Author(s): Gulnur Kalimuldina, Izumi Taniguchi
  • Journal Title: Materials Letters Volume: 282 Pages: 128705-128705
  • DOI: 10.1016/j.matlet.2020.128705
  • Peer Reviewed
• [Presentation] 噴霧熱分解法を基盤としたピロリン酸コバルトリチウムの合成と そのリチウム二次電池特性 (2023)
  • Author(s): 水口博貴、谷口泉
  • Organizer: 化学工学会第54回秋季大会