Pursuit of magic number for extension of potential window of electrolyte solutions
Project/Area Number |
19K22238
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Research Category |
Grant-in-Aid for Challenging Research (Exploratory)
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Allocation Type | Multi-year Fund |
Review Section |
Medium-sized Section 36:Inorganic materials chemistry, energy-related chemistry, and related fields
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Research Institution | Doshisha University |
Principal Investigator |
Doi Takayuki 同志社大学, 理工学部, 教授 (30404007)
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Project Period (FY) |
2019-06-28 – 2021-03-31
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Project Status |
Completed (Fiscal Year 2020)
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Budget Amount *help |
¥4,940,000 (Direct Cost: ¥3,800,000、Indirect Cost: ¥1,140,000)
Fiscal Year 2020: ¥1,690,000 (Direct Cost: ¥1,300,000、Indirect Cost: ¥390,000)
Fiscal Year 2019: ¥3,250,000 (Direct Cost: ¥2,500,000、Indirect Cost: ¥750,000)
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Keywords | リチウムイオン電池 / 濃厚電解液 / 高濃度 / 溶媒和 / 正極 / 二次電池 / 電解液 / 酸化 / 高電圧 |
Outline of Research at the Start |
5 V級リチウムイオン電池の実現に向けて酸化側の電位窓が広い電解液を開発し、その溶液構造と電位窓の相関を明らかにする。すでに4.6 Vまでの電位窓拡大に成功しているため、この三元系エステル電解液を足掛かりとして新規エステル溶媒とLi塩を用いて電解液組成を詳細に検討し、酸化側の電位窓を調べる。また、得られた電解液の溶液構造を調べることにより、特に異種溶媒分子間の双極子-双極子相互作用に注目して電位窓との相関を解析する。
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Outline of Final Research Achievements |
Electrolyte solutions for lithium ion batteries have solvent systems composed of cyclic and chain carbonic acid esters, and have solvent composition ratios (magic number) that specifically exhibit high stability against oxidation. As this cause, we focused on a dipole-dipole interaction between different solvent molecules. Electrolyte solutions with high oxidative stability were developed, and the solution structure was investigated to use the imperceptible interaction as a new design principle for further extension of the potential window. For three types of positive electrode materials such as LiNi0.8Co0.1Mn0.1O2, we found electrolyte systems that showed superior charge/discharge cycle characteristics, and investigated the solvation number and the concentration of free solvents to correlate with charge/discharge performance. Based on the results, three findings were obtained as the fundamental design principle for extending the potential window of electrolyte solutions.
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Academic Significance and Societal Importance of the Research Achievements |
低炭素社会の実現に向けてリチウムイオン電池の高容量化や高電圧化が必要不可欠であるが,本研究は,これを実現するための高性能電解液の開発とその設計原理を提示することを目指した点に社会的意義がある。また、これまで、電解液の電位窓拡大には、溶媒および電解質自身の耐酸化還元性向上,および濃厚化によるイオン-双極子相互作用の強化が有効と考えられてきたが、本研究では異種溶媒分子間の双極子-双極子相互作用に注目し、これが電解液の電位窓拡大に与える効果を検証した点に学術的意義がある。本研究で得られた知見は、マグネシウム二次電池やナトリウム二次電池などの次世代蓄電池用電解液の開発に対しても有用と考えられる。
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Report
(3 results)
Research Products
(1 results)