安全電池実現のための適切添加剤を用いた先端的非引火性電解液の理論的設計

使用适当的安全电池添加剂的先进不可燃电解质的理论设计

• 批准号: 19F19040
• 负责人: 長岡 正隆
• 金额: $ 0.96万
• 依托单位: Nagoya University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for JSPS Fellows
• 财政年份: 2019
• 资助国家: 日本
• 起止时间: 2019-04-25 至 2021-03-31
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-19F19040/
• 关键词: Computational design; Nonflammable electrolyte; Dilution; SEI film formation; Red Moon methodology

The main goal of this study is to design computationally an advanced non-flammable electrolyte for a practical safe Li-ion batteries. For that, we focused on the dilution the highly salt-concentrated (HC) electrolyte based on non-flammable trimethyl-phosphate (TMP) solvent. First, we aimed to investigate the microscopic mechanism of the solid electrolyte interphase (SEI) layer formation in HC TMP-based electrolyte. Using Red Moon methodology, it was revealed that a large amount of salt anions is localized on the SEI surface in HC electrolyte, enhancing the network formation of a dense inorganic layer with SEI salt-derived species. Next, we aimed to “dilute” such HC TMP-based electrolyte in order to address its low ionic conductivity and high viscosity. For that, new hydrofluoroethers (HFEs) were designed with high degree of fluorination. Using MD and QM calculations, self-diffusion constant of Li+ and the ionic conductivity should be significantly improved by dilution with bis(1,1,2,2-tetrafluoro ethyl) ether (B2E) and bis(pentafluoro ethyl) ether (BPE) compared to other common HFE diluents. In addition, HFEs have high ability to form a localized-concentrated electrolyte in HC TMP-based solution, leading to high expectation for the formation of a stable and a compact inorganic SEI film. Finally, the elasticity of the SEI layer was investigated through the microscopic analysis of the composition effect of the SEI on its mechanical properties. The ductility of the SEI were evaluated as well as the role of each electrolyte compound on the SEI stability.

这项研究的主要目的是在计算上为实用的安全锂离子电池设计高级非易燃电解质。为此，我们集中在基于非易易易光三甲基磷酸（TMP）溶液的高盐浓缩（HC）电解质上的稀释液。首先，我们旨在研究基于HC TMP的电解质中固体电解质相（SEI）层形成的显微​​机制。使用红色月亮方法，可以发现大量盐阴离子位于HC电解质中的SEI表面上，从而增强了具有SEI盐衍生物种的致密无机层的网络形成。接下来，我们旨在“稀释”此类基于HC TMP的电解质，以解决其低离子电导率和高粘度。为此，设计了新型的氢氟心（HFE），其氟化量高。使用MD和QM计算，与其他常见的HFE稀释剂相比，LI+的自扩散常数应通过BIS（1,1,1,2,2-二氟乙基）醚（B2E）（B2E）（B2E）（B2E）（B2E）（B2E）（B2E）（B2E）（B2E）（B2E）（B2E）（B2E）（B2E）（B2E）（B2E）和BIS（BIS（B2E）（BPE）显着提高离子电导率。此外，HFE具有很高的能力，可以在基于HC TMP的溶液中形成局部浓缩的电解质，从而高度期望形成稳定和紧凑的无机SEI膜。最后，通过微观分析SEI对其机械性能的组成效应研究了SEI层的弹性。评估了SEI的延展性以及每种电解质化合物在SEI稳定性上的作用。

项目成果

Theoretical Study of Salt Concentration Effect on SEI Film Formation in Non-Flammable Electrolyte

不可燃电解液中盐浓度对SEI膜形成影响的理论研究

• 发表时间: 2019
• 作者: A. Bouibes;N. Takenaka;S. Saha;M. Nagaoka
• 通讯作者: M. Nagaoka

Microscopic Mechanism of SEI Layer Formation in Highly Concentrated Electrolytes Based on the Nonflammable Trimethyl Phosphate Solvent

基于不可燃磷酸三甲酯溶剂的高浓度电解质中 SEI 层形成的微观机制

• 发表时间: 2019
• 作者: A. Bouibes;N. Takenaka;S. Saha;M. Nagaoka
• 通讯作者: M. Nagaoka

Microscopic Mechanism of SEI Film Formation in Highly Concentrated Electrolytes Based on Nonflammable Trimethyl Phosphate Solvent

基于不易燃磷酸三甲酯溶剂的高浓度电解液中SEI膜形成的微观机制

• 发表时间: 2019
• 作者: A. Bouibes;N. Takenaka;S. Saha;M. Nagaoka
• 通讯作者: M. Nagaoka

Microscopic Origin of the Solid Electrolyte Interphase Formation in Fire-Extinguishing Electrolyte: Formation of Pure Inorganic Layer in High Salt Concentration

• DOI: 10.1021/acs.jpclett.9b02392
• 发表时间: 2019-10-03
• 期刊: JOURNAL OF PHYSICAL CHEMISTRY LETTERS
• 影响因子: 5.7
• 作者: Bouibes, Amine;Takenaka, Norio;Nagaoka, Masataka
• 通讯作者: Nagaoka, Masataka