电双层 (EDL) 在电池中的多元件电解质减少和固体电解质间相 (SEI) 形成的影响
Qisheng Wu1, Matthew T McDowell2, Yue Qi1
1School of Engineering, Brown University, Providence, Rhode Island 02912, United States.
Journal of the American Chemical Society
|January 23, 2023
概括
一个新的模型揭示了电双层 (EDL) 如何影响离子电池中的固体电解质交相 (SEI) 形成. 了解EDL效应对于通过控制SEI组成来优化电池性能和耐用性至关重要.
科学领域:
- 电化学
- 材料科学
- 电池技术
背景情况:
- 稳定的固体电解质间相 (SEI) 形成对于离子电池的性能和寿命至关重要.
- 电极附近的电双层结构 (EDL) 显著影响SEI的组成,但仍然不太了解.
- 乙烯碳酸盐 (FEC) 是一种常见的添加剂,用于制造含有F的SEI成分,如LiF.
研究的目的:
- 调查EDL对不同电解质系统中的SEI形成的影响.
- 阐明FEC在碳酸盐和以太电解质中的不同作用.
- 解释FEC在以太基电解质中观察到的依赖温度的影响.
主要方法:
- 使用一个新开发的计算模型来模拟SEI的形成.
- 在两个不同的电解质系统中分析了SEI形成:碳酸和以太基.
- 在不同的条件下检查EDL中的FEC和离子的行为.
主要成果:
- 在碳酸盐电解质中减少的唯一含有F的物种是FEC,而离子从EDL中除外.
- 在以太基电解质中,FEC和离子 (TFSI-) 都在EDL中竞争减少.
- 在EDL内部的竞争解释了以太基电解质在低温下FEC的增强有效性.
结论:
- 在SEI形成机制中,EDL结构起着关键作用.
- 将EDL效应纳入模拟和实验对于预测和控制SEI属性至关重要.
- 这种理解可以指导开发更稳定,更耐用的离子和金属电池.
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