在金属表面解读以太和化以太电解质的分解机制:来自CMD和AIMD模拟的见解
Fuming Du1, Tuo Ye2, Tiezheng Lv2
1School of Materials Science and Engineering, Hunan Institute of Technology, Hengyang 421002, China.
The journal of physical chemistry. B
|August 20, 2024
概括
化以太电解质通过形成保护性固体电解质间相 (SEI) 层来增强金属电池. 分子动力学模拟揭示了溶剂化如何影响SEI组成,这对电池性能至关重要.
科学领域:
- 电化学 电化学 电化学
- 材料科学 材料科学 材料科学
- 计算化学计算化学
背景情况:
- 金属电池 (LMB) 提供高能量密度,但患有树生长和周期寿命低.
- 化以太基电解质对提高LMB性能有希望.
- 金属上的固体电解质介相 (SEI) 形成机制至关重要,但尚未完全理解.
研究的目的:
- 通过使用化以太电解质,研究金属上的SEI形成机制.
- 阐明溶剂化在电解质分解和SEI结构中的作用.
- 了解电化学双层 (EDL) 对SEI形成的影响.
主要方法:
- 经典和初始分子动力学模拟.
- 电子预测状态密度和电荷转移动态的分析.
- 研究LiFSI (二 (甲) 硫) 胺) 在DEE,F5DEE和F2DEE中与金属的分解.
主要成果:
- F5DEE电解质形成富含FSI的溶解;F2DEE电解质形成富含溶剂的溶解.
- 在阳极附近的EDL中的FSI离子耗尽因溶剂化而变化 (F5DEE < DEE < F2DEE).
- DEE产生无机SEI;F2DEE产生有机丰富的SEI;F5DEE产生具有高LiF含量的无机丰富的混合SEI.
结论:
- 溶剂化显著影响LMB中的EDL结构和SEI组成.
- 溶剂减少和LiFSI分解的程度决定了SEI的无机/有机性质.
- 定制化功能组是控制SEI特性和增强LMB稳定性的关键.
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