了解Li2S固态电池涂层中的离子扩散机制:为多尺度模拟开发定制的反应力场
Maddalena D'Amore1, Moon Young Yang2, Tridip Das2
1Dipartimento di Chimica, Università di Torino, Via P. Giuria 5, Torino 10125, Italy.
The journal of physical chemistry. C, Nanomaterials and interfaces
|December 6, 2023
概括
硫化 (Li2S) 的新反应力场可以进行大规模的模拟. 这使得研究电池的保护涂层成为可能,这对于理解电极-电解质接口至关重要.
科学领域:
- 材料科学 材料科学 材料科学
- 计算化学计算化学
- 电化学 电化学 电化学
背景情况:
- 硫化 (Li2S) 是离子电池的保护涂层的一个有前途的材料.
- 在相关尺度 (>10,000原子,>纳秒) 上模拟Li2S是量子力学计算上不可行的.
- 需要精确的建模来理解Li2S在电极-电解质接口上的行为.
研究的目的:
- 为Li2S系统开发一个反应力场 (ReaxFF).
- 用反应分子动力学 (RMD) 来研究Li2S中的扩散机制和导电性.
- 为了能够对电池中的Li2S涂层进行预测模拟.
主要方法:
- 基于密度函数理论 (DFT) 计算 (PBE0/TZVP和M062X/TZVP) 为Li2S开发了一个ReaxFF.
- 进行了高达20 ns的RMD模拟,以研究Li2S扩散作为空隙密度的函数.
- 验证的模型系统结果与ab initio分子动力学 (AIMD).
主要成果:
- 开发的ReaxFF准确地预测了Li2S扩散和导电性,与实验数据有很好的一致性.
- RMD模拟成功捕获了扩散机制,并确定了激活障碍.
- 该ReaxFF可实现实用的RMD模拟在10-100纳米和20纳米的尺度.
结论:
- 新的ReaxFF为Li2S是一个强大的工具,用于大规模模拟电池组件.
- 这种方法有助于对阳极电池与超离子电解质的接口进行预测研究.
- 模拟提供了关于Li2S作为防护涂层的性能的见解.
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