纳米颗粒的缓慢电压放松使用化学机械核心外模型
Lukas Köbbing1,2, Yannick Kuhn1,2, Birger Horstmann1,2,3
1Institute of Engineering Thermodynamics, German Aerospace Center (DLR), Wilhelm-Runge-Straße 10, Ulm 89081, Germany.
ACS applied materials & interfaces
|November 26, 2024
概括
离子电池中的阳极由于巨大的体积变化而表现出电压歇斯底里. 一个新的化学机械模型使用核心外结构解释了这种歇斯底里,改善了充电状态估计,以提高电池性能.
科学领域:
- 材料科学 材料科学 材料科学
- 电化学 电化学 电化学
- 机械工程 机械工程
背景情况:
- 阳极为离子电池提供高容量,但在化/脱过程中会发生显著的体积变化.
- 这些体积变化导致电压歇斯底里,效率降低,热量产生和复杂的电荷状态估计.
- 在无形纳米粒子中观察到几天的电压放松缺乏明确的物理解释.
研究的目的:
- 开发一种基于物理的模型,解释阳极中的电压歇斯底里和放松现象.
- 研究化学机械效应在电池循环过程中的粒子行为中的作用.
- 提供一个可以改善充电状态估计和电池性能的模型.
主要方法:
- 应用一个具有核心外几何学的化学机械连续模型,表示被固体电解质介相覆盖的颗粒.
- 模拟的粘性-弹性行为,以解释循环过程中的歇斯底里和放松期后的歇斯底里.
- 将开发的模型与实证的普莱特模型进行比较,并引入了用于简化估计的缩小模型.
主要成果:
- 化学机械核心外模型成功地解释了阳极中观察到的电压歇斯底里.
- 一个符合加洛法罗定律的对数电压放松被确定并通过外的粘性-弹性可解释.
- 拟议的模型在描述电压歇斯底里现象方面优于实证的普莱特模型.
结论:
- 阳极的机械行为,特别是核心外结构中的固体电解质介面相的粘性-弹性,是电压歇斯底里的主要原因.
- 开发的化学机械模型为阳极电压歇斯底里和放松提供了强有力的解释.
- 鼓励对阳极力学进行进一步的研究,以优化电池设计和性能.
相关概念视频
Atomic Nuclei: Types of Nuclear Relaxation
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Nuclear relaxation restores the equilibrium population imbalance and can occur via spin–lattice or spin–spin mechanisms, which are first-order exponential decay processes.
In spin–lattice or longitudinal relaxation, the excited spins exchange energy with the surrounding lattice as they return to the lower energy level. Among several mechanisms that contribute to spin–lattice relaxation, magnetic dipolar interactions are significant. Here, the excited nucleus transfers...
In spin–lattice or longitudinal relaxation, the excited spins exchange energy with the surrounding lattice as they return to the lower energy level. Among several mechanisms that contribute to spin–lattice relaxation, magnetic dipolar interactions are significant. Here, the excited nucleus transfers...
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In the absence of an external magnetic field, nuclear spin states are degenerate and randomly oriented. When a magnetic field is applied, the spins begin to precess and orient themselves along (lower energy) or against (higher energy) the direction of the field. At equilibrium, a slight excess population of spins exists in the lower energy state. Because the direction of the magnetic field is fixed as the z-axis, the precessing magnetic moments are randomly oriented around the z-axis.
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