离子电池电极的对分布函数分析和固态核磁共振研究:了解 (去) 化机制
Baris Key1, Mathieu Morcrette, Jean-Marie Tarascon
1Department of Chemistry, SUNY at Stony Brook, Stony Brook, New York 11794-3400, United States.
Journal of the American Chemical Society
|December 22, 2010
概括
离子电池中的负电极在循环过程中经历结构变化. 新的研究使用NMR和X射线分析来理解这些转变,揭示了解释电池性能的无形化化物.
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
- 固态化学 固态化学
背景情况:
- 负电极为离子电池 (LIB) 提供高容量.
- 最初的放电会导致的晶态到无形相变,使结构性能关系复杂化.
- 了解短期订单变化对于优化LIB业绩至关重要.
研究的目的:
- 为了研究在初始充放电周期期间负电极的结构变化.
- 为了将观察到的电化学概况与特定的结构转变相关联.
- 阐明阳极中歇斯底里和电化学步骤背后的机制.
主要方法:
- 现场 (7) 核磁共振 (NMR) 光谱检测局部环境.
- 对分布函数 (PDF) 分析X射线衍射数据以确定短距离顺序.
- 电极的电化学循环.
主要成果:
- 在第一次放电后,形成了明显的无形化化物结构.
- 第二次放电涉及无形的化,形成集群,演变为孤立的离子.
- 这些结构变化与观察到的电化学概况和hysteresis相关.
结论:
- 特定无形化的形成决定了阳极的电化学行为.
- 一个详细的 (脱化) 模型解释了观察到的电化学步骤和歇斯底里.
- 这项工作提供了对LIBs中控制阳极性能的基本机制的见解.
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