通过单粒子电化学测量对电极/电解质接口与添加剂的直接评估
Shinji Matsumoto1, Koji Hiraoka1, Hiroyuki Tokuda2
1Graduate School of Applied Chemistry and Chemical Engineering, Kogakuin University, 2665-1 Nakano-machi, Hachioji, Tokyo 192-0015, Japan.
ACS applied materials & interfaces
|January 31, 2025
概括
单粒子电化学测量 (SPEM) 允许直接观察添加剂如何在离子电池颗粒上形成保护性介相层,这对于提高电池性能和寿命至关重要.
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
- 电池技术 电池技术
背景情况:
- 控制接口反应是高性能离子电池 (LIB) 的关键.
- 电解质添加剂形成保护性介相膜,但由于复合电极结构,观察它们在单一活性材料上的形成是困难的.
- 单粒子电化学测量 (SPEM) 为研究这些现象提供了一种新的方法.
研究的目的:
- 为了研究在单个LiCoO2粒子 (LCO-SP) 上*in-situ*添加剂引入过程中的电化学和电阻变化.
- 为了证明SPEM在观察电极/电解质接口的相间层形成的能力,在单颗粒水平上.
主要方法:
- 使用开放型电池进行单颗粒电化学测量 (SPEM).
- 采用交流阻抗光谱来分析电阻组件.
- 引入 LiPO2F2 添加剂 *in-situ* 在乙烯碳酸-LiN(SO2F) 2 电解质中的带电的 LCO-SP 中.
主要成果:
- 没有添加剂的LCO-SP在阻抗光谱中显示了一个单一的不对称的半圆弧,代表内部,电荷转移和相间电阻.
- 添加剂的存在改变了阻抗光谱,表明了电荷转移过程的变化.
- *在现场*的添加剂引入导致了两个半圆弧和增加的低频电阻,证实了LCO-SP上的相间层增长.
结论:
- 在单粒子尺度上,SPEM能够有效地直接和精确地观察电极/电解质接口上的电阻行为.
- 这种技术为在添加剂引入过程中介相层的*in-situ*形成和影响提供了宝贵的见解.
- 通过研究接口现象,SPEM是理解和优化LIB性能的一种强大工具.
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