关于离子在离子电池电解液中的氧化状态
Anjan Banerjee1, Yuliya Shilina1, Baruch Ziv1
1Department of Chemistry, Bar-Ilan University , Ramat-Gan 5290002, Israel.
Journal of the American Chemical Society
|January 26, 2017
概括
离子电池中的离子化学物质得到了澄清:Mn3+,而不是Mn2+,在LiPF6电解质中占主导地位,无论电池的充电状态如何. 这一发现影响了电池的性能和稳定性.
科学领域:
- 电化学
- 材料科学
- 电池技术
背景情况:
- 在离子电池电解质中溶解的物种对于理解降解机制至关重要.
- 之前的假设支持Mn2+作为主要的溶解阳离子,影响了电池性能的理论模型.
研究的目的:
- 准确识别用于离子电池的 LiPF6 基电解质中占主导地位的溶解离子.
- 在各种电化学条件下 (充电,放电,循环) 量化的物种化.
- 为了阐明溶解的物种的稳定性和不成比例行为.
主要方法:
- 使用电子偏磁共振 (EPR) 和感应合等离子谱 (ICP) 的综合分析.
- 用X射线吸收近边光谱 (XANES) 确定溶解的平均氧化状态.
- 用于验证实验结果的分类图分析.
主要成果:
- Mn3+被确定为主要的溶解阳离子,在完全放电和充电状态下约占80%,在循环细胞中占60%.
- 这些结果与XANES数据和分类图分析一致.
- 随着时间的推移,Mn3+的分量保持不变,观察到非常缓慢的不成比例率.
结论:
- 一般认为Mn2+占主导地位是不正确的;Mn3+是这些电池电解质中普遍存在的物种.
- 证实了Mn3+在非水性电解质中的稳定性,这表明了对离子电池溶解的重新理解.
- 这些发现对预测和减轻酸旋电池中与有关的降解具有重要意义.
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