对于高能电池的降低容忍电解质设计
Chuangchao Sun1, Ruhong Li1,2, Suting Weng3
1State Key Laboratory of Silicon and Advanced Semiconductor Materials, School of Materials Science and Engineering, Zhejiang University, Hangzhou, 310027, China.
Angewandte Chemie (International ed. in English)
|March 18, 2024
概括
研究人员发现,控制溶剂减少稳定性可以改善电池中的固体电解质界面 (SEI). 溶剂中较低的电友性和协调能力创造了稳定,富含无机的SEI,提高了下一代能源存储的电池循环性能.
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
- 储能 储能 储能 储能 储能 储能
背景情况:
- 和阳极对于下一代电池至关重要,但由于不稳定的固体电解质界面 (SEI) 而导致容量退化.
- 目前的离子衍生的SEI受到溶剂减少的限制,导致SEI异质性和电池循环期间的断裂.
研究的目的:
- 阐明溶剂还原稳定性与和阳极上SEI形成之间的关系.
- 确定控制SEI特性的关键溶剂特性,即电友性 (EPT) 和协调能力 (CDA).
- 设计和合成新型溶剂,促进稳定,有无机丰富的SEI,以提高电池性能.
主要方法:
- 研究了基于电友性 (EPT) 和协调能力 (CDA) 的溶剂分解机制.
- 合成了三种针对和阳极量身定制的新型溶剂.
- 通过使用阳极和无阳极囊细胞评估电解质性能 (Cu California NCM523).
主要成果:
- 具有较低EPT和CDA的溶剂表现出增强的还原稳定性,形成均的,富含无机物的SEI.
- 优化的电解质 (1M LiFSI in TFSPY) 使阳极能够在600个周期内保持81%的容量.
- 使用优化的电解质,无阳极袋细胞表现出超过100个周期,容量保留82%.
结论:
- 减少溶剂分解对于高能电池中形成稳定的SEI至关重要.
- 溶剂EPT和CDA是设计具有改进SEI特性的电解质的关键描述符.
- 这项工作为开发下一代电池技术的先进电解质提供了途径.
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