使用聚合物交织的外层构建LiF主导的界面,可以实现Si阳极的长期循环
Yaozong Yang1, Jie Wang1,2, Zhaolin Li1,2
1School of Material Science and Engineering, University of Science and Technology Beijing, Beijing 100083, People's Republic of China.
ACS nano
|February 28, 2024
概括
研究人员开发了一种新方法,用于为基于的离子电池创建稳定的固体电解质介相 (SEI). 这一突破通过控制SEI的组成和结构来提高电池性能和寿命.
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
- 电池技术 电池技术
背景情况:
- 开发基于高能量密度 (Si) 的离子电池至关重要.
- 构建一个强大的固体电解质介面 (SEI) 是一个关键的挑战.
- 精确操纵SEI的化学成分和结构仍然是难以捉摸的.
研究的目的:
- 为了实现 LiF 主导的 SEI 薄膜与高度弹性的聚合物交织在一起.
- 调节Si电极表面上化碳酸盐添加剂的脱机制.
- 为了提高基于Si的离子电池的性能和稳定性.
主要方法:
- 对SEI形成的添加效应进行实验和计算分析.
- 使用转二乙烯碳酸盐 (DFEC) 和二氧化 (LiDFOB) 添加剂.
- 研究DFEC的脱机制和聚合.
主要成果:
- LiDFOB添加剂改变了DFEC的分解,诱导了直接的除和专属LiF-SEI的形成.
- 脱的DFEC聚合为聚乙烯碳酸,增强SEI的弹性.
- 由LiF主导的SEI具有聚合物外层,可以提高离子导电性和机械稳定性.
- 具有设计的双添加剂的Si电极显示出卓越的循环稳定性和速率性能 (1487.3mAhg-1在2Ag-1的1000个循环后).
结论:
- 用LiDFOB调节DFEC的脱机制对于SEI建设至关重要.
- 由此产生的SEI膜增强了电极反应动力学和结构完整性.
- 这一策略显著提高了基于Si的离子电池的电化学性能.
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