解读基于Na和K碳酸盐的电池中固体电解质间相的形成和积累
Junyang Hu1, Huwei Wang1, Fu Yuan1
1Shenzhen Geim Graphene Center, Institute of Materials Research, Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen 518055, China.
Nano letters
|January 25, 2024
概括
和电池中的持续固体电解质间相 (SEI) 积累是由正在进行的溶液相反应引起的. 这导致碳阳极的容量迅速丧失,阻碍了电池的性能.
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:
- 碳阳极上的持续固体电解质间相 (SEI) 积累会导致 (Na) 和 (K) 电池的容量迅速丧失.
- 在Na和K系统中,这种SEI层的精确组成和形成化学仍然不完全理解.
研究的目的:
- 用乙烯碳酸盐 (EC) /二乙烯碳酸盐 (DEC) 电解质阐明Na和K电池中的SEI组成和形成机制.
- 确定有助于SEI增长和产能下降的关键有机物种.
主要方法:
- 核磁共振 (NMR) 光谱学被用来分析SEI组件.
- 模型化合物的合成和表征,包括金属乙烯碳酸盐 (MEC),长链金属乙烯碳酸盐 (LCMEC) 和聚乙烯氧化物 (PEO) 寡合物.
主要成果:
- 在Na和KSEI中确定了MEC,LCMEC和PEO寡合物与乙烯碳酸盐末端组.
- 证明这些成分通过由乙氧化物启动的溶液相核友反应不断产生.
- 在Na和K系统中观察到连续的核友反应,与Li系统形成鲜明对比.
结论:
- 在Na和K电池中的SEI积累归因于通过溶液相反应不断产生有机物种.
- 与相比,中间体的增强核友性可能推动了Na和K系统中的这些连续反应.
- 了解这种化学反应对于减轻容量损失和提高Na和K电池性能至关重要.
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