电解质设计削弱了离子溶解对于快速充电和长循环Si阳极的作用
Min Li1,2, Shuai Li1, Dong Yan1
1School of Materials and Energy, University of Electronic Science and Technology of China Chengdu 611731 China lipingwang@uestc.edu.cn.
Chemical science
|January 15, 2025
概括
使用乙酸 (EFA) 和乙烯碳酸 (FEC) 溶剂的新电解质提高了离子电池中的阳极性能. 这提高了循环稳定性和下一代能源存储的速度能力.
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:
- 阳极为离子电池提供高容量,但由于体积膨胀和不稳定的固体电解质介相 (SEI) 形成,其循环和速率性能不佳.
- 不兼容的电解质加剧了离子传输问题和SEI不稳定性,阻碍了阳极的实际应用.
- 开发先进的电解质对于克服阳极的局限性和释放其潜力至关重要.
研究的目的:
- 调查新型电解质配方在离子电池中提高阳极性能方面的有效性.
- 探索溶剂特性,特别是与Li+和相对介电常数的结合能,在改善阳极循环性和速率能力方面的作用.
- 为了展示一个高性能碳阳极和一个使用这些优化电解质的完整细胞.
主要方法:
- 使用乙烯酸 (EFA) 和乙烯碳酸 (FEC) 作为电解质溶剂,因低Li+结合能和高介电常量而被选用.
- 合成并测试了具有优化电解质组成的碳阳极.
- 评估了碳阳极和Si/C‖LiFePO4 (LFP) 全电池的电化学性能,包括循环稳定性,速率能力和容量保留.
主要成果:
- 优化的电解质显著提高了阳极的循环和速率能力.
- 碳阳极实现了1709.1mAhg-1的可逆容量,在250个循环中保持了性能,并在0.2C时保持了85.2%的容量.
- Si/C‖LiFePO4 (LFP) 全电池的使用寿命延长,超过了500个周期.
结论:
- 具有特定溶剂特性 (低结合能,高介电常数) 的弱溶解电解质有效地提高了阳极的性能.
- 开发的电解质系统克服了与阳极相关的关键挑战,实现了卓越的循环和速率能力.
- 这项研究为设计高性能基离子电池的先进电解质提供了宝贵的见解.
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