电解质添加剂对丰富的离子电池阴极的界面稳定性的影响
Nikita S Dutta1, Madison King1,2, Bingning Wang3
1Materials, Chemistry, and Computational Sciences, National Renewable Energy Laboratory, Golden, Colorado 80401, United States.
概括
研究人员使用电解质添加剂提高了无电池阴极的稳定性. 在LMR- NM细胞中,LiDFOB和TMSPi的组合提高了28%的循环性能和特定容量.
科学领域:
- 材料科学
- 电化学
- 能量储存
背景情况:
- 无,富和 (LMR-NM) 阴极为离子电池提供了具有成本效益的替代品,但长期循环稳定性不佳.
- 传统的含有的阴极面临成本和供应链的挑战,需要大量的材料解决方案.
研究的目的:
- 研究电解质添加剂的有效性,特别是二氧化 (LiDFOB),三甲酸 (TMSPi) 和乙烯碳酸 (VC),以提高LMR-NM细胞的循环性能.
- 通过先进的纳米尺度表征,建立阴极电解质间相 (CEI) 特性和电化学性能之间的结构功能关系.
主要方法:
- 用各种电解质添加剂组合的LMR-NM细胞的电化学循环.
- 低温扫描传输电子显微镜 (cryo-STEM) 与电子能量损失光谱 (EELS) 相结合,用于CEI的纳米分析.
- 对离子溶解和CEI形态和化学的分析.
主要成果:
- 与单个添加剂和基线电解质相比,2% TMSPi + 1% LiDFOB的组合显示出更高的性能.
- 在长期循环使用TMSPi + LiDFOB添加剂组合后,获得了28%的特定容量改善.
- 发现LiDFOB可以缓解离子溶解,在CEI表面稳定Mn,而TMSPi则有助于保护CEI结构 (∼7-15nm).
结论:
- 电解质工程,特别是使用TMSPi和LiDFOB,可以显著提高LMR-NM阴极的长期循环稳定性和性能.
- LiDFOB和TMSPi的协同作用增强了CEI的形成和稳定性,这对于防止电解质降解和保持电池性能至关重要.
- 这些发现为未来储能应用开发更实惠,更可靠的离子电池铺平了道路.
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