从常见的阴极材料在电解质中溶解过渡金属的规范
Leah Rynearson1, Cali Antolini1, Chamithri Jayawardana1
1Department of Chemistry, University of Rhode Island, Kingston, RI-02881, USA.
Angewandte Chemie (International ed. in English)
|December 11, 2023
概括
过渡金属溶解导致离子电池的容量损失. 这项研究表明,溶解的和的氧化状态取决于阴极材料,而不是循环潜力.
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
- 电池技术 电池技术
背景情况:
- 离子电池的容量衰减与阴极中的过渡金属溶解有关.
- 过渡金属离子通过电解质迁移并沉积在阳极上,影响电池性能.
- 有限的研究存在于电解质中溶解过渡金属的氧化状态.
研究的目的:
- 为了研究在电解质中溶解的 (Mn) 和 (Ni) 离子的氧化状态.
- 为了将过渡金属的氧化状态与不同的阴极活性材料和循环潜力相关联.
- 为了量化阳极上沉积的过渡金属离子.
主要方法:
- 从循环离子电池中提取电解质,使用四种阴极材料:LiMn2O4 (LMO),LiNi0.5Mn1.5O4 (LNMO),LiNi0.8Mn0.1Co0.1O2 (NMC811),以及LMRNMC.
- 使用X射线吸收光谱 (XAS) 来确定电解质中Mn和Ni的氧化状态.
- 感应合等离子体质谱法 (ICP-MS) 量化了阳极上的过渡金属度.
主要成果:
- 在所有电解质中检测到过渡金属离子.
- 发现溶解的和的氧化状态取决于所使用的特定阴极材料.
- 循环电位 (高与标准) 并没有影响电解质中Mn和Ni的氧化状态.
结论:
- 阴极材料是离子电池电解质中溶解过渡金属离子氧化状态的主要决定因素.
- 了解这些氧化状态对于减轻容量衰减机制至关重要.
- 进一步的研究可以利用这些知识来设计更稳定的阴极材料和电解质.
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