在商业离子电池中使用的正极材料的热演变
B D K K Thilakarathna1, Timothy A Ablott2, Taren Cataldo1,2
1School of Chemistry, UNSW Sydney NSW 2052, Australia. neeraj.sharma@unsw.edu.au.
Physical chemistry chemical physics : PCCP
|November 20, 2025
概括
在各种充电状态下研究了离子电池阴极 (NFM) 的结构演变. 研究人员观察到显著的热分解和相变,特别是在充满电的状态下,影响电池性能.
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
- 固态化学 固态化学
背景情况:
- 离子电池 (SIB) 是离子电池的一个有希望的替代品.
- 分层过渡金属氧化物是SIB的关键阴极材料.
- 了解不同电化学条件下的阴极结构演变对于SIB的发展至关重要.
研究的目的:
- 为了研究NaxNi1/3Fe1/3Mn1/3O2 (NFM) 阴极的结构演变.
- 分析NFM阴极在各种充电状态 (完全充电,部分充电,完全放电) 的热稳定性和相变.
主要方法:
- 射线吸收光谱 (XAS) 探测氧化状态和局部结构.
- 可变温度的X射线衍射 (XRD) 来识别相变.
- 热重力测量分析 (TGA) 和差分扫描热量测量 (DSC) 用于评估热稳定性.
- 扫描电子显微镜-能量分散光谱 (SEM-EDS) 用于形态和组成分析.
主要成果:
- XAS揭示了跨不同电荷状态的过渡金属氧化状态的变化.
- 可变温度XRD显示了从分层O3 / P3到立方金属氧化物和金属相的相变.
- TGA/DSC显示显著的质量损失和外热活动,特别是在完全充电的NFM中,与分解有关.
- 在热处理后,SEM-EDS识别出缺乏氧气的,组成差异化的颗粒.
结论:
- 在电化学循环和热应力过程中,NFM阴极经历了显著的结构和化学变化.
- 热分解和相演变强烈依赖电荷状态.
- 这些发现强调了理解热反应对于设计稳定的NFM阴极用于离子电池的重要性.
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