层层的过渡金属氧化物阴极内微粒裂变的起源和重要性
Jędrzej K Morzy1,2,3, Wesley M Dose2,3, Per Erik Vullum4,5
1Department of Materials Science and Metallurgy, University of Cambridge, 27 Charles Babbage Road, Cambridge CB3 0FS, United Kingdom.
ACS applied energy materials
|May 17, 2024
概括
富含的多层过渡金属氧化物 (LTMO) 阴极的内微粒裂变会导致电动汽车电池的降解. 了解这些纳米级裂是提高电池寿命和性能的关键.
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:
- 富含的多层过渡金属氧化物 (LTMO) 阴极由于其高容量和较低成本,对电力运输至关重要.
- 然而,这些材料的降解速度比低替代品更快,限制了它们的实际应用.
研究的目的:
- 为了研究纳米尺度的起源和性能影响的内微粒裂变在丰富的LTMO阴极.
- 确定导致裂形成的因素及其对电池退化的影响.
主要方法:
- 高分辨率的电子显微镜.
- 频谱学技术的使用.
- 在循环后分析充电和放电的正极样本.
主要成果:
- 在充电的丰富的LTMO标本中,其周期生命早期的内粒裂变很普遍.
- 裂变与不均的应力源有关,包括异型粒子膨胀/收缩和Li/TM分布.
- 在排放样本中,裂是不常见的,这表明一种依赖状态的现象.
结论:
- 颗粒内部裂变源于丰富的LTMOs的初级晶体内的局部应力.
- 这些裂可以导致容量减弱,阻抗通过诸如粒子脱离和电接触损失等机制上升.
- 缓解微粒内部裂纹对于提高离子电池中LTMO阴极的耐用性至关重要.
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