通过基于MEMS的现场TEM研究,在分层阴极中的电荷转移效应
Yujia Guan1,2, Jia Yu1,2, Jiajing Wang1,2
1State Key Laboratory of Advanced Technology for Materials Synthesis and Processing WUT Nano Key Lab, Wuhan, Hubei, 430070, China.
Small (Weinheim an der Bergstrasse, Germany)
|January 10, 2025
概括
层状氧化物阴极由于相位过渡而遭受氧气释放. 这项研究表明,缺陷阴极中的金属分离在过渡之前,由氧空缺和Mn迁移驱动,改变降解途径.
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:
- 不可逆转的晶格氧释放是分层氧化物阴极的关键故障机制.
- 这种降解通常与相变和氧含量降低有关.
研究的目的:
- 为了研究氧空缺缺陷层层氧化物阴极的早期降解机制.
- 了解当地的氧空位异质性在阴极降解中的作用.
主要方法:
- 电子能量损失光谱 (EELS) 用于分析元素和电子结构的变化.
- 密度函数理论 (DFT) 模拟以建模原子迁移和电子相互作用.
- 对氧气空缺缺陷层层阴极的调查.
主要成果:
- 在有缺陷的阴极中观察到异常的金属分离途径,发生在相位过渡之前.
- 从氧2p到 (Mn) 3d轨道的早期电荷转移被确定为原因.
- 当地氧空位异质性显著降低了的迁移障碍.
- 氧的释放始于有缺陷的地方,而不是完美的晶体区域,改变了降解路径.
结论:
- 局部氧空位异质性在分层阴极的相位降解中起着至关重要的作用.
- 这些发现挑战了对正极降解途径的传统理解.
- 由于空隙诱导的Mn迁移导致的早期金属分离是分层阴极故障的关键因素.
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