{"title":"Mesoscale interplay among composition heterogeneity, lattice deformation, and redox stratification in single-crystalline layered oxide cathode","authors":"","doi":"10.1016/j.esci.2024.100251","DOIUrl":null,"url":null,"abstract":"<div><p>Single-crystalline layered oxide materials for lithium-ion batteries are featured by their excellent capacity retention over their polycrystalline counterparts, making them sought-after cathode candidates. Their capacity degradation, however, becomes more severe under high-voltage cycling, hindering many high-energy applications. It has long been speculated that the interplay among composition heterogeneity, lattice deformation, and redox stratification could be a driving force for the performance decay. The underlying mechanism, however, is not well-understood. In this study, we use X-ray microscopy to systematically examine single-crystalline NMC particles at the mesoscale. This technique allows us to capture detailed signals of diffraction, spectroscopy, and fluorescence, offering spatially resolved multimodal insights. Focusing on early high-voltage charging cycles, we uncover heterogeneities in valence states and lattice structures that are inherent rather than caused by electrochemical abuse. These heterogeneities are closely associated with compositional variations within individual particles. Our findings provide useful insights for refining material synthesis and processing for enhanced battery longevity and efficiency.</p></div>","PeriodicalId":100489,"journal":{"name":"eScience","volume":"4 4","pages":"Article 100251"},"PeriodicalIF":42.9000,"publicationDate":"2024-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2667141724000302/pdfft?md5=22f22b362881440bc7895637938156c9&pid=1-s2.0-S2667141724000302-main.pdf","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"eScience","FirstCategoryId":"1085","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S2667141724000302","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"ELECTROCHEMISTRY","Score":null,"Total":0}
引用次数: 0
Abstract
Single-crystalline layered oxide materials for lithium-ion batteries are featured by their excellent capacity retention over their polycrystalline counterparts, making them sought-after cathode candidates. Their capacity degradation, however, becomes more severe under high-voltage cycling, hindering many high-energy applications. It has long been speculated that the interplay among composition heterogeneity, lattice deformation, and redox stratification could be a driving force for the performance decay. The underlying mechanism, however, is not well-understood. In this study, we use X-ray microscopy to systematically examine single-crystalline NMC particles at the mesoscale. This technique allows us to capture detailed signals of diffraction, spectroscopy, and fluorescence, offering spatially resolved multimodal insights. Focusing on early high-voltage charging cycles, we uncover heterogeneities in valence states and lattice structures that are inherent rather than caused by electrochemical abuse. These heterogeneities are closely associated with compositional variations within individual particles. Our findings provide useful insights for refining material synthesis and processing for enhanced battery longevity and efficiency.
用于锂离子电池的单晶层状氧化物材料与多晶材料相比,具有出色的容量保持能力,因此成为备受追捧的正极候选材料。然而,在高压循环条件下,它们的容量衰减会变得更加严重,从而阻碍了许多高能量应用。长期以来,人们一直推测成分异质性、晶格变形和氧化还原分层之间的相互作用可能是性能衰减的驱动力。然而,人们对其内在机制还不甚了解。在本研究中,我们使用 X 射线显微镜在中尺度上对单晶 NMC 粒子进行了系统检测。通过这种技术,我们可以捕捉到衍射、光谱和荧光的详细信号,从而提供空间分辨的多模态洞察力。以早期高压充电循环为重点,我们发现了价态和晶格结构的异质性,这些异质性是固有的,而不是电化学滥用造成的。这些异质性与单个颗粒内部的成分变化密切相关。我们的研究结果为改进材料合成和加工以提高电池寿命和效率提供了有益的启示。