2022-04-18 オークリッジ国立研究所(ORNL)
エネルギー貯蔵材料の特性は、その原子構造に直接起因しており、それは電子顕微鏡を用いなければ見ることができません。現在の電子顕微鏡は、重元素を原子レベルの分解能で画像化することができる。しかし、現代の電池に不可欠なリチウム、ナトリウム、カリウムなどの軽元素を同時に観察することは、一つの課題となっています。
ORNLのナノフェーズ材料科学センターの科学者たちは、「質量中心」走査透過電子顕微鏡（CoM-STEM）を使用して、電池材料中のリチウムとより重い元素を原子レベルの分解能で観察しました。
＜関連情報＞
- https://www.ornl.gov/news/imaging-lithium-light-bright
- https://pubs.acs.org/doi/abs/10.1021/acsnano.1c09374
質量分析型走査透過電子顕微鏡による電池材料中のリチウムのロバストな原子分解能イメージング Robust Atomic-Resolution Imaging of Lithium in Battery Materials by Center-of-Mass Scanning Transmission Electron Microscopy
Michael J. Zachman,Zhenzhong Yang,Yingge Du and Miaofang Chi
ACS Publications Publication Date:January 9, 2022
https://doi.org/10.1021/acsnano.1c09374
Abstract
The performance of energy storage materials is often governed by their structure at the atomic scale. Conventional electron microscopy can provide detailed information about materials at these length scales, but direct imaging of light elements such as lithium presents a challenge. While several recent techniques allow lithium columns to be distinguished, these typically either involve complex contrast mechanisms that make image interpretation difficult or require significant expertise to perform. Here, we demonstrate how center-of-mass scanning transmission electron microscopy (CoM-STEM) provides an enhanced ability for simultaneous imaging of lithium and heavier element columns in lithium ion conductors. Through a combination of experiments and multislice electron scattering calculations, we show that CoM-STEM is straightforward to perform and produces directly interpretable contrast for thin samples, while being more robust to variations in experimental parameters than previously demonstrated techniques. As a result, CoM-STEM is positioned to become a reliable and facile method for directly probing all elements within energy storage materials at the atomic scale.
