It is essential to understand the nanoscale structure and chemistry of energy storage materials due to their profound impact on battery performance. However, it is often challenging to characterize them at high resolution, as they are often fundamentally altered by sample preparation methods. Here, we use the cryogenic lift-out technique in a plasma-focused ion beam (PFIB)/scanning electron microscope (SEM) to prepare air-sensitive lithium metal to understand ion-beam damage during sample preparation. Through the use of cryogenic transmission electron microscopy, we find that lithium was not damaged by ion-beam milling although lithium oxide shells form in the PFIB/SEM chamber, as evidenced by diffraction information from cryogenic lift-out lithium lamellae prepared at two different thicknesses (130 and 225 nm). Cryogenic energy loss spectroscopy further confirms that lithium was oxidized during the process of sample preparation. The Ellingham diagram suggests that lithium can react with trace oxygen gas in the FIB/SEM chamber at cryogenic temperatures, and we show that liquid oxygen does not contribute to the oxidation of lithium process. Our results suggest the importance of understanding how cryogenic lift-out sample preparation has an impact on the high-resolution characterization of reactive battery materials.
Electron microscopy allows the extraction of multidimensional spatiotemporally correlated structural information of diverse materials down to atomic resolution, which is essential for figuring out their structure–property relationships. Unfortunately, the high‐energy electrons that carry this important information can cause damage by modulating the structures of the materials. This has become a significant problem concerning the recent boost in materials science applications of a wide range of beam‐sensitive materials, including metal–organic frameworks, covalent–organic frameworks, organic–inorganic hybrid materials, 2D materials, and zeolites. To this end, developing electron microscopy techniques that minimize the electron beam damage for the extraction of intrinsic structural information turns out to be a compelling but challenging need. This article provides a comprehensive review on the revolutionary strategies toward the electron microscopic imaging of beam‐sensitive materials and associated materials science discoveries, based on the principles of electron–matter interaction and mechanisms of electron beam damage. Finally, perspectives and future trends in this field are put forward.
more » « less- Award ID(s):
- 1936882
- PAR ID:
- 10457815
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- Advanced Materials
- Volume:
- 32
- Issue:
- 16
- ISSN:
- 0935-9648
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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