Li Xiangyan, Han Bing, Yang Xuming, Deng Zhipeng, Zou Yucheng, Shi Xiaobo, Wang Liping, Zhao Yusheng, Wu Sudong, Gu Meng
Academy for Advanced Interdisciplinary Studies, Southern University of Science and Technology, Shenzhen 518055, China.
Department of Materials Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, China.
iScience. 2021 Nov 9;24(12):103418. doi: 10.1016/j.isci.2021.103418. eCollection 2021 Dec 17.
The structure of lithium (Li) metal anode, including the Li metal and the solid electrolyte interphase (SEI), is critical to the investigation of cycle stability or decay mechanisms. The three-dimensional (3D) visualization of Li metal and SEI, however, has not been demonstrated yet, owing to the lack of 3D characterization techniques and the susceptibility of Li metal anode toward oxygen, moisture, as well as electron beam. Herein, we introduce a successful 3D presentation of deposited Li metal and SEI established via low-dose cryogenic electron microscopy tomography. The Li metal anode is imaged in low-dose mode at different tilt angles and then aligned and reconstructed into a 3D image through an expectation-maximization algorithm. The spherical Li deposits and SEI are confirmed in the 3D tomography of Li metal anode. It is also discovered that the Li metal corrodes and SEI turns concave owing to possible self-discharge after long-time rest.
锂（Li）金属阳极的结构，包括锂金属和固体电解质界面（SEI），对于循环稳定性或衰减机制的研究至关重要。然而，由于缺乏三维表征技术以及锂金属阳极对氧气、水分和电子束的敏感性，锂金属和SEI的三维（3D）可视化尚未得到证实。在此，我们介绍了一种通过低剂量低温电子显微镜断层扫描成功实现的沉积锂金属和SEI的三维呈现。锂金属阳极在不同倾斜角度下以低剂量模式成像，然后通过期望最大化算法对齐并重建为三维图像。在锂金属阳极的三维断层扫描中确认了球形锂沉积物和SEI。还发现，由于长时间静置后可能发生的自放电，锂金属会腐蚀，SEI会变凹。
