Zhai Wenbo, Yuan Biao, Fan Yaqi, Zhang Yue, Zhang Xiuli, Ma Yanhang, Liu Wei, Yu Yi
School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, China.
Shanghai Key Laboratory of High-resolution Electron Microscopy, ShanghaiTech University, Shanghai 201210, China.
J Am Chem Soc. 2022 Mar 9;144(9):4124-4132. doi: 10.1021/jacs.1c13213. Epub 2022 Feb 28.
The uncontrolled deposition/dissolution process of lithium dendrites during electrochemical cycling in batteries limits the large-scale application of Li metal anodes. Investigating the microstructure of Li dendrites is a focal point. Currently, the only way to protect and observe sensitive Li dendrites is through low-temperature transmission electron microscopy (LT-TEM), whereas room-temperature characterization is still lacking. In this work, the room-temperature microstructure of Li dendrites was obtained by TEM using both vacuum- and inert-gas-transfer methods. Detailed comparison between LT- and room-temperature (RT-)TEM characterizations was provided to show the pros and cons of each method. Especially, RT-TEM shows the advantage of flexible incorporation with multifunctional characterizations, such as 3D tomography. By using RT-TEM, microstructural evolution of Li dendrites during the electrodeposition/dissolution process, including increase of the quantity of inorganic LiO compounds in the solid electrolyte interphase, lateral growth behavior, and two types of inactive Li, has been revealed, enriching the understanding of the structure-property relationship of Li dendrites.
电池中锂枝晶在电化学循环过程中不受控制的沉积/溶解过程限制了锂金属负极的大规模应用。研究锂枝晶的微观结构是一个重点。目前，保护和观察敏感锂枝晶的唯一方法是通过低温透射电子显微镜（LT-TEM），而室温表征仍然缺乏。在这项工作中，通过使用真空和惰性气体转移方法的透射电子显微镜获得了锂枝晶的室温微观结构。提供了低温和室温（RT-）TEM表征之间的详细比较，以展示每种方法的优缺点。特别是，RT-TEM显示了与多功能表征（如三维断层扫描）灵活结合的优势。通过使用RT-TEM，揭示了锂枝晶在电沉积/溶解过程中的微观结构演变，包括固体电解质界面中无机LiO化合物数量的增加、横向生长行为以及两种类型的非活性锂，丰富了对锂枝晶结构-性能关系的理解。
