Yildirim Can, Flatscher Florian, Ganschow Steffen, Lassnig Alice, Gammer Christoph, Todt Juraj, Keckes Jozef, Rettenwander Daniel
European Synchrotron Radiation Facility, Grenoble Cedex 9, France.
Department of Material Science and Engineering, NTNU Norwegian University of Science and Technology, Trondheim, Norway.
Nat Commun. 2024 Sep 18;15(1):8207. doi: 10.1038/s41467-024-52412-4.
Lithium dendrite growth in inorganic solid-state electrolytes acts as a main stumbling block for the commercial development of all-solid-state lithium batteries. Indeed, Li dendrites often lead to solid-state electrolyte fractures, undermining device integrity and safety. Despite the significance of these issues, the mechanisms driving the solid-state electrolyte fracture process at the microscopic level remain poorly understood. Here, via operando optical and ex situ dark field X-ray microscopy measurements of LiSn∣single-crystal LiLaZrTaO∣LiSn symmetric cells, we provide insights into solid-state electrolyte strain patterns and lattice orientation changes associated with dendrite growth. We report the observation of dislocations in the immediate vicinity of dendrite tips, including one instance where a dislocation is anchored directly to a tip. This latter occurrence in single-crystalline ceramics suggests an interplay between dendrite proliferation and dislocation formation. We speculate that the mechanical stress induced by dendrite expansion triggers dislocation generation. These dislocations seem to influence the fracture process, potentially affecting the directional growth and branching observed in lithium dendrites.
无机固态电解质中锂枝晶的生长是全固态锂电池商业发展的主要绊脚石。实际上，锂枝晶常常导致固态电解质破裂，破坏器件的完整性和安全性。尽管这些问题很重要，但在微观层面驱动固态电解质破裂过程的机制仍知之甚少。在此，通过对LiSn∣单晶LiLaZrTaO∣LiSn对称电池进行原位光学和非原位暗场X射线显微镜测量，我们深入了解了与枝晶生长相关的固态电解质应变模式和晶格取向变化。我们报告了在枝晶尖端紧邻区域观察到位错，包括有一个位错直接锚定在尖端的情况。这种在单晶陶瓷中的后一种情况表明枝晶增殖和位错形成之间存在相互作用。我们推测枝晶扩展引起的机械应力触发了位错的产生。这些位错似乎影响破裂过程，可能影响锂枝晶中观察到的定向生长和分支。
