Mechanical suppression, e.g., by applying stack pressures and using functionalized coatings, has been considered a promising approach to inhibit the formation of lithium (Li) dendrites and improve the cycling stability of the Li metal electrode. However, a lack of understanding of the mechanical behavior of electroplated mossy Li, consisting of loosely packed Li dendrites that are covered by solid electrolyte interphase, hinders the development of mechanical suppression strategies and limits the understanding of the electromechanical behavior of mossy Li. In this study, we investigated, using flat punch indentation in an argon-filled glovebox, the room temperature mechanical behavior and its relationship with the microstructure of mossy Li electroplated using different current densities (between 0.25 and 10 mA/cm²) in several electrolytes. The dendrite size decreases and the porosity of mossy Li increases with increasing current density. Mossy Li has lower Young’s modulus (E) but significantly higher creep resistance than bulk Li. A scaling relationship between E and porosity is established for mossy Li. The creep behavior of mossy Li exhibits a strong size effect, i.e., the steady-state impression velocity decreases with decreasing dendrite size. These findings provide a comprehensive understanding of the relationship between the microstructure and mechanical behavior of mossy Li.

机械抑制，例如通过施加堆叠压力并使用功能化涂层，已被认为是抑制锂（Li）树枝状晶体形成并改善Li金属电极循环稳定性的一种有前途的方法。然而，对由纯电解质中间相覆盖的松散包装的锂树枝状晶体组成的电镀苔藓型锂的机械行为的缺乏了解，阻碍了机械抑制策略的发展，并限制了对苔藓型锂的机电行为的理解。在这项研究中，我们使用充氩气的手套箱中的平冲头压痕研究了室温机械性能及其与使用不同电流密度（0.25和10 mA / cm ²之间）电镀的苔藓锂的微观结构的关系。）在几种电解质中。随着电流密度的增加，枝晶尺寸减小并且长满苔藓的锂的孔隙率增大。苔藓型锂的杨氏模量（E）较低，但抗蠕变性能却比块状锂高。对于长满苔藓的锂，E和孔隙率之间存在比例关系。长满苔藓的锂的蠕变行为表现出强烈的尺寸效应，即，稳态印象速度随枝晶尺寸的减小而降低。这些发现提供了对长满苔藓的锂的微观结构与力学行为之间关系的全面理解。