Development of high energy density solid-state batteries with Li metal anodes has been limited by uncontrollable growth of Li dendrites in liquid and solid electrolytes (SEs). This, in part, may be caused by a dearth of information about mechanical properties of Li, especially at the nano- and microlength scales and microstructures relevant to Li batteries. We investigate Li electrodeposited in a commercial LiCoO2/LiPON/Cu solid-state thin-film cell, grown in situ in a scanning electron microscope equipped with nanomechanical capabilities. Experiments demonstrate that Li was preferentially deposited at the LiPON/Cu interface along the valleys that mimic the domain boundaries of underlying LiCoO2 (cathode). Cryogenic electron microscopy analysis of electrodeposited Li revealed a single-crystalline microstructure, and in situ nanocompression experiments on nano-pillars with 360–759 nm diameters revealed their average Young's modulus to be 6.76 ± 2.88 GPa with an average yield stress of 16.0 ± 6.82 MPa, ~24x higher than what has been reported for bulk polycrystalline Li. We discuss mechanical deformation mechanisms, stiffness, and strength of nano-sized electrodeposited Li in the framework of its microstructure and dislocation-governed nanoscale plasticity of crystals, and place it in the parameter space of existing knowledge on small-scale Li mechanics. The enhanced strength of Li at small scales may explain why it can penetrate and fracture through much stiffer and harder SEs than theoretically predicted.

具有锂金属阳极的高能量密度固态电池的开发受到液态和固态电解质（SE）中锂树枝状晶体不可控制的增长的限制。部分原因可能是由于缺乏有关Li的机械性能的信息，尤其是在与Li电池有关的纳米和微米长度尺度以及微观结构方面。我们调查电沉积在商业LiCoO 2 / LiPON / Cu固态薄膜电池中的锂，该电池在具有纳米机械功能的扫描电子显微镜中原位生长。实验表明，Li优先沿着模仿底层LiCoO 2的畴边界的谷沉积在LiPON / Cu界面上（阴极）。电沉积锂的低温电子显微镜分析揭示了单晶微观结构，并且是原位的在直径为360–759 nm的纳米柱上进行的纳米压缩实验显示，它们的平均杨氏模量为6.76±2.88 GPa，平均屈服应力为16.0±6.82 MPa，比已报道的多晶Li高出约24倍。我们在微观结构和位错控制的晶体纳米可塑性的框架内，讨论了纳米级电沉积锂的机械变形机制，刚度和强度，并将其置于小规模锂力学的现有知识的参数空间中。Li在小尺度上增强的强度可以解释为什么它可以通过比理论上预测的更硬和更坚硬的SE渗透和破裂。