Lithium-ion batteries have enabled the widespread use of portable electronic devices and are propelling the growing electric vehicle market, but new battery technologies with improved performance are necessary for emerging applications such as electric aircraft. The solid-state battery is one such technology that could exhibit enhanced safety and higher energy density compared to conventional lithium-ion batteries. The use of a pure lithium metal anode within solid-state batteries is key for higher energy density (Figure 1a), and it is thought that using solid-state electrolytes instead of conventional liquids could increase the chemical and structural stability of lithium metal.1 Despite continued progress in the development of new inorganic solid-state electrolyte materials; however, a persistent problem has emerged: lithium metal tends to grow as filaments during charging instead of as a flat film, and these filaments can penetrate and fracture the stiff solid-state electrolyte to short circuit the cell (Figure 1b).2–4 To prevent this chemo-mechanical degradation process and enable filament-free charging, it is critical to understand the mechanical properties of lithium metal, which have been elusive because of the highly reactive nature of lithium.

锂离子电池已使便携式电子设备得以广泛使用，并推动了不断增长的电动汽车市场，但是对于电动飞机等新兴应用而言，性能更高的新型电池技术必不可少。固态电池是一种这样的技术，与传统的锂离子电池相比，它可以表现出更高的安全性和更高的能量密度。在固态电池中使用纯锂金属阳极是提高能量密度的关键（图1a），并且认为使用固态电解质代替常规液体可以提高锂金属的化学和结构稳定性。1个尽管新型无机固态电解质材料的开发不断取得进展；但是，出现了一个持续存在的问题：锂金属在充电过程中趋于以细丝的形式生长，而不是形成平坦的膜，并且这些细丝会渗透并破坏坚硬的固态电解质，从而使电池短路（图1b）。2–4为防止此化学机械降解过程并实现无灯丝充电，了解锂金属的机械性能至关重要，由于锂的高反应性，锂金属的机械性能难以捉摸。