Fracture behavior of metallic sodium and implications for battery applications
Fracture behavior of metallic sodium and implications for battery applications
复制标题
金属钠的断裂行为及其对电池应用的影响
DOI：
10.1039/d2mh01021f
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发表时间：
2022
影响因子：
13.3
通讯作者：
Pharr, Matt
中科院分区：
文献类型：
--
作者：
Shin, Jungho;Pharr, Matt
金属钠由于其高理论容量、低标准还原电位以及在地壳中的丰富性而成为可充电电池的候选负极材料。在实际部署之前，彻底评估钠的机械性能至关重要，以便充分理解并帮助减轻潜在的故障机制。在这里，我们通过惰性环境中的拉伸测试来检查钠金属的断裂行为。我们发现钠对缺陷（类似裂纹的特征）几乎不敏感，即它的有效强度几乎不受缺陷存在的影响。相反，在张力下，钠会表现出极度颈缩，导致最终失败。我们还通过扫描电子显微镜研究表征了与钠断裂相关的微观结构特征，这些特征表明了高延性断裂的几个特征，包括波状滑移和微孔形成。最后，我们讨论这些实验观察结果在电池应用中的含义。
Sodium metal has emerged as a candidate anode material in rechargeable batteries owing to its high theoretical capacity, low standard reduction potential, and abundance in the earth's crust. Prior to practical deployment, it is critical to thoroughly assess sodium's mechanical properties, as to fully understand and thus help mitigate potential failure mechanisms. Herein, we examine the fracture behavior of sodium metal through tensile tests in an inert environment. We find that sodium is nearly insensitive to flaws (crack-like features), i.e., its effective strength is virtually unaffected by the presence of flaws. Instead, under tension, sodium exhibits extreme necking that leads to eventual failure. We also characterize the microstructural features associated with fracture of sodium through scanning electron microscopy studies, which demonstrate several features indicative of highly ductile fracture, including wavy slip and microvoid formation. Finally, we discuss the implications of these experimental observations in the context of battery applications.