Lithium Mechanics: Roles of Strain Rate and Temperature and Implications for Lithium Metal Batteries
Lithium Mechanics: Roles of Strain Rate and Temperature and Implications for Lithium Metal Batteries
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DOI：
10.1149/2.0221902jes
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发表时间：
2019-01-08
影响因子：
3.9
通讯作者：
Dasgupta, Neil P.
中科院分区：
文献类型：
--
作者：
LePage, William S.;Chen, Yuxin;Dasgupta, Neil P.
缺乏可靠的可充电锂金属（Li-金属）阳极是下一代电池的关键瓶颈。锂的独特机械性质影响锂金属阳极在循环期间的动态演变。虽然最近的模型旨在了解锂-金属阳极的耦合电化学-机械行为，但缺乏关于锂的本体机械性能的严格实验数据。这项工作提供了全面的力学测量锂使用的数字图像相关和拉伸测试在惰性气体环境中的组合。在很宽的应变速率和温度范围内测量了Li的变形，并将其拟合为幂律蠕变模型。应变硬化仅在高应变速率和低温下观察到，并且蠕变是在宽范围的电池相关条件下的主要变形机制。为了说明蠕变对锂金属阳极行为的作用，讨论了固态电池、“死”锂和锂阳极上的保护涂层的实例。这项工作提出了新的研究方向，并可用于为锂金属阳极的未来电化学-机械模型提供信息。(C)作者（S）2019由ECS发布。
The lack of a reliable rechargeable lithium metal (Li-metal) anode is a critical bottleneck for next-generation batteries. The unique mechanical properties of lithium influence the dynamic evolution of Li-metal anodes during cycling. While recentmodels have aimed at understanding the coupled electrochemical-mechanical behavior of Li-metal anodes, there is a lack of rigorous experimental data on the bulk mechanical properties of Li. This work provides comprehensive mechanical measurements of Li using a combination of digital-image correlation and tensile testing in inert gas environments. The deformation of Li was measured over a wide range of strain rates and temperatures, and it was fitted to a power-law creep model. Strain hardening was only observed at high strain rates and low temperatures, and creep was the dominant deformation mechanism over a wide range of battery-relevant conditions. To contextualize the role of creep on Li-metal anode behavior, examples are discussed for solid-state batteries, "dead" Li, and protective coatings on Li anodes. This work suggests new research directions and can be used to inform future electrochemical-mechanical models of Li-metal anodes. (C) The Author(s) 2019. Published by ECS.