Adair Keegan R, Banis Mohammad Norouzi, Zhao Yang, Bond Toby, Li Ruying, Sun Xueliang
Department of Mechanical and Materials Engineering, University of Western Ontario, London, ON, N6A 5B9, Canada.
Canadian Light Source, Saskatoon, SK, S79 2V3, Canada.
Adv Mater. 2020 Aug;32(32):e2002550. doi: 10.1002/adma.202002550. Epub 2020 Jul 1.
The Li metal anode has been long sought-after for application in Li metal batteries due to its high specific capacity (3860 mAh g ) and low electrochemical potential (-3.04 V vs the standard hydrogen electrode). Nevertheless, the behavior of Li metal in different environments has been scarcely reported. Herein, the temperature-dependent behavior of Li metal anodes in carbonate electrolyte from the micro- to macroscales are explored with advanced synchrotron-based characterization techniques such as X-ray computed tomography and energy-dependent X-ray fluorescence mapping. The importance of testing methodology is exemplified, and the electrochemical behavior and failure modes of Li anodes cycled at different temperatures are discussed. Moreover, the origin of cycling performance at different temperatures is identified through analysis of Coulombic efficiencies, surface morphology, and the chemical composition of the solid electrolyte interphase in quasi-3D space with energy-dependent X-ray fluorescence mappings coupled with micro-X-ray absorption near edge structure. This work provides new characterization methods for Li metal anodes and serves as an important basis toward the understanding of their electrochemical behavior in carbonate electrolytes at different temperatures.
锂金属阳极因其高比容量（3860 mAh g）和低电化学势（相对于标准氢电极而言为-3.04 V），长期以来一直是锂金属电池应用中备受追捧的对象。然而，锂金属在不同环境中的行为却鲜有报道。在此，利用先进的基于同步加速器的表征技术，如X射线计算机断层扫描和能量相关X射线荧光映射，从微观到宏观尺度探究了锂金属阳极在碳酸盐电解质中的温度依赖性行为。文中举例说明了测试方法的重要性，并讨论了在不同温度下循环的锂阳极的电化学行为和失效模式。此外，通过结合能量相关X射线荧光映射和微X射线吸收近边结构，在准三维空间中分析库仑效率、表面形态以及固体电解质界面的化学成分，确定了不同温度下循环性能的来源。这项工作为锂金属阳极提供了新的表征方法，并为理解其在不同温度下碳酸盐电解质中的电化学行为奠定了重要基础。
