Mechanical failure of garnet electrolytes during Li electrodeposition observed by in-operando microscopy
Mechanical failure of garnet electrolytes during Li electrodeposition observed by in-operando microscopy
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DOI：
10.1016/j.jpowsour.2018.11.041
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发表时间：
2019-02-01
影响因子：
9.2
通讯作者：
Kilner, John
中科院分区：
文献类型：
--
作者：
Manalastas, William, Jr.;Rikarte, Jokin;Kilner, John
金属锂阳极是下一代固态电池实现高能量密度的关键，但存在的主要问题是锂在界面处的不均匀沉积和锂金属在运行过程中的渗透能力，这将导致陶瓷电解质失效、内部短路和电池寿命过早结束。在这项工作中，我们探讨了锂金属-石榴石电解质体系在锂电沉积过程中阳极-电解质界面的不稳定性，以及它对机械断裂、锂金属扩展和电解质失效的影响。利用光学显微镜和扫描电镜研究了电化学循环过程中降解机理。在界面的局部区域中大量的锂电沉积导致陶瓷断裂，随后通过导体锂金属丝进行电极到电极的电连接。这项工作使人们能够更深入地了解含有陶瓷电解质膜的全固态电池的电池故障模式。
Metallic Li anodes are key to reaching high energy densities in next-generation solid-state batteries, however, major problems are the non-uniform deposition of Li at the interface and the penetrative power of Li metal during operation, which cause failure of the ceramic electrolyte, internal short-circuits and a premature end of battery life. In this work, we explore the anode-electrolyte interface instability of a Li metal-garnet electrolyte system during Li electrodeposition, and its implications for mechanical fracture, Li metal propagation, and electrolyte failure. The degradation mechanism was followed step-by-step during in-operando electrochemical cycling using optical and scanning electron microscopy. High amounts of Li electrodeposition in a localized zone of the interface lead to ceramic fracture followed by an electrode-to-electrode electrical connection via a conductor Li metal filament. This work enables deeper understanding of battery failure modes in all-solid-state batteries containing a ceramic electrolyte membrane.