Liquid Metal Alloys as Self-Healing Negative Electrodes for Lithium Ion Batteries
Liquid Metal Alloys as Self-Healing Negative Electrodes for Lithium Ion Batteries
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DOI：
10.1149/1.3591094
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发表时间：
2011-01-01
影响因子：
3.9
通讯作者：
Verbrugge, Mark W.
中科院分区：
文献类型：
--
作者：
Deshpande, Rutooj D.;Li, Juchuan;Verbrugge, Mark W.
提高电极材料的容量和耐久性是当前锂离子电池技术面临的关键挑战之一。几种很有前途的负极材料，如硅、锗和锡，其理论容量是商业使用的石墨负极的几倍。然而，由于扩散应力(DISS)引起的断裂和电化学循环过程中体积变化较大，导致循环寿命短，限制了它们的应用。在这里，我们提出了一种使用低熔点金属合金来实现高容量和提高电极材料耐用性的策略。以镓为例，我们证明了在高于镓熔点的温度下，镓的锂化(锂插入)和脱锂(脱锂)发生了可逆的固液相变。因此，一旦电极脱氢后回到液态镓中，在锂化固态中形成的裂纹就可以“愈合”。这项工作表明，裂纹作为一种失效模式，可以通过使用液态金属电极来补救。(C)2011年成立的电化学学会。[DOI：10.1149/1.3591094]版权所有。
Improving the capacity and durability of electrode materials is one of the critical challenges lithium-ion battery technology is facing presently. Several promising anode materials, such as Si, Ge, and Sn, have theoretical capacities several times larger than that of the commercially used graphite negative electrode. However, their applications are limited because of the short cycle life due to fracture caused by diffusion-induced stresses (DISs) and the large volume change during electrochemical cycling. Here we present a strategy to achieve high capacity and improved durability of electrode materials using low-melting point metallic alloys. With gallium as an example, we show that at a temperature above the melting point of Ga, a reversible solid-liquid transition occurs upon lithiation (lithium insertion) and delithiation (lithium extraction) of Ga. As a result, cracks formed in the lithiated solid state can be "healed" once the electrode returns to liquid Ga after delithiation. This work suggests that cracking as a failure mode can be remedied by using liquid metal electrodes. (C) 2011 The Electrochemical Society. [DOI: 10.1149/1.3591094] All rights reserved.