Crack Pattern Formation in Thin Film Lithium-Ion Battery Electrodes
Crack Pattern Formation in Thin Film Lithium-Ion Battery Electrodes
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DOI：
10.1149/1.3574027
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发表时间：
2011-01-01
影响因子：
3.9
通讯作者：
Cheng, Yang-Tse
中科院分区：
文献类型：
--
作者：
Li, Juchuan;Dozier, Alan K.;Cheng, Yang-Tse
电化学循环过程中大体积变化和相关的锂扩散引起的应力引起的电极开裂是使用高容量负极材料（例如硅和锡）的锂离子电池循环寿命短的主要原因之一。在这项工作中，我们研究了电化学循环导致的非晶硅薄膜电极的断裂行为和裂纹模式。改进的弹簧块模型可以捕捉电极材料裂纹模式的基本特征，包括自相似性。结果表明，厚膜中的裂纹是直的，但在薄膜中则显示出更多的蠕动。随着薄膜厚度的减小，由裂纹分隔开的岛的平均尺寸减小。对于非晶硅薄膜，发现了低于该材料不会破裂的临界厚度。这项工作的实验和模拟结果为通过电极图案化和减小薄膜厚度来设计循环过程中无裂纹的薄膜锂离子电池电极提供了指导。 (C) 2011 年电化学协会。 [DOI：10.1149/1.3574027]
Cracking of electrodes caused by large volume change and the associated lithium diffusion-induced stress during electrochemical cycling is one of the main reasons for the short cycle life of lithium-ion batteries using high capacity anode materials, such as Si and Sn. In this work, we study the fracture behavior and cracking patterns in amorphous Si thin film electrodes as a result of electrochemical cycling. A modified spring-block model is shown to capture the essential features of cracking patterns of electrode materials, including self-similarity. It is shown that cracks are straight in thick films, but show more wiggles in thin films. As the thickness of film decreases, the average size of islands separated by cracks decreases. A critical thickness bellow which material would not crack is found for amorphous Si films. The experimental and simulation results of this work provide guidelines for designing crack free thin-film lithium ion battery electrodes during cycling by patterning the electrode and reducing the film thickness. (C) 2011 The Electrochemical Society. [DOI: 10.1149/1.3574027]