Mechanical behavior of a battery separator in electrolyte solutions
Mechanical behavior of a battery separator in electrolyte solutions
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DOI：
10.1016/j.jpowsour.2011.06.026
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发表时间：
2011-10-15
影响因子：
9.2
通讯作者：
Hitt, Jonathon
中科院分区：
文献类型：
--
作者：
Sheidaei, Azadeh;Xiao, Xinran;Hitt, Jonathon
隔膜的结构完整性对于电池的滥用耐受性至关重要。为了估计其在电池中的应力水平，必须知道隔膜在电池环境中的原位机械性质。采用动态力学分析仪（DMA）研究了单层聚丙烯（PP）隔膜在锂离子电池电解液中的拉伸行为。在干燥（环境）和湿润条件下对纵向（MD）和横向（TD）进行测量。在湿条件下，将样品浸没在DMC溶剂中或浸没在EC/DMC（体积比1/1）中的1.1M LiPF 6的电解质溶液中。DMA实验在单轴拉伸、蠕变和频率扫描模式下进行。在所有三种模式下的结果表明，隔膜的机械性能在潮湿条件下显著较低。例如，在MD中，相对于干燥条件，对于DMC和EC/DMC中的1.1M LiPF 6，杨氏模量的比率分别为约0.49和0.52。结果表明，在干燥条件下使用已在溶液中预处理的样品测量的机械性能不足以代表原位材料行为。(C)2011 Elsevier B. V.保留所有权利。
The structural integrity of the separator is crucial to the abuse tolerance of a battery. To estimate its stress level in a battery, the mechanical property of the separator in situ in the battery environment must be known. This work investigated the tensile behavior of a single layer polypropylene (PP) separator in electrolyte solutions for Li-ion batteries using a dynamic mechanical analyzer (DMA). The measurements were carried out in both dry (ambient) and wet conditions for both the machine direction (MD) and the transverse direction (TD). In the wet condition, samples were submerged either in a DMC solvent or in a electrolyte solution of 1.1 M LiPF6 in EC/DMC (1/1 by volume). The DMA experiments were performed under uniaxial tension, creep, and frequency sweep modes. The results in all three modes demonstrated that the mechanical properties of the separator were significantly lower in wet conditions. For instance, in the MD, relative to the dry condition, the ratio of the Young's modulus was about 0.49 and 0.52 for DMC and 1.1 M LiPF6 in EC/DMC, respectively. The results indicate that the mechanical properties measured in dry condition using samples that had been preconditioned in solutions are not sufficient to represent the in situ material behavior. (C) 2011 Elsevier B.V. All rights reserved.