Comparison of PVDF and PVDF-TFE-P as binders for electrode materials showing large volume changes in lithium-ion batteries
Comparison of PVDF and PVDF-TFE-P as binders for electrode materials showing large volume changes in lithium-ion batteries
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DOI：
10.1149/1.1586922
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发表时间：
2003-08-01
影响因子：
3.9
通讯作者：
Dahn, JR
中科院分区：
文献类型：
--
作者：
Chen, ZH;Christensen, L;Dahn, JR
三元共聚物聚（偏二氟乙烯-四氟乙烯-丙烯）（PVDF-TFE-P，BRE-7131 X，Dyneon Corp.）的机械和电气性能及其炭黑填充复合材料（无活性阳极材料）进行了仔细研究，并与PVDF（Solef 1008）进行了比较。高容量阳极材料如a-Si和a-Si0. 64Sn0. 36在充电/放电循环期间具有高达250%的体积变化，这对锂离子电池电极中使用的标准粘合剂的机械性能提出了挑战。对干燥聚合物膜和浸入Li离子电池中常用的非水溶剂（碳酸亚乙酯/碳酸二乙酯，EC/DEC，1：2体积比）中的膜进行测量。PVDF及其碳填充复合材料显示出小于10%的最大断裂前伸长率。然而，三乙烯四胺交联的BRE-7131X及其碳填充复合材料在空气中和EC/DEC（体积比1：2）中断裂之前可以拉伸到超过100%的应变。此外，在拉伸/收缩循环期间，碳填充的交联BRE-7131X膜的应力和电阻率可逆地变化。(C)2003年电化学学会。
The mechanical and electrical properties of a terpolymer, poly(vinylidene fluoride-tetrafluoroethylene-propylene) (PVDF-TFE-P, BRE-7131X, Dyneon Corp.) and its carbon black-filled composites (without active anode material) have been investigated carefully and are compared to those of PVDF (Solef 1008). High capacity anode materials such as a-Si and a-Si0.64Sn0.36 have up to 250% volumetric changes during charge/discharge cycling which challenges the mechanical properties of standard binders used in Li-ion battery electrodes. The measurements were carried out on dry polymer films and on films immersed in a nonaqueous solvent commonly used in Li-ion cells (ethylene carbonate/ diethyl carbonate, EC/DEC, 1: 2 by volume). PVDF and its carbon-filled composites show a maximum elongation before break of less than 10%. However, triethylenetetramine crosslinked BRE-7131X and its carbon-filled composites can be stretched to more than 100% strain before breaking in air and in EC/DEC (1: 2 by volume). Furthermore, the stress and the resistivity of the carbon-filled crosslinked BRE-7131X films changes reversibly during elongation/contraction cycles. (C) 2003 The Electrochemical Society.