加载角度和线型缺口对锂离子电池隔膜拉伸性能的影响

Effects of Loading Angle and Linear Notch on Tensile Properties of Lithium-Ion Battery Separator

锂离子电池隔膜作为防止正负极接触的物理屏障,其结构完整性对于电池安全至关重要。进行了4种商业隔膜单轴拉伸实验,分析加载角度和线型缺口对隔膜材料拉伸强度、弹性模量、断裂模式的影响。结果表明:无缺口试样在0°方向上的拉伸强度最大,90°方向上拉伸强度最小;当两个无缺口试样的加载角度互为补角时,它们的拉伸强度接近。对于缺口试样而言,缺口方向沿着90°的试样有最大破坏载荷;线型缺口试样有更高的弹性模量,但是塑性变形大幅减少。无缺口试样和缺口试样在拉伸过程中的断裂模式相同,即除0°试样沿横向断裂外,其他加载角度的试样均沿着纵向断裂。

Lithium-ion battery separators act as the physical barriers to prevent contact between the positive and negative electrodes,and their structural integrity is critical to battery safety.In this paper,uniaxial tensile tests were carried out on four kinds of commercial separators,and the effects of loading angle and linear notch on tensile strength,elastic modulus and fracture mode were analyzed.The results show that the tensile strength of the 0°specimens without notch is the largest and the tensile strength of 90°specimens is the smallest.When the loading angles of two notched specimens are supplementary,their tensile strength is close to each other.For the notched specimens,the failure load is the largest when the notched direction is along 90°.The linear notched specimens have higher elastic modulus,but the plastic deformation is greatly reduced.Both the unnotched specimens and the notched specimens are broken along MD(machine direction)except for the 0°specimens along TD(transverse direction).