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

Abstract

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).