储能科学与技术2024，Vol.13Issue(6)：1755-1766,12.DOI:10.19799/j.cnki.2095-4239.2024.0056
锂离子电池用PET-Cu复合集流体拉伸性能研究
Study on the tensile properties of PET-Cu composite current collectors for lithium-ion batteries
摘要
Abstract
With the advancement of lithium-ion battery technology,composite current collectors have garnered significant interest due to their role in enhancing battery energy density and safety.The mechanical performance of composite current collectors is crucial for ensuring their reliable operation.This study systematically investigates the mechanical properties of commercial polyethylene terephthalate-copper(PET-Cu)composite current collectors.The surface morphology,microstructure,and tensile fracture behavior of the PET-Cu composite were characterized using scanning electron microscopy,laser confocal microscopy,and X-ray diffraction.Stress distribution in dog-bone-shaped and long-strip-shaped samples during tensile testing was analyzed and compared through finite element simulation.The effects of sampling direction,strain rate,and specimen geometry on the tensile properties were assessed using tensile tests supported by digital image correlation technology.The dog-bone-shaped samples were found to be more effective in evaluating mechanical properties,as their transition arcs alleviate stress concentration.The mechanical properties along the machined direction proved superior to those along the transverse directions,attributed to the orientation structures of the matrix.Higher loading strain rates enhanced the overall mechanical properties of the current collector.While the geometric size of the samples had minimal impact on strength,it significantly affected elongation at fracture.The primary deformation mechanism during tensile testing was identified as dislocation slip,with surface defects such as holes acting as favorable sites for crack initiation.Considering these factors is essential when testing the tensile properties of PET-Cu composite current collectors.This research provides a theoretical foundation and reliability demonstration for the practical application of composite collectors and offers a reference for developing relevant testing standards.This study's findings are poised to advance the development of lithium-ion batteries with improved energy density and safety.关键词
复合集流体/拉伸性能/有限元模拟/数字图像相关技术/应变速率敏感性/几何尺寸效应Key words
composite current collector/tensile properties/finite element simulation/digital image correlation technique/strain rate sensitivity/geometric size effect分类
信息技术与安全科学引用本文复制引用
肖峰,程福来,罗雪梅,张广平,张滨..锂离子电池用PET-Cu复合集流体拉伸性能研究[J].储能科学与技术,2024,13(6):1755-1766,12.基金项目
国家自然科学基金面上项目(52071319),中国科学院B类先导专项(XDB0510303). （52071319）
