锂离子电池用铜箔集流体的力学性能分析  

Mechanical properties of copper current collection foils of Li-ion batteries

作　　者：朱建宇[1] 冯捷敏 王宇晖[1] 郭战胜[1,2] 

机构地区：[1]上海市应用数学和力学研究所,上海200072 [2]上海市力学在能源工程的应用重点实验室,上海200072 [3]上海大学力学系,上海200072

出　　处：《储能科学与技术》2014年第4期360-363,共4页Energy Storage Science and Technology

基　　金：国家自然科学基金(11332005);上海市自然科学基金(12ZR1410200)项目

摘　　要：集流体作为锂离子电池电极的重要组成部分,其力学性能对电极结构的设计和优化至关重要。通过表征负极用铜箔集流体的力学性能(弹性模量、屈服强度和断裂强度等),实现对集流体的合理、可靠使用,为优化电极结构提供指导。本文分别研究了三种不同厚度压延铜箔和电解铜箔的力学性能,发现电解铜箔和压延铜箔的弹性模量分别为70 GPa和50 GPa左右。铜箔的屈服强度随厚度减小而增大,表现出越薄越强的趋势。使用扫描电镜(SEM)观察微拉伸试验后的不同厚度铜箔集流体的断裂面,发现电解铜箔的断裂方式为脆性断裂,压延铜箔为韧性断裂。Mechanical properties of current collection foils, particularly the elastic moduli, and yield and fracture strengths, are critical for the design and fabrication of electrodes of Li-ion batteries. Characterization of these mechanical properties provides useful guidance for the design and subsequent manufacture of the current collectors. This paper reports our recent work on the mechanical properties of rolled copper foils and electrolytic copper foils for Li-ion batteries. Microtensile experiments were carried out and the mechanical properties are compared for two manufacturing processes and six different thicknesses. It was found that the elastic moduli were about 70 GPa and 50 GPa for electrolytic copper foils and rolled copper foils, respectively. The yield strength of the copper foils increased with decreasing thickness, showing a trend of smaller being stronger. To investigate fracture mechanisms of the copper foils, selected cross-sections of the copper foils were observed using a scanning electron microscope （SEM）. The results suggested the electrolytic copper foils failed in the brittle fracture mode, whereas the failure of the rolled copper foils was through ductile fracture.

关 键 词：集流体 铜箔 锂离子电池 断裂 

分 类 号：TM911[电气工程—电力电子与电力传动]