(1. 中国科学院力学研究所 先进制造工艺力学重点实验室，北京 100190；
2. 山东聚信新能源科技有限公司，滨州 256200)
摘 要: 针对铝箔集流体表面改性的要求，基于激光毛化技术轧制13 μm厚的1070铝箔，研究表面毛化参数对铝箔的力学性能和作为锂离子电池正极集流体的加工性能的影响。表面毛化铝箔的表面粗糙度Ra达到0.7~1.0 μm，为常规铝箔的7.4~9.7倍，表面毛化坑诱导的应力集中效应使铝箔的屈服强度和拉伸强度降低4%~10%，而表面毛化坑造成的铝箔局部减薄和板型变化对伸长率的影响更加显著。采用相互分离的低密度毛化坑(分布参数140 μm×140 μm)时，表面毛化铝箔的伸长率仅降低约10%。而采用相切的高密度毛化坑(分布参数70 μm×70 μm)时，表面毛化铝箔的伸长率降低约50%。两种表面毛化铝箔制成的正极极片的LiCoO2涂层剥离强度均达到常规铝箔极片的1.6倍，分散性仅为常规铝箔极片的16%~32%。毛化铝箔的表面粗糙度Ra值在0.7 μm附近存在临界点，继续增大不能有效地提高涂层对铝箔集流体的剥离强度，反而损失其力学性能。模拟锂离子电池正极极片的辊压和烘干工艺后，表面毛化铝箔(分布参数140 μm×140 μm)的力学性能与常规铝箔的相当，但铝箔表面毛化坑诱导的应力集中现象能够促进铝箔均匀变形，抵抗局部损伤能力强，提高电池卷芯对整形压力的宽容度，有助于避免最内层极片的局部断裂现象。
关键字: 激光表面毛化；铝箔集流体；力学性能；剥离强度
（1. Key Lab of Mechanics in Advanced Manufacturing, Institute of Mechanics, Chinese Academy of Science, Beijing 100190, China;
2. Shan Dong JU XIN Amperex Technology Ltd, Binzhou 256200, China）
Abstract:According to the requirement of surface modification of aluminum foil as current collector, a kind of 1070 aluminum foil with the thickness of 13 μm was rolled by laser texturing technology. The effects of surface texturing parameters on the mechanical properties of aluminum foil and its processing properties as a positive electrode current collector for lithium-ion battery were studied. The Ra value of surface textured aluminum foil is about 0.7-1.0 μm, which is 7.4-9.7 times than that of normal aluminum foil. It is found that the stress concentration effect induced by the surface textured craters reduced the yield strength and tensile strength of aluminum foil from 3.4%-11.5%, and the local thinning of aluminum foil and the change of plate shape caused by the surface texturing craters have more significant effect on the elongation of aluminum foil. With the separated low density surface textured craters (distribution parameter 140 μm×140 μm), the elongation of the aluminum foil is only reduced about 10%. However, with the tangential high density surface textured crater (distribution parameter 70 μm×70 μm), the elongation of the aluminum foil is reduced by about 50%. The adhesion strength of LiCoO2 coating of positive electrode slice to the surface textured aluminum foil is 1.6 times than that to the normal aluminum foil, and the mean squared error of the former is only 16%-32% than the latter. It is a critical point of surface roughness about Ra 0.7 μm for the surface textured aluminum foil that higher Ra than it can not effectively improve the adhesion strength of the positive electrode coating to aluminum foil as current collector, but loses the mechanical properties of aluminum foil. After simulating the rolling process and drying process of the positive electrode slice of lithium-ion battery, the mechanical properties of the surface textured aluminum foil (distribution parameter 140 μm×140 μm) are similar with those of the normal aluminum foil. However, the uniform deformation of aluminum foil is promoted by the stress concentration phenomenon induced by textured craters on the surface of aluminum foil to have strong resistance to local damage of aluminum foil and higher tolerance to the shaping pressure of the battery coil. It is helpful to avoid the local fracture phenomenon of the innermost positive electrode splice.
Key words: laser surface texturing; aluminum foil current collector; mechanical property; adhesion strength
