The battery performance of electric vehicles depends on the density and capacity of the battery; thus, the battery cells must be assembled in as many layers as possible. Electric vehicle batteries are typically composed of several cells which form modules connected by busbars, with dozens of modules manufactured as battery packs. The ultrasonic metal welding (UMW) technology is applied to such multilayered foil welding. This study analyzed UMW to ensure the weldability of multilayered Cu foils and a Ni-plated Cu strip in lithium-ion battery cells through various approaches. In UMW, the effect of the alignment on weld production and quality were examined through the energy and mechanical performance of the weld by conducting comparative experiments on the alignment of the horn and anvil. Additionally, the effects of UMW process parameters, such as the welding pressure, amplitude, and welding time, were statistically analyzed. The weldability evaluation and characteristic analysis were performed based on these variables. Furthermore, the cross-sectional shapes and microstructure behavior of the Ni layers were analyzed based on the weld quality.

中文翻译：

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锂离子电池中多层铜箔与镀镍铜片的超声波金属焊接

电动汽车的电池性能取决于电池的密度和容量；因此，电池单元必须尽可能多地组装。电动汽车电池通常由多个电芯组成，这些电芯形成由母线连接的模块，其中数十个模块制造为电池组。超声波金属焊接（UMW）技术应用于这种多层箔焊接。本研究分析了 UMW，以通过各种方法确保锂离子电池中多层铜箔和镀镍铜带的可焊性。在 UMW 中，通过对焊头和砧座的对准进行比较实验，通过焊缝的能量和机械性能来检验对准对焊缝生产和质量的影响。此外，UMW 工艺参数的影响，对焊接压力、振幅、焊接时间等进行统计分析。基于这些变量进行可焊性评价和特性分析。此外，基于焊接质量分析了镍层的横截面形状和微观结构行为。