The effect of horn knurl geometry on battery tab ultrasonic welding quality: 2D finite element simulations

Ultrasonic welding has become a major joining technique in battery and battery electric vehicles. Even though there have been several numerical analyses, simulations of ultrasonic welding for multiple sheets and dissimilar metals with the actual tool geometry (such as the knurl pattern of the horn, or horn) have not been reported. In this study, finite element procedures for the ultrasonic welding process are developed using 2D plain-strain elements. The procedure focuses on simulating localized deformation behavior of battery tab welding for different knurl geometries with very affordable computations. The procedure has been validated, and the results provide guidelines for designing the horn knurl geometry to improve the weld quality. The research provides scientific understanding and guidelines for improving ultrasonic weld quality of battery packs.