Comparison of Tab-To-Busbar Ultrasonic Joints for Electric Vehicle Li-Ion Battery Applications

Abstract

Recent uptake in the use of lithium-ion battery packs within electric vehicles has drawn significant attention to the selection of busbar material and corresponding thickness, which are usually based on mechanical, electrical and thermal characteristics of the welded joints, material availability and cost. To determine joint behaviour corresponding to critical-to-quality criteria, this study uses one of the widely used joining technologies, ultrasonic metal welding (UMW), to produce tab-to-busbar joints using copper and aluminium busbars of varying thicknesses. Joints for electrical and thermal characterisation were selected based on the satisfactory mechanical strength determined from the T-peel tests. Electrical contact resistance and corresponding temperature rise at the joints were compared for different tab-to-busbar joints by passing current through the joints. The average resistance or temperature increase from the 0.3 mm Al tab was 0.6 times higher than the 0.3 mm Cu[Ni] tab, irrespective of busbar selection.

Blue laser welding of multi-layered AISI 316L stainless steel micro-foils

“…Under these alarming circumstances, various national and international legislative authorities are setting out stringent emission targets to reduce greenhouse gas generation for all surface transport vehicles, especially for automotive vehicles [4,7]. However, with continually growing energy needs, energy storage, including high capacity batteries and supercapacitors, is the technology of choice [8][9][10]. Energy storage devices are used as alternative power sources for electric vehicles or hybrid/ plug-in hybrid electric vehicles as well as in telecommunications and for standby power systems.…”

Ultrasonic Metal Welding of Multilayered Copper Foils to Nickel-Plated Copper Sheet in Lithium-Ion Battery Cell

“…Su et al studied recrystallization behavior by analyzing the microstructures and mechanical properties of pure Cu materials [15]. Das et al investigated welding quality through various analyzes using Al and Cu materials used for tab-to-busbar welding combination [16], and compared mechanical strength, electrical resistance, and thermal behavior [17]. Most related studies focused on single tab-to-tab or tab-to-busbar welding.…”

Impact of ultrasonic welding on multi-layered Al–Cu joint for electric vehicle battery applications: A layer-wise microstructural analysis

“…For example, multiple tabs protruded from the battery cell terminals are welded with the busbar within the battery pack of the electric vehicle [3]. Joint strength and electrical conductivity of tab to busbar joint are extremely important criteria for a successful connection [4]. The electrical conductivity through the weldments should be high enough so that the energy loss would be minimum possible [3], [5].…”