Which welding techniques can be used for connecting battery cells?

Brass (CuZn37) test samples are used for the quantitative comparison of the welding techniques, as this metal can be processed by all three welding techniques. At the end of the presented work, the suitability of resistance spot, ultrasonic and laser beam welding for connecting battery cells is evaluated.

Can a battery cell casing be welded?

The findings are applicable to all kinds of battery cell casings. Additionally, the three welding techniques are compared quantitatively in terms of ultimate tensile strength, heat input into a battery cell caused by the welding process, and electrical contact resistance.

Does ultrasonic welding cause damage to lithium ion cells?

The highest heat input occurred at ultrasonic welding, but for all welding techniques the heat was very localized and no damaging temperatures occurred at the lithium-ion cells. The results presented in this paper were gathered within the research project EEBatt, funded by the Bavarian Ministry of Economic Affairs and Media, Energy and Technology.

What is the smallest energy storing component in a battery?

Within any battery storage, the smallest energy storing component is the battery cell or short cell. Whereas for mobile devices, e.g., laptops, only a few cells are combined, in large battery assemblies up to several thousand cells have to be connected.

Can ultrasonic weld damage a battery cell?

The counterpart has to be fixed but may have any thickness. It was reported that ultrasonic weld vibrations can damage the inside of a pouch cell, especially when the conductors inside the battery cell are also ultrasonically welded. In order to prevent the propagation of the vibrations into the cell, the terminal tabs need to be clamped .

What is laser beam welding?

For battery assemblies, joining of two different metals can be required, e.g., an aluminum cell terminal with a copper external conductor . When laser beam welding is used, the two molten materials are mixed and a metallurgical system is generated, which influences the mechanical properties.