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.

Do welding processes need a power source?

Traditionally, welding processes in the construction sector have relied on conventional power sources, presenting a myriad of challenges. From erratic power supply to high operational costs and environmental concerns, the limitations of these traditional solutions have been evident.

What materials can be welded?

This means that highly electrically conductive materials, such as copper or aluminum, can be welded, but some difficulties arise with hard materials such as steel. The needed welding power depends on the thickness of the metal sheet vibrated by the sonotrode. The counterpart has to be fixed but may have any thickness.

How is welding heat generated?

The welding heat is generated by the electrical power Pweld, which results from the welding current Iweld flowing through the contact resistance at the interface of the work pieces Rweld (see Fig. 4) , . (4) P w e l d = R w e l d × I w e l d 2

What is ultrasonic welding?

Ultrasonic welding is a solid-state welding technique and does not depend on the melting temperatures of the work pieces. The temperatures of the welding process are low, as will be discussed in detail in Section 6. Ultrasonic welding is capable of joining dissimilar materials , . Furthermore, also multiple metal layers can be joined .

How does welding energy affect electrical contact resistance and tensile force?

Further increasing the welding energy leads to electrode sticking and significant expulsion of bulk material , , , . Fig. 6. Electrical contact resistance and ultimate tensile force as function of welding energy.