Energy storage welding bonding strength

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.

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.

How much force should be used to weld materials?

Among the results, the authors found that a modest amount of force is most desirable to avoid spatter, poor weld joints, or severe deformation of the materials. Welding time and voltage have similar effects such as excessive heat generation, the creation of burn marks, and deformation of the workpieces.

What is resistance spot welding?

Resistance spot, ultrasonic or laser beam welding are mostly used for connecting battery cells in the production of large battery assemblies. Each of these welding techniques has its own characteristics depending on the material properties and contact geometry. Cell casing and terminal dimensions may constrain possible contact geometries.

Why is welding important for EV battery systems?

Welding is a vitally important family of joining techniques for EV battery systems. A large battery might need thousands of individual connections, joining the positive and negative terminals of cells together in combinations of parallel and series blocks to form modules and packs of the required voltage and capacity.

How does resistance welding work?

Resistance welding passes an electric current between a pair of electrodes and though the materials to be joined, relying on the heat generated by ohmic resistance to melt and fuse them. It is a proven and relatively cheap process, but has limitations in the applications and geometries to which it is suited.