In this work, the process of keyhole welding was used to connect battery cells. The functional principle is shown in the illustration in Fig. The laser beam reaches high power densities I > 10 12 W/m 2, which melt and evaporate the metals.
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 does resistance welding affect a battery cell?
4.1.2 Effect on the battery cell Small-scale resistance welding is often the preferred method for joining Li–ion batteries into battery packs. This process ensures strong joints with an almost complete elimination of the heat impact on the joined workpieces during a short time.
Which welding process is best for Li-ion battery applications?
The bonding interface eliminates metallurgical defects that commonly exist in most fusion welds such as porosity, hot-cracking, and bulk inter-metallic compounds. Therefore, it is often considered the best welding process for li-ion battery applications.
Why is parameter control important in battery cell welding?
Parameter control also allows LBW to adapt to the thickness of the material tabs and can create thin or thick weld nuggets. In battery cell welding it is important to create thin welds due to the relatively thin battery cases and the risk of the weld penetrating the case and thus damaging the core.
How does welding affect a battery?
Thus the welding method has a minimal impact on the battery as there are no catalyzing reactions in the battery caused by the heat. On the other hand deformation may occur if too great of a welding force is applied by the electrodes. This deformation may alter the temperature distribution and hinder the current from flowing the shortest path.
Does a weld cause resistance heating of a battery?
Hence, the weld would not cause any significant resistance heating of the battery during charge or discharge . 4.3.2 Effect on the battery cell High currents must flow through the welds between battery cells in order to deliver the electricity needed to power a battery electric vehicle. These welds are the bottleneck of the electric circuit.