Energy storage lithium battery welding process

Can laser beam welding reduce electrical losses between lithium-ion cells?

In the course of developing high performance battery systems, which consist of over a hundred single cells, the energy efficiency still needs to be increased. One promising measure concerning this purpose is to reduce the electrical losses of contacts between the lithium-ion cells using laser beam welding.

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 can battery terminal welding prevent damage to a battery cell?

In order to prevent damage to the battery cell, it is necessary to ensure that the heat input of the battery terminal welding process is kept low and that the depth of penetration is uniform. Due to the significant impact on energy input, battery welding requires lasers with a small focal point diameter and high energy density [106, 107].

Why do battery cells need to be welded?

Battery cells are most often put into modules or packs when produced for electrically driven vehicles. The variable of greatest influence when welding battery packs is the contact resistance between the cell and the connection tab. It is crucial to minimize this variable as much as possible to prevent energy loss in the form of heat generation.

How do you Weld a battery?

The search was then performed using Uppsala University’s Library database and Google scholar which cover a wide range of articles and sources. Three methods for welding batteries were given in the template, being laser beam-, ultrasonic-, and resistance spot welding.

Why are lithium-ion battery cells used in energy storage devices?

Due to the high energy density of Lithium-ion battery cells of 18650-type (in this case 162 Wh/kg) the usage in energy storage devices increases. Furthermore these cells offer ready availability and low prices. To reach high and suitable energy capacity several of the cells have to be connected in parallel.