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.
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.
Laser welding is widely used in lithium-ion batteries and manufacturing companies due to its high energy density and capability to join different materials. Welding quality plays a vital role in the durability and effectiveness of welding structures. Therefore, it is essential to monitor welding defects to ensure welds quality.
Furthermore, battery tabs or connector bars with a thickness of several millimeters can be joined by keyhole welding , . Especially for metal surfaces, the reflection of the laser beam is problematic, because it can damage objects in close vicinity.
This welding process is used primarily for welding two or more metal sheets, in case of battery it is generally a nickel strip and positive terminal/negative terminal of the battery together by applying pressure and heat from an electric current to the weld area. Advantages: Low initial costs.
Can be used to weld critical parts like battery tabs and foils. Challenges faced by using laser welding: Wire bonding is well matured technology which was invented for the semiconductor industry and standard technology for semiconductor chips since 1970s, and also Tesla and ola electric batteries are wire bonded.