Typically, battery interconnects are made from nickel strips, ideally designed with bifurcations and projections which are then resistance welded using parallel gap or step welding methods.
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.
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.
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.
This therefore provides a highly controlled method of developing localised welding temperatures that are suitable for joining materials up to 0.5 mm thick onto conductive battery cans. The TIG battery welding process has been tested and proven with a number of battery pack designs using nickel, aluminium and copper flat.
Can ultrasonic welding be used for complex battery design or shape?
Cannot be used for complex battery design or shape. Ultrasonic welding is a solid-state welding technique. In this type of welding workpieces are not melted but pressed and scrubbed together with high frequency vibrations hence no need of electrode, filler material.
Can keyhole welding be used on battery tabs & connector bars?
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.