Investigations on laser beam welding of thin foils of copper and aluminum regarding weld seam quality using different laser beam sources

Abstract

Nowadays, there is a strong and growing ambition to switch from combustion technology to battery-electric drives, and energy storage is spotlighted. Laser beam welding is an appropriate and favorable welding technology in battery production. Due to the high welding speed, the local heat input, the contact freeness efficient, and automatable processes can be established. Materials used in batteries for electrodes that have to be connected are commonly copper and aluminum. Specifically, copper is highly reflective for widely used infrared laser beam wavelengths. Furthermore, the thickness in the area of 10 μm is quite challenging to deal with, in terms of gap free clamping and avoidance of damage to the material as well as distortion during welding. There is a fine line regarding energy input between burning the material and generating a lack of fusion. In the presented research, welding approaches with different laser beam sources emitting laser beams with infrared wavelengths, various beam shapes, and welding modes (continuous and pulsed) are studied. A total of 40 copper foils with a thickness of 10 μm and 40 aluminum foils with a thickness of 15 μm are welded to similar sheet metals. Aim of the process development are welds with high quality and high connection widths to provide the best electric conductivity.

Achievement of defect-free and high-properties Multilayer copper foils soft connection by Friction Stir Welding

“…As shown in Table 1, the welding material adopts the commercial copper foils material grade TU1 with a density of 8-9 g / cm 3 and a melting point of 1083 ° C. It has very low oxygen and impurity content, high purity, strong electrical conductivity, strong thermal conductivity, strong ductility, low air permeability, strong processing performance, strong corrosion resistance and strong cold resistance. The special properties are mainly used for various wires.…”

“…In the eld of multilayer copper foils welding, Resistance Spot Welding(RSW),Melt Inert Gas Welding(MIG),Laser Beam Welding(LBW) and Ultrasonic Welding (USW), the multilayer copper foils material welded together to facilitate the connection of related devices. When the above process methods are used to weld multilayer copper foils materials, there are mainly high temperatures or vibrations that affect the safety performance of the batteries and the high cost of use, which has become the major problem in the soft connection of new energy vehicles [2][3][4][5].…”

Weld Image Processing Algorithm Based on Machine Vision Detection and Industrial Internet of Things

“…Real time monitoring and remote control: With the help of industrial Internet of Things platforms, welding equipment and production processes can be monitored and controlled in real time. The data obtained through sensors can be uploaded to the cloud platform in real-time, and engineers can remotely monitor the welding process and make real-time adjustments to ensure welding quality and production efficiency [13][14] .…”

Laserstrahlschweißen in der Batteriezellproduktion/Laser beam welding in battery cell production- Contacting of thermally sensitive electrode stacks for advanced cell technologies

“…Vor dem Hintergrund dieser vielfältigen Vorteile für die Batterieproduktion und der steigenden Bedeutung von Stromkollektorfolien aus Aluminiumwerkstoffen ist es nötig, die bisher auftretenden Fehler zu eliminieren. Die Rissbildung im Nahtnebenbereich wurde weder durch die Verwendung von Strahloszillation [6] noch durch den Einsatz eines Singlemode-Faserlasers [14] oder grüner Laserstrahlung [12] vollständig vermieden. Das Schweißen des Folienstapels in einem Multi-Überlappstoß zwischen zwei Blechen ist eine Maßnahme, die Rissbildung zu reduzieren [15].…”