Goals

The aim of the project is to increase the efficiency in the production of battery modules and packs by modularizing the battery design, the electrical connection concepts on the cell level, and the development of a cost-effective joining technology for variable connection cross-sections. This is to be achieved by the use of a newly developed laser bonding technique, which does not require complicated contact-plate structures and is designed flexibly with regard to line cross-section and connector geometry. This technique is based on the combination of known ribbon bonding and laser beam welding. This results in a novel, hybrid joining technology, the potential of which is primarily the high flexibility. The combination with laser beam welding as the actual joining process overcomes the existing limitations of ultrasonic bonding technology, since both the surface condition of the terminals do not have to meet the high requirements with regard to bondability, and the freedom of the material selection and possible geometry with regard to the ribbons increases.

Summary objectives in the project:

• Realization of a laser-based bonding and joining process for aluminum and copper strips with contact cross-sections  ³ 500 μm thickness and up to 10 mm width
• Integration of the laser bond into a bond machine for bond rates of up to 5 bonds / second
• Development of a flexible and robust laser joining process for multi-layer hybrid materials and a combination of punching grid and bonding tape
• Development of a form-flexible punching grid system for contacting several cells in combination with single bonds
• Development of multilayer bond ribbons for maximum conductivity with high process robustness