Ultrasonic Metal Welding is the standard process for welding aluminum and copper foils in battery cell production. Batteries for Electric Vehicles and Energy Storage bring new requirements to the industry and to ultrasonic metal welding.

The trend is going to batteries with more energy content. Besides improvements in battery chemistries, this is done by bigger foils, more foils and thinner foils. Due to higher current bigger welding areas are used to reduce the electrical resistance.
For ultrasonic metal welding this means that more power is needed to weld the applications and they are more sensitive due to the thinner copper and aluminum foils.

Originally lithium-ion batteries were used mainly for electronics, like smartphones. Now they are used more and more in electric vehicles, which requires them to be produced according to automotive requirements. This brings new requirements, especially regarding process reliability and process documentation.

In this presentation a short introduction to ultrasonic metal welding is given. Additionally, the current possibilities of ultrasonic metal welding to solve the challenges for these new applications are shown. Up to 150 aluminum or copper foils can be welded with ultrasonic metal welding. The welding width can be up to 90mm.

Besides that, the possibilities for documentation of process data, integration with MES systems and the tracking possibilities are shown. If there would be a failure in a battery cell during the life-cycle, the process data for each specific cell will be tracked.