Strong industry partnerships
for more sustainability
Batteries are the guarantor for emission-free and sustainable mobility. They are drivers of the energy and transport revolution. However, their production is still often accompanied by high scrap rates and high energy consumption. Herrmann Ultraschall and Customcells have set themselves the goal of changing this and looked for ways to optimize battery production from the ground up. The solution: modern ultrasonic welding machines, smart technologies and know-how accumulated over decades ensure safe, efficient and sustainable production.
"With Herrmann Ultraschall, we have a reliable partner in the field of safe welded joints at our side. Herrmann's ultrasonic equipment makes a significant contribution to improving our product quality. At Customcells, we attach great importance to sustainability and energy efficiency and are therefore extremely satisfied with the excellent cooperation and the joint implementation of the latest technologies. We can recommend Herrmann Ultraschall without reservation."
Christian Zender, Director Customcells Tübingen GmbH
Although batteries are a green technology, the production of pouch cells is often still not sustainable enough. Sensitive cell materials are joined together using thermal joining processes such as heat sealing. This not only involves high energy consumption, but also the risk of damaging the sensitive materials. Rejection rates of up to 20 percent are therefore often the norm in the industry. A safer and more environmentally friendly alternative is now available, which is already providing high savings potential in another industry and, thanks to Customcells' cooperation with Herrmann Ultraschall, is now also finding its way into pouch cell production.
Specifically, pouch packaging has been sealed with ultrasound for decades. The process allows companies to save up to 75 percent energy by eliminating the need for external heat. Also, the ultrasonic sealers do not heat up. Herrmann Ultraschall has succeeded in transferring this know-how to the welding of pouch cells and, together with Customcells, has brought it into actual application, where the process has already proven successful.
"We are making an important contribution to the continent's technological sovereignty with the development and production of application-specific battery cells in the heart of Europe. At the same time, it is absolutely clear that we can only be successful in the long term if we are able to further reduce reject rates and thus costs. Innovative industrial partners such as Herrmann Ultraschalltechnik help us to achieve precisely this goal."
Dirk Abendroth, CEO of the Customcells Group
Specifically, the welding technology from Karlsbad is used to perform the pre-weld and main weld on pouch cells. The first step in the pre-welding process is to weld together the individual layers of copper foil for the anode and the layers of aluminum foil for the cathode. In a second step, the main welding, the so-called tabs are welded to the cathode and anode, with which the individual battery cells are later joined together. The HiS VARIO B 20 kHz systems from Herrmann Ultraschall, which were specially developed for welding battery applications with multilayer foils, provide a stable process for joining the individual layers.
To achieve reject rates close to 0 percent in the respective application fields, process monitoring comes into play. Up to 150 parameters are recorded and stored for each individual weld. This enables reproducible welding results and thus minimized scrap. This also applies to the process transferred to battery cell production, which significantly reduces material consumption.
For the application at Customcells, the sonotrodes of the ultrasonic welding machines were precisely adapted to the respective size of the tabs, which are smaller than usual for this welding project at Customcells. The adjustment to the size of the tabs enables a reliable, material-locked connection between the tab and the anode or cathode. Welding tests in the ultrasonic laboratory showed that the cells used by Customcells could be joined reliably and gently with a sonotro design already developed. After a short time, the appropriate welding parameters could also be defined. This rapid evaluation of appropriate welding parameters in turn made it possible to switch production at the Tübingen site to Herrmann Ultraschall's systems with virtually no downtime.
In a further step, a welding process for sealing pouch cells is now being jointly developed. Up to now, welding processes have mainly been developed for use at manual workstations for smaller quantities. With the development of a process for sealing battery cells in automated systems, there is further potential to make production considerably more efficient with shorter cycle times.
"In CUSTOMCELLS, we have found a reliable and innovative development partner that helps us to prove our empirical values and know-how from our ultrasonic laboratories in practice as well. This will enable us to further optimize processes and achieve our goal of truly sustainable, process-safe battery production."
Markus Haas, Global Sales Director METALS at Herrmann
As a specialist in ultrasonic welding, Herrmann has been about inspiring its customers for over 60 years. For this purpose, a combination of services was developed with Herrmann Engineering, with which more than 600 employees in over 20 countries successfully implement projects together with their customers. "Bonding - more than materials" is the guiding principle here, which stands for trusting cooperation at eye level. As a result, more than 2,000 different applications in key industries such as automotive, medical, hygiene, and packaging can be solved every year.