Battery technology – the heart of electromobility
It is expected that by 2030 the majority of cars produced will be electrically operated. That is why the production capacity for battery cells is rising and the predicted investments in battery cell factories are already exceeding by several fold the global production volume in 2022. A core process in the production of battery cells is the processing of the electrode foils and separators. Different processes are used for different cell types. This includes the winding of foil tracks to produce so-called “jelly rolls”. Various stacking processes ensure that cell stacks are formed from the individual anodes, cathodes and separators. The winding processes are already characterized by high speeds and process stability. And the stacking of battery cells offers advantages for the electrical performance of the batteries. The combination of the two processes is referred to as Z-folding, where individual electrode sheets are connected with a separator just prior to folding.
High stacking speed as key challenge
When further developing the stacking and Z-folding processes for battery cells, increasing the stacking speed is a key challenge. A team lead by Prof. Franz Dietrich, Professor for Handling and Assembly Technology at the Institute of Machine Tools and Factory Management, TU Berlin, is tackling this challenge. One related task is: The speeding up of the processes must not, however, have a negative impact on the precise placement accuracy of the stacked electrode sheets. In contrast to conventional process alternatives that use sequential pick-and-place operations, TU Berlin therefore developed a continuous process sequence: from pickup and handling right through to positioning and alignment of the electrode sheets. Compared to established process sequences, the aim in future is to significantly increase the productivity with a constant and up to 2,000 mm/s fast feed rate for the materials.
