The battery cell is assuring the structural integrality of the battery and safely confines the electrolyte and the chemical reaction taking place inside. Since the chemical reaction is associated with the generation of heat and swelling of the battery material, the internal arrange of the battery components, the sealing of the cells and the arrange of the cells into packs needs to be controlled.
For the battery cell itself the stacking of the battery sheets inside the cell is critical since misplacement can lead to short circuits. Upon assembly of the cells the distances between the battery material and the cell housing needs to be controlled, as well as the position of the current collector foils and the welding quality for e.g. the sealing. Finally, a defect free burst membrane and a correct electrolyte filling level needs to be assured to guarantee overall battery safety and performance. Non-destructive X-ray imaging and metrology can provide answers to the above questions and thus are also able to reveal quality issues in the battery cell assembly process.
A battery pack has a huge number of cells, which is why stacking and connecting them is a fully automated process. Robots bring all of the different cells and spacers between them together to create battery modules. Each complete battery pack consists of a few battery modules. ZEISS coordinate measuring machines are the ideal solution to make sure every single cell is in the right position in the tray. Non-contact measuring technology like ZEISS laser triangulation is safe and reliable due to the high voltage inside the battery packs. ZEISS X-ray technology is a fast, non-destructive solution to check the connection weld seams between the single cells – ensuring full functionality and capacity.