Quality assurance for battery production

The slurry is typically applied to copper or aluminum foil using various coating processes, such as dry coating or slot-die coating either in continuous or intermittent modes. The upper and lower sides of the foil may be coated on a single side, in tandem, or simultaneously, after which the material is dried and rewound. Our coating quality assurance solutions cover key product areas, including web guiding, automatic alignment, precise control of top-to-bottom layer positioning, and comprehensive surface and edge inspection for all relevant coating configurations.

In the calendering or roll-press process, the coated copper or aluminum foil is compressed by a rotating pair of drums. Challenges in this process are the uniformity of coating thickness, density and porosity. For this process, BST offers surface inspection systems for simultaneous inspection of top and bottom side generating lift-off signal preventing infeed material damaging the calander rollers and measure material quality after calandering. Additional web guiding systems ensure the wrinkle-free positioning requirements of this production process.

During slitting, the parent roll is divided into multiple narrow webs using rotating blades. At this stage, SLITTINGControl^® simultaneously measures the daughter roll width relative to the coating positions on the top and bottom sides. In closed-loop operation with an upstream web guiding system, it ensures that any deviations are corrected before they become quality issues. In addition, iPQ-Surface ENERGY can replace the SLITTINGControl^® cameras to provide advanced particle and surface defect detection.

In the cell assembly process, for the production of prismatic, round or pouch cells, the separated electrodes are brought together with the separator in a highly precise winding, laminating or folding process to form single sheets or a 4-layer mono-cell. BST solves this application by networking multiple web guiding systems that additionally use functions such as chase/follow and offset correction. In this way, any deviation of the target positions of the individual edges can be eliminated and the precise guiding of different webs to each other can be ensured. The use of a high-resolution camera system enables reliable edge detection of all layers for returning to the production process.