Numerical and experimental investigation on the defect formation in lithium-ion-battery electrode-slot coating

Defect-free slot coating is important in the design and manufacturing of lithium-ion-battery electrodes. However, the defect formation in electrode-slot coating is not clearly understood because of the involvement and coupling of many parameters. Here, we investigate the defect formation mechanisms in electrode-slot coating by using numerical and experimental methodologies. Three defects, namely, striped, spotted, and irregular, are observed. The striped defect is related to downstream menisci contraction; however, the spotted and irregular defects are associated with the unstable development of the sawtooth dynamic contact line. In addition, three regions for the capillary number and minimumthickness-based coating window are found, and the dominant force in each region is clarified. The results indicate that a higher maximum coating speed can be obtained for a lower coating gap, and the maximum coating speed of the underbite die configuration increases by 25.6% compared with that of the normal die configuration. (C) 2022 Elsevier Ltd. All rights reserved.

Automated summary

In this study, the defect formation mechanisms in electrode-slot coating were investigated using numerical and experimental methodologies. Three types of defects, namely striped, spotted, and irregular, were observed. The dominant forces in different coating window regions were identified, and it was found that the underbite die configuration had a higher maximum coating speed compared to the normal die configuration.