Classification of Calendering-Induced Electrode Defects and Their Influence on Subsequent Processes of Lithium-Ion Battery Production

The production of lithium-ion cells consists of a series of highly interlinked process steps. Calendering, as the last step of electrode manufacturing, has a significant impact on electrode characteristics. The process primarily aims at enhancing the electrode energy density and hereinafter, minimizing the plastic deformability, improving the conductivity, and determining the pore structure of the electrode. So far, electrode characteristics are mainly investigated regarding the impact on cell quality. However, they also affect their subsequent processabilities in the process chain, which is crucial for cost improvement, for example, by reduction of scrap rates. Herein, a methodical identification, description, and categorization of electrode characteristics is conducted based on a literature review, an expert survey, and operating experience. The methodical classification will provide a basis for the modeling of the interaction between the influencing factors (product properties, process parameters, and machine characteristics) and electrode characteristics during calendering.