Modelling of the Calendering Process of NMC‐622 Cathodes in Battery Production Analyzing Machine/Material–Process–Structure Correlations

Abstract

The shift in the transport sector from internal combustion engines to battery‐powered electric vehicles and the continued demand for portable applications increases the need for batteries in the coming years. To optimize battery technologies, it is essential to fully understand the production process and the associated parameters as well as their influence on the chemical processes within the cell. At the Institute for Machine Tools and Industrial Management (iwb), extensive knowledge of the calendering process is gathered including the investigation of the displacement behavior for both the calender rolls and the bearing, as well as the adhesion strength. The process parameters such as roll temperature and velocity, structure parameters (e. g., coating thickness, adhesion strength), and machine behavior parameters (displacement and bending line) are investigated using three calender models. The achieved porosities are verified via porosity consistency measurements. Based on the collected data, qualitative machine/material–process–structure models are built up. Scanning electron microscopy (SEM) and light microscopy support the relations made. In addition, a connection between vertical displacement and line load is established.

Accelerating Battery Manufacturing Optimization by Combining Experiments, In Silico Electrodes Generation and Machine Learning

“…One of them is the contacts between the solid phase and the CC, which is closely related to the adhesion strength and contact resistance of the electrode, and is modulated by the calendering process. 51,52 Figure 8 shows the ML-predicted %CC-CBD, i.e. the percentage of current collector surface covered by the CBD phase, based on the pressure applied during the calendering for different and AM mass fractions.…”

Calendering of Li(Ni0.33Mn0.33Co0.33)O2‐Based Cathodes: Analyzing the Link Between Process Parameters and Electrode Properties by Advanced Statistics

“…Note that line speed was not considered, as in all the ANCOVA tests performed no significant impact on the observables’ variabilities was found. This is probably due to low line speed operating interval (which is constrained by the calendering machine) and it is expected that at higher line speeds this parameter should have some effect [33] . Porosity is mainly controlled by the calendering pressure (negative correlation) while the mechanical properties have a shared temperature/pressure control (positive correlation).…”

“…This is probably due to low line speed operating interval (which is constrained by the calendering machine) and it is expected that at higher line speeds this parameter should have some effect. [33] Porosity is mainly controlled by the calendering pressure (negative correlation) while the mechanical properties have a shared temperature/ pressure control (positive correlation). For the case of the particle contact strength/electrode adhesion (W el /W pl ), a very low percentage of its variability is explained by the calendering parameters, as discussed before.…”

The Role of Pilot Lines in Bridging the Gap Between Fundamental Research and Industrial Production for Lithium‐Ion Battery Cells Relevant to Sustainable Electromobility: A Review

“…[ 104 ] In general, the targeted porosity during calendaring is a compromise between good ionic conductivity (high porosity) and high electrical conductivity (low porosity). [ 135 ] Coating detachment describes a separation of coating from the current collector foil. To some extent, this defect can be reduced by adjusting the calendering parameters, as adhesion properties can be improved by calendering.…”