Optimal electrode structure and density by design of mixing and calendering procedures (MiKal)

Project duration:
01.11.2019 – 31.10.2022

Institutes:

  • Institute for Particle Technology (iPAT)
  • Institute for Machine Tools and Industrial Management (iwb)
  • Münster Electrochemical Energy Technology (MEET), Center for Solar Energy and Hydrogen Research Baden-Württemberg (ZSW) – Deparment Production Research (ECP)
  • Institute for Applied Materials – Materials for Electrical and Electronic Engineering (IAM-WET)
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Partner:

KIT
TU München
MEET
ZSW
TU berlin

Electrochemical energy storage is becoming increasingly important. As a result of the German energy transition, energy storage for electric vehicle applications is a particular focus. Due to the limited installation space, a high volumetric and gravimetric energy density is decisive. On electrode level the compaction process of the coating, the calendering process, has a crucial influence of the volumetric energy density. This project focuses on the determination of the interaction of mixing processes, the resulting machine and product calendering behavior as well as the generated and performance-determining microstructure of the electrodes. This should enable the identification of optimal calendering conditions and the prediction of both the machine settings and product structure settings. For this purpose, electrodes with different conductive agent structures will be adjusted by varying the mixing intensity, the mixer types and different combinations of conductive agents (with constant total content). The aim is to derive an optimized recipe for energy electrodes and to investigate their compaction behavior, especially the interaction with the substrate. The interdependency between mixing and calendaring process is emphasized with the aim to achieve volumetrically higher energy densities with high performance. Complementary to the empirical examination, DEM simulation models will be developed to predict structural evolution and process design. Throughout the entire project, the 3D microstructure will be reconstructed for selected electrodes. FIB/SEM (sub-μm scale conductive agent structure) as well as µCT (μm scale particle and conductive agent agglomerates) will be used for a holistic view of the electrode structure. Important evaluation criteria during the project are methods of structural, mechanical and electrical characterization as well as electrochemical analyzation in full- and half-cells.