PEM Aims at Optimizing Final Production Steps of Lithium-Ion Batteries
The chair "Production Engineering of E-Mobility Components" (PEM) of RWTH Aachen University is dedicated to the optimization and consolidation of the final production steps of lithium-ion battery cells in the research project "FormEL". The background is that the first charge and discharge cycles of a lithium-ion battery during formation have a decisive influence on the performance, aging and safety of the cell. After "aging", the cell quality parameters of capacity, impedance, internal resistance and self-discharge are finally determined in the end-of-line (EoL) test and checked for a position within a specified tolerance window. These steps are bislag costly and time consuming.
Physical models for electrochemical processes
In the project "Determination of process-quality relationships of the formation and the end-of-line test for function-integrated overall process optimization" (FormEL), physical models are therefore to represent the electrochemical processes during the formation and the EoL test in order to derive interactions and prognoses with regard to the cell properties as a function of the formation procedure. In addition, a modular carrier concept for combining the forming process and the EoL test is to be developed, which can cover different battery cell variants with little conversion effort and includes the necessary measurement and control technology. These optimization approaches will be analyzed and validated by experimental investigations.
Increasing cell quality and reducing process time
In this way, the research project combines several objectives. On the one hand, the cell quality is to be increased by said physical models representing the electrochemical processes during the formation and the EoL test in order to derive interactions and predictions with regard to the cell properties depending on the formation procedure. The sensitive parameters are to be optimized on the basis of the model and thus lead to an improvement in the cell properties and diagnostic quality of the EoL test. On the other hand, the process costs and the process time shall be reduced. The reduction of the duration is aimed at by the model-based optimization of the individual processes. The faster process time due to the functional integration of the two process steps leads to a reduction of the energy costs per cell and enables the increase of the production throughput, thus reducing the fixed costs per cell. The necessary measurement technology for the formation including EoL testing is to be implemented in a flexible product carrier for several cells and later battery cell generations.
"FormEL": Determination of process-quality relationships of the formation and end-of-line test for function-integrated overall process optimization
- Increase of cell quality
- Mapping of the electrochemical processes during the formation and the EoL test by physical models to derive interactions and predictions regarding the cell properties depending on the formation procedure
- Model-based optimization of sensitive parameters to improve cell properties and diagnostic quality of the EoL test
- Reduction of process costs and process time
- Model-based optimization of the individual processes
Research and project partners
PEM of RWTH Aachen University
Institute for High Voltage Technology and Power Systems (elenia) (project coordinator)
Münster Electrochemical Energy Technology (MEET)
Institute of Energy and Process Systems Engineering (InES)
Institute for Electrical Energy Storage Technology (EES)
08/01/2020 through 07/31/2023