In lithium-ion battery manufacturing, wetting of active materials is a time-critical process. Consequently, the impact of possible process chain extensions such as lamination needs to be explored to potentially improve the efficiency of the electrode and separator stacking process in battery cell manufacturing. This paper addresses the research gap of the unexplored effects of lamination on the wetting rate of electrode-separator assemblies in pouch cells. Based on the triangulation of three measurement techniques (gravimetric, optical, electrochemical), a correlation between lamination and wettability of electrode-separator assemblies is experimentally demonstrated, thus providing an important research contribution.

In today’s cell production, the focus lies on maximizing productivity while maintaining product quality. To achieve this, the lamination of electrode and separator is one key process technology, as it bonds the electrode and separator to form mechanically resilient intermediate products. These mechanically resilient intermediates are necessary to enable high throughput processes. Although the lamination process has significant effects on the electrochemical performance of battery cells, it has not been sufficiently researched with regard to its process-product interdependencies. Therefore, this paper addresses the investigation of these interdependencies and proposes three characterization methods (grey scale analysis, high potential tests, electrochemical cycling and C-rate tests). The results of the three methods show that the lamination process with its process parameters (lamination temperature, lamination pressure and material feed rate) has an influence on both the properties of the intermediate product and the cell properties. In conclusion, the knowledge of the process-product interdependencies is essential in order to utilize the advantages of lamination integrated into the process chain and consequently achieve quality-assured cell production.

Due to the energy transition and the growth of electromobility, the demand for lithium-ion batteries has increased in recent years. Great demands are being placed on the quality of battery cells and their electrochemical properties. Therefore, the understanding of interactions between products and processes and the implementation of quality management measures are essential factors that requires inline capable process monitoring. In battery cell lamination processes, a typical problem source of quality issues can be seen in missing or misaligned components (anodes, cathodes and separators). An automatic detection of missing or misaligned components, however, has not been established thus far. In this study, acoustic measurements to detect components in battery cell lamination were applied. Although the use of acoustic measurement methods for process monitoring has already proven its usefulness in various fields of application, it has not yet been applied to battery cell production. While laminating battery electrodes and separators, acoustic emissions were recorded. Signal analysis and machine learning techniques were used to acoustically distinguish the individual components that have been processed. This way, the detection of components with a balanced accuracy of up to 83% was possible, proving the feasibility of the concept as an inline capable monitoring system.

What are the benefits of simulation-driven design and optimization of stacking processes in battery cell production? This question is addressed within the scope of the paper. This work proposes a method to reduce the effort for model-based design and optimization. Based on three case studies which originate from the development of high-speed stacking processes, this paper illustrates how the relevant loads on the intermediate products are determined with the help of the method. Subsequently, it is shown how the specific material models for battery electrodes and separators are identified, created and validated, as well as how process models are created and process limits are identified and optimized. It was possible to prove how process simulations can be used to minimize the effort required to validate developments and to efficiently determine optimized process parameters for a format and material change in a model-based manner. Consequently, more and more model-based processes should be taken into account during development and start-up in the future.

In today's cell production, the focus lies on maximising productivity while maintaining product quality. To achieve this, the lamination process is one key technology, as it bonds the electrode and separator to form mechanically resilient intermediate products. These mechanically resilient intermediates are necessary to enable high throughput processes. Although the lamination process has significant effects on the electrochemical performance of battery cells, it has been not sufficiently researched with regard to its process-product interdependencies. Therefore, this paper addresses the investigation of these interdependencies and proposes three characterisation methods (grey scale analysis, high potential tests, electrochemical cycling and c-rate tests). The results of the three methods show that the lamination process with its process parameters (lamination temperature, lamination pressure and material feed rate) has an influence on both the properties of the intermediate product and the cell properties. In conclusion, the knowledge of the process-product interdependencies is essential in order to utilise the advantages of lamination integrated into the process chain and consequently to achieve a quality-assured cell production.