Demand for lithium-ion battery cells (LIB) for electromobility has risen sharply in recent years. In order to continue to serve this growing market, large-scale production capacities require further expansion and the overall effectiveness of processes must be increased. Effectiveness can be significantly optimized through innovative manufacturing technology and by identifying scrap early in the production chain. To enable these two approaches, it is imperative to quantify safety- and function-critical product features in critical manufacturing steps through appropriate measurement techniques. The overview in this paper on quality control in LIB production illustrates the necessity for improved inspection techniques with X-rays to realize a fast, online measurement of inner features in large-scale cell assembly with short cycle times and to visualize inner product-process interactions for the optimization in electrolyte filling. Therefore, two new inspection techniques are presented that contribute to overcoming the aforementioned challenges through the targeted use of X-rays. First, based on the results of previous experiments in which the X-ray beam directions were deliberately varied, a online coordinate measurement of anode-cathode (AC) overhang was developed using a line detector. Second, a new concept and the results of a continuous 2D visualization of the electrolyte filling process are presented, which can be used in the future to optimize this time-critical process step. By using a X-ray-permeable and portable vacuum chamber it is possible to quantify the influence of process parameters on the distribution of the electrolyte in the LIB.

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.

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Today, lithium-ion batteries are a promising technology in the evolution of electro mobility, but still have potential for improvement in terms of performance, safety and cost. In order to exploit this potential, one promising approach is the replacement of liquid electrolyte with solid-state electrolyte and the use of lithium metal electrode as an anode instead of graphite based anodes. Solid-state electrolytes and the lithium metal anode have favorable electrochemical properties and therefore enable significantly increased energy densities with inherent safety. However, these materials are both, mechanically and chemically sensitive. Therefore, material-adapted processes are essential to ensure quality-assured manufacturing of all-solid-state lithium-ion battery cells. This paper presents the development of a scaled and flexible automated assembly station adapted to the challenging properties of the new all-solid-state battery materials. In the station various handling and gripping techniques are evaluated and qualified for assembly of all-solid-state battery cells. To qualify the techniques, image processing is set up as a quality measurement technology. The paper also discusses the challenges of enclosing the entire assembly station in inert gas atmosphere to avoid side reactions and contamination of the chemically reactive materials.