The growing demand for advanced energy storage systems requires the development of next-generation battery technologies with superior energy density and cycle stability, with lithium-sulfur (Li-S) batteries representing a promising solution. Sulfur-containing polyacrylonitrile cathodes (SPAN) for Li-S batteries are a significant advancement for this next-generation battery chemistry, addressing the major issue of limited cycle life encountered in conventional carbon/sulfur composite cathodes. In the presented study, the influence of available ionic and electronic conduction pathways within the cathode on the electrochemical performance of SPAN-based Li-S batteries is studied in details. To this end, a series of SPAN cathodes with different microstructures is prepared by adapting the compression degree of calendering. Mechanical and morphological characterizations confirm a pronounced springback effect due to a characteristic elastic deformation behavior of SPAN. Electrochemical impedance spectroscopy (EIS) shows increased cathode impedance values with multiple overlapping processes in the high- to mid-frequency region in highly compressed SPAN cathodes. Moreover, while the (first) discharge capacity is unaffected, the subsequent charge capacity decreases substantially for highly compressed cathodes. The electrochemical experiments and electrochemical continuum simulations confirm that this phenomenon is mainly due to the disturbance of the electronic percolation pathways caused by the springback behavior during calendering.

Sulfur‐polyacrylonitrile (SPAN) is a sulfur‐based active material for next‐generation lithium‐sulfur battery cathodes. Due to the covalent bonding between sulfur chains and the polymeric backbone, the shuttle effect degrading classical sulfur‐based cathodes can be suppressed while also achieving a high active material content in the cathode. In this paper, we investigate the processability of an industrially scalable SPAN active material with 38 wt.‐% of sulfur in a water‐based and scalable process route. The potential of the SPAN material for industrial adoption and the impact of the process route on the cell performance are discussed. We show that when processed correctly, the SPAN material delivers exceptional cycling stability and good C‐rate performance with ether‐based electrolytes. However, the performance of the SPAN cathode is influenced by the mixing characteristic. Using higher mixing intensities during the slurry preparation leads to deterioration of the electrochemical performance. This can be attributed to a decreasing carbon black percolation with increasing tip speed in combination with the kinetic limitation of sulfur cathodes during Li2S2 and Li2S oxidation.

Die Performance einer Batterie hängt signifikant von den Eigenschaften der kleinen Partikel im Submikro‐ und Mikrometerbereich und ihrer Mikrostruktur ab. Für die Herstellung von maßgeschneiderten Batterien müssen diese im Verlauf des Herstellungsprozesses präzise und reproduzierbar eingestellt werden. Im Zuge der Produktion von Lithium‐‐Ionen‐Batterien haben sich hierfür bewährte Verfahren etabliert. Jeder Produktionsschritt trägt somit auf seine Weise zur Performance der Batterie bei. Durch die Optimierung bekannter oder neuer Verfahren ergibt sich zudem das Potenzial zur Senkung der Produktionskosten oder Nutzung neuer zukunftsträchtiger Materialien. Antworten hierzu finden Sie in diesem Trendbericht.

With the ongoing demand for lithium‐ion batteries in the automotive industry, the longevity of the cells is more important than ever. Previous studies on high intensive dry mixing of cathode materials have shown significant changes in product properties across the process chain. Despite a decrease in electrical conductivity, due to the fixation of carbon black particles on the active materials’ surface, electrochemical results have shown more stable long‐term cycling performance of the lithium‐ion battery cells. Despite that, no research studies investigating this process for anode materials have been published yet. Therefore, the effect of an intensive dry mixing process, using a ring shear device and state‐of‐the‐art anode materials, on the slurry, electrode, and cell properties is investigated. The tangential velocity and, therefore, the mechanical stress have been varied, as well as the amount of carbon black in the dry mixing process. The results reveal new insights into material interactions between the binder, carbon black, and the active material that can be purposefully modified. Based on the results, an optimum parameter set is suggested, which not only improves the product characteristics across the process chain, but also increases the long‐term cycling performance of the battery cells significantly.

In order to reduce the cost of lithium-ion batteries, production scrap has to be minimized. The reliable detection of electrode defects allows for a quality control and fast operator reaction in ideal closed control loops and a well-founded decision regarding whether a piece of electrode is scrap. A widely used inline system for defect detection is an optical detection system based on line scan cameras and specialized lighting. The cameras scan the electrode, and brightness differences on the surface are detected and processed inline. The characteristics of the defect image are used for automated classification of the defects based on image features. Furthermore, the detailed detection of defects allows for the identification of causes. This paper describes the working principle of such an inline detection system, the catalog of typical defects, and the image features used to classify them automatically. Furthermore, we propose and discuss causes and effects of the different defect types on the basis of the literature and expert experience. In combination with tracking and tracing, this enables the manufacturer to reduce scrap by detecting defects early in the production chain.