The research focuses on the development of components for large-format planar bipolar batteries that can be used in the automotive sector, among others (EMBATT concept). Polymer-based plastic foils are being developed to create an alternative to the aluminium foils used so far. The goal is a film with a thickness of approx. 50 µm that can be produced continuously on a pilot plant scale. The challenge in the development of the formulation and process lies not only in the homogeneous surface quality, but also in the required high electrical conductivity of the film. In extruded electrically conductive polymer composite films, there are different electrical conductivities depending on the direction. During the stretching process in film extrusion, 1D fillers such as carbon nanotubes are oriented, resulting in a conductive network in the stretching direction and allowing only a few conductive paths in the direction of the film thickness. By adding spherical fillers, such as conductive carbon black, which are less oriented, higher electrical conductivity can be generated by the film [Kunz et al., Krause et al.]. By combining suitable material and processing parameters (in cooperation with the department of processing technology), thin homogeneous films can be produced at the IPF, which have a conductivity of approx. 1 S/m through the film. The functional proof of the polymeric conducting film in the EMBATT concept was successfully demonstrated using Swagelok cells based on a PVDF composite film and LNMO and LTO electrodes [Fritsch et al.]. Thus, polymeric feedthrough foils (PVDF, PP) represent a suitable alternative to aluminium feedthroughs.

Projects

• BMWi-Projekt 03ETE043D „BiPoLiS - Development of lithium-sulphur bipolar batteries", TP: Material development and production of the conducting film, BMWK, Special Fund "Climate and Transformation Fund", joint project: LioVolt GmbH, Eisenhuth GmbH & Co. KG, Fraunhofer Institute for Material and Beam Technology IWS, IPF Dresden e.V., Duration: 1/2023 - 12/2025
  
  
• AIF-ZIM Projekt ZF4028415ZG8 „Planare Materialien für Batteriekomponenten für Automobile Anwendungen (PLANAR MABAT)“ TP: Materialentwicklung für elektrisch leitfähige Durchleiterfolien zur Anwendung in Batterien, 3/2019 - 6/2021
  
  
• BMBF-Projekt 03XP00068-E „EMBATT2.0 - Material- und Prozessentwicklung für die effiziente Fertigung der großformatigen Bipolarbatterie EMBATT“, Kooperationsprojekt: Glatt Ingenieurtechnik GmbH , IAV GmbH, Fraunhofer IKTS Dresden, IPF Dresden, Isocoll Chemie GmbH, KMS Technology Center GmbH , Litarion GmbH, thyssenkrupp System Engineering GmbH, ULT AG, Laufzeit: 7/2016 - 6/2019

Related publications

• Karina Kunz, Beate Krause, Bernd Kretzschmar, Levente Juhasz, Oliver Kobsch, Wolfgang Jenschke, Mathias Ullrich, Petra Pötschke, Direction dependent electrical conductivity of polymer/carbon filler composites, Polymers 2019, 11(4), 591

• Beate Krause, Karina Kunz, Bernd Kretzschmar, Ines Kühnert and Petra Pötschke, Effect of Filler Synergy and Cast Film Extrusion Parameters on Extrudability and Direction-Dependent Conductivity of PVDF/Carbon Nanotube/Carbon Black Composites, Polymers 2020, 12(12), 2992

• Marco Fritsch, Matthias Coeler, Karina Kunz, Beate Krause, Peter Marcinkowski, Petra Pötschke, Mareike Wolter, Alexander Michaelis, Lightweight polymer-carbon composite current collector for lithium-ion Batteries, Batteries 2020, 6(4), 60

Contact persons

Dr. Beate Krause
Dr. Petra Pötschke