All-solid-state batteries offer great potential as next-generation batteries as they enable the use of a lithium metal anode. This technology offers the potential to improve fast charging properties, the achievable energy density as well as safety [1]. In order to develop competitive all-solid-state batteries, cost efficient and highly scalable manufacturing methods need to be identified and evaluated. As the manufacturing process influences the transport structure and interfaces within the electrode [2], it is still a topic of current research to build polymer-based all-solid-state cathodes and separators by scalable processes and achieve the requested transport properties.

Therefore, the production of a polymer solid electrolyte (PSE) separator was investigated to gain deep knowledge on how the process parameters influences product quality and reproducibility. A novel highly scalable film casting process was developed for solvent-free manufacturing of PEO block copolymer based separator films. Structural and electrochemical properties like density, ionic conductivity and electrochemical performance as well as scalability and energy consumption were evaluated compared to a reference process [3]. The developed film casting process showed improved precision at higher throughputs regarding a constant film thickness below 30 µm and PSE density. Furthermore, the novel film casting process showed a significantly lowered energy consumption, which is of major importance with respect to production costs and sustainability. At the same time, the electrochemical performance was preserved with an ionic conductivity of approx. 0.2 mS cm-1 at 80 °C as well as a rate capability of approx. 60 mAh gLFP-1 at 1C discharge rate.

References
[1] Kato Y, Hori S, Saito T, Suzuki K, Hirayama M, Mitsui A, Yonemura M, Iba H and Kanno R 2016 Nat. Energy 1 16030
[2] Kwade A et al 2018 Nature Energy 3, 290-300
[3] Helmers L, Froböse L, Friedrich K, Steffens M, Kern D, Michalowski P, Kwade A, 2021, Energy Technology vol. 9: 2000923