New energy systems such as all-solid-state battery (ASSB) technology are becoming increasingly important today. Recently, researchers have been investigating the transition from the lab-scale production of ASSB components to a larger scale. Poly(ethylene oxide) (PEO) is a promising candidate for the large-scale production of polymer-based solid electrolytes (SPEs) because it offers many processing options. Hence, in this work, the thermal processing route for a PEO-Lithium bis(trifluoromethylsulfonyl)imide (LiTFSI) SPE in the ratio of 20:1 (EO:Li) is investigated using kneading experiments. Here, we clearly show the sensitivity of PEO during thermal processing, especially for high-molecular-weight PEO (M_w = 600,000 g mol⁻¹). LiTFSI acts as a plasticizer for low-molecular-weight PEO (M_w = 100,000 g mol⁻¹), while it amplifies the degradation of high-molecular-weight PEO. Further, LiTFSI affects the thermal properties of PEO and its crystallinity. This leads to a higher chain mobility in the polymer matrix, which improves the flowability. In addition, the spherulite size of the produced PEO electrolytes differs from the molecular weight. This work demonstrates that low-molecular-weight PEO is more suitable for thermal processing as a solid electrolyte due to the process stability. High-molecular-weight PEO, especially, is strongly influenced by the process settings and LiTFSI.

All-solid-state battery (ASSB) technology is a new energy system that reduces the safety concerns and improves the battery performance of conventional lithium-ion batteries (LIB). The increasing demand for such new energy systems makes the transition from laboratory scale production of ASSB components to larger scale essential. Therefore, this study investigates the dry extrusion of poly(ethylene oxide):lithium bis (trifluoromethylsulfonyl)imide (PEO:LiTFSI) all-solid-state electrolytes at a ratio of 20:1 (EO:Li). We investigated the influence of different extruder setups on the product quality. For this purpose, different screw designs consisting of conveying, kneading and mixing elements are evaluated. To do so, a completely dry and solvent-free production of PEO:LiTFSI electrolytes using a co-rotating, intermeshing, twin-screw extruder under an inert condition was successfully carried out. The experiments showed that the screw design consisting of kneading elements gives the best results in terms of process stability and homogeneous mixing of the electrolyte components. Electrochemical impedance spectroscopy was used to determine the lithium-ion conductivity. All electrolytes produced had an ionic conductivity (σ_ionic) of (1.1–1.8) × 10⁻⁴ S cm⁻¹ at 80 °C.

The next‐generation technology that promises to reduce safety concerns and improve the battery performance of currently used Lithium‐ion batteries (LiB) is the so‐called all‐solid‐state batteries (ASSBs). The future energy demands are forcing research and industry to move from laboratory‐scale production of ASSB components to larger industrial‐scale production. Thus, this study investigates the hot melt extrusion process of poly(ethylene oxide):Lithium bis (trifluoromethylsulfonyl)imide (PEO:LiTFSI) solid‐state electrolytes at a ratio of 20:1 (EO:Li) using automated material addition. For extrusion, a co‐rotating, intermeshing twin‐screw extruder with two feeders that works under inert conditions is used. We investigate the influence of process parameters and screw design on the product quality. Therefore, we used different screw designs consisting of conveying, kneading, and mixing elements for the extrusion. This study elucidates that screw designs with kneading elements give the best results in terms of mixing and dissolving Li salt within the polymer matrix. These findings are supported by microscopy, by the determination of T _m using DMA showing the lowest T _m of 43°C, and by the calculated ionic conductivity of (8.4 ± 0.2) × 10 ⁻⁴ S cm ⁻¹ at 80°C using electrochemical impedance spectroscopy.