Solvent Reduced Extrusion‐Based Anode Production Process Integrating Granulate Coating, Drying, and Calendering

A novel electrode production process, based on a minimal solvent content, is developed for highly viscous water‐based graphite anodes, using a solid mass content of 50% or more compared to conventionally processed anodes. The electrode paste is prepared by mixing the solids with solvent inside of a twin‐screw extruder. Afterward, the extrudate is cut with a strand pelletizer to granules. By inserting the granules into the gap of a two‐roller calender, the current collector foil is coated directly. It is shown that the highly viscous pastes are capable of extended storage stability over several weeks, whereby a temporal and local decoupling of paste preparation and electrode manufacturing can be realized. To enable this innovative electrode processing, a combined development incorporating a selection of new anode binder materials, machinery design, and process parameters has been essential due to strong material‐process interaction, as known in the field of battery electrode production. Because the binder is exposed to greater shear stresses and a short duration time during extrusion mixing, the selection of novel anode binder materials is particularly important. This then needs to be combined with machine design and process parameter optimization, in order to establish this innovative electrode processing method.