During the multi-step process from raw materials to the final battery cell, the use of a twin-screw extruder can improve the critical step of electrode material production (aka battery slurries).

Battery slurry production is commonly realized by batchwise mixing of active materials, carbon black, solvents, binders, and additives in stirred vessels. This process is labor-intensive, bears the risk of batch-to-batch variations, and requires production downtimes for cleaning.

Twin-screw compounding offers a continuous production process with precisely controlled material shear, heat transfer, material throughput, and residence time. The twin-screw extrusion process provides high reproducibility, less cleaning time, and high material and labor efficiency.

The excellent dispersive and distributive mixing capabilities of a twin-screw extruder enable much more homogeneous cathode pastes as compared to alternative batch mixing in, for example, a dissolver. In return, this can lead to improved material properties.

Twin-screw extrusion can help improve the classic production of cathode and anode slurries by moving from a batch that is challenging to scale up to a well-controlled continuous process. A reduction of solvent from the process can save up to 30% of the total energy consumption; here, extruders can help produce almost-dry battery pastes. Ways to overcome the risk of shorting and fire caused by flammable organic electrolyte novel battery types are being investigated. Extruders provide excellent capabilities for solid state battery (SSB) development.

An understanding of the rheological properties of an electrode slurry is necessary for a precise printing process to obtain batteries with a high capacity and a high number of charging cycles.