Abstract. Lithium-ion batteries (LIBs) are widely used in portable electronics, electric vehicles, and grid storage, due to their high energy density and long cycle life. LIBs consist of a graphite-coated copper foil, which acts as the anode, an aluminum foil coated with active materials as cathode, and a polymer separator film that separates both electrodes and only allows lithium ions to pass. A liquid electrolyte in which lithium salt is dissolved completes the setup.
The lithium-ion battery manufacturing process involves many steps and includes the preparation and coating of anode and cathode slurries. Proper mixing and homogenous coating processes are essential for achieving batteries with a high capacity and high number of charging cycles. During the manufacturing and coating steps, battery slurries are exposed to a wide range of shear conditions. Rotational and oscillatory rheometry enables the quantification of the viscoelastic properties, that are needed to verify the proper mixing and homogeneous distribution of active components, to predict storage behavior and stability of the electrode slurries, and to understand behavior during the coating process.
In this contribution we will introduce continuous twin-screw compounding for the manufacturing of electrode slurries, along with the advantages of a complete rheological investigation using a rotational rheometer over single-point measurements with traditional spindle viscometers.