A Scale‐Up Study on the Continuous Production of Battery Slurry in Twin‐Screw Extruders Based on Flow Behavior and Material Dispersion

Driven by the increasing demand for high-performance batteries, this study addresses the need for efficient and scalable mixing processes in battery manufacturing, focusing on continuous mixing in twin-screw extruders. While extruders can operate at different production rates, process limitations require a scale-up to larger extruder sizes to further increase production capacity. This work compares the quality of anode slurries produced under equivalent process conditions on four different scales of twin-screw extruders. It was shown that the transfer from laboratory to pilot and production scale, while maintaining consistent product quality, i.e. dispersion of the conductive additive, is feasible. Flow simulations were used to quantify the material strain in each process setup, thereby facilitating the identification of relevant scale-up criteria and even allowing for process transfer to similar but not geometrically equivalent screw geometries. Additionally, the influences of different process parameters such as screw
speed and mass flow rate on the dispersion quality were quantified and compared between scales. In short, processing with a specific feed load smaller than 0.01 was shown to provide better dispersion and electrode quality across scales.