Continuous Processing of Cathode Slurry by Extrusion for Lithium-Ion Batteries

Abstract

In this work, detailed investigations concerning a continuous mixing process for lithium-ion battery (LIB) electrodes are conducted. NCM622 (Li(Ni0.6Co0.2Mn0.2)O2) cathode electrodes are fabricated on behalf of a corotating twin screw extruder. Studies are performed concerning different material compositions and processing parameters, such as screw speed. Processing routes in relation to feeding of binder to the process zones as a dry powder or presolved in a liquid are examined. The produced cathode slurries are analyzed concerning rheological properties and dispersing degree, meaning particle size distribution. Subsequently, the coated electrodes are characterized regarding electrical conductivity, mechanical properties, and pore size distribution. Up to the present, the continuous mixing process of LIB electrodes is barely investigated. This study provides deep insight into the process–structure–property relations of the continuous mixing process.