Modifying the Network Structures of High Energy Anodes for Lithium-Ion Batteries through Intensive Dry Mixing

Abstract

With the ongoing demand for lithium-ion batteries in the automotive industry, the longevity of the cells is more important than ever. Previous studies on high intensive dry mixing of cathode materials have shown significant changes in product properties across the process chain. Despite a decrease in electrical conductivity, due to the fixation of carbon black particles on the active materials’ surface, electrochemical results have shown more stable long-term cycling performance of the lithium-ion battery cells. Despite that, no research studies investigating this process for anode materials have been published yet. Therefore, the effect of an intensive dry mixing process, using a ring shear device and state-of-the-art anode materials, on the slurry, electrode, and cell properties is investigated. The tangential velocity and, therefore, the mechanical stress have been varied, as well as the amount of carbon black in the dry mixing process. The results reveal new insights into material interactions between the binder, carbon black, and the active material that can be purposefully modified. Based on the results, an optimum parameter set is suggested, which not only improves the product characteristics across the process chain, but also increases the long-term cycling performance of the battery cells significantly.