Multicomponent Comminution within a Stirred Media Mill and Its Application for Processing a Lithium-Ion Battery Slurry

This study presents an approach for targeted comminution of component mixtures within a wet-operated stirred media mill. In the first step, a general understanding of the interactions between individual components on the grinding result with mixtures could be gained with basic experiments and following our former research work. In particular, a protective effect of the coarser particles on the fines could be elucidated. These findings were used to develop a process for the production of a battery slurry containing fine ground silicon particles as well as dispersed carbon black and graphite particles. By a tailored sample preparation applying a combination of particle dissolution and separation, the particle size distributions of carbon black and graphite particles were analyzed separately within the produced battery slurries. Based on the selective particle size analysis, the slurry preparation could be transferred from a complex multistage batch process using a dissolver to a stirred media mill, which was finally operated in a continuous one-passage mode. The prepared slurries were subsequently further processed to silicon-rich anodes using a pilot scale coating and drying plant. Afterward, the produced anodes were electrochemically characterized in full cells. The cell results prove a comparable electrochemical behavior of anode coatings derived from a dissolveror mill-based slurry production process. Therefore, we could demonstrate that it is possible to integrate the mixing process for the production of multicomponent slurries into the comminution process for the preparation of individual materials upstream. Even with nearly identical starting sizes of their feed materials, the targeted particle size distributions of the single components can be reached, taking into account the different material-dependent particle strengths and sequential addition of single components to the multicomponent comminution process.

Automated summary

This study presents a targeted comminution approach for component mixtures in a wet-operated stirred media mill. The researchers developed a process for producing battery slurries with fine ground silicon particles, carbon black, and graphite particles. By analyzing the particle size distributions of the carbon black and graphite particles separately, the slurry preparation process was transferred from a complex multistage batch process to a continuous one-passage mode. The prepared slurries were further processed into silicon-rich anodes and tested in full cells, showing comparable electrochemical behavior to anodes produced using a dissolver or mill-based slurry production process.