Time-Dependent Tap Density Modeling of Graphite Milled by Vibrating Disc Mill

Abstract

Graphite, which is a key anode material for LIB, needs to have a high tap density (dt) to reach a high volumetric energy density. Since dt is directly correlated with particle size, particle size distribution, and particle shape, it can usually be improved by optimized grinding. So, determining the ideal grinding time by modeling the change in dt over grinding time can yield substantial benefits like time, energy, and economy. However, the grinding time-dependent dt modeling of graphite has never been reported before. Therefore, in this study, the relationship between the measured dt values and grinding times of graphite particles by a vibrating disc mill (VDM) was investigated. Then, the empirical time-dependent dt models were established with high R2 values. The experimental and predicted dt values were found to be close to each other. Among all tested fitting models, the exponential model (dt = ae−bt) was found to be the best-fitting model, having the highest R2 and lowest error values. This approach provides guidance in the powder flow and processing of ground mineral materials, in the preparation processes of high-density graphite LIB anode material, as well as in graphite grinding in other mills in the industry, as well as in different electrode materials.