To improve the battery capacity and cycling stability, the calendering process is applied to reduce electrode thickness and increase packing density. The electrochemical performance of compacted electrodes is strongly affected by their mechanical and electrical properties. In this work, four groups of lithium cobalt oxide (LiCoO 2 ) powders are used as representative electrode materials, and a universal measurement method is presented to investigate the effect of pressure on the mechanical and electrochemical properties of powder electrodes. Using this novel measurement system, electrochemical and mechanical data of the electrode powders are obtained, serving as calibration targets for discrete element method (DEM) parameters. Moreover, the DEM is employed to explain the evolution of mechanical properties during powder compaction using the Edinburgh elasto-plastic adhesion (EEPA) contact model. A mapping relationship between DEM parameters and the powder stress–strain curve is then established to obtain a standard model that fits the experimental data well. From the calibrated model, internal anisotropic stress states of the powder are analyzed to better design the die and punch. Our model shows the plasticity ratio of lithium cobalt oxide powder is around 92–99%. Furthermore, the confining stress between particles and the die has been calculated, which can provide critical guidance for the selection of mold materials. Therefore, the calibrated DEM model can effectively predict the mechanical behavior inside the electrode powder in the pre-treatment process and benefits equipment design.
Liu et al. (Sat,) studied this question.