Statistical analysis of electrode fabrication process for all-solid-state batteries and effects of electrode fabrication conditions on battery performance

This study presents a statistical analysis of the influence of the fabrication conditions of cathode electrodes on the performance of an all-solid-state half-cell based on the design of experiment approach. We focused on three electrode fabrication conditions: mass ratio of the solid electrolyte in the composite cathode, compression pressure for preparing the electrode pellet, and bolt tightening torque for stacking the cell. The half-cells were fabricated from the dry-coated particles including the core–shell structure along with the simple mixture with random mixing state. A comparison of these two half-cells determines the critical factors in the electrode fabrication from each sample. The statistical analysis of the initial electrochemical performance demonstrated that in the cell fabricated from the simple mixture, the compression pressure was the most influential factor on the initial discharge capacity, whereas in the dry-coated particles, the solid electrolyte ratio was the most influential factor. The statistical analysis of the cycle performances also demonstrated that in the simple mixture, the solid electrolyte ratio was the most influential factor on capacity retention, whereas in the dry-coated particles, fabrication conditions such as compression pressure and stacking torque were less influential. Furthermore, the statistical analysis demonstrated that the dry-coated particles can provide equivalent or higher cell performances when compared to the simple mixture, even when the values of the solid electrolyte ratio, compression pressure, and stacking torque were small.