Dry-Pressed Fabrication of Lithium-Ion Electrodes Over 500 μm Thick

In stationary storage, thick electrodes can minimize inactive material components to increase energy density and decrease cost, but they face challenges in performance and manufacturability. This work discusses a method to fabricate thick-format lithium-ion electrodes and a model to explore transport constraints for functional thick electrodes. Thick lithium iron phosphate (LFP) electrodes were fabricated using a solvent-free pressing process that adopts methods from alkaline electrode manufacturing for low-cost scale-up. LFP electrodes with thicknesses up to 1 mm and capacities up to ~15 mAh/cm² exhibited good rate performance (~98 % utilization at C/10, ~95 % at C/5, ~76 % at C/2). A physics-based LFP half-cell model was developed to aid in characterizing transport within these thick electrodes, revealing opportunities to further improve performance by decreasing tortuosity.