Integrated one-step dry process enabling prelithiated thick electrodes without primer coating for high energy density and initial coulombic efficiency

Abstract

Dry-processed thick electrodes are a key strategy for increasing the energy density of batteries. However, thick dry electrodes, especially anodes, suffer from limited ion mobility, causing non-uniform solid-electrolyte interphase (SEI) formation and high irreversible capacity loss during the initial cycle. Moreover, the adhesive primer layer required during processing increases electrical resistance and necessitates additional wet-processing steps, thereby undermining both performance and process integrity. To address these issues, we propose an underlayer lithium-metal-configured prelithiation strategy for thick electrodes. Here, a lithium metal underlayer simultaneously functions as a primer, compensates for irreversible lithium loss during the initial cycle, and promotes uniform SEI formation through a chemical reaction. Consequently, this strategy enhances the initial coulombic efficiency and cycle stability of high-energy-density silicon-graphite/NCM811 full-cells. By overcoming the limitations of the conventional dry process, a fully dry manufacturing process is enabled and advances the development of next-generation high-energy-density batteries.