Microporous lithium film prelithiation: a scalable strategy for high-performance dry-processed anodes in lithium-ion batteries

Driven by the surging demand for high-energy-density lithium-ion batteries, dry electrode technology demonstrated remarkable advantages including high electrode loading, low manufacturing cost, and environmental benignity, making it a highly promising route for advanced high-capacity lithium-ion batteries. Solvent-free, high-loading graphite (Gr) electrodes and high-loading dry 8Si/C electrodes were prepared by a dry processing method of powder dry mixing and calendering.Nevertheless, dry-processed anodes are plagued by the fundamental bottleneck of low initial Coulombic efficiency (ICE), which primarily arises from detrimental side reactions tied to the intrinsic electrochemical instability of PTFE binders.To address this critical challenge, prelithiation emerged as an effective strategy to compensate for the initial lithium loss and improve the overall Coulombic efficiency of dry-processed anodes. In this work, a tailored microporous lithium film was rationally designed via theoretical calculations, which was then directly laminated onto the high-loading dry-processed graphite and silicon-carbon anodes. The PTFE fiber network remained intact after prelithiation, confirming the synergistic effect of the microporous lithium film technology with dry-process electrodes. When the battery ICE design improvement value was 14%, the ICE of the dry graphite anode pouch full cell after prelithiation could reach 84.75%, and the reversible capacity remained at 134.2 mAh with a capacity retention rate of 89.52% after 100 cycles at 0.2 C.