Stress-dissipative, ambient-compatible prelithiation protocol for dry-processed Si anodes at extremely high areal capacities

Roll-to-roll dry processing offers a sustainable pathway for manufacturing high-energy lithium batteries with high-mass-loading electrodes, yet faces severe challenge from reductive degradation of polytetrafluoroethylene (PTFE) binders in anodes that irreversibly deplete Li⁺ source from cathodes/electrolyte reservoirs. Conventional prelithiation protocols prove unsuitable for dry processing, as their slurry-dependent implementations would exacerbate stress heterogeneity within densely-packed electrodes. Herein, this study innovates a stress-dissipative, moisture-tolerant prelithiation strategy for dry-coated anodes. The solvent-free processing fabricates the anode configuration at areal capacities of 5–8 mAh cm⁻², comprising shear-mixed Si@C, ethylene-vinyl acetate (EVA)-encapsulated Li₂₂Si₅ agents, vapor-grown carbon fiber (VGCF), and PVDF-HFP modified PTFE binder. Hydrophobic EVA encapsulation stabilizes Li₂₂Si₅ against moisture (≤50% relative humidity), enabling controlled lithium supplementation under ambient conditions. Paired with dry-coated LiNi_xMn_yCo_1−x−yO₂ cathodes (NCM, x ≥ 0.9), the 1 Ah pouch cell delivers an energy density of ∼389 Wh kg−1, peak power output of 2256 W kg−1 and 85.7% capacity retention over 900 cycles. Multiscale modeling reveals that the electrode architecture reconciles mechanical integrity, low tortuosity, and stress dissipation via Li⁺ redistribution process; while operando XRD/Micro-CT validate efficient cation replenishment and phase/microstructure reversibility upon cycling. This ambient-compatible prelithiation strategy establishes a universal platform for dry-processed anodes (e.g., SiO_x@C, hard carbon), overcoming the industry-wide bottleneck of stringent dry-room dependency for energy/power-dense battery manufacturing.