Dual-Layered Organo-Fluorinated Hetero-Interphase: A Robust Shield for Ultra-Stable Lithium Metal Batteries

• • Symmetric cells with PFOE-LiF@Li anodes sustain over 1400 h of Li plating/stripping at 30 mA cm−2 and 5 mAh cm−2, demonstrating exceptional dendrite suppression and interfacial stability under harsh conditions. • • Full cells with LiFePO4 cathodes achieve 350 cycles at 1 C and over 550 cycles at 2 C, with high capacity retention and Coulombic efficiency, indicating practical viability for high-rate applications. • • The dual-layer ASEI integrates a LiF-rich inner layer that lowers Li-ion diffusion barriers and provides mechanical integrity, with an outer PFOE layer that resists electrolyte oxidation, addressing both kinetic and chemical stability bottlenecks. • • The roll-pressing fabrication technique is facile and scalable, offering a cost-effective pathway for industrial adoption compared to vacuum-based methods like ALD.