Interfacial Interaction-Engineered Dual Lithiophilic Ultrathin Interlayers for Dendrite-Suppressed Lithium Metal...

Lithium (Li) metal, known for its exceptional theoretical capacity and low redox potential, represents a promising anode material for next-generation Li-based batteries. However, its practical implementation is often compromised by uncontrolled dendritic Li growth during cycling, leading to safety hazards and accelerated degradation. In this study, we present a novel dual-interface engineering strategy aimed at mitigating Li dendrite formation through the incorporation of ultrathin lithiophilic interlayers on both the electrode (∼44 nm) and separator (∼2 nm). We utilize a Ni-electroplated textile as a conductive host, onto which lithiophilic Ag nanoparticles and amine-based molecular linkers are uniformly assembled via a ligand-exchange-mediated approach, resulting in an ultrathin lithiophilic interlayer. Simultaneously, the separator is modified through a hydrogen-bonding-driven assembly of NH₂-functionalized poly(ethylene imine) and COOH-functionalized poly(acrylic acid), forming a ∼2 nm interlayer that redistributes Li⁺ flux. This synergistic interfacial design enables symmetric cells to operate stably for over 2200 h at 1 mA cm^{- 2}/1 mAh cm^{- 2}, while lithium iron phosphate-based full cells retain approximately 72% capacity after 5000 cycles at 1 C. Our findings underscore dual-interface engineering as an effective and scalable approach for the development of safe and durable Li metal batteries.