Design of Low‐Alloyed, Parasitic‐Reaction‐Regulating Lithiophilic Composite Interlayer for Anode‐free Lithium Batteries

ABSTRACT Anode‐free lithium batteries represent an ideal high‐energy‐density battery system. However, their practical development has been hindered by severe active lithium loss, primarily caused by side reactions, significant volume expansion, and irreversible alloying with lithiophilic substrates. On this basis, we compared silver nanowires (AgNWs) and silver nanoparticles (AgNPs) as lithiophilic coating substrates, and developed a composite coating of AgNWs and lithium carboxymethyl cellulose (CMC‐Li) on copper current collectors. More precisely, lithiophilic AgNWs with a lower specific surface area lead to the formation of uniform and controllable lithium nuclei and less lithium loss. The polymer layer formed by the cross‐linking of CMC‐Li contributes to alleviating the volumetric expansion of the lithium deposition layer during cycling, reducing the continuous side reactions. The Li||Cu cells demonstrate an average Coulombic efficiency (CE) of 99.0% over 500 cycles at 1 mA cm ‒2 . When paired with a high‐loading NCM811 cathode, the anode‐free cell achieves 63.1% capacity retention after 100 cycles, with an average CE of 99.4%. Furthermore, the anode‐free pouch cell with the ultra‐thin coating can realize a volumetric energy density exceeding 800 Wh L ‒1 .