Electrode‐Specific Janus Separator Towards High‐Performance Lithium Metal Batteries

flux and dendrite suppression while simultaneously providing enhanced thermal and mechanical stability. The cathode-facing layer, composed of ion-capturing inorganic particles of polydopamine-coated boehmite (PDA@BM), acts as a selective barrier, mitigating TM ion migration by over 96%. These dual functionalities yield superior interfacial stability and long-term cycling performance. The Janus separator design and fabrication strategy enables compositionally distinct, directionally targeted layers to deliver synergistic regulation for anode- and cathode-driven asymmetric failure mechanisms for the practical realization of high-performance LMBs.