Ultrathin Cu/Ni-PBA Nanolayers on Ni-Plated Cu Foam Stabilize Anode-Free Li-Metal Interfaces

초록

Anode-free lithium-metal batteries (AFLMBs) promise higher energy density but suffer from low Coulombic efficiency, early capacity fade, and large overpotentials due to uncontrolled Li nucleation/stripping on bare copper. We propose a current-collector design that forms an ultrathin, lightweight, lithiophilic interfacial nanolayer by one-pot solution self-assembly of mixed Cu/Ni Prussian-blue analogues (Cu/Ni-PBAs) on Ni-electroplated Cu foam. The cyanoferrate framework provides densely and uniformly distributed Li-affinitive sites and an ion-percolating porous network, while the Ni underlayer improves electronic continuity and mechanical anchoring. This two-step surface route is scalable, binder-free, and requires no high-temperature conversion. In parallel, the AFLMB field actively explores lithiophilic seed layers (Ag, Au, Zn, alloys), 3D scaffold geometries, and locally high-concentration electrolytes (LHCE) with LiNO₃/fluorinated additives to lower nucleation barriers and homogenize Li? flux. Self-assembled Cu/Ni-PBA nanolayers on Ni-plated Cu foam present polar M?NC (M = Cu, Ni) coordination sites within an open microporous framework that enhance electrolyte wetting, redistribute ionic/electric fields, and reduce the Li nucleation barrier. The Ni underlayer maintains electronic continuity and provides mechanical anchoring across the 3D ligaments, suppressing local current hotspots. Together, lithiophilic nucleation sites, field homogenization, and stabilized current distribution directly address the dominant failure modes of anode-free cells?Coulombic-efficiency loss, overpotential growth, and early-cycle fade.