Lithiophilic Current Collector Without Interfacial Penalty in Zero-Excess Lithium Metal Batteries

Abstract

Highly reversible lithium (Li) plating/stripping in zero-excess Li metal batteries (ZE-LMBs) demands lithiophilic current collectors to suppress Li dendrite formation and Li pulverization. Although Li-alloyable metals have been recognized as lithiophilic substrates, their structural and interfacial stability over cycling are still poorly understood. Here, we present a bimetallic lithiophilic current collector through sequential coatings of platinum (Pt) and silver (Ag). Experimental and computational studies reveal that Ag facilitates uniform Li nucleation and seamless solid electrolyte interphase (SEI) formation owing to the low Li diffusion barrier and strong anion adsorption, whereas Pt maintains lithiophilicity and structural integrity. Leveraging this complementarity, the Ag-outer/Pt-inner bilayer (Ag/Pt@Cu) achieves superior cycling stability through location-specific functional decoupling: the outer Ag layer ensures uniform Li deposition and robust SEI formation, whereas the inner Pt layer supports long-term lithiophilicity, thereby outperforming the reversed configuration (Pt/Ag@Cu). Given that the structural robustness of lithiophilic coatings is essential for enhancing the cycling performance of ZE-LMBs, this study provides a versatile design framework for multi-component, multi-layer architectures, enabling the rational engineering of structurally resilient, lithiophilic current collectors.