A Cross-Scale Collaborative Design of Copper Current Collectors for Practical Anode-Free Lithium Metal Batteries

Abstract

Anode-free lithium metal batteries (AFLMBs) represent the pinnacle of next-generation energy storage, promising exceptional energy densities and seamless integration with existing manufacturing infrastructure. However, their commercialization is critically hindered by the uncontrollable lithium deposition behavior on the inherently lithiophobic copper current collector (Cu CC), leading to low Coulombic efficiency, dendritic growth, and rapid failure. While extensive efforts have been dedicated to modifying the Cu CC, a fragmented view often prevails, lacking a unified design principle that bridges different scales. This review moves beyond conventional summaries by proposing a novel paradigm of cross-scale collaborative design. We construct a comprehensive strategic framework that systematically integrates modification strategies from the atomic/nano-scale (crystal facet engineering, artificial SEI), through the micro-scale (3D porous, scaffold, and gradient structures), to the macro-scale (magnetic field introduction). A particular focus is placed on elucidating the synergistic mechanisms by which these multi-scale interventions collectively regulate the initial nucleation barrier, guide homogeneous Li⁺ flux, and accommodate deposition-induced volume changes. Crucially, our analysis is consistently guided by the stringent performance benchmarks of the 'zero Li inventory' anode-free configuration, serving as a critical lens to assess the practical viability of each strategy. We further provide a forward-looking perspective on the fundamental challenges and scalable manufacturing pathways for translating these advanced current collectors from laboratory prototypes to industrial applications. This review aims to establish foundational design principles and inspire innovative solutions for developing practical high-energy-density lithium metal batteries.