Simultaneously Homogenized Electric Field and Ionic Flux for Reversible Ultrahigh-Areal-Capacity Li Deposition.

High areal capacity and stable Coulombic efficiency (CE) in lithium metal anodes (LMAs) play pivotal roles in developing high-energy-density rechargeable batteries. However, few reported LMAs delivering high and stable CE (> 50 cycles) under ultrahigh areal capacity (>10 mA h cm-2). We demonstrated that the simultaneous homogenization of electric field and Li ion flux by using self-supported and surface-oxidized 3D hollow porous copper fibers (3D-HPCFs) can greatly increase both the areal capacity and reversibility of Li deposition. Li can be easily confined inside the hollow porous fibers and within the interspaces among fibers without uncontrollable Li dendrites. The 3D-HPCF-based anode can be deeply cycled at high capacity of 15 mA h cm-2 with average CE of 98.87% for 53 cycles, enabling a practical cell to realize high capacity retentions at a surplus Li of 10%. This work provides a novel Li deposition-regulation technology in LMAs targeting for next-generation high-energy-density batteries.