Uniform Deposition of Li-Metal Anodes Guided by 3D Current Collectors with In Situ Modification of the Lithiophilic Matrix

Enhancing Lithium-Ion Diffusion Kinetics in a 3D Lithium Metal Host through Surface Modification with Hierarchical Multimetal Oxides

Lithium metal is a promising anode candidate to achieve high-energy-density lithium metal batteries (LMBs) due to its ultrahigh theoretical capacity (3860 mA h g-1) and low electrochemical potential (-3.04 V vs S.H.E). Unfortunately, the commercialization of lithium metal anodes is hindered by the growth of Li dendrites and the infinite Li volume changes during the cycling process. Herein, we introduce a 3D hierarchical multimetal oxide nanowire framework as a current collector for Li metal anodes. The hierarchical metal oxide layers of CoO and CuxO provide abundant Li nucleation sites and thus offer uniform Li plating and regulate Li nucleation during the charge/discharge process. As a result, half cells present a prolonging Coulombic efficiency of 97% at 1 mA cm-2 with a capacity of 1 mA h cm-2 for over 300 cycles. A stable cyclability of symmetric cells is demonstrated under 1 mA cm-2 with a capacity of 1 mA h cm-2 for 1500 h. Full cells paired with an LFP cathode show a stable capacity of 131.5 mA h g-1 with a capacity retention of 92% for 200 cycles. These results will shed insights into the design of 3D Cu current collectors for high-performance composite Li metal anodes.

Functionalized Halloysite Scaffold Controls Sodium Dendrite Growth

Sodium metal is one of the most promising anodes for the prospective low-cost rechargeable batteries. Nevertheless, the commercialization of Na metal anodes remains restricted by sodium dendrite growth. Herein, halloysite nanotubes (HNTs) were chosen as the insulated scaffolds, and Ag nanoparticles were introduced as sodiophilic sites to achieve uniform sodium deposition from bottom to top under the synergistic effect. Density functional theory (DFT) calculation results demonstrated that the presence of Ag greatly increased the binding energy of sodium on HNTs/Ag (-2.85 eV) vs HNTs (-0.85 eV). Meanwhile, thanks to the opposite charges on the inner and outer surfaces of HNTs, faster Na⁺ transfer kinetics and selective adsorption of SO₃CF₃^- on the inner surface of HNTs were achieved, thus avoiding the formation of space charge. Accordingly, the coordination between HNTs and Ag afforded a high Coulombic efficiency (about 99.6% at 2 mA cm^-2), long lifespan in a symmetric battery (for over 3500 h at 1 mA cm^-2), and remarkable cycle stability in Na metal full batteries. This work offers a novel strategy to design a sodiophilic scaffold by nanoclay for dendrite-free Na metal anodes.