Enabling high-performance sodium metal anode via a presodiated alloy-induced interphase

Abstract

Irreversible plating/stripping process induces the dendritic/mossy Na growth and cracks propagation, which hinder the practical utilization of sodium metal anode. Herein, a heterogeneous interfacial layer, which composed of the carbon-coated ZnO microflowers and the encapsulated Sb nanocrystals ([email protected]/C), is employed to optimize the cycling stability. Upon the voltage-induced presodiation process, the sodiophilic species in-situ transform into the Na-Zn and Na-Sb intermediates and preferentially induce the metallic plating process, mitigating the nucleation overpotential without sacrificing the energy density; while the microflower substrate spatially accommodates the deposit propagation over the repetitive plating/stripping cycling. Consequently, the [email protected]/C dramatically reduces the nucleation barrier to one-third that of the bare Cu foil (4 mV vs. 12 mV at 0.5 mA cm−2) and obtains satisfactory coulombic efficiency values (>99.5%) even at the high rates. Besides, the in-situ presodiation of the [email protected]/C composite allows the stable Na plating/stripping cycling in energy-dense full-cell evaluations (paired with the NASICON type NaVPO4F cathode). The impressive energy/power densities (251.5 W h kg−1 at 1257.5 W kg−1) realized in the prototype construction, coupled with a facile voltage-induced presodiation process, suggest a feasible strategy to extend the performance limits of metal battery systems.