Stratified adsorption strategy facilitates highly stable dendrite free zinc metal anode

Abstract

Aqueous zinc-ion batteries (ZIBs) are considered promising candidates for energy storage systems because of their high capacity and low cost. However, zinc metal anodes suffer from dendritic growth and electrolyte corrosion, which severely hinder the practical application of ZIBs. Herein, we present a method to construct an ultrathin two-dimensional exfoliated black phosphorus nitrogen-doped graphene (EBP-NG) protective layer on a zinc anode. The step-by-step coating strategy promotes the formation of a dense and stable artificial interface modification layer. Multiphysics field simulations and theoretical calculations show that this stratified structure can effectively regulate the desolvation of H2O and nucleation of Zn. The EBP can induce the homogenization of the electric field and promote the desolvation of [Zn(H2O)6]2+, while the higher Zn affinity of the NG promotes the uniform deposition of Zn along the (002) plane. This surface hydrophilic and internal zinc-philic coating reduces the mutual interference between the H2O and Zn. Benefiting from the strategy, EBP-NG/Zn symmetric cells achieve stability for nearly 3000 h at the current density of 4.0 mA cm−2. In addition, EBP-NG/Zn||MnO2 full cells maintain more than 92.5% capacity after 2000 cycles at 2.0 A g−1. In short, this work provides a reasonable strategy for achieving high reversible dendrite-free zinc anodes.