Alleviating salt depletion at the Zinc anode interface by an ion-releasing separator to achieve ultra-stable Zinc anode

Abstract

The challenges of Zn dendrite growth and corrosion are closely tied to salt depletion at the Zn anode interface, arising from Zn²⁺ ions consumption and the reverse migration of anions during zinc deposition. Herein, a functional separator (GFZP), composed of ultra-thin ZrP nanosheets with oxygen defects affixed to glass fiber, is developed to resolve these challenges. The GFZP separator effectively mitigates salt depletion by rapidly adsorbing and releasing significant quantities of ions under an electric field, preventing Zn²⁺ depletion and replenishing SO₄^2- anions through reverse diffusion, ensuring uniform zinc anode deposition. In addition, the absence of a salt depletion region at the Zn interface, coupled with the strong interaction between GFZP and water molecules, suppresses water activity, thereby reducing Zn anode corrosion and side reactions. As a result, the Zn||Zn symmetric cells with GFZP separator survive 3000 h at 1 mA cm^-2 and 1 mAh cm^-2. Furthermore, Zn||Na₂V₆O₁₆•3H₂O full cell achieves a high capacity of 4.9 mAh cm^-2 and excellent cycling stability under limited zinc resources (N/P = 2.4).