Construction of hydrophilic and hydrophobic hybrid interface to achieve controlled zinc deposition for aqueous Zn-ion batteries

Abstract

Aqueous Zn-ion batteries show superior development prospects and competitiveness with high theoretical capacity, abundant reserves and low potential. However, the inhomogeneous electrodeposition of zinc anodes and zinc dendrite growth highly limit their commercialization. To address these issues, multifunctional hybridized interfaces consisting of layered double hydroxide (LDH) and graphene quantum dots (GQDs) are constructed on the surface of zinc metal anodes. LDH with hydrophobicity will effectively shield the corrosion of aqueous electrolyte on the zinc anode, and simultaneously serve as a mechanical skeleton for zinc deposition. The hydrophilic GQDs will control the coordination environment of solvated Zn²⁺, reduce the reactivity of water and promote the uniform deposition of zinc ions along the (002) crystal surface. The interfacially modified Zn anode achieves more than 1000 h and 1200 h of stable cycling at 1 and 2 mA cm⁻², respectively. Moreover, the assembled Zn@LDH@GQDs//NH₄V₄O₁₀ full cells achieve 2000 stable cycles at a high current density of 10 A g⁻¹. The present work reveals the intrinsic mechanism of inhibiting zinc dendrites by the protective layer of multifunctional hybrid materials, which provides an important idea for stabilizing zinc anodes.