Facet-selective zinc deposition and kinetics enhancement via aromatic and zinc-affinitive compounds for long-term stable zinc anodes

Abstract

Aqueous zinc-ion batteries (AZIBs) face critical challenges due to zinc dendrite growth and hydrogen evolution reactions, which degrade both battery performance and longevity. To address these issues, we introduce phenethyl alcohol (PA), a multifunctional additive that enhances zinc anode stability by regulating the solvation structure of Zn²⁺ ions and promoting facet-selective zinc deposition. The hydroxyl group of PA exhibits a strong affinity for zinc ions, reconfiguring the solvation shell by displacing coordinated water molecules, which effectively suppresses HER. Additionally, the conjugated aromatic π-π stacking interactions between PA's benzene ring and the zinc (002) crystal facet direct the preferential deposition of zinc on this low-energy plane, significantly improving deposition kinetics and ensuring a uniform zinc layer. This dual mechanism not only stabilizes the zinc interface but also enhances the cycling reversibility of the anode. As a result, symmetric cells with PA-modified electrolytes achieve over 1600 h of stable cycling at 2 mA cm⁻², while Zn||Ti half-cells maintain a remarkable Coulombic efficiency of 99.74 % at 4 mA cm⁻². These findings underscore PA's potential as a highly effective electrolyte additive, offering a promising strategy for improving both the electrochemical performance and long-term stability of zinc anodes in the next generation of high-performance AZIBs.