Zincophilic/Hydrophobic Valine Enabled Electrolyte Coordination Environment Optimization and Electrical Double-Layer Regulation for a Highly Stable and Dendrite-Free Zinc Metal Anode

Economically viable and biologically compatible amino acids demonstrate significant potential as electrolyte microstructure modifiers in aqueous zinc-ion batteries (AZIBs). Compared to polar amino acids, nonpolar amino acids simultaneously own zincophilicity and hydrophobicity, showing great potential in the industrial application of AZIBs. However, nonpolar amino acids have been comparatively understudied in existing research investigations. Herein, this study reveals that the nonpolar alkyl functional group of valine (VAL) renders it particularly advantageous as an AZIB electrolyte modifier. VAL serves as a multifunctional additive that reorganizes the electrolyte coordination sphere while engineering the electrode–electrolyte interface, thereby synergistically stabilizing the anode and facilitating Zn 2+ desolvation kinetics. Leveraging VAL’s distinctive molecular characteristics, Cu//Zn batteries incorporating this additive exhibited exceptional cycling durability (3500 cycles) and near-perfect Coulombic efficiency (99.86%). This study presents an effective electrolyte modulation approach for achieving dendrite-free zinc anodes and stable full-cell configurations, offering promising potential for advanced AZIBs and related energy storage systems.