Interfacial Phospholipid Self-Assembly Steering Ion Flux Distribution toward Ultrastable Zinc-Ion Batteries

Owing to high theoretical capacity, low cost, intrinsic safety, and abundant zinc reserves, aqueous zinc-ion batteries (AZIBs) are emerging as promising alternatives to lithium-ion batteries for energy storage. However, the zinc metal anode (ZMA), one of the most promising candidates, suffers from severe parasitic reactions and dendrite growth, significantly compromising the cycling stability and Coulombic efficiency (CE). Herein, we introduce lecithin, an amphiphilic biomolecule, as an electrolyte additive to construct an oriented phospholipid adsorption layer at the ZMA/electrolyte interface. This engineered layer establishes ordered ion transport channels that facilitate 3D diffusion of Zn2+, enabling uniform zinc deposition and thereby suppressing dendrite formation. Simultaneously, the directionally arranged phospholipid adsorption layer can prevent active water molecules in the electrolyte from coming into direct contact with ZMA, mitigating the water-induced hydrogen evolution reaction (HER). Benefiting from this synergy, the ZMA exhibits highly reversible deposition/stripping behavior with exceptional CE. Specifically, the Zn||Zn symmetric cell achieves ultralong cycling stability over 3500 h at 1 mA cm–2, while the Zn||Cu asymmetric cell maintains an average CE of 99.6% after 500 cycles. This work provides a simple yet effective strategy for constructing long-term stability AZIBs, offering novel insights into interfacial engineering for zinc anodes.