Anion Induced Electric Double Layer Compression and Desolvation Optimization Enable Long Life Zinc Anodes under High‐Rate

Aqueous zinc-ion batteries (AZIBs) represent a promising next-generation energy storage solution. However, AZIBs suffer from severe dendrite growth caused by rampant Zn²⁺ 2D diffusion and sluggish desolvation kinetics, thus exhibiting extremely short cycle life under high-rate conditions. Here in, a novel additive DL-O-Methylserine (MeSer) is reported, which effectively optimizes Zn²⁺ diffusion behavior and facilitates the desolvation process. Experimental and computational results reveal that MeSer^- adsorption on the electrode surface compresses the electric double layer (EDL), thereby reducing repulsive forces within it. The decrease in repulsion further enhances Zn²⁺ 3D diffusion leading to uniform deposition. Furthermore, MeSer^- interacts with Zn²⁺ located in solvation sheath, reducing desolvation energy barriers and improving rate capability. Consequently, Zn||Zn symmetric cells with MeSer exhibits superior cycling stability of 2320 h under 5 mA cm^-2 and 5 mA h cm^-2 and can endure extreme high-current conditions (20 mA cm^-2, 20 mA h cm^-2) for up to 600 h, such performance exceeds most of the previously documented results. The Zn||V₂O₅ full cells maintained 86% capacity retention after 3500 cycles at 5 A g^-1. This work demonstrates the remarkable effectiveness of a simple EDL regulation strategy in enhancing AZIB performance.