Optimizing Interface Multi‐Physical Fields via (R)‐3‐Aminobutyric Acid Cations for Enhanced Zinc Deposition Behavior Realizes the Highly Efficient Zinc‐Iodine Batteries

Abstract A major dilemma faced by Zn anodes is the complicated interfacial processes and uncontrollable deposition behavior, which leads to unstable interphases and severe dendrite growth issues. Indeed, these issues are closely related to the irregular dynamic disturbance of interfacial complex multi‐physics fields during the electrochemical reaction process. Herein, this work constructs a (R)‐3‐aminobutyric acid evolutive cationic interface layer to disclose the interfacial multi‐physics fields variation (including concentration field, electric field, and stress field) after forming this interface structure via in situ spectroscopy analysis, COMSOL multi‐physics simulations, and static energy calculations. It is proven that the R‐3‐ABA ⁺ cationic interfacial layer restrains the Zn ²⁺ concentration polarization formation via interfacial charge/molecule/ion rearrangement, homogenizing the electric field distribution by restraining the anion depletion and the space charge region emergence, thus promoting uniform zinc deposition. Further, the cationic interfacial layer also regulates the stress field of the deposited Zn layer by optimizing the stress state to avoid stress concentration. Consequently, Zn anodes with the cationic interfacial layer achieved an extra‐long life exceeding 2200 cycles with a high average Coulombic efficiency of 99.5%. Importantly, multi‐physics field regulation effects enable Zn||I ₂ batteries at an ultralow N/P ratio (1.44) to exhibit long‐cycling durability.