In Situ Construction of Bionic Self‐Recognition Layer for High‐Performance Zinc–Iodine Batteries

Abstract Aqueous Zinc–Iodine (Zn–I 2 ) batteries are promising candidates as energy storage system because of their high safety and low cost, but their application is hindered by the dendrite growth, the hydrogen evolution reaction (HER) and corrosion, the shuttle and self‐discharge effect of I 3 − at electrode/electrolyte interface. Inspired by self‐recognition mechanism of Zn supplement for human body, a self‐recognition layer (SR) is in situ constructed on Zn surface through the coordination of chondroitin sulfate (CHS) molecules with Zn 2+ ions and Zn metal, which can induce the uniform Zn 2+ deposition via the self‐recognition of Zn 2+ , suppress the HER and corrosion via physical shielding, as well as restrain the self‐discharge effect of I 3 − ions via electrostatic repulsion. The in situ SR affords the highly reversible plating/stripping for 9000 h. Remarkably, Zn–I 2 full batteries with SR achieve long cycling‐life of 16 000 cycles, which is verified by pouch cell with stable charge/discharge capacity of ≈130 mAh g −1 for 200 cycles. This bionic self‐recognition methodology opens novel avenues to design the optimal electrode/electrolyte interface for high‐performance Zn–I 2 batteries.