Single-Atom Catalysis with Anion-Enriched Environments for Enhanced Stability of Zn–I 2 Batteries

High Resolution Image Download MS PowerPoint Slide Aqueous zinc–iodine batteries (AZIBs) are promising next-generation energy storage systems owing to their low-cost, high-energy density, and fast redox kinetics. However, their performance remains limited by sluggish iodine conversion, severe I 2 dissolution, and Zn corrosion. Here, zinc single atoms anchored on nitrogen-doped carbon (Zn-NC) serve as a signal atom catalyst to construct an anion-rich surface microenvironment, which lowers the energy barrier for I 2 redox and accelerates reaction kinetics. Meanwhile, Zn-NC enhances electrochemical activity, effectively adsorbs polyiodides, and suppresses the shuttle effect, collectively improving the rate performance and cycling stability. Electrochemical analyses reveal higher capacitive contributions, reduced polarization, and uniform Zn deposition. Consequently, Zn|I 2 cells deliver over 16000 cycles at 10 C, and pouch cells maintain >300 cycles with >8 mAh cm –2 areal capacity at 54.7% Zn utilization.