Elucidating Synergistic Mechanism of Zinc Single‐Atom Sites and Lewis Acid–Base Pairs to Boost Zinc–Iodine Batteries Performance

Abstract Zinc–iodine batteries (ZIBs) are promising energy storage devices due to their nonflammable aqueous electrolyte and intrinsically safe zinc (Zn) anode but encounters thorny challenges, including soluble polyiodides shuttling and sluggish iodine redox kinetics. Here, an ionic porous organic polymers (iPOPs) with Lewis acid–base pairs (e.g., pyridine cation and free Br⁻) and Zn single‐atom sites (iPOP‐TPyPZn) is developed as an advanced I₂ host to notably enhance the performance of ZIBs. The iPOP‐TPyPZn can not only significantly prevent polyiodides shuttling via the synergy of Lewis acid–base pairs but also expedite redox kinetics of I₂ species through the combined action of Lewis acid sites and Zn single‐atom catalytic sites. Benefiting from the double synergistic mechanism, the assembled ZIBs with I₂ loaded iPOP‐TPyPZn cathode exhibit outstanding electrochemical performance with ultra‐high cycling stability over 40 000 cycles at 8 A g⁻¹. Combined in/ex situ spectral characterizations and theoretical calculations clearly reveal the reversible reaction mechanism of I₂ species and the vital role of double synergistic mechanism in enhancing ZIBs performance. This work not only provides a promising path for precise preparation of advanced I₂ hosts but also offers new insights into the reaction mechanism toward metal–I₂ batteries.