Aqueous zinc-iodine batteries (AZIBs) are gaining attentionas next-generation energy storage systems due to their hightheoretical capacity, enhanced safety, and cost-effectiveness.However, their practical application is hindered by challenges such asslow reaction kinetics and the persistent polyiodide shuttle effect. Toaddress these limitations, we developed a novel class of covalentorganic frameworks (COFs) featuring electron-rich nitrogen sites withvaried density and distribution (N1-N4) along the pore walls. Thesenitrogen sites enhance iodine species confinement and masstransport. Our experimental and theoretical studies reveal that thecontinuous and optimized distribution of nitrogen sites within the COFstructure significantly reduces internal resistance and boosts redoxactivity. Moreover, the N4-COF demonstrates superior performancecompared to other porous materials, due to its high density andstrategic alignment of active sites. The I2@N4-COF cathode achievesa remarkable specific capacity of 348 mAh g?1at 1 C, almost 1.8 timesgreater than that of the I2@N1-COF, while also maintaining excellentcycling stability. This integration of a porous framework with alignednitrogen sites in the N4-COF structure not only enhances iodine redoxbehavior but also offers a promising design strategy for developinghigh-performance AZIB electrodes.
https://onlinelibrary.wiley.com/doi/10.1002/anie.202423265