Aqueous zincIodine batteries are considered as a promising energy storage system due to their high energy/power density, and safety. However, polyiodide shuttling leads to severe active mass loss, which results in lower Coulombic efficiency and limits the cyclic life. Herein, a novel structurelimiting strategy to pre-embed iodide ions into Prussian blue (PBI) is proposed. The DFT calculations and electrochemical characterization reveal that the formation of FerrumIodine bond reduces the electrochemical reaction energy barrier of subsequent iodide-ions at the pre-embedding sites, improves the I − oxidation reaction kinetic process, and suppresses the polyiodide self-shuttle. The PBI//Zn batteries exhibit a low Tafel slope (155 mV dec −1 ). Moreover, UV-vis spectroscopy confirms that the proposed strategy suppresses the polyiodide self-shuttle. As a result, the PBI//Zn battery achieves high iodide utilization and Coulomb efficiency (242 mAh g −1 at 0.2 A g −1 , CEs ≈ 100%), as well as high multiplicity performance of 197.2 mAh g −1 even at 10 A g −1 (82% of initial capacity). The PBI//Zn battery also renders excellent cyclic stability with a capacity retention of 94% at 4 A g −1 after 1500 cycles. The device exhibits a high energy density of 142 W h kg −1 at a power density of 5538 W kg −1 .

maximize the energy density of the used energy storage devices and slow down its energy loss during the energy transport process. Although significant progress has been achieved, there is still massive room for improvement in the energy density of energy storage equipment (10-100 Wh kg −1 ). [6] Traditional electricdouble-layer (EDL) electrode materials that store charges via a surface-controlled ion adsorption/desorption mechanism cannot overcome the problem of low energy density. [7] To this end, extensive efforts have been devoted to exploring pseudocapacitive materials with surface Faradaic redox activities. However, conventional pseudocapacitive materials (such as, metal oxides, metal sulfides, and conducting polymers) generally suffer from either low economy of electrode material (i.e., accessible electrochemical active portion) or frustrating structure stability, resulting in limited actual energy density and inferior cycling stability. All the research experience indicates that the well-designed electrode materials with good conductivity and stable structure have far-reaching significance to achieve outstanding capacity and cycling performance for highperforming energy storage devices.Recently, conductive 2D conjugated metal−organic frameworks (c-MOFs), constructed by metal ions and π-conjugated organic ligands, possess the advantages of large specific surface areas (up to 900 m 2 g −1 ), [8][9][10] remarkable electrical conductivities (up to 2500 S cm −1 ), [11][12][13] tailorable structures and good thermal/chemical stability, which have emerged as a class of promising electrode materials for high-performing energy storage devices. [14][15][16][17] More impressively, the abundant unsaturated bonds and functional groups in the π-conjugated ligands and the multi-valences of the metal ions of the 2D c-MOFs make it also possible to accept or lose electrons, and thereby batteries with high capacity could be expected. Feng et al. reported that redox-active linkages (e.g., transition metal centers and radicals) of 2D c-MOFs could contribute to considerable pseudocapacitances (>300 F g −1 ) in 1 m KOH aqueous electrolyte. [12] Zhang et al. reported that metal-bis-(iminobenzosemiquinoid) of 2D c-MOFs can be used as the adsorption/desorption site of the anion (SO 4 2− ), which shows a significantly improved charge Conductive 2D conjugated metal−organic frameworks (c-MOFs) are attractive electrode materials due to their high intrinsic electrical conductivities, large specific surface area, and abundant unsaturated bonds/functional groups. However, the 2D c-MOFs reported so far have limited charge storage capacity during electrochemical charging and discharging, and the energy density is still unsatisfactory. In this work, a strategy of selective center charge density to expand the traditional electrode materials to the electrode−electrolyte coupled system with the prototypical of 2D Co-catecholate (Co-CAT) is proposed. Electrochemical mechanism studies and density functional theory calculations reveal that dual re...