Efficient Charge Storage in Zinc–Iodine Batteries based on Pre‐Embedded Iodine‐Ions with Reduced Electrochemical Reaction Barrier and Suppression of Polyiodide Self‐Shuttle Effect

作者：Wenzheng Gao, Situo Cheng, Yaxiong Zhang, Erqing Xie, Jiecai Fu · 发表于：Advanced Functional Materials · 年份：2023 · DOI：10.1002/adfm.202211979 · 被引用次数：135 · 研究领域：Advanced battery technologies research、Perovskite Materials and Applications、Advanced Battery Materials and Technologies

Abstract 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 structure‐limiting 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 .