Lattice distortion and structure collapse are two intrinsic issues of intercalative-type electrodes derived from repeated ion shuttling. In contrast, rechargeable iodine batteries (RIBs) based on the conversion reaction of iodine stand out for high reversibility and satisfying voltage output characteristics no matter when dealing with both monovalent and multivalent ions. Foreseeable performance superiorities lead to an influx of considerable focus and thus a renaissance in RIBs. This review provides a comprehensive overview of the fundamental chemistry of RIBs from the perspectives of physicochemical properties, conversion mechanism, and existing issues. Furthermore, we refine the optimization strategies for high-performance RIBs, focusing on physical adsorption and chemical interaction strengthening, electrolytes regulation, and nanoscale-iodine design. Then the pros and cons of tremendous RIBs are compared and specified. Ultimately, we conclude with remaining challenges and perspectives to our best knowledge, which may inspire the construction of next-generation RIBs.
Keywords: conversion mechanism; electrochemical performance; electrolytes regulation; energy storage; iodine batteries; multivalent ions; physical/chemical interaction; shuttling effect.