Prospects for Iodide Ion Batteries

Iodide-ion batteries have emerged as a prominent technology in the energy storage field due to their high theoretical capacity, high redox potential, inherent safety, environmental benignity, and low cost. However, the shuttle effect of polyiodides generated during cycling leads to active material loss, rapid capacity fade, and self-discharge. Furthermore, side reactions between these migrating species and the metal anode cause irreversible corrosion and passivation. To address these challenges, this review first details the working principles of iodide-ion batteries, with a specific focus on the reaction mechanisms within the cathode. It then systematically examines strategies to mitigate the shuttle effect across four key components—the cathode, anode, separator/interlayer, and electrolyte—in various iodide-ion battery systems. Finally, the review concludes by discussing future research directions based on current developments, aiming to guide further progress and pave the way for the large-scale application of this promising technology.