Aqueous zinc-iodine batteries (ZIBs),‌ exploiting reversible conversion between diverse iodine species, ‌have drawn significant research interest due to their advantages of ‌ fast redox kinetics and the capability for multi-electron transfer. Despite considerable advances in ZIBs utilizing the two-electron I₂/I⁻ redox pathway (2eZIBs), their inherently limited energy density impedes practical deployment. Achieving the additional reversible conversion reaction of high-valence iodine species, particularly I⁺/I₂ redox chemistry, offers a substantial potential for improved energy density. Nonetheless, Zn-I₂ batteries based on this four-electron I⁺/I₂/I⁻ conversion (4eZIBS) suffer from severe reversibility issues due to the shuttle of the iodide-intermediates and the detrimental hydrolysis of I⁺ species during conversion process. In this perspective, we comprehensively elucidate the fundamental principles of the I₂/I⁻ and I⁺/I₂ redox chemistry, while critically evaluating the merits and limitations of diverse strategies for enhancing the performance of 4eZIBs. Significantly, we propose specific methodological approaches from multiple angles for enhance the reversibility of I⁺/I₂/I⁻ conversion. These findings aim to provide valuable insights for developing advanced ‌metal-halogen battery energy storage systems.