Hypervalent organoiodine compounds have been extensively
utilized
in organic synthesis, yet their electrochemical properties remain
unexplored despite their theoretically high redox potential compared
with inorganic iodine, which primarily relies on the I–/I0 redox couple in battery applications. Here, the fundamental
redox mechanism of hypervalent organoiodine in a ZnCl2 aqueous
electrolyte is established for the first time using the simplest iodobenzene
(PhI) as a model compound. We validated that the PhI to PhICl2 transition is a single-step and reversible reaction, enabling
two-electron transfer of I+/I3+ redox chemistry
(1.9 V vs Zn2+/Zn) with high capacity (422 mAh giodine
–1, and 262.6 mAh g–1 based on
PhI) and high theoretical energy density (801.8 Wh kg–1). It was also elucidated that such organoiodine electrochemistry
exhibits rich tunability in terms of the global reactivity of various
PhI derivatives, including multiple iodine-substituted isomers and
functional substituents. Additionally, the stabilizing anion ligands
affect the reversibility and stability of trivalent organoiodine compounds.
By limiting side reactions and improving the stability of trivalent
organoiodine at low temperatures, the zinc-PhI battery demonstrated
the feasibility of I+/I3+ conversion and sustained
stable performance over 400 cycles. This work bridges the gap between
hypervalent organoiodine chemistry and battery technology, highlighting
the potential for future high-performance battery applications.