Rethinking the Four-Electron Iodine Redox Mechanism in Zn–I 2 Batteries
Abstract
Four-electron Zn–I 2 batteries (FEZIBs) have garnered increasing research interest due to their potential in grid-scale energy storage. Compared with the energy density (600 Wh kg –1 . However, the formation of I + species is hindered by the high energy barrier of I 0 /I + oxidation and their intrinsic chemical instability. In this Perspective, we elucidate the S N 2-type nucleophilic mechanism as a fundamental principle for activating the I 0 /I + conversion and propose that the instability of I + species originates from shuttling effects and hydrolysis reactions. Based on these insights, feasible strategies for I 0 /I + activation and I + species stabilization are proposed. Moreover, we outline the key targets, opportunities, and challenges for the future development of FEZIBs. This Perspective may provide insights into further advancement of Zn–I 2 batteries.
Fields of Study & Subjects
Advanced battery technologies research
CO2 Reduction Techniques and Catalysts
Advancements in Battery Materials
Publication details
- Journal / source
- ACS Energy Letters
- Publisher
- American Chemical Society (ACS)
- Volume
- 11
- Issue
- 2
- Pages
- 1117–1124
- Publication date
- 2 February 2026
- Language
- EN