Two‐Electron Redox Chemistry Enabled High‐Performance Iodide‐Ion Conversion Battery
Xinliang Li, Yanlei Wang, Ze Chen, Pei Li, Guojin Liang, Zhaodong Huang, Qi Yang, Ao Chen, Huilin Cui, Binbin Dong, Hongyan He, Chunyi Zhi
Abstract
Abstract A single‐electron transfer mode coupled with the shuttle behavior of organic iodine batteries results in insufficient capacity, a low redox potential, and poor cycle durability. Sluggish kinetics are well known in conventional lithium–iodine (Li−I) batteries, inferior to other conversion congeners. Herein, we demonstrate new two‐electron redox chemistry of I − /I + with inter‐halogen cooperation based on a developed haloid cathode. The new iodide‐ion conversion battery exhibits a state‐of‐art capacity of 408 mAh gI −1 with fast redox kinetics and superior cycle stability. Equipped with a newly emerged 3.42 V discharge voltage plateau, a recorded high energy density of 1324 Wh kgI −1 is achieved. Such robust redox chemistry is temperature‐insensitive and operates efficiently at −30 °C. With systematic theoretical calculations and experimental characterizations, the formation of Cl−I + species and their functions are clarified.