Solvent Chemistry Manipulated Iodine Redox Thermodynamics For Durable Iodine Batteries

Abstract The diverse valences of iodine enable it with multi‐electron transfer capability for energy dense batteries. However, previous studies indicate that the primary I − /I 2 redox couple exhibits distinct behaviors depending on electrolyte choice, with the mechanistic basis of aqueous versus nonaqueous systems remaining unclear. Here, we elucidated the solvent effect on iodine redox, particularly focusing on polyiodide formation and their molecular interaction correlations. We validate that a thermodynamically one‐step conversion reaction (I 2 ↔ I − ) occurs in the protic solvents, while it is a two‐step transformation (I 2 ↔ I 3 − ↔ I − ) in aprotic solvents. This distinction arises from strong…

• NN
  National Natural Science Foundation of China

  Award: 22479043