Organic pH Buffer for Dendrite‐Free and Shuttle‐Free Zn‐I 2 Batteries

Abstract Aqueous Zn‐Iodine (I 2 ) batteries are attractive for large‐scale energy storage. However, drawbacks include, Zn dendrites, hydrogen evolution reaction (HER), corrosion and, cathode “shuttle” of polyiodines. Here we report a class of N‐containing heterocyclic compounds as organic pH buffers to obviate these. We evidence that addition of pyridine /imidazole regulates electrolyte pH, and inhibits HER and anode corrosion. In addition, pyridine and imidazole preferentially absorb on Zn metal, regulating non‐dendritic Zn plating /stripping, and achieving a high Coulombic efficiency of 99.6 % and long‐term cycling stability of 3200 h at 2 mA cm −2 , 2 mAh cm −2 . It is also confirmed that pyridine inhibits…

• UO
  University of Adelaide
• AR
  Australian Research Council

  Awards: DP200101862, FL210100050