All‐Climate Energy‐Dense Cascade Aqueous Zn‐I 2 Batteries Enabled by a Polycationic Hydrogel Electrolyte

Abstract The practical development of aqueous zinc‐iodine (Zn‐I 2 ) batteries is greatly hindered by the low energy density resulting from conventional I 0 /I − conversion and the limited temperature tolerance. Here, a temperature‐insensitive polycationic hydrogel electrolyte borax‐bacterial cellulose / p (AM‐ co ‐VBIMBr) (denoted as BAVBr) for achieving an energy‐dense cascade aqueous Zn‐I 2 battery over a wide temperature range from −50 to 50 °C is designed. A comprehensive investigation, combining advanced spectroscopic investigation and DFT calculations, has revealed that the presence of Br species in the gel electrolyte facilitates the conversion reaction of Br 0 /Br − . Simultaneously, it activates the…

• NN
  National Natural Science Foundation of China

  Awards: 52302205, 52172173
• AU
  Anhui University
• NS
  Natural Science Foundation of Anhui Province

  Awards: 2108085J25, 2208085QE130