An Anti‐Freezing Hydrogel Electrolyte for Flexible Zinc‐Ion Batteries Operating at −70 °C

Abstract Aqueous zinc‐ion batteries (ZIBs) are considered as the promising candidate of flexible energy storage devices due to their high safety, eco‐friendliness, and low‐cost. However, conventional flexible aqueous ZIBs undergo severe capacity loss at bending and subzero temperature states. Herein, an anti‐freezing hydrogel electrolyte based on zinc tetrafluoroborate (Zn(BF 4 ) 2 ) and polyacrylamide (PAM) is developed. Owing to the strong electronegativity of F atoms, BF 4 − anions interact with water molecules by OH···F to replace the OH···O between water molecules in Zn(BF 4 ) 2 ‐PAM hydrogel electrolyte, inhibiting the formation of ice crystal lattice in hydrogel electrolyte at low‐temperature.…

• NN
  National Natural Science Foundation of China

  Award: 51972231
• MO
  Ministry of Science and Technology of the People's Republic of China

  Award: 2019YFA0705600
• NU
  Nankai University

  Award: 63181206