Cosolvent Electrolyte Design for High-Voltage Aqueous Zinc–Sulfur Batteries

Aqueous zinc–sulfur batteries (AZSBs) offer cost and safety advantages but face challenges related to severe cell polarization. Herein, we introduce a cosolvent, N,N-diethylformamide (DEF), in the ZnSO4 electrolyte to facilitate the sulfur cathode conversion reaction. Compared to Zn(H2O)62+, the reconstructed solvated [Zn(H2O)5DEF]2+ in the cosolvent electrolyte exhibits a narrower HOMO–LUMO gap (0.74 eV vs 1.31 eV), leading to faster charge transfer kinetics at the electrolyte–electrode interface. Due to the strong interaction between DEF and sulfur electrode, the electrons donated by DEF occupy the antibonding orbitals of sulfur, increasing the electron density and electrostatic repulsion between sulfur…

• NS
  Natural Science Foundation of Hebei Province

  Award: B2021203016
• NS
  Natural Science Foundation of Liaoning Province

  Award: 2023-MS-080
• HP
  Hebei Provincial Department of Bureau of Science and Technology

  Award: 226Z4404G
• HE
  Higher Education Discipline Innovation Project

  Award: B16009