Water-in-Salt Electrolytes (WISE) for Aqueous Zinc-Ion Battery, 20-100 g/bottle, CAZIBWISE

Water-in-Salt Electrolytes (WISE) represent a paradigm shift in aqueous battery chemistry. By radically shifting the salt-to-solvent mass ratio—often exceeding ao 1:1 molar ratio or high molality (3 m to 20 m)—WISE formulations overcome the traditional limitations of water-based systems. 

The design concepts of WISE are: (1) Elimination of Free Water: In a conventional dilute electrolyte, cations are surrounded by a hydration shell, leaving a vast network of free water molecules. In WISE, the massive concentration of salt forces virtually all water molecules into the primary solvation sheaths of the metal cations. (2) Inner Helmholtz Layer (IHL) Modification: Anions are pulled directly into the inner coordination sphere of zinc ions, altering the electrode-electrolyte interface and preventing direct water contact with the active metal surface.

The key electrochemical advantages of WISE are: (1) Widened Stability Window: By suppressing free water activity, WISE formulations push the electrochemical stability window far beyond the thermodynamic 1.23 V limit of pure water, often approaching 3.0 V to 4.0 V. (2) HER and Dendrite Mitigation: The absence of free water virtually halts the hydrogen evolution reaction (HER), while anion-derived inorganic interphases promote uniform, dendrite-free zinc stripping and plating.

References: 

1. Z. Khan, et al. Does Water-in-Salt Electrolyte Subdue Issues of Zn Batteries?, Adv. Mater., 2023, 35, 2300369
2. J. Wei, et al. Advanced electrolytes for high-performance aqueous zinc-ion batteries, Chem Soc. Rev., 2024, 53, 10335–10369.