A New Zinc Salt Chemistry for Aqueous Zinc-Metal Batteries.

Aqueous zinc-ion batteries (ZIBs) are promising energy storage solutions with low cost and superior safety, but they suffer from chemical and electrochemical degradations closely related to the electrolyte. Here we report a new zinc salt design and a drop-in solution for long cycle-life aqueous ZIBs. The salt Zn(BBI) 2 with a rationally designed anion group N-(benzenesulfonyl)benzenesulfonamide (BBI - ) has a special amphiphilic molecular structure, which combines the benefits of hydrophilic and hydrophobic groups to properly tune the solubility and interfacial condition. This new zinc salt does not contain fluorine and is synthesized via a high-yield and low-cost method. We show that 1 M Zn(BBI) 2 aqueous electrolyte with a widened cathodic stability window effectively stabilizes Zn metal/H 2 O interface, mitigates chemical and electrochemical degradations, and enables both symmetric and full cells using zinc metal electrode. This article is protected by copyright. All rights reserved.