Sulfamate-Derived Solid Electrolyte Interphase for Reversible Aqueous Zinc Battery

Abstract

Despite environmental benignancy, the Zn metal anode for aqueous zinc batteries is still hindered due to the instability of the anode/electrolyte interface, which originates from the electrolyte not having the ability to form a protective solid electrolyte interphase (SEI) on the anode. Herein, an SEI-forming electrolyte based on zinc sulfamate (Zn(NH2SO3)2) is proposed. Specifically, the sulfamate anion can be adsorbed on the anode easily to construct an anion-rich Helmholtz plane. With a lower unoccupied molecular orbital energy, NH2SO3– would be preferentially electroreduced to form a stable SEI to suppress the parasitic reactions. Significantly, the Zn anode in the proposed electrolyte can achieve a high Coulombic efficiency of 99.65% for over 1000 cycles. Zn|| NH4V4O10 and Zn||I2 full batteries by adopting the sulfamate electrolyte can retain a high capacity retention of 95.0% for more than 5000 cycles at 5 A g–1, and 93.0% capacity retention for more than 100 cycles at 1 A g–1, respectively.