Sulfamate-Derived Solid Electrolyte Interphase for Reversible Aqueous Zinc Battery

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.