Bi-functional electrolyte additive leading to a highly reversible and stable zinc anode

Abstract

A stable stripping/plating process of the zinc anode is extremely critical for the practical application of aqueous zinc metal batteries. However, obstacles, including parasitic reactions and dendrite growth, notoriously deteriorate the stability and reversibility of zinc anode. Herein, Methyl l-α-aspartyl-l-phenylalaninate (Aspartame) is proposed as an effective additive in the ZnSO4 system to realize high stability and reversibility. Aspartame molecule with rich polar functional groups successfully participates in the solvation sheath of Zn2+ to suppress water-induced side reactions. The self-driven adsorption of Aspartame on zinc anode improves uniform deposition with a dose of 10 mm. These synergetic functions endow the zinc anode with a significantly long cycling lifespan of 4500 h. The cell coupled with a vanadium-based cathode also exhibited a high-capacity retention of 71.8% after 1000 cycles, outperforming the additive-free counterparts.