Regulating the Zn electrode/electrolyte interface with lactose additive for high performance Zn anode.

[Display omitted] • Cycling performance of Zn electrodes is enhanced via adding lactose. • Regulating Zn electrode/electrolyte interface by lactose contributes to uniform Zn deposition, as well as higher CE. • The zinc ion electrodeposition process is effectively regulated by lactose's dynamic regulatory interface. The practical utilization of rechargeable aqueous zinc metal batteries (AZMBs) has been constrained by the formation of zinc dendrites and other associated issues. This article introduces lactose, a compound rich in hydroxyl groups, as an electrolyte additive into the aqueous solution of the electrolyte with the objective of suppressing the harmful growth of zinc dendrites. The lactose additive, with its strong zincophilicity, robust intermolecular hydrogen bonding, and a large number of exposed high electronegativity hydroxyl groups, enables lactose to effectively modulate the electrode/electrolyte interface in a dynamic manner, thereby achieving the stability and reversibility of the zinc anode. The findings presented in this work demonstrate the uniform deposition and stripping of zinc in a 2 M ZnSO 4 electrolyte with the addition of lactose, thereby enhancing the cycling performance of Zn||Zn batteries. The alteration of the zinc ion environment on the surface of the zinc electrode, in conjunction with the dynamic modulation of the Gouy-Chapman-Stern (GCS) layer by lactose, increases the nucleation overpotential, thereby facilitating to a uniform deposition morphology in lieu of the formation of large-scale dendrites. Furthermore, the formation of hydrogen bonds serves to prevent the occurrence of side reactions. These factors act in concert to enhance the electrochemical performance of AZMBs. The addition of lactose to the electrolyte has resulted in a significant enhancement in the Coulombic efficiency of the card-type Zn||Cu asymmetric battery, reaching 99.7 %. The biodegradability of lactose and the sustainability of its source make this research conducive to the development of environmentally friendly battery electrolyte additives. [ABSTRACT FROM AUTHOR]