Natural honey helps stabilize zinc anode for dendrite-free aqueous zinc ion batteries

Abstract

Aqueous zinc-ion batteries (AZIBs) have garnered significant attention as energy storage devices due to their high theoretical capacity, low cost, and superior safety. However, uncontrolled Zn dendrite growth and parasitic side reactions have hindered their practical applications. Herein, a novel low-cost and non-toxic electrolyte additive, honey, is incorporated into the typical ZnSO4 electrolyte to stabilize the Zn anode for high performance AZIBs. Both simulation and experimental results suggest that the natural honey additive can regulate the interaction of Zn2+ with SO42− and H2O molecules, thereby promoting the desolvation of Zn2+. Concurrently, glucose and fructose molecules in honey tend to absorb onto the Zn anode, facilitating the uniform deposition of Zn2+. Therefore, the honey additive can effectively inhibit the growth of Zn dendrites and side reactions. As expected, the Zn-symmetric cell with ZnSO4-honey electrolyte achieves excellent Zn stripping/plating reversibility, maintaining stable potentials over 2000 h at 1 mA cm−2 and nearly 1200 h at 5 mA cm−2. When coupling with MnO2 cathode, the full cell with the honey additive also displays improved long-term durability. Furthermore, the packaged pouch cell demonstrates surprising flexibility and satisfactory security under different harsh environments, showing practical feasibility in future wearable devices.