Bifunctional electrolyte additive ammonium persulfate for high-performance aqueous zinc-ion batteries

The main issues encountered in aqueous zinc-ion batteries (ZIBs) include corrosion and passivation of the zinc anode , electrolyte decomposition leading to hydrogen evolution , and dissolution consumption of cathode materials . This study proposes the use of ammonium persulfate (APS) as an electrolyte additive to enhance battery performance. The addition of APS not only adjusts the solvation structure of Zn 2+ , reduces water activity, but also allows NH 4+ ions to preferentially adsorb onto the surface of the zinc electrode, forming a protective layer and achieving dendrite-free zinc anodes. Results indicate that the inclusion of APS additive in the electrolyte can increase the specific capacity of zinc-ion batteries from 321 mAh g −1 to 418 mAh g −1 . Additionally, batteries with APS exhibit superior stability. Under low current density , the battery lifespan can reach 2100 h and a coulombic efficiency can up to 99.6%. This study delves into the design of multifunctional electrolyte additives and provides valuable insights for the development of practical ZIBs.