LAUSR

Abstract In this article, we report the development of a novel Zn-air rechargeable battery with charcoal/graphite cathode and dicarboxyl telehelic polyethylene glycol (PEG) additives with different molecular weights (Mn: 600 Da, 1500 Da, 3300 Da). The battery is free of heavy metals and all of the used materials are easily available and non-toxic. The dicarboxyl telechelic PEGs were successfully applied to suppress the formation of dendritic and mossy deposits on the surface of the zinc electrode at both 7.5 and 2 mAcm−2 charging current density. The stability of the rechargeable battery was tested, where stable operation was achieved with all the synthesized dicarboxyl telechelic PEGs. Furthermore, the long-term cyclic performance was investigated with charging/discharging cycles up to 68 hours, where stable battery potentials were obtained with near 100% Coulombic efficiency during the entire measurement. In the presence of additives, the discharging steps were also mathematically modeled. The electrode surfaces were analyzed by Scanning Electron Microscopy (SEM) and Energy Dispersive Spectroscopy (EDS). The additive-free systems resulted in mossy-like deposition, while in the presence of dicarboxyl telechelic PEG additives the surface of the zinc electrode remained smooth and the weight of the electrode did not change after the long-term test.