Preserving Zinc Electrode Morphology in Aqueous Alkaline Electrolytes Mixed with Highly Concentrated Organic Solvent

Abstract

Zinc-based secondary batteries are promising power sources with high energy density but their deterioration modes such as dendritic growth and shape changes need to be solved. These drastic morphology changes of the zinc electrode come from the nature of the discharged product that is easily dissolved in the alkaline electrolyte as zincate species. In this study, we attempt to preserve the zinc electrode morphology by employing the zinc oxidation-reduction processes in the vicinity of electrode, which is attained by controlling the electrolyte solvent property with mixing an organic solvent propylene carbonate (PC). The results show that the use of PC-water mixed solvent is effective in restricting the zincates dissolution into the electrolyte and preserving the zinc electrode morphology with no dendrite formation through 500 oxidation-reduction cycles is demonstrated in the electrolyte with high PC concentrations.