Zn–air batteries are a promising route that might be used in a range of energy sectors. Significant disadvantages, such as passive film and hydrogen gas evolution (HGE) in alkaline corrosive medium; restrict the possible usage of Zn–air batteries. To address these problems and increase the performance of zinc-air batteries, an ionic liquid (tris(2hydroxyethyl) hydroxymethylammonium methyl sulfate [IL]+[MS]-) has been used in this study. The usage of [IL]+[MS]- in 7.0 M KOH solution has a considerable effect on suppressing hydrogen gas creation, with an effectiveness of 86.2%. Increasing the depth of the Bode-phase angle and the charge transfer resistance by adding [IL]+[MS]- also indicates a slower hydrogen gas production rate. The application of the [IL]+[MS]- additive improves the zinc-air battery's specific discharge capacity and capacity retention. To support these findings, SEM/EDX has been used to analyze the morphological features of Zn anodes in various electrolytes.