In Al-air batteries, the self-corrosion of Al electrodes and the parasitic hydrogen evolution during battery discharge are the major defects that lead to the degradation in the performance of the battery. Here, the ionic liquid (1-Allyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide) (IL) is used as an organic additive to minimize the H2 gas evolution and corrosion rate in the alkaline electrolyte (4.0M NaOH) for Al-air battery. The efficiency of IL compound is investigated using H2 gas evolution, polarization, electrochemical frequency modulation (EFM) and battery performance measurements. The surface morphology of Al electrode was characterized by scanning electron microscopy (SEM) coupled with energy dispersive X-ray (EDX) analysis. The results presented below show that the IL compound inhibits both the H2 gas evolution and the self-corrosion of Al electrode. In addition to this, the presence of IL compound enhances the capacity density of battery reaching to the maximum value (2554 mAhg-1) at 1.5mM of IL.