Ionic liquids belong to new branch of salts with unique properties that have ever increasing applications in electrochemical systems especially lithium-ion batteries. For the first time, the effect of these compounds on lead acid battery's performance has been considered in this study. The effects of 6 ionic liquid additive in battery's electrolyte was studied on the hydrogen and oxygen evolution overpotential and anodic layer formation on lead-antimony-tin grid alloy of lead acid battery by using cyclic voltammetry (CV) and linear sweep voltammetry (LSV) in aqueous sulfuric acid solution. The grid surface morphology after cyclic redox reaction was studied by using scanning electron microscopy (SEM). The results show that by increasing this additives to the electrolyte, hydrogen and oxygen overpotential were increased and so crystalline structure of O 4 layer changed. Also cyclic voltammogram on carbon-PbO paste electrode shows that with presence of these additives in the electrolyte, oxidation and reduction peak current intensively increased and oxidation and reduction of PbO become more reversible in some ionic liquids.
