Electrochemical properties of positive electrode in lead-acid battery modified by ammonium-based ionic liquids

The influence of selected types of ammonium ionic liquid (AIL) additives on corrosion and functional parameters of lead-acid battery positive electrode was examined. AILs with a bisulfate anion used in the experiments were classified as protic, aprotic, monomeric, and polymeric, based on the structure of their cation. Working electrodes consisted of a lead-calcium-tin alloy utilized in the industry for manufacturing current collectors of positive electrodes in lead-acid batteries (LABs). This alloy was used in the first part of the study for the evaluation of corrosion intensity and stability of electrolyte with AIL additives. In the second part, the grid made of the examined alloy was covered with positive active mass, the composition of which was modified by selected AIL. The selection of an appropriate substance was made based on parameters such as corrosion potential, corrosion current, polarization resistance, and hydrogen and oxygen evolution potentials. Techniques such as linear sweep voltammetry, corrosimetry, and electrochemical impedance spectroscopy were used. The conducted measurements revealed that polymeric AIL additive had an exceptionally positive influence on the inhibition of the corrosion process in LAB and electrochemical window of the electrolyte. The influence of this compound on the specific capacity and resistance of the active mass was also discussed.