Nature of contact corrosion layers on lead alloys: A study by impedance spectroscopy

Corrosion layers on lead, lead–antimony and lead–calcium alloys doped with various components (Cd, Sn, Ba, and Ag) were studied using impedance spectroscopy. The films were formed under different potentials and polarization conditions in 4.8 M sulfuric acid solution. The nature of the corrosion layer formed at the alloy-oxidation products interphase was studied using impedance spectroscopy. The results show that the processes proceeding at this boundary can be simulated with an equivalent circuit corresponding to a two-layer model of the corrosion film (an outer high-conducting part and an inner low-conducting one). Parameters of the proposed equivalent circuits were estimated.

► The nature of the corrosion layer formed at the lead alloys was studied by impedance spectroscopy.
► An equivalent circuit corresponding to a two-layer model of the corrosion film was proposed.
► Parameters of the proposed equivalent circuits were estimated.
► This is important at choosing alloys for grids used in VRLA batteries.