engleski

Impedance Spectroscopy as a Tool for Characterization of Surface Films on Lead and Lead Alloys

The effect of varying antimony content in lead alloys (with Sb content of 1.3 ; 2.7 and 3.5 wt.%) on electrochemical processes taking place on lead-antimony alloy electrodes was studied in sulphuric acid solution. Electric and structural properties of anodic films formed on the electrode surface during the 'charging' and 'discharging' processes of the negative and positive electrodes in the lead-acid battery were studied in situ using electrochemical impedance spectroscopy. It was found that antimony present in the alloy catalyzes the solid phase transition of PbO to non-stoichiometric PbO_n oxide (n < 2) in the anodic layer, while it inhibits the formation of electronically conducting beta-PbO_2 phase. This causes an increase in oxygen evolution potential and expands the region of discharging of the positive electrode in the lead-acid battery.

lead; antimony; lead-acid battery; anodic layer; impedance spectroscopy

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