Effect of barium sulfate and strontium sulfate on charging and discharging of the negative electrode in a lead-acid battery

摘要

A fundamental study is undertaken of the mechanism of the formation and dissolution of lead sulfate on the negative electrode in a lead-acid battery. This involves in situ examination of a lead sheet, on which a small amount of BaSO_4 or SrSO_4 powder is fixed by pressing, in sulfuric acid solution by means of electrochemical atomic force microscopy (EC-AFM) combined with cyclic voltammetry (CV). It is found that both BaSO_4 and SrSO_4 provide seed crystals for the precipitation of PbSO_4. The PbSO_4 crystals are formed more rapidly on SrSO_4 than on BaSO_4 during the oxidation (discharge) process. The dissolution of PbSO_4 crystals formed on SrSO_4 crystals is very slow during the reduction (charge) process.