A study on charge acceptance of the lead-acid battery through in-situ EC-AFM observation -influence of the open-circuit standing time on the negative electrode

摘要

Influence of the open-circuit standing time after oxidation of the lead electrode was investigated for understanding charge acceptance of the negative electrode of the lead-acid battery. It was confirmed by a potentiostatic transient experiment that charge acceptance of the lead electrode heavily depended on the standing time before charging, and decreased as the standing time became longer. This tendency was conspicuous at the initial period of the reduction process in particular. When the behavior of the lead electrode surface during the open-circuit standing after oxidation was observed by in-situ EC-AFM, it was found that some lead sulfate crystals gradually grew with time to bigger crystals having a smooth surface, retaining their basic morphologies. We have concluded that the standing time dependence of the charge acceptance is caused by this behavior of the crystals. Also, it was confirmed that charge acceptance of a valve regulated lead-acid battery with various standing times was similar to that in the result of the potentiostatic transient test of the lead electrode.