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Abstract: The influence of quinone structures related to the formation of the “colloidal deposit” on Pb electrode immersed into water containing lignin preparations or pure organic compounds has been investigated. It was found that quinone structures in lignin preparations, as well as in pure organic compounds, play an important role in the formation of the “colloidal deposit”. [Copyright &y& Elsevier]

The reaction between lignin and the surface oxide layer on Pb plates was studied by dipping experiments in ultra pure water with lignin, anodic polarograms in sulfuric acid solution with or without lignin and also scanning electron microscopy (SEM) observations of the sample surface after anodic polarization. It is found that the lignin reacts with the surface oxide on the Pb plates in ultra pure water with lignin to reaction products containing Pb and the lignin and they grew preferentially at the interface between Pb and the surface oxide. The deposits formed on the surface suppress to passivate the Pb surface under sulfuric acid solution. [Copyright &y& Elsevier]

Abstract: Negative plate lugs of flooded lead-acid battery were corroded during partial state-of-charge (PSoC) pattern cycle life tests simulated from stop and go vehicle driving. Potential step was applied to Pb–Ca–Sn alloy electrode at various potential and time regimes, and the electrode surface was observed by in situ electrochemical atomic force microscope (EC-AFM) to investigate the corrosion mechanisms during the potential step cycles. It was found out that the severe corrosion occurs when the oxidation of Pb to PbSO4 and partial reduction of passive layer of PbSO4 take turns many times. It was also found out that the periodic full charge, the optimization of the alloy composition, addition of the material that may make the reaction mechanism change to electrolyte were effective to suppress the corrosion rate. [Copyright &y& Elsevier]

Abstract: Potential step was applied to Pb–Ca–Sn alloy electrode at various potential and time regimes. No severe corrosion was observed during potential step cycle with cathodic potential under −140mV or over −40mV versus Pb/PbSO4 (3.39M H2SO4), or at constant potential without stepping. On the other hand, the Pb–Ca–Sn alloy was severely corroded during potential step with cathodic potential from −120mV to −60mV and with anodic potential of +40mV or more positive. The corrosion could not be decreased with periodical rest at 0mV, while it could be decreased with periodical reduction at high polarization of, e.g. −160mV. It was found out that the severe corrosion occurs when the oxidation of Pb to PbSO4 and partial reduction of passive film of PbSO4 take turns many times. [Copyright &y& Elsevier]

Abstract: Electrochemical properties of lead dioxides, formed on various lead alloy substrates (Pb–In, Pb–Sn, Pb–Sb, Pb–Tl and Pb–Bi), were investigated using electrochemical techniques with X-ray diffraction (XRD) and electron probe micro analyzer (EPMA). Additive elements, selected by applying Hume-Rothery rules, have similar atomic radius and electronegativity to lead. The reduction capacity of lead dioxides that were formed on Pb–Sb and Pb–Sn alloy substrates decreased, whereas the reduction capacity of lead dioxides formed on Pb–In, Pb–Tl and Pb–Bi alloy substrate increased, compared with those formed on the pure lead substrate. The change of the lattice constant of β-lead dioxides and the existence of additive elements in the lead dioxide layer were confirmed from the analysis results of XRD and EPMA. We concluded that the substitution of additive elements for lead in the β-lead dioxide caused the change of its lattice constant to affect the reduction capacity. [Copyright &y& Elsevier]

The surface morphologies of lead dioxide layers, which were formed on a pure lead substrate and the Pb–Sb a (100 ppm–3%) alloy substrate, were directly observed with the electrochemical atomic force microscope (EC-AFM) in 1.250 g/cm3 sulfuric acid electrolyte and then they were analyzed with X-ray diffraction (XRD). The particle size of the lead dioxide became significantly smaller with the increase of the amount of antimony in the substrate alloy. From this result, it was considered that such small particle size serves to increase the reaction area of the positive electrode and the total electrical contact area between the positive active material (PAM) particles. Also, the interface resistance between grid and the PAM can become lower, if the density of the corrosion layer formed around the grid were to be higher for the small particles. By XRD analysis, it was found that the inter-atomic distance of the lead dioxide on the Pb–3 wt.% Sb alloy substrate shrank compared to that on a pure Pb substrate. [Copyright &y& Elsevier]