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The precise observation of a solid–liquid interface by means of frequency modulation atomic force microscopy (FM-AFM) was performed, demonstrating its applicability to a study on lead acid batteries using an electrochemical test cell for in-liquid FM-AFM embedded with a specialized cantilever holder. The consistency and reproducibility of each surface profile observed via amplitude modulation AFM and FM-AFM were verified properly in a strong acidic electrolyte. In terms of FM-AFM, the ability to observe remarkable changes in the force mapping is the most beneficial, especially near the negative electrode surface. The localization of lignosulfonate (LS) added into the electrolyte as an expander could be visualized since this characteristic force mapping was captured when LS was added to electrolyte. [ABSTRACT FROM AUTHOR]

Abstract: The effect of lignosulfonate (LS) on electrochemical reaction of lead electrode (as a model of negative electrode) has been investigated in 1M, 3M, or 7.1M H2SO4 aqueous solution with 0, 10, 100 or 1000mgl−1 of LS using cyclic voltammetry (CV) combined with in situ electrochemical atomic force microscopy (EC-AFM), as well as rotating ring disk electrode (RRDE). The anodic peaks of the CVs, which correspond to overall reaction of , shifted positive when LS was added or the concentration of H2SO4 was lower. The anodic capacities of the CVs increased with addition of LS when the concentration of H2SO4 was lower. When LS was added, the anodic capacities of the CVs usually increased especially in less concentrated H2SO4 solution at higher sweep rate, while the anodic capacity slightly decreased in 7.1M H2SO4 solution with addition of LS at sweep rate of 10mVmin−1; that is, in most concentrated H2SO4 solution at lower sweep rate in this paper. Two cathodic peaks of the CVs were observed when LS was added, and the peak at lower potential shifted more negative with increase of LS. Lead sulfate crystals dissolved at more negative potential with increase of LS. LS up-took Pb2+ ions in H2SO4 aqueous solution during discharging. [Copyright &y& Elsevier]

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]

Pb(1 0 0) and Pb(1 1 1) single crystals in 50 mM H2SO4 aqueous solution have been investigated by in situ electrochemical atomic force microscopy (EC-AFM) under potential control. We have succeeded in observating high resolution images of Pb(1 0 0) and Pb(1 1 1) single crystals, as well as high resolution and morphological images of PbSO4 crystals formed on the Pb single crystals. We found that the top face of PbSO4 crystals formed on Pb(1 0 0) is PbSO4(0 0 1), while that on Pb(1 1 1) is PbSO4(1 0 0). We also found that the atomic rows along the [1 0 0] and [0 1 0] direction of PbSO4(0 0 1) surface were parallel with those along the [0 1 1] and [0 1 1¯] direction of the Pb(1 0 0) substrate, while those along the [0 1 0] and [0 0 1] direction of the PbSO4 (1 0 0) surface were parallel with those along the [0 1 1¯] and [1¯ 1 1] direction of the Pb(1 1 1) substrate. [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]

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]