Electrochemistry
Online ISSN : 2186-2451
Print ISSN : 1344-3542
ISSN-L : 1344-3542
Volume 73 , Issue 2
Showing 1-12 articles out of 12 articles from the selected issue
Preface
Communication
  • Koichi UI, Kohei ISHIKAWA, Takao FURUYA, Yasushi IDEMOTO, Nobuyuki KOU ...
    2005 Volume 73 Issue 2 Pages 120-122
    Published: February 05, 2005
    Released: June 01, 2019
    JOURNALS OPEN ACCESS

    The positive electrode performance of the LiCoO2 electrode in the LiCl saturated AlCl3-1-ethyl-3-methylimizadolium chloride (EMIC) + SOCl2 melt as the electrolyte for nonflammable lithium secondary batteries was evaluated. In the cyclic voltammogram of the LiCoO2 electrode in the melt, the oxidation and reduction waves corresponding to the electrochemical intercalation / deintercalation reactions of Li+ were observed at 3.5~4.2 V vs. Li+/Li, and it suggested that the LiCoO2 electrode operated well in this melt. From charge and discharge evaluations, it was known that the discharge capacity was about 130 mAh g-1 and the coulomb efficiency was maintained of more than 93% during ten cycles. It became clear that the LiCoO2 electrode operates quite as a positive electrode in the melt.

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Articles
  • Kiyoshi ITO, Shinji YAE, Takahiro HAMADA, Hisatsugu NAKANO, Naoki FUKU ...
    2005 Volume 73 Issue 2 Pages 123-127
    Published: February 05, 2005
    Released: June 01, 2019
    JOURNALS OPEN ACCESS

    A solution has been developed for autocatalytic (electroless) pure Ni plating using hydrazine as a reducing agent that has three desired characteristics: high stability, a high deposition rate, and high deposit brightness. The solution components are nickel acetate, hydrazine, ethylenediaminetetraacetic acid, lactic acid, and boric acid. Saccharin sodium and formaldehyde are used as additives in some cases. The deposition rate and surface morphology of the films change with the composition of the plating solution. The deposition rate reaches 3.0 nm s-1. The brightness of the Ni films depends on the surface morphology. The reflectance of the deposited films at a wavelength of 550 nm changes from 0.6% (black) to 54%, the same level as autocatalytic Ni-P alloy films. The total impurity content (C, N, B and S) of the deposited Ni films is less than 0.4 mass%. The lowest value of the total content is 0.12 mass%. Electrical conductivity increases with purity and reaches 11.3 × 106 S m-1, which is equivalent to pure Ni foil with a purity of 99.7%. The deposition rate, surface morphology, brightness, and electrical conductivity of autocatalytic pure Ni films can be controlled by changing the composition of the plating solution.

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  • Shinsuke SUZUKI, Hiroyuki UCHIDA, Masahiro WATANABE
    2005 Volume 73 Issue 2 Pages 128-134
    Published: February 05, 2005
    Released: June 01, 2019
    JOURNALS OPEN ACCESS

    Mixed conducting samaria-doped ceria (SDC) anodes with a small amount of Ni nanoparticles (8 vol.%) exhibited a higher performance in SOFC operated at 700-900℃ than that of Ni-SDC cermet. Microstructural analyses of Ni-dispersed SDC showed that nanometer-sized Ni catalysts enhanced the anodic reaction rate by increasing the active reaction sites and lowering the electronic resistance in the anode effectively. The Ni-dispersed SDC anode exhibited a stable performance at 800℃ and 0.6 A cm-2 in humidified H2 for a long term over 1100 h.

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  • Nobuyuki KOURA, Kenta KASUYA, Koichi UI, Yuki TAKIGUCHI, Yasushi IDEMO ...
    2005 Volume 73 Issue 2 Pages 135-140
    Published: February 05, 2005
    Released: June 01, 2019
    JOURNALS OPEN ACCESS

    The corrosion behavior of the exposed part of the Pb alloy negative electrode from the electrolyte was analyzed upon charging, i.e., under the reduced state. Dissolved oxygen in the electrolyte affected the generation rate and the grain size of the PbSO4. From the potential measurements at the exposed part, it was found that the part not under reducing conditions and the generation reaction of PbSO4 progressed by the Jocal cell reaction. Furthermore, when the dissolved oxygen concentration in the electrolyte film on the exposed part increased, the potential at the exposed part became noble and the PbSO4 generation rate increased. On the other hand, the most anti-corrosive Pb alloy was the Pb-1.8% Sn-0.03% Se alloy. The reason was attributed to the dense corrosion layer formed on the surface, because the PbSO4 grain size became small by the synergistic effect of Sn and Se.

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  • Noriyuki KITAORI, Mitsuo TAKAHASHI
    2005 Volume 73 Issue 2 Pages 141-144
    Published: February 05, 2005
    Released: June 01, 2019
    JOURNALS OPEN ACCESS

    Sodium hypochlorite solution is one of the most useful and important sterilizers. It has high sterilizing power even in low concentrations and with various bacteria. In addition, the risk for the human body is low and the preparation cost is cheap. However its weak point is that it's sterilizing power for the spores of Bacillus cereus is very low. Improvements in the sterilization performance of Sodium hypochlorite for the spore have been investigated. Two methods for killing the spore have been found. The technical methods are as follows (1) the spore of Bacillus cereus can be destroyed by accelerating the evolution of the hydroxyl radical by adding Fe2+ as a reducing agent (same as Fenton’s reagent) and (2) by non-ionization of NaOCl by including NaCl to be the strong electrolyte in the Sodium hypochlorite solution. As a result, the sterilizing properties of the Sodium hypochlorite solution by improved six orders of magnitude and had the same performance as HOCl by non-ionization of NaOCl by adding NaCl.

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  • Chieko WADA, Hidetaka ASOH, Sachiko ONO
    2005 Volume 73 Issue 2 Pages 145-149
    Published: February 05, 2005
    Released: June 01, 2019
    JOURNALS OPEN ACCESS

    The differences in properties of anodic films formed on aluminum in ammonium adipate solution at low voltage and high voltage were clarified by investigating the relation between current density and the thickness which was evaluated by voltage jump at re-anodizing of anodized specimen. The film thickness formed at constant current density up to 80V decreased with increasing current density. The film thickness had liner relation with log of current density. This liner relation could be ascertained for all the films formed even at low voltages such as 5V when Galvano-static polarization measurement was applied to avoid iR-drop caused by solution resistance. The thickness became the same value after 20 min sustaining of anodizing voltage accompanied by current decay. Furthermore, it was confirmed that the film thickness was determined by final current density during anodizing.

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