Electrochemistry
Online ISSN : 2186-2451
Print ISSN : 1344-3542
ISSN-L : 1344-3542
Volume 68 , Issue 8
Showing 1-10 articles out of 10 articles from the selected issue
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Communications
  • Hiroki SAKAGUCHI, Hitoshi MAETA, Masaaki KUBOTA, Hitohiko HONDA, Takao ...
    2000 Volume 68 Issue 8 Pages 632-635
    Published: August 05, 2000
    Released: November 10, 2019
    JOURNALS OPEN ACCESS

    To obtain a new anode material of lithium battery, electrochemical properties were investigated on Mg2Sn intermetallic compound synthesized by mechanical alloying (MA) method. As a result, we found that the reversible insertion-extraction of a large amount of lithium can electrochemically occur in mechanically alloyed Mg2Sn. The Mg2Sn changed its own crystal structure from cubic to orthorhombic with increasing MA time. The compound exhibiting good performances as an anode had a mixture of cubic and orthorhombic phases. The discharge capacity of the Mg2Sn electrode was still maintained at 250-300 mA h g−1 even after the 20 times charge-discharge cycling. The reaction proceeded without any phase separation and/or decomposition of the compound. Mg2Sn would be a promising anode material for lithium secondary batteries.

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  • Hiroaki YAMAMOTO, Kensuke KURODA, Ryoichi ICHINO, Masazumi OKIDO
    2000 Volume 68 Issue 8 Pages 636-638
    Published: August 05, 2000
    Released: November 10, 2019
    JOURNALS OPEN ACCESS

    Several plateau potentials corresponded to La-Ni alloys were observed in measuring the potential change after molten salts electrolysis of La onto the Ni substrate. Lanthanum element was dissolved into molten salts as well as the alloying with the Ni substrate to form LaNi5. This La dissolution was found to be caused by the moisture in molten salts. Moisture in molten salts acted as an oxidant. and La dissolution from LaNi5 ingot and LaNi5 film formed after La molten salts electrolysis took place.

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Technical Papers
  • Yulia V. BASOVA
    2000 Volume 68 Issue 8 Pages 639-644
    Published: August 05, 2000
    Released: November 10, 2019
    JOURNALS OPEN ACCESS

    A method for potential-dependant separation by an electrochemical reactor based on flow-through mode with a fluidized-bed carbon layer was described. In this method, activated synthetic carbons were used as a fluidized-bed electrode. Influence of surface acidic functional groups, applied potential and pH of surrounding electrolyte on the adsorption capacity of the activated carbons for benzoic acid and phenol was studied. Anodic polarization of the activated carbons was found to result in increase in adsorption capacity of the activated carbons for benzoic acid and entire oxidation of phenol. Application of cathodic external potential allowed regeneration of spent activated carbons. A practically available technique for developing and regenerating materials for effective electrochemical separation suitable for further application in electro adsorption was described in this work.

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  • Makoto KAWASE, Yoshihiro MUGIKURA, Takao WATANABE
    2000 Volume 68 Issue 8 Pages 645-650
    Published: August 05, 2000
    Released: November 10, 2019
    JOURNALS OPEN ACCESS

    The effects of NOx on the performance of MCFC were examined by cyclic voltammetry and bench-scale cell tests with the oxidant gas containing several levels of NOx. NOx poisoning has a larger effect on cell voltage in the early operating stage, but this effect tends to decrease with operating time. The main cause of the cell voltage drop is the increase in internal resistance, which is caused by the production of high resistance substances. As a result of the analyses of the electrolyte composition in the operated cells, gas composition and cyclic voltammograms, the behavior of NOx in the cell was found as follows. NOx reacts with carbonate to dissolve in the electrolyte as NO2 and NO3. These ions react with hydrogen in the fuel gas to form to N2 and a small amount of NH3. Consequently, NO2 and N O3 are not accumulated in the electrolyte, and the effects of NOx on the cell life-time are small.

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Note
  • Kunio NAGASHIMA, Masaki INOUE, Hiroshi NAMIKI
    2000 Volume 68 Issue 8 Pages 651-652
    Published: August 05, 2000
    Released: November 10, 2019
    JOURNALS OPEN ACCESS

    Potassium peroxodisulfate (5 g/dm3) reacted readily with water by UV irradiation (30 W mercury arc tube) even at room temperature. The reaction rate constant was estimated to be 3.5×10−3 S−l from the relationship between irradiation time and logarithm of concentration of remaining potassium peroxodisulfate. The volume of oxygen produced by the reaction was well accordance with the stoichiometric value. The oxidation of ammonia (2.00 mg N/dm3) in water into nitrate ion also proceeded in 5 minutes at room temperature if UV irradiation was made to the solution in the presence of NH3.

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