Electrochemistry
Online ISSN : 2186-2451
Print ISSN : 1344-3542
ISSN-L : 1344-3542
Volume 69 , Issue 8
Showing 1-13 articles out of 13 articles from the selected issue
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Technical Papers
  • Mariko KIHO, Kotetsu MATSUNAGA, Shigeru MORIKAWA, Osamu KATO
    2001 Volume 69 Issue 8 Pages 580-586
    Published: August 05, 2001
    Released: September 25, 2019
    JOURNALS OPEN ACCESS

    The durability of the Phosphoric Acid Fuel Cell (PAFC) is greatly affected by the corrosion rate of carbon which is an essential material of PAFC. This study examines the influence of carbon material impurities on corrosion rates in hot phosphoric acid. Impurity doping was found to enhance oxidation of carbon materials in phosphoric acid. The influence of vanadium (V) and calcium (Ca), which were highly dispersed on the carbon surface, was significant. Impurity doping content was found to increase corrosion current.

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  • Kazutoshi MURATA, Masateru SHIMOTSU
    2001 Volume 69 Issue 8 Pages 587-591
    Published: August 05, 2001
    Released: September 25, 2019
    JOURNALS OPEN ACCESS

    A fuel-electrode-supported planar cell with an effective electrode area of 150 cm2 was developed. A three-cell stack was built with ceramic gas separators with an electric resistance lower than 5 mΩ. An electric power generation test was carried out at 1000°C with hydrogen gas and air which were fed to the cells in series. The stack attained a maximum output power of 106 W at a fuel utilization of 70%.

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  • Benjamin KAPLAN, Henri GROULT, Naoaki KUMAGAI, Shinichi KOMABA, Frédér ...
    2001 Volume 69 Issue 8 Pages 592-597
    Published: August 05, 2001
    Released: September 25, 2019
    JOURNALS OPEN ACCESS

    A new theoretical approach of the intercalation/deintercalation process of lithium cations into host materials is proposed in that paper taking into account the dependence of the lithium diffusion coefficient on concentration is considered for the integration of the mass balance equation. Numerical simulation of chronopotentiograms is used to solve the diffusion equation. The component and chemical diffusion coefficients corresponding to the Li+ intercalation into Nb2O5 in 1 M LiClO4-PC were determined. It was found that and DLi decrease from 1.4 × 10−10 cm2 s−1 to 5.7 × 10−11 cm2 s−1 and from 1.2 × 10−11 cm2 s−1 to 6.4 × 10−13 cm2 s−1, respectively, with increasing values of the intercalation ratio, y, comprised between 0.4 and 1.6. Impedance measurements performed in an equilibrium situation give and DLi values which were rather constant but higher.

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  • Takayuki KUWAHARA, Naoko YAMAKAWA, Toshiyuki MOMMA, Tetsuya OSAKA
    2001 Volume 69 Issue 8 Pages 598-602
    Published: August 05, 2001
    Released: September 25, 2019
    JOURNALS OPEN ACCESS

    A potentiometric acetylcholine microsensor was fabricated by use of a composite film consisting of polyion complex (PIC), which consisted with acetylcholine esterase (AChE), and the electrochemically inactive poly-1-aminopyrrole (iPAPy). The iPAPy-PIC (AChE) composite film on Pt electrode displayed potential response to acetylcholine concentration owing to pH change during the enzymatic reaction, where the product contains weak acid CH3COOH. The sensitivity of the iPAPy-PIC (AChE) electrode clearly demonstrated higher sensitivity with low detection limit (1 × 10−6 mol dm−3) than that of the iPPy-PIC (AChE) electrode of detection limit (1 × 10−5 mol dm−3). The mechanism of increasing the sensitivity of iPAPy-PIC (AChE) electrode was discussed the interaction of –NH2 of iPAPy with CH3COOH, which would accelerate the dissociation of weak acid CH3COOH.

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Technological Report
  • Tatsuhiro ATSUMI, Yuki NAKATA, Koichi KOBAYAKAWA, Katsuyuki NEGISHI, N ...
    2001 Volume 69 Issue 8 Pages 603-607
    Published: August 05, 2001
    Released: September 25, 2019
    JOURNALS OPEN ACCESS

    To improve the performance of the positive electrodes for lithium-ion batteries, the particle-size and the mixing ratio effect of different size LiCoO2 powders on discharge capacity were investigated. The optimum mixing ratio between large (average diameter: 30 µm) and small (average diameter: 0.5 µm) powder particle size has been found. The largest capacity and the smallest electrode resistance are obtained when the large particle size fraction is about 70 wt%. The smaller the particle size ratio, the larger the discharge capacity and the smaller the electrode resistance, where the particle size ratio is the ratio of the average diameter of the smaller component to that of the larger one. These results indicate that discharge capacity is closely related to LiCoO2 powder packing.

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Notes
Microchip Capillary Electrophresis—Frontier of m-TAS
Techniques in Electrochemical Measurements
ECSJ News 2001
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