Online ISSN : 2186-2451
Print ISSN : 1344-3542
ISSN-L : 1344-3542
Volume 79 , Issue 1
Showing 1-17 articles out of 17 articles from the selected issue
  • Xiaoyu CAO, Dawei DONG, Lingling XIE
    2011 Volume 79 Issue 1 Pages 2-5
    Published: January 05, 2011
    Released: March 30, 2012
    One-dimensional (1D) nanostructured β-AgVO3 fibers have been successfully synthesized at 300°C for 3 h via the low-temperature molten salt synthesis (LT-MSS) method where LiNO3 was employed as reaction media. The crystal structure and morphology of the as-obtained β-AgVO3 fibers were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM), respectively. The results revealed that the LT-MSS product displayed a high crystallinity and consisted of fibrous crystals with widths of 150 nm to 1 µm and lengths of several to several tens of micrometers. Electrochemical measurements indicated that the as-synthesized β-AgVO3 fibers exhibited higher discharge capacity and better cycleability compared with the counterparts from the liquid phase synthesis (LPS) and the high temperature solid state synthesis (HT-SSS) methods.
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  • Shinichi KOMABA, Tomoaki OZEKI, Naoaki YABUUCHI, Keiji SHIMOMURA
    2011 Volume 79 Issue 1 Pages 6-9
    Published: January 05, 2011
    Released: March 30, 2012
    Polyacrylates were applied as binder for the electrode of a particulate mixture of silicon, graphite, and Ketjen black for lithium-ion batteries. We found that poly(alkali acrylate) binder remarkably improved the electrochemical lithiation and delithiation performance of the silicon-graphite electrode compared to that of conventional binders. The polyacrylate coating on Si and graphite particles suppressed the electrode deterioration. When the electrode was prepared with 30 wt% poly(sodium acrylate) binder, the higher specific capacity and initial efficiency were obtained with much improved cycleability.
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Technological Report
  • Shigenori MITSUSHIMA, Yoshio FUJITA, Yoshiki NAGAHARA, Seiho SUGAWARA, ...
    2011 Volume 79 Issue 1 Pages 24-29
    Published: January 05, 2011
    Released: March 30, 2012
    As a simultaneous electrochemical measurement of oxygen reduction reaction (ORR) and surface oxidation/reduction on Pt/C, a shielding measurement using rotating ring disk electrode (RRDE) has been investigated. The ORR current was determined by the decrease of the ring current which was the diffusion limiting current of oxygen with collection efficiency of the RRDE. The difference between the disk current and the oxygen reduction reaction current was corresponded to cyclic voltammogram (CV) in inert atmosphere with correction of transient delay for the response of the ring electrode from the disk electrode. The delay of the ring electrode was 0.31 s for 6 mm in diameter of the disk electrode and 7 mm in the inner diameter of the ring at 900 rpm. To separate ORR current and CV clearly, significant level of the CV component in the disk current was needed. More than 40 µg cm−2 of Pt loading allowed the clear separation. At that time, apparent activity of Pt/C was less than one third of 10 µg cm−2 in Pt loading because of too thick the catalyst layer for the activity measurements. The mentioned above, the shielding measurement using RRDE could be applied for simultaneous separation of ORR and surface oxidation/reduction on Pt/C, and will be a strong tool to measure the relationship between the catalytic activity and the degree of the surface oxidation.
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