Electrochemistry
Online ISSN : 2186-2451
Print ISSN : 1344-3542
Search
OR
Browse
Search
Volume 82 , Issue 6
Showing 1-21 articles out of 21 articles from the selected issue
    • |<
    • <
    • 1
    • >
    • >|
Preface
Review
Communication
Articles
  • Minoru TAKEUCHI, Yoshihiro ANAMI, Yasutaka YAMADA, Masaru BUNYA, Shoko ...
    Volume 82 (2014) Issue 6 Pages 430-437
    Released: June 05, 2014
    JOURNALS OPEN ACCESS
    In previous studies of additives for via-filling by copper deposition, we succeeded in the complete filling of via holes by copper deposition through the use of a single diallylmethylamine-type additive instead of the conventional combination of four different additives. However, work had yet to be started on analyzing the structure and function of the polymer additive. Therefore, we synthesized a series of diallylmethylamine-type polymers with different polymer counter ions, and used these polymers as single additives in the basic bath for the copper electrodeposition. We studied the characteristics of the action of these additives using an optical microscope to observe the filling of the vias in the substrate, and by performing cyclic voltammetry (CV) and linear sweep voltammetry (LSV) measurements with a rotating disk electrode. Via-filling was not possible with the diallylmethylamine-type polymers containing counter ions such as acetate ions, but with polymers containing halogen counter ions, we achieved good via-filling and were able to observe clear hysteresis in the CV curves.
    View full abstract
    Download PDF (3333K)
  • Shingo KANEKO, Bingbo XIA, Qian ZHANG, Guoqing FANG, Weiwei LIU, Hongd ...
    Volume 82 (2014) Issue 6 Pages 438-443
    Released: June 05, 2014
    JOURNALS OPEN ACCESS
    A lithium-rich layered cathode material, Li1.2Ni0.18Mn0.59Co0.03O2, was synthesized from size-regulated precursor nanoparticles, which were prepared by a reverse microemulsion technique. The resulting material demonstrated a good cycle stability (50th cycle discharge capacity: 281 mAh g−1 at 20 mA g−1) without any additional modifications or treatments and a high capacity retention (52%) even at 640 mA g−1 compared to the one (5% at 640 mA g−1) obtained via a spray-drying synthesis as a reference. This article is the first report of trying to synthesize a lithium-rich layered cathode material having a high rate capability by controlling the morphology and homogeneity of the precursor particles based on a reverse microemulsion technique.
    View full abstract
    Download PDF (3133K)
  • Akira KOTANI, Tomoko KOTANI, Satoshi KOJIMA, Hideki HAKAMATA, Fumiyo K ...
    Volume 82 (2014) Issue 6 Pages 444-447
    Released: June 05, 2014
    JOURNALS OPEN ACCESS
    A high-performance liquid chromatography with electrochemical detection (HPLC-ECD) system has been developed for determining aristolochic acids I and II (AA1 and AA2). HPLC using an octadecylsilica (ODS) column and a mobile phase of methanol-water-phosphoric acid (65:35:0.5, v/v/v) was conducted for the separation of the AA1 and AA2. Both of the chromatographic peak heights for AA1 and AA2 at the detection potential of −0.7 V vs. Ag/AgCl were found to be linearly related to the concentrations injected, ranging from 10 ng mL−1 to 50 µg mL−1 (r > 0.997). The detection limits (S/N = 3) of AA1 and AA2 were 3.4 and 3.1 ng mL−1, respectively. Considering the detection limits, the present method makes it possible to be a purity test of the quantity of AA1 and AA2 contained as impurities in herbal medicines. The present HPLC-ECD was applied to determine AA1 and AA2 content in Radix et Rhizoma Asari and Radix Aristolochiae Fangchi.
    View full abstract
    Download PDF (608K)
  • Tatsuya MASUDA, Hidetaka ASOH, Satoshi HARAGUCHI, Sachiko ONO
    Volume 82 (2014) Issue 6 Pages 448-455
    Released: June 05, 2014
    JOURNALS OPEN ACCESS
    We investigated the optimum conditions for the fabrication of an α-alumina membrane by the anodizing and subsequent heat treatment of an anodic film after detachment from an aluminum substrate and through-hole treatment. We evaluated the nanoporous structure of anodic alumina including pore diameter, the regularity of pore array and the surface morphology with respect to the thermal deformation of the membrane during heat treatment under loading with ceramic plates. Because the regularity of the pore arrangement of the film formed by two-step anodizing was greatly improved compared with that of the film formed by one-step anodizing, the deformation caused by heat treatment was suppressed. To detach the anodic film from the substrate, an advanced anodic polarization method was better than the conventional cathodic polarization method with a stepwise decrease in anodizing voltage, because the through-hole treatment was accomplished in a shorter time. As a result, the combination of two-step anodizing and the detachment by anodic polarization process was suggested to be optimum. Thermogravimetry and differential thermal analysis indicated a weight loss of approximately 1% originating from dehydration during the temperature change from room temperature to 400°C. Moreover, the desorption of oxalate anions from the alumina film occurred at 900°C, associated with a weight loss of approximately 5% and the anodic alumina simultaneously crystallized from amorphous to γ-alumina. Finally, the crystal structure transformed to α-alumina at 1250°C. It was found that a crack-free alumina membrane that maintained straight channels similar to those of amorphous anodic alumina was successfully obtained.
    View full abstract
    Download PDF (4241K)
  • Yoshihiro KADOMA, Koichi HARATA, Hisashi WATANABE, Naoaki KUMAGAI, Koi ...
    Volume 82 (2014) Issue 6 Pages 456-461
    Released: June 05, 2014
    JOURNALS OPEN ACCESS
    The olivine-type LiMnPO4 was synthesized from LiH2PO4 and Mn(CH3COO)2·4H2O by a solvothermal method at several heating temperatures for 90–180°C. The XRD and SEM results indicated that the obtained LiMnPO4 samples consisted of a single phase with nano sized tabular particles. The prepared LiMnPO4 and acetylene black as a carbon source were ball-milled for preparing carbon/LiMnPO4 composite (LiMnPO4/C) samples. The milled LiMnPO4/C sample heated at 120°C showed the highest first discharge capacity of 147 mAh g−1 with excellent cycleability at a 0.1C rate (CC-CV mode) and 25°C. It was found that the electrochemical properties of LiMnPO4 were significantly enhanced by ball milling with a conductive carbon.
    View full abstract
    Download PDF (3123K)
  • Dae-Hyeon KIM, Sang-Eun BAE, Tae-Hong PARK, Jong-Yun KIM, Yang-Soon PA ...
    Volume 82 (2014) Issue 6 Pages 462-466
    Released: June 05, 2014
    JOURNALS OPEN ACCESS
    The electrochemcal reactions of uranium trichloride on the surfaces of dimensionally very dissimilar carbon-based materials such as glassy carbon (GC) and graphene in LiCl-KCl eutectic melt were investigated using cyclic voltammetry (CV) and scanning electron microscopy (SEM). The cathodic scanning of CV displayed that the Li intercalation reaction into the GC electrode governs at the potential of approximately −1.45 V vs. Ag|Ag+ where the electrodeposition reaction of uranium may occur. On the other hand, the graphene electrode presented electrodeposition current of the uranium without interference at −1.45 V vs. Ag|Ag+ because the Li intercalation reaction was extensively diminished on the very thin graphene film. In addition, it was successful to measure the electrodeposition current of gadolinium at more positive than −2.1 V without the interference of the Li intercalation into the graphene substrate. Consequently, the significant reduction of the Li intercalation reaction on the nanometer thick carbon electrode extensively expands the electrochemical potential window of the carbon-based electrode with respect to the bulk carbon electrode in LiCl-KCl melt, emphasizing that the graphene has a great potential as a cathode electrode in high temperature molten salt electrolytes.
    View full abstract
    Download PDF (1300K)
  • Soichiro KAWAKAMI, Kiyoshi KANAMURA
    Volume 82 (2014) Issue 6 Pages 467-473
    Released: June 05, 2014
    JOURNALS OPEN ACCESS
    In this paper, we report on the preparation of nanocrystalline/amorphous composite structured tin alloys prepared by mechanical milling (mechanical alloying) and their application as anode materials of lithium-ion batteries. The Sn-Co alloys were prepared by mechanical alloying method. The charge-discharge cycle life of the cell with tin alloy anode was prolonged when the crystallite size of the alloy decreased. Adding elements to nanocrystallize or amorphize tin alloy have been evaluated. Alloying elements such as Co, Cu, Ni, Ti, Zr, Nb, and La were effective for nanocrystallization or amorphization of tin alloy. Electrochemical tests demonstrated that a lithium ion battery with the nanocrystalline/amorphous compositetin alloy anode had a nice performance at high rate discharge.
    View full abstract
    Download PDF (2599K)
Topic
 
 
Salon
 
 
    • |<
    • <
    • 1
    • >
    • >|
feedback
Top