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Volume 2011 (2011)
- Issue 250 Pages 231-
- Issue 249 Pages 161-
- Issue 248 Pages 89-
- Issue 247 Pages 49-
- Issue 246 Pages 1-
Volume 2011, Issue 248
Displaying 1-10 of 10 articles from this issue
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Award Review
Integrated Paper
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Hirotomo Nishihara, Hiroyuki Itoi, Masashi Ito, Somlak Ittisanronnacha ...Article type: Integrated Paper
2011 Volume 2011 Issue 248 Pages 89-95
Published: June 15, 2011
Released on J-STAGE: July 15, 2011
JOURNAL FREE ACCESSOur recent work on the template synthesis of carbon-based uniform nanoporous materials and their applications for energy storage is summarized. It is demonstrated that the unique nanostructure prepared by the template technique has many benefits. The materials the authors deal with in this work are zeolite-templated carbon and carbon-coated anodic aluminum oxide. These materials are not only promising candidates for energy storage applications, but also very useful model materials for understanding fundamental phenomena.View full abstractDownload PDF (701K)
Review Paper
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Noboru AkuzawaArticle type: Review Paper
2011 Volume 2011 Issue 248 Pages 96-101
Published: June 15, 2011
Released on J-STAGE: July 15, 2011
JOURNAL RESTRICTED ACCESSThree types of reactions of alkali metal-graphite intercalation compounds (AM-GICs) are described: Extraction of alkali metals, penetration of molecules into alkali metal layers and polymerization of molecules on the surface. Oxygen extracts alkali metal atoms of MC8 (and MC24, M=K, Rb) from the bulk to the edge surface, leaving a mixture of higher stage AM-GICs inside and graphitic area on the edge surface. Ammonia molecules penetrate into alkali metal layers of MC8 (M=K, Rb, Cs) by ion-dipole interaction and are accommodated into the nanospace of MC24 (M=K, Rb, Cs). Water molecules penetrate into MC24 (M=K, Cs) and react with alkali metals. Hydrogen is adsorbed in the interlayer nanospace at low temperature (77 K). Butadiene monomers adsorbed on the surface of AM-GICs polymerize.View full abstractDownload PDF (615K)
Special Issue on the Japan-Germany Joint Seminar
Short Paper
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Naokatsu Kannari, Jun-ichi OzakiArticle type: Short Paper
2011 Volume 2011 Issue 248 Pages 102-104
Published: June 15, 2011
Released on J-STAGE: July 15, 2011
JOURNAL FREE ACCESSThe aim of this study is to investigate whether the defects in carbon structure can be active sites for electrocatalysis of the oxygen reduction reaction (ORR). A fullerene mixture (FM) was used to modify the carbon structure of a naphthalene pitch-derived carbon. The addition of FM induced non-planar structures in the carbon, which was revealed by TEM and by XRD analysis with Diamond's theory. The addition also increased the oxygen adsorption ability, as shown by the O2-TPD and the ORR activity of the carbon. These results lead us to conclude that the defects relating to non-planar structure induced in the layered structure of the FM added carbon act as the ORR active sites.View full abstractDownload PDF (335K)
Review Papers
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Nobuyuki MurofushiArticle type: Review Paper
2011 Volume 2011 Issue 248 Pages 105-111
Published: June 15, 2011
Released on J-STAGE: July 15, 2011
JOURNAL RESTRICTED ACCESSFrom a commercial standpoint, the Chinese market and two different types of carbon, graphite electrodes and isostatically pressed graphite, are gaining increased attention. The growth in steel production has prompted China to become the largest graphite electrode producing country in the world as well as a strong exporter of small diameter graphite electrodes, while the emergence of photovoltaic applications has made the country the world factory of crystal silicon ingots and cells, hence the largest consumer of isostatically pressed graphite in the world.View full abstractDownload PDF (1658K) -
Eiichi YasudaArticle type: Review Paper
2011 Volume 2011 Issue 248 Pages 112-121
Published: June 15, 2011
Released on J-STAGE: July 15, 2011
JOURNAL RESTRICTED ACCESS50 years ago, research on traditional carbon fiber was started for rayon-based carbon fiber in the USA. Dr. A. Shindo invented a method for producing high performance carbon fiber by oxidizing PAN fiber in 1960. In 1963 Prof. S. Otani invented high performance pitch-based carbon fiber by aligning the mesophase molecules in the fiber direction by applying a shear stress at the spinneret. In addition to their excellent inventions, other key persons such as Dr. K. Morita of Toray and Dr. K. Gomi of Kureha Corporation were behind the success of carbon fiber development and the cultivation of new fields of application.
Recently new technologies have been developed for carbon nanofiber production, such as CCVD, electro-spinning, super growth and spinning of a polymer blend. In this paper the history of carbon fibers will be reviewed to learn lessons from past efforts and, making use of the results, to develop an excellent carbon nano-fiber.View full abstractDownload PDF (1518K)
Research Paper
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Mitsuhiro Hamada, Takaya Nakamura, Kiyoharu Nakagawa, Hirokazu OdaArticle type: Research Paper
2011 Volume 2011 Issue 248 Pages 122-126
Published: June 15, 2011
Released on J-STAGE: July 15, 2011
JOURNAL FREE ACCESSIt is shown how to remove nitrate ions from aqueous solution by electrosorption in a way that has a low environmental impact and is energy saving. In order to elucidate adsorption/desorption mechanism of nitrate ions, ion removal using flow through capacitor and cyclic voltammetry measurements were investigated. Characterization of suitable electrodes for electroadsorption was determined. The static attraction by surface charges of carbon electrodes had a profound effect on adsorption of nitrate ions. It is difficult for nitrate ion to desorb from the electrode, therefore an electrode with pHPZC (point zero of charge) of a weak acid is appropriate. Due to the overlapping effect of diffusion layers in pores, it is thought that large mesopores (>20 nm) and the voids between particles are effective in dilute solution for nitrate ion removal.View full abstractDownload PDF (792K)
Short Papers
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Hironobu AbikoArticle type: Short Paper
2011 Volume 2011 Issue 248 Pages 127-132
Published: June 15, 2011
Released on J-STAGE: July 15, 2011
JOURNAL FREE ACCESSTo understand the hygroscopic properties of recent activated carbon products for industrial and occupational hygiene, we measured their pore and chemical properties, and water vapor isotherms at around room temperature (at 283, 293 and 298 K). The activated carbon specimens examined were used in 11 types of gas filter for Japanese respirators. The N2-BET specific surface areas of the specimens are in the region of approximately 1,200–1,600 m2/g. The water vapor isotherms show that keeping relative humidity below 40 % in storage is efficient to eliminate moisture adsorption of the activated carbon products around room temperature.View full abstractDownload PDF (1382K)
Review Papers
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Hironobu AbikoArticle type: Review Paper
2011 Volume 2011 Issue 248 Pages 133-143
Published: June 15, 2011
Released on J-STAGE: July 15, 2011
JOURNAL RESTRICTED ACCESSThe Wheeler-Jonas equation is an effective function for understanding gaseous adsorption in a compact activated carbon bed. This report presents a summary of the derivation process described by Wheeler et al. and the modification of the equation by Yoon et al. The mathematical properties of the equation are also discussed from the viewpoints of adsorption capacity, breakthrough concentration and time for 50% breakthrough (stoichiometric time). The equation is also useful for estimating the breakthrough time of the carbon bed in gas filters for respirators, and it has been used in many previous studies of breakthrough time simulation. Particularly, the estimation model reported by Wood et al., which makes use of the Wheeler- Jonas equation, the Dubinin-Radushkevich equation and several empirical formulas for constants in the above mentioned equations, can also take into consideration the effects of temperature and relative humidity. We also summarized the components of Wood's estimation model, and investigated the points of relevance in application of the model for actual measurement.View full abstractDownload PDF (1151K) -
Yasuhiko ItoArticle type: Review Paper
2011 Volume 2011 Issue 248 Pages 144-151
Published: June 15, 2011
Released on J-STAGE: July 15, 2011
JOURNAL RESTRICTED ACCESSElectrochemical formation of a carbon film can be achieved by either anodic oxidation of C22− ions or cathodic reduction of CO32− ions dissolved in a molten salt. A dense and adherent carbon film coating can be achieved by the anodic oxidation reaction. The obtained carbon-coated metal shows advantageous features for a fuel cell separator as well as a current collector for a Li-ion secondary battery. On the other hand, the carbon film obtained by the cathodic reduction of CO32− ions has a micro-porous structure, which is advantageous for an electrochemical capacitor. It is also possible to electrochemically form a porous carbon film on a very thin, dense and adherent carbon film that is electrochemically formed on the metal surface beforehand. The layered carbon film thus obtained shows a high operating voltage span in an electrochemical capacitor. The cathodic reduction process is attractive also from the aspects of fixation and effective use of CO2.View full abstractDownload PDF (799K)
Recent Doctoral Thesis
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Yuki YamadaArticle type: Recent Doctoral Thesis
2011 Volume 2011 Issue 248 Pages 154-155
Published: June 15, 2011
Released on J-STAGE: July 15, 2011
JOURNAL RESTRICTED ACCESSThe present thesis focused its attention on the mechanism and kinetics of the electrochemical lithium intercalation into graphite, which is an important reaction in lithium-ion batteries. In Part 1, the electrochemical behavior of graphite was studied in various electrolyte solutions. A clear correlation was observed between the intercalation behavior (intercalation, coinercalation, or exfoliation) and the solvation number of propylene carbonate (PC) and dimethylsulfoxide (DMSO), leading to the conclusion that the solvation structure of lithium-ion was one of the determining factors in the electrochemical lithium intercalation into graphite. Part 2 described the activation energy of the electrochemical lithium intercalation into graphite. A series of ac impedance studies indicated that the activation energy depended on two factors: 1) solvation strength of the solvent used and 2) composition of the surface film (SEI) on graphite. In Part 3, the kinetics of lithium intercalation was studied from a viewpoint of the active-site (edge-plane) density on graphite (highly oriented pyrolytic graphite, HOPG) , which was evaluated from the standard rate constant of Ru(NH3)63+/2+ in a nondestructive manner. There was an inversely-proportional relation between the edge-plane density and the charge-transfer resistance of lithium intercalation, while the activation energy was kept almost constant, suggesting that the edge-plane density determined the frequency factor of lithium intercalation. In summary, the present thesis revealed the electrochemical reaction mechanism at the graphite/electrolyte interface and the determining factors in the kinetics (i.e., activation energy and frequency factor) of lithium intercalation into graphite.View full abstractDownload PDF (228K)
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