Faculty Profiles - HIBINO, Takashi

Improvement of a reduction-resistant Ce0.8Sm0.2o1.9 electrolyte by optimizing a thin BaCe1-xSmxO3-α layer for intermediate-temperature SOFCs Reviewed

Daisuke Hirabayashi, Atsuko Tomita, Shinya Teranishi, Takashi Hibino, Mitsuru Sano

Solid State Ionics Vol. 176 page： 881-887 2005.3

Single-chamber SOFCs with a Ce0.9Gd0.1O1.95 electrolyte film for low-temperature operation Reviewed Open Access

Atsuko Tomita, Daisuke Hirabayashi, Takashi Hibino, Masahiro Nagao, Mitsuru Sano

Electrochemical and Solid-State Letters Vol. 8 ( 1 ) page： A63-A65 2005.1

総説：マイクロリアクターによる水素製造

冨田衷子，日比野高士，佐野　充

ケミカルエンジニアリング Vol. 50 page： 18-23 2005

総説：MP2O7系固体電解質のプロトン導電性とその応用

長尾征洋，冨田衷子，日比野高士，佐野　充

Vol. 73 page： 846-850 2005

Single-chamber SOFCs with a Ce0.9Gd0.1O1.95 electrolyte film for low-temperature operation Reviewed Open Access

Tomita A, Hirabayashi D, Hibino T, Nagao M, Sano M

ELECTROCHEMICAL AND SOLID STATE LETTERS Vol. 8 ( 1 ) page： A63 - A65 2005

Language：Japanese Publishing type：Research paper (scientific journal) Publisher：Electrochemical and Solid-State Letters

Single-chamber solid oxide fuel cells (SOFCs) with an anode-supported Ce0.9Gd0.1O1.95 electrolyte were operated in a mixture of butane and air at furnace temperatures of 200-300°C. The electromotive force (emf) of the cell and the voltage drop were strongly influenced by the catalytic activity of the anode for the partial oxidation of butane. The promotion of hydrogen formation by the addition of Ru to the anode caused an increase in the emf and a reduction in the voltage drop. As a result, stable power densities of 44 and 176 mW cm-2 were obtained at 200 and 300°C, respectively. © 2004 The Electrochemical Society. All rights reserved.

DOI： 10.1149/1.1836120

Surface modification of a doped BaCeO3 to function as an electrolyte and as an anode for SOFCs Reviewed Open Access

Tomita A, Hibino T, Sano M

ELECTROCHEMICAL AND SOLID STATE LETTERS Vol. 8 ( 7 ) page： A333 - A336 2005

Language：Japanese Publishing type：Research paper (scientific journal) Publisher：Electrochemical and Solid-State Letters

Dual functions of BaCe0.8Y0.2O3-α, (BCY) as an electrolyte and as an anode were improved for solid oxide fuel cell (SOFC) applications. A porous Ce-rich phase with fluorite structure was formed with a depth of ∼10 μm from the BCY surface by vaporization of BaO from the BCY surface at 1700°C. The resulting BCY surface showed enough electronic conductivity to provide electrical collection and a high electrocatalytic activity for hydrogen oxidation. A hydrogen-air fuel cell with the BCY electrolyte exhibited reasonable performances without using an anode material between 750 and 950°C. © 2005 The Electrochemical Society. All rights reserved.

DOI： 10.1149/1.1928230

SOFC-type microreactors that generate hydrogen for PEFC applications Reviewed

Tomita A., Hirabayashi D., Nagao M., Sano M., Hibino T.

Solid State Ionics Vol. 174 ( 1-4 ) page： 9 - 13 2004.10

Language：Japanese Publishing type：Research paper (scientific journal) Publisher：Solid State Ionics

A fuel cell-type microreader that generates both hydrogen and electrical power from dry butane around 700°C is presented for polymer-electrolyte fuel cell (PEFC) applications. To demonstrate this concept, solid-oxide fuel cells (SOFCs) with different Fe2O3-based anodes were fabricated, and their performances were evaluated. A Fe2O3/Cr 2O3 composite anode met this criterion the most; hydrogen was produced with increasing current density; CO2/CO concentration ratios in the outlet gases were more than 2; polarization resistances were about 1 Ω cm2; carbon deposition was much more suppressed with these anodes than with a Ni/SDC cermet anode. The resulting peak power density was 110 mW cm-2 by using a 0.25-mm-thick Ce0.9Gd 0.1O1.95 (GDC) electrolyte. The effect of Cr 2O3 added into the Fe2O3 anode was also discussed in detail. © 2004 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.ssi.2004.07.023

Electrochemical properties of lithium manganese oxides with different surface areas for lithium ion batteries Reviewed

Design of a reduction-resistant Ce0.8Sm0.2O1.9 electrolyte through growth of a thin BaCe1-xSmxO3-α layer over electrolyte surface Reviewed

Daisuke Hirabayashi, Atsuko Tomita, Takashi Hibino, Masahiro Nagao, Mitsuru Sano

Electorochemical and Solid-State Letters Vol. 7 page： A318-A320 2004.10

Takahashi K, Saitoh M, Asakura N, Hibino T, Sano M, Fujita M, Kifune K

JOURNAL OF POWER SOURCES Vol. 136 ( 1 ) page： 115 - 121 2004.9

Language：Japanese Publishing type：Research paper (scientific journal) Publisher：Journal of Power Sources

Two lithium manganese oxides, Li1.03Mn1.96O 4, with different surface areas of 3.55 and 0.68m2/g were prepared and their electrochemical properties were studied as positive electrodes for lithium ion batteries. Cycle performance tests gave capacity losses of 9 and 18% at 25°C, and 28 and 33% at 55°C for the samples with larger and smaller surface areas, respectively. The recovery of capacity losses have been found on the addition of the conductor after cycles. The defect of the conductivity between the active materials and the conductors was found mostly responsible for the capacity loss in the smaller surface sample at 25°C. Cycle performance tests in each region of the charge states divided into five regions show that larger capacity losses are observed in rather lower potential states. Storage performances show the largest capacity loss at 10 and 20% of SOC and the less capacity losses at both 0 and 50-100% of SOC in both of the samples. However, in every region, the capacity loss is much smaller in the larger surface sample than in the smaller surface sample. The maximum Mn dissolution is observed to occur at 100% of SOC (4.5V) and the next is found around 10-20% of SOC in either sample. © 2004 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.jpowsour.2004.05.014

Proton conduction at the surface of Y-doped BaCeO<inf>3</inf> and its application to an air/fuel sensor Reviewed

Bi-based oxide anodes for direct hydrocarbon SOFCs at intermediate temperatures Reviewed Open Access

Daisuke Hirabayashi, Atsuko Hashimoto, Takashi Hibino, Ushio Harada,Mitsuru Sano

Electrochemical and Solid-State Letters Vol. 7 page： A108-A110 2004.5

Proton conduction at the surface of Y-doped BaCeO3 and its application to an air/fuel sensor Reviewed

Tomita A, Hibino T, Suzuki M, Sano M

JOURNAL OF MATERIALS SCIENCE Vol. 39 ( 7 ) page： 2493 - 2497 2004.4

Tomita A., Hibino T., Suzuki M., Sano M.

Journal of Materials Science Vol. 39 ( 7 ) page： 2493 - 2497 2004.4

Language：Japanese Publishing type：Research paper (scientific journal) Publisher：Journal of Materials Science

25 mol% Y3+-doped BaCeO3 (BCY25) showed an extremely low activation energy of 0.3 eV for proton conduction at the surface. The resulting overall conductivity at the surface reached 8.24 × 10 -3 S cm-1 at 400°C, which was 3, 8, and 28 times higher than those in the bulk of BCY25, 20 mol% Sm3+-doped ceria, and 8 mol% yttria-stabilized zirconia, respectively. Such fast proton conduction enabled an air/fuel (A/F) sensor using BCY25 as the solid electrolyte to work above 150°C for H2 and above 250°C for C2H 4. © 2004 Kluwer Academic Publishers.

DOI： 10.1023/B:JMSC.0000020015.80430.d8

Proton conduction at the surface of Y-doped BaCeO3 and its application to an air/fuel sensor Reviewed

Atsuko Hashimoto, Takashi Hibino, Masanori Suzuki, Mitsuru Sano

Journal Of Materials Science Vol. 39 page： 2493-2497 2004.4

Solid oxide fuel cells operating without using an anode material Reviewed

Hirabayashi D, Tomita A, Brito ME, Hibino T, Harada U, Nagao M, Sano M

SOLID STATE IONICS Vol. 168 ( 1-2 ) page： 23 - 29 2004.3

Solid oxide fuel cells operating without using an anode material Reviewed

Hirabayashi D., Tomita A., Brito M.E., Hibino T., Harada U., Nagao M., Sano M.

Solid State Ionics Vol. 168 ( 1-2 ) page： 23 - 29 2004.3

Language：Japanese Publishing type：Research paper (scientific journal) Publisher：Solid State Ionics

We proposed a new type of solid oxide fuel cell (SOFC) operating without using an anode material, where the anode was spontaneously formed by reduction of the electrolyte surface under reducing gas conditions. A BaCe 0.76Y0.20Pr0.04O3-α electrolyte most successfully met this criterion. This material showed high mixed protonic-electronic conduction, whereas the open circuit voltage (OCV) of the cell was slightly lower than the theoretical value. The resulting SOFC exhibited reasonable fuel cell performances together with a good stability to thermal and redox cyclings and high resistance to carbon deposition up to 800 °C for dry methane, ethane, and propane. © 2004 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.ssi.2004.01.024

SOFC-type microreactors that generate Hydrogen for PEFC applications Reviewed

Atsuko Tomita, Daisuke Hirabayashi, Masahiro Nagao, Mitsuru Sano, Takashi Hibino

Solid State Ionics Vol. 174 page： 9-13 2004

Solid oxide fuel cells operating without using an anode material Reviewed

Daisuke Hirabayashi, Atsuko Tomita, M.E.Brito, Takashi Hibino, Ushio Harada, Masahiro Nagao, Mitsuru Sano

Solid State Ionics Vol. 168 page： 23-29 2004

Bi-based oxide anodes for direct hydrocarbon SOFCs at intermediate temperatures Reviewed Open Access

Hirabayashi D, Hashimoto A, Hibino T, Harada U, Sano M

ELECTROCHEMICAL AND SOLID STATE LETTERS Vol. 7 ( 5 ) page： A108 - A110 2004

Language：Japanese Publishing type：Research paper (scientific journal) Publisher：Electrochemical and Solid-State Letters

Doped Bi-based oxides were investigated as potential anode materials for direct hydrocarbon solid oxide fuel cells (SOFCs) at intermediate temperatures. (Bi2O3)0.85(Ta2O5) 0.15 met this criterion most successfully. A fraction of Bi 2O3 in this material was reduced to BiO and Bi metal under fuel conditions, which yielded high conductivities (>1 S cm-1) based on oxide ions and electrons above 500°C. Carbon deposition was successfully prevented when butane was used as the fuel below 800°C. The catalytic activities for hydrocarbon oxidation were high enough to promote the complete oxidation of butane during cell operation. These abilities provided an enhanced anode performance with increasing temperature from 600 to 750°C, and the resulting polarization resistance reached 1.4 Ω cm2 at 750°C. © 2004 The Electrochemical Society. All rights reserved.

DOI： 10.1149/1.1667791

Design of a reduction-resistant Ce0.8Sm0.2O1.9 electrolyte through growth of a thin BaCe1-xSmxO3-alpha a layer over electrolyte surface Reviewed Open Access

Hirabayashi D, Tomita A, Hibino T, Nagao M, Sano M

ELECTROCHEMICAL AND SOLID STATE LETTERS Vol. 7 ( 10 ) page： A318 - A320 2004

Language：Japanese Publishing type：Research paper (scientific journal) Publisher：Electrochemical and Solid-State Letters

A method that can block off electronic current through a samaria-doped ceria (SDC, Ce0.8Sm0.2O1.9) electrolyte is proposed. A thin BaCeO3-based layer 12 μm thick was grown by a solid-state reaction of the electrolyte substrate and a BaO film deposited previously over the substrate surface at 1500°C. A homogeneous junction between the layer and the electrolyte was formed, thus allowing no delamination and cracking of the layer. Tolerance of this layer to CO2 was high enough to suppress decomposition into BaCO3 and CeO2. Open-circuit voltages of a hydrogen-air fuel cell with the coated SDC electrolyte were near 1 V or more in the range of 600-950°C. The resulting peak power density was higher than that of a fuel cell with an uncoated SDC electrolyte. © 2004 The Electrochemical Society.

DOI： 10.1149/1.1786231