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Masanobu Awano - One of the best experts on this subject based on the ideXlab platform.

  • Investigation of shrinkage behavior of Ni–Fe bimetallic Anode Tube support and the densification of electrolyte using co-sintering temperature
    Journal of Power Sources, 2011
    Co-Authors: Bo Liang, Koichi Hamamoto, Toshio Suzuki, Yoshinobu Fujishiro, Toshiaki Yamaguchi, Masanobu Awano, Brian J. Ingram, John David Cater
    Abstract:

    Abstract NiO–Fe 2 O 3 /gadolinium-doped CeO 2 (GDC), NiO–Fe 2 O 3 /yttria-stabilized ZrO 2 (YSZ) Anode supported fuel cells were fabricated at co-sintering temperatures of Anode-electrolyte from 1250 °C to 1400 °C. The volumetric shrinkage of the Anode-electrolytes and the porosity of the Anode Tube were studied systematically at different temperatures. 1300 °C is the marginal temperature to obtain sufficient electrocatalytic activity of electrodes, and a higher temperature is needed to suppress gas leakage through the scandia-stabilized zirconia (ScSZ) electrolyte. At each co-sintering temperature from 1250 °C to 1400 °C, the porosity of NiO–Fe 2 O 3 /GDC Anode Tubes is nearly 10% higher than that of NiO–Fe 2 O 3 /YSZ Anode Tubes. SEM results exhibited the Anode-supported electrolyte tends to be more dense as co-sintering temperature increasing to 1400 °C from 1250 °C. However, the high co-sintering temperature of 1400 °C will result in low porosity of Anode which negatively affected the power density.

  • Fabrication of micro-tubular solid oxide fuel cells with a single-grain-thick yttria stabilized zirconia electrolyte
    Journal of Power Sources, 2010
    Co-Authors: Toshio Suzuki, Yoshinobu Fujishiro, Toshiaki Yamaguchi, Masanobu Awano, Hasan Zahir, Nigel Sammes
    Abstract:

    Abstract This study discusses the fabrication and electrochemical performance of micro-tubular solid oxide fuel cells (SOFCs) with an electrolyte consisting a single-grain-thick yttria stabilized zirconia (YSZ) layer. It is found that a uniform coating of an electrolyte slurry and controlled shrinkage of the supported Tube leads to a dense, crack-free, single-grain-thick (less than 1 μm) electrolyte on a porous Anode Tube. The SOFC has a power density of 0.39 W cm −2 at an operating temperature as low as 600 °C, with YSZ and nickel/YSZ for the electrolyte and Anode, respectively. An examination is made of the effect of hydrogen fuel flow rate and shown that a higher flow rate leads to better cell performance. Hence a YSZ cell can be used for low-temperature SOFC systems below 600 °C, simply by optimizing the cell structure and operating conditions.

  • Effect of Anode microstructure on the performance of micro tubular SOFCs
    Solid State Ionics, 2008
    Co-Authors: Toshio Suzuki, Yoshinobu Fujishiro, Toshiaki Yamaguchi, Yoshihiro Funahashi, Masanobu Awano
    Abstract:

    Abstract Here we report the effect of Anode microstructure on the SOFC performance using two types of micro tubular SOFCs, 0.8 and 1.6mm in diameter with different Anode microstructure (Cells A and B). The cells consisted of NiO-Gd doped ceria (GDC) as an Anode (support Tube), GDC as an electrolyte and (La, Sr)(Fe, Co)O 3 (LSCF)-GDC as a cathode. The Anode Tube for Cell A was prepared using NiO (d g ~ 5µm) and GDC (d g ~ 0.2µm) powders without using a pore former, while the Anode Tube for Cell B was prepared using NiO (d g ~ 0.5µm)and GDC(d g ~ 0.2µm) powders using a pore former. The peak power density of these cells were shown to be 203, 400 and 857mW cm − 2 for Cell A and 273, 628 and 1017mW cm − 2 for Cell B, respectively at 450, 500, and 550°C operating temperature. Both cells showed outstanding performance, and furthermore the Anode microstructure of Cell B was shown to be more optimized for better cell performance.

  • Fabrication and Characterization of Microtubular SOFCs with Multilayered Electrolyte
    Electrochemical and Solid-State Letters, 2008
    Co-Authors: Toshio Suzuki, Yoshinobu Fujishiro, Toshiaki Yamaguchi, Yoshihiro Funahashi, Zahir Hasan, Masanobu Awano
    Abstract:

    Multilayered electrolytes for microtubular solid-oxide fuel cells (SOFCs) have been prepared and their electrochemical properties investigated. SC 2 O 3 -stabilized ZrO 2 (ScSZ) and Gd 2 O 3 -doped CeO 2 (GDC) were selected for the electrolyte materials; the multilayered electrolyte of GDC-ScSZ-GDC was successfully prepared on an Anode Tube (1.8 mm diameter) using multiple dip coating and a cofiring technique. The thickness of each electrolyte layer was about 3, 3, and 12 μm, respectively. The cell performance test showed an open-circuit voltage (OCV) of over 1 V at 600°C or higher temperature for the SOFC with a multilayered electrolyte, while a SOFC with a 12 μm thick GDC electrolyte showed an OCV of 0.84 V at 600°C. The cell performances of 0.35 W cm -2 at 0.7 V and 0.27 W cm -2 at 0.8 V were obtained for the SOFC with multilayered electrolyte at the operating temperature of 650°C.

  • Current collecting efficiency of micro tubular SOFCs
    Journal of Power Sources, 2007
    Co-Authors: Toshio Suzuki, Yoshinobu Fujishiro, Toshiaki Yamaguchi, Masanobu Awano
    Abstract:

    Abstract In this study, current collecting efficiency of the micro tubular solid oxide fuel cell (SOFC) was estimated to determine optimum size of the micro tubular SOFC. Two models for collecting current from single terminal (ST) and double terminal (DT) of Anode Tube were proposed and used to calculate the current collecting efficiency as functions of Anode thickness, Tube length and operating temperature. It was shown that design of the cell geometry and current correcting method are significantly important to achieve high performance micro tubular SOFC stacks. The efficiency loss estimated from the DT model was about 2–4-fold lower than those of obtained from the ST model. The DT model was shown to be more effective for higher operating temperature and the Tube length.

Toshio Suzuki - One of the best experts on this subject based on the ideXlab platform.

  • Effect of nanostructured Anode functional layer thickness on the solid-oxide fuel cell performance in the intermediate temperature
    International Journal of Hydrogen Energy, 2014
    Co-Authors: Toshiaki Yamaguchi, Koichi Hamamoto, Hirofumi Sumi, J. David Carter, Toshio Suzuki, Yoshinobu Fujishiro, Scott A. Barnett
    Abstract:

    Abstract Effect of Anode functional layer thickness on the performance of solid-oxide fuel cells (SOFCs) has been investigated in the intermediate temperatures of 600–650 °C. Three types of cells with different thickness (0, 4, 10 micron) of nanostructured Anode functional layer (AFL) consisting of Ni-ScSZ (Scandia stabilized zirconia) are prepared. The SOFCs consist of Ni-3YSZ (3 mol% yttria stabilized zirconia) Anode Tube support with the AFL, ScSZ electrolyte, and LSCF (lanthanum strontium cobalt ferrite) and GDC (gadolinium doped ceria) mixture cathode. It is shown that the performance of the cell is improved as the thickness of the Anode functional layer increases. Power densities of the cell with 10 micron thick AFL at 600 and 650 °C are shown to be 0.22 and 0.27 W/cm2 at 0.75 V, respectively. According to impedance spectroscopy, improvement of both ohmic and polarization resistances has been observed by increasing the thickness of the AFL, suggesting that the AFL also acts as a better contact layer between the electrolyte and the Anode support, and the effectiveness of the AFL by optimizing the thickness.

  • Investigation of shrinkage behavior of Ni–Fe bimetallic Anode Tube support and the densification of electrolyte using co-sintering temperature
    Journal of Power Sources, 2011
    Co-Authors: Bo Liang, Koichi Hamamoto, Toshio Suzuki, Yoshinobu Fujishiro, Toshiaki Yamaguchi, Masanobu Awano, Brian J. Ingram, John David Cater
    Abstract:

    Abstract NiO–Fe 2 O 3 /gadolinium-doped CeO 2 (GDC), NiO–Fe 2 O 3 /yttria-stabilized ZrO 2 (YSZ) Anode supported fuel cells were fabricated at co-sintering temperatures of Anode-electrolyte from 1250 °C to 1400 °C. The volumetric shrinkage of the Anode-electrolytes and the porosity of the Anode Tube were studied systematically at different temperatures. 1300 °C is the marginal temperature to obtain sufficient electrocatalytic activity of electrodes, and a higher temperature is needed to suppress gas leakage through the scandia-stabilized zirconia (ScSZ) electrolyte. At each co-sintering temperature from 1250 °C to 1400 °C, the porosity of NiO–Fe 2 O 3 /GDC Anode Tubes is nearly 10% higher than that of NiO–Fe 2 O 3 /YSZ Anode Tubes. SEM results exhibited the Anode-supported electrolyte tends to be more dense as co-sintering temperature increasing to 1400 °C from 1250 °C. However, the high co-sintering temperature of 1400 °C will result in low porosity of Anode which negatively affected the power density.

  • Fabrication of micro-tubular solid oxide fuel cells with a single-grain-thick yttria stabilized zirconia electrolyte
    Journal of Power Sources, 2010
    Co-Authors: Toshio Suzuki, Yoshinobu Fujishiro, Toshiaki Yamaguchi, Masanobu Awano, Hasan Zahir, Nigel Sammes
    Abstract:

    Abstract This study discusses the fabrication and electrochemical performance of micro-tubular solid oxide fuel cells (SOFCs) with an electrolyte consisting a single-grain-thick yttria stabilized zirconia (YSZ) layer. It is found that a uniform coating of an electrolyte slurry and controlled shrinkage of the supported Tube leads to a dense, crack-free, single-grain-thick (less than 1 μm) electrolyte on a porous Anode Tube. The SOFC has a power density of 0.39 W cm −2 at an operating temperature as low as 600 °C, with YSZ and nickel/YSZ for the electrolyte and Anode, respectively. An examination is made of the effect of hydrogen fuel flow rate and shown that a higher flow rate leads to better cell performance. Hence a YSZ cell can be used for low-temperature SOFC systems below 600 °C, simply by optimizing the cell structure and operating conditions.

  • Effect of Anode microstructure on the performance of micro tubular SOFCs
    Solid State Ionics, 2008
    Co-Authors: Toshio Suzuki, Yoshinobu Fujishiro, Toshiaki Yamaguchi, Yoshihiro Funahashi, Masanobu Awano
    Abstract:

    Abstract Here we report the effect of Anode microstructure on the SOFC performance using two types of micro tubular SOFCs, 0.8 and 1.6mm in diameter with different Anode microstructure (Cells A and B). The cells consisted of NiO-Gd doped ceria (GDC) as an Anode (support Tube), GDC as an electrolyte and (La, Sr)(Fe, Co)O 3 (LSCF)-GDC as a cathode. The Anode Tube for Cell A was prepared using NiO (d g ~ 5µm) and GDC (d g ~ 0.2µm) powders without using a pore former, while the Anode Tube for Cell B was prepared using NiO (d g ~ 0.5µm)and GDC(d g ~ 0.2µm) powders using a pore former. The peak power density of these cells were shown to be 203, 400 and 857mW cm − 2 for Cell A and 273, 628 and 1017mW cm − 2 for Cell B, respectively at 450, 500, and 550°C operating temperature. Both cells showed outstanding performance, and furthermore the Anode microstructure of Cell B was shown to be more optimized for better cell performance.

  • Fabrication and Characterization of Microtubular SOFCs with Multilayered Electrolyte
    Electrochemical and Solid-State Letters, 2008
    Co-Authors: Toshio Suzuki, Yoshinobu Fujishiro, Toshiaki Yamaguchi, Yoshihiro Funahashi, Zahir Hasan, Masanobu Awano
    Abstract:

    Multilayered electrolytes for microtubular solid-oxide fuel cells (SOFCs) have been prepared and their electrochemical properties investigated. SC 2 O 3 -stabilized ZrO 2 (ScSZ) and Gd 2 O 3 -doped CeO 2 (GDC) were selected for the electrolyte materials; the multilayered electrolyte of GDC-ScSZ-GDC was successfully prepared on an Anode Tube (1.8 mm diameter) using multiple dip coating and a cofiring technique. The thickness of each electrolyte layer was about 3, 3, and 12 μm, respectively. The cell performance test showed an open-circuit voltage (OCV) of over 1 V at 600°C or higher temperature for the SOFC with a multilayered electrolyte, while a SOFC with a 12 μm thick GDC electrolyte showed an OCV of 0.84 V at 600°C. The cell performances of 0.35 W cm -2 at 0.7 V and 0.27 W cm -2 at 0.8 V were obtained for the SOFC with multilayered electrolyte at the operating temperature of 650°C.

Toshiaki Yamaguchi - One of the best experts on this subject based on the ideXlab platform.

  • Effect of nanostructured Anode functional layer thickness on the solid-oxide fuel cell performance in the intermediate temperature
    International Journal of Hydrogen Energy, 2014
    Co-Authors: Toshiaki Yamaguchi, Koichi Hamamoto, Hirofumi Sumi, J. David Carter, Toshio Suzuki, Yoshinobu Fujishiro, Scott A. Barnett
    Abstract:

    Abstract Effect of Anode functional layer thickness on the performance of solid-oxide fuel cells (SOFCs) has been investigated in the intermediate temperatures of 600–650 °C. Three types of cells with different thickness (0, 4, 10 micron) of nanostructured Anode functional layer (AFL) consisting of Ni-ScSZ (Scandia stabilized zirconia) are prepared. The SOFCs consist of Ni-3YSZ (3 mol% yttria stabilized zirconia) Anode Tube support with the AFL, ScSZ electrolyte, and LSCF (lanthanum strontium cobalt ferrite) and GDC (gadolinium doped ceria) mixture cathode. It is shown that the performance of the cell is improved as the thickness of the Anode functional layer increases. Power densities of the cell with 10 micron thick AFL at 600 and 650 °C are shown to be 0.22 and 0.27 W/cm2 at 0.75 V, respectively. According to impedance spectroscopy, improvement of both ohmic and polarization resistances has been observed by increasing the thickness of the AFL, suggesting that the AFL also acts as a better contact layer between the electrolyte and the Anode support, and the effectiveness of the AFL by optimizing the thickness.

  • Investigation of shrinkage behavior of Ni–Fe bimetallic Anode Tube support and the densification of electrolyte using co-sintering temperature
    Journal of Power Sources, 2011
    Co-Authors: Bo Liang, Koichi Hamamoto, Toshio Suzuki, Yoshinobu Fujishiro, Toshiaki Yamaguchi, Masanobu Awano, Brian J. Ingram, John David Cater
    Abstract:

    Abstract NiO–Fe 2 O 3 /gadolinium-doped CeO 2 (GDC), NiO–Fe 2 O 3 /yttria-stabilized ZrO 2 (YSZ) Anode supported fuel cells were fabricated at co-sintering temperatures of Anode-electrolyte from 1250 °C to 1400 °C. The volumetric shrinkage of the Anode-electrolytes and the porosity of the Anode Tube were studied systematically at different temperatures. 1300 °C is the marginal temperature to obtain sufficient electrocatalytic activity of electrodes, and a higher temperature is needed to suppress gas leakage through the scandia-stabilized zirconia (ScSZ) electrolyte. At each co-sintering temperature from 1250 °C to 1400 °C, the porosity of NiO–Fe 2 O 3 /GDC Anode Tubes is nearly 10% higher than that of NiO–Fe 2 O 3 /YSZ Anode Tubes. SEM results exhibited the Anode-supported electrolyte tends to be more dense as co-sintering temperature increasing to 1400 °C from 1250 °C. However, the high co-sintering temperature of 1400 °C will result in low porosity of Anode which negatively affected the power density.

  • Fabrication of micro-tubular solid oxide fuel cells with a single-grain-thick yttria stabilized zirconia electrolyte
    Journal of Power Sources, 2010
    Co-Authors: Toshio Suzuki, Yoshinobu Fujishiro, Toshiaki Yamaguchi, Masanobu Awano, Hasan Zahir, Nigel Sammes
    Abstract:

    Abstract This study discusses the fabrication and electrochemical performance of micro-tubular solid oxide fuel cells (SOFCs) with an electrolyte consisting a single-grain-thick yttria stabilized zirconia (YSZ) layer. It is found that a uniform coating of an electrolyte slurry and controlled shrinkage of the supported Tube leads to a dense, crack-free, single-grain-thick (less than 1 μm) electrolyte on a porous Anode Tube. The SOFC has a power density of 0.39 W cm −2 at an operating temperature as low as 600 °C, with YSZ and nickel/YSZ for the electrolyte and Anode, respectively. An examination is made of the effect of hydrogen fuel flow rate and shown that a higher flow rate leads to better cell performance. Hence a YSZ cell can be used for low-temperature SOFC systems below 600 °C, simply by optimizing the cell structure and operating conditions.

  • Effect of Anode microstructure on the performance of micro tubular SOFCs
    Solid State Ionics, 2008
    Co-Authors: Toshio Suzuki, Yoshinobu Fujishiro, Toshiaki Yamaguchi, Yoshihiro Funahashi, Masanobu Awano
    Abstract:

    Abstract Here we report the effect of Anode microstructure on the SOFC performance using two types of micro tubular SOFCs, 0.8 and 1.6mm in diameter with different Anode microstructure (Cells A and B). The cells consisted of NiO-Gd doped ceria (GDC) as an Anode (support Tube), GDC as an electrolyte and (La, Sr)(Fe, Co)O 3 (LSCF)-GDC as a cathode. The Anode Tube for Cell A was prepared using NiO (d g ~ 5µm) and GDC (d g ~ 0.2µm) powders without using a pore former, while the Anode Tube for Cell B was prepared using NiO (d g ~ 0.5µm)and GDC(d g ~ 0.2µm) powders using a pore former. The peak power density of these cells were shown to be 203, 400 and 857mW cm − 2 for Cell A and 273, 628 and 1017mW cm − 2 for Cell B, respectively at 450, 500, and 550°C operating temperature. Both cells showed outstanding performance, and furthermore the Anode microstructure of Cell B was shown to be more optimized for better cell performance.

  • Fabrication and Characterization of Microtubular SOFCs with Multilayered Electrolyte
    Electrochemical and Solid-State Letters, 2008
    Co-Authors: Toshio Suzuki, Yoshinobu Fujishiro, Toshiaki Yamaguchi, Yoshihiro Funahashi, Zahir Hasan, Masanobu Awano
    Abstract:

    Multilayered electrolytes for microtubular solid-oxide fuel cells (SOFCs) have been prepared and their electrochemical properties investigated. SC 2 O 3 -stabilized ZrO 2 (ScSZ) and Gd 2 O 3 -doped CeO 2 (GDC) were selected for the electrolyte materials; the multilayered electrolyte of GDC-ScSZ-GDC was successfully prepared on an Anode Tube (1.8 mm diameter) using multiple dip coating and a cofiring technique. The thickness of each electrolyte layer was about 3, 3, and 12 μm, respectively. The cell performance test showed an open-circuit voltage (OCV) of over 1 V at 600°C or higher temperature for the SOFC with a multilayered electrolyte, while a SOFC with a 12 μm thick GDC electrolyte showed an OCV of 0.84 V at 600°C. The cell performances of 0.35 W cm -2 at 0.7 V and 0.27 W cm -2 at 0.8 V were obtained for the SOFC with multilayered electrolyte at the operating temperature of 650°C.

Yoshinobu Fujishiro - One of the best experts on this subject based on the ideXlab platform.

  • Effect of nanostructured Anode functional layer thickness on the solid-oxide fuel cell performance in the intermediate temperature
    International Journal of Hydrogen Energy, 2014
    Co-Authors: Toshiaki Yamaguchi, Koichi Hamamoto, Hirofumi Sumi, J. David Carter, Toshio Suzuki, Yoshinobu Fujishiro, Scott A. Barnett
    Abstract:

    Abstract Effect of Anode functional layer thickness on the performance of solid-oxide fuel cells (SOFCs) has been investigated in the intermediate temperatures of 600–650 °C. Three types of cells with different thickness (0, 4, 10 micron) of nanostructured Anode functional layer (AFL) consisting of Ni-ScSZ (Scandia stabilized zirconia) are prepared. The SOFCs consist of Ni-3YSZ (3 mol% yttria stabilized zirconia) Anode Tube support with the AFL, ScSZ electrolyte, and LSCF (lanthanum strontium cobalt ferrite) and GDC (gadolinium doped ceria) mixture cathode. It is shown that the performance of the cell is improved as the thickness of the Anode functional layer increases. Power densities of the cell with 10 micron thick AFL at 600 and 650 °C are shown to be 0.22 and 0.27 W/cm2 at 0.75 V, respectively. According to impedance spectroscopy, improvement of both ohmic and polarization resistances has been observed by increasing the thickness of the AFL, suggesting that the AFL also acts as a better contact layer between the electrolyte and the Anode support, and the effectiveness of the AFL by optimizing the thickness.

  • Investigation of shrinkage behavior of Ni–Fe bimetallic Anode Tube support and the densification of electrolyte using co-sintering temperature
    Journal of Power Sources, 2011
    Co-Authors: Bo Liang, Koichi Hamamoto, Toshio Suzuki, Yoshinobu Fujishiro, Toshiaki Yamaguchi, Masanobu Awano, Brian J. Ingram, John David Cater
    Abstract:

    Abstract NiO–Fe 2 O 3 /gadolinium-doped CeO 2 (GDC), NiO–Fe 2 O 3 /yttria-stabilized ZrO 2 (YSZ) Anode supported fuel cells were fabricated at co-sintering temperatures of Anode-electrolyte from 1250 °C to 1400 °C. The volumetric shrinkage of the Anode-electrolytes and the porosity of the Anode Tube were studied systematically at different temperatures. 1300 °C is the marginal temperature to obtain sufficient electrocatalytic activity of electrodes, and a higher temperature is needed to suppress gas leakage through the scandia-stabilized zirconia (ScSZ) electrolyte. At each co-sintering temperature from 1250 °C to 1400 °C, the porosity of NiO–Fe 2 O 3 /GDC Anode Tubes is nearly 10% higher than that of NiO–Fe 2 O 3 /YSZ Anode Tubes. SEM results exhibited the Anode-supported electrolyte tends to be more dense as co-sintering temperature increasing to 1400 °C from 1250 °C. However, the high co-sintering temperature of 1400 °C will result in low porosity of Anode which negatively affected the power density.

  • Fabrication of micro-tubular solid oxide fuel cells with a single-grain-thick yttria stabilized zirconia electrolyte
    Journal of Power Sources, 2010
    Co-Authors: Toshio Suzuki, Yoshinobu Fujishiro, Toshiaki Yamaguchi, Masanobu Awano, Hasan Zahir, Nigel Sammes
    Abstract:

    Abstract This study discusses the fabrication and electrochemical performance of micro-tubular solid oxide fuel cells (SOFCs) with an electrolyte consisting a single-grain-thick yttria stabilized zirconia (YSZ) layer. It is found that a uniform coating of an electrolyte slurry and controlled shrinkage of the supported Tube leads to a dense, crack-free, single-grain-thick (less than 1 μm) electrolyte on a porous Anode Tube. The SOFC has a power density of 0.39 W cm −2 at an operating temperature as low as 600 °C, with YSZ and nickel/YSZ for the electrolyte and Anode, respectively. An examination is made of the effect of hydrogen fuel flow rate and shown that a higher flow rate leads to better cell performance. Hence a YSZ cell can be used for low-temperature SOFC systems below 600 °C, simply by optimizing the cell structure and operating conditions.

  • Effect of Anode microstructure on the performance of micro tubular SOFCs
    Solid State Ionics, 2008
    Co-Authors: Toshio Suzuki, Yoshinobu Fujishiro, Toshiaki Yamaguchi, Yoshihiro Funahashi, Masanobu Awano
    Abstract:

    Abstract Here we report the effect of Anode microstructure on the SOFC performance using two types of micro tubular SOFCs, 0.8 and 1.6mm in diameter with different Anode microstructure (Cells A and B). The cells consisted of NiO-Gd doped ceria (GDC) as an Anode (support Tube), GDC as an electrolyte and (La, Sr)(Fe, Co)O 3 (LSCF)-GDC as a cathode. The Anode Tube for Cell A was prepared using NiO (d g ~ 5µm) and GDC (d g ~ 0.2µm) powders without using a pore former, while the Anode Tube for Cell B was prepared using NiO (d g ~ 0.5µm)and GDC(d g ~ 0.2µm) powders using a pore former. The peak power density of these cells were shown to be 203, 400 and 857mW cm − 2 for Cell A and 273, 628 and 1017mW cm − 2 for Cell B, respectively at 450, 500, and 550°C operating temperature. Both cells showed outstanding performance, and furthermore the Anode microstructure of Cell B was shown to be more optimized for better cell performance.

  • Fabrication and Characterization of Microtubular SOFCs with Multilayered Electrolyte
    Electrochemical and Solid-State Letters, 2008
    Co-Authors: Toshio Suzuki, Yoshinobu Fujishiro, Toshiaki Yamaguchi, Yoshihiro Funahashi, Zahir Hasan, Masanobu Awano
    Abstract:

    Multilayered electrolytes for microtubular solid-oxide fuel cells (SOFCs) have been prepared and their electrochemical properties investigated. SC 2 O 3 -stabilized ZrO 2 (ScSZ) and Gd 2 O 3 -doped CeO 2 (GDC) were selected for the electrolyte materials; the multilayered electrolyte of GDC-ScSZ-GDC was successfully prepared on an Anode Tube (1.8 mm diameter) using multiple dip coating and a cofiring technique. The thickness of each electrolyte layer was about 3, 3, and 12 μm, respectively. The cell performance test showed an open-circuit voltage (OCV) of over 1 V at 600°C or higher temperature for the SOFC with a multilayered electrolyte, while a SOFC with a 12 μm thick GDC electrolyte showed an OCV of 0.84 V at 600°C. The cell performances of 0.35 W cm -2 at 0.7 V and 0.27 W cm -2 at 0.8 V were obtained for the SOFC with multilayered electrolyte at the operating temperature of 650°C.

Rak-hyun Song - One of the best experts on this subject based on the ideXlab platform.

  • Fabrication of Anode-supported tubular Ba(Zr0.1Ce0.7Y0.2)O3−δ cell for intermediate temperature solid oxide fuel cells
    Ceramics International, 2014
    Co-Authors: Sung Hwan Min, Rak-hyun Song, Jin Goo Lee, Myoung-geun Park, Kwang Hyun Ryu, Yukwon Jeon, Yong-gun Shul
    Abstract:

    Abstract The characteristics and performance of the Anode-supported tubular cells with thin and dense Ba(Zr0.1Ce0.7Y0.2)O3−δ (BZCY) electrolyte was investigated. The fine BZCY powder was prepared by a co-precipitation method. The Ni–BZCY Anode Tube was fabricated by an extrusion process. Ni–BZCY/BZCY nanocomposite slurry was coated on the Anode Tube as an Anode fuctional layer (AFL) by using the dip-coating method. The BZCY electrolyte and LSCF–BZCY cathode was coated by vacuum slurry coating and dip-coating method, respectively. The Anode Tube had 0.381 µm in pore size (porosity: 34%). The impedance analysis of the tubular BZCY cells was conducted under open circuit condition. The ohmic resistance and the polarization resistance of the BZCY electrolyte were about 0.78 Ω cm2 and 0.035 Ω cm2 at 700 °C, respectively. The performance was measured under humidified H2 (5% H2O) atmosphere at 600–700 °C. The maximum power density of the tubular BZCY cell was about 0.5 Wcm−2 at 700 °C.

  • Effect of fabrication parameters on coating properties of tubular solid oxide fuel cell electrolyte prepared by vacuum slurry coating
    Journal of Power Sources, 2010
    Co-Authors: Hui Jeong Son, Rak-hyun Song, Tak-hyoung Lim, Seung-bok Lee, Sung Hyun Kim, Dong Ryul Shin
    Abstract:

    Abstract The process of vacuum slurry coating for the fabrication of a dense and thin electrolyte film on a porous Anode Tube is investigated for application in solid oxide fuel cells. 8 mol% yttria stabilized zirconia is coated on an Anode Tube by vacuum slurry-coating process as a function of pre-sintering temperature of the Anode Tube, vacuum pressure, slurry concentration, number of coats, and immersion time. A dense electrolyte layer is formed on the Anode Tube after final sintering at 1400 °C. With decrease in the pre-sintering temperature of the Anode Tube, the grain size of the coated electrolyte layer increases and the number of surface pores in the coating layer decreases. This is attributed to a reduced difference in the respective shrinkage of the Anode Tube and the electrolyte layer. The thickness of the coated electrolyte layer increases with the content of solid powder in the slurry, the number of dip-coats, and the immersion time. Although vacuum pressure has no great influence on the electrolyte thickness, higher vacuum produces a denser coating layer, as confirmed by low gas permeability and a reduced number of defects in the coating layer. A single cell with the vacuum slurry coated electrolyte shows a good performance of 620 mW cm−2 (0.7 V) at 750 °C. These experimental results indicate that the vacuum slurry-coating process is an effective method to fabricate a dense thin film on a porous Anode support.

  • fabrication and characteristics of Anode supported flat Tube solid oxide fuel cell
    Journal of Power Sources, 2003
    Co-Authors: Jonghee Kim, Rak-hyun Song, Dong Ryul Shin, Keunsuk Song, Sanghoon Hyun, Harumi Yokokawa
    Abstract:

    Abstract An Anode-supported flat-Tube solid oxide fuel cell (SOFC) is developed to increase the cell power density and thermal stability by combining tubular and planar cell structures. The Anode-supported flat Tube is fabricated by an extrusion process. The porosity and pore size of the Ni/YSZ (8 mol% yttria-stabilized zirconia) cermet Anode are 50.6% and 0.23 μm, respectively. The Ni particles are distributed uniformly and are well connected to each other in the cermet. An electrolyte of YSZ and a multi-layered cathode of a (La 0.85 Sr 0.15 ) 0.9 MnO 3 (LSM)/YSZ composite, LSM, and La 0.6 Sr 0.4 Co 0.2 Fe 0.8 O 3 (LSCF) are coated on the Anode Tube by slurry dip coating. The Anode-supported flat-Tube cell produces 225 mW cm −2 (0.6 V, 375 mA cm −2 ) at 750 °C. A ceramic interconnect for the cell stack, La 0.75 Ca 0.27 CrO 3 (LCC), is synthesized by the Pechini method and is coated on the Anode substrate by a plasma spray. A dense layer is obtained. A metallic interconnection plate of Fe–16Cr alloy is coated with LSM by a slurry dip coating process and sintered in a Ar+10% H 2 atmosphere. The resistance of the LSM-coated alloy is 148 mΩ cm 2 at 750 °C and decreases to 43 mΩ cm 2 after 450 h.