Article
Chemistry, Physical
Tolga Altan, Cigdem Timurkutluk, Sezer Onbilgin, Bora Timurkutluk
Summary: This study presents a new solid oxide fuel cell structure called bolt-microtubular. The anode supports of this structure are formed by winding tape cast anode support strip on a threaded rod and then isostatically pressing. The results show that the bolt-microtubular cells outperform conventional microtubular cells due to the enhanced electrolyte-electrode interfaces and effective current collection. The highest peak electrochemical performance of 0.293 Wcm(-2) is achieved with the bolt-microtubular cell, indicating the promising potential of this design.
JOURNAL OF POWER SOURCES
(2023)
Article
Chemistry, Physical
Cigdem Timurkutluk, Fuat Yildirim, Furkan Toruntay, Sezer Onbilgin, Mikail Yagiz, Bora Timurkutluk
Summary: Anode supported microtubular solid oxide fuel cells with LSM catalyst infiltrated LSM-YSZ cathodes are developed to increase triple phase boundary density in the cathode and improve cell performance.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2023)
Article
Materials Science, Ceramics
Cigdem Timurkutluk, Furkan Toruntay, Sezer Onbilgin, Gamze Atalmis, Bora Timurkutluk
Summary: This study investigates the effect of ceramic fibers with different sizes on the sealing performance of glass ceramic seals for microtubular solid oxide fuel cell applications. Experimental results show that sealing pastes with ceramic bulk fiber and ceramic fiber rope gasket can effectively improve the sealing performance, while pastes without filler and with ceramic blanket exhibit poor sealing performance.
CERAMICS INTERNATIONAL
(2022)
Article
Chemistry, Physical
Yue Yao, Chenpeng Wang, Yue Ma, Hao Ye, Yinglong Liu, Jiawei Liu, Xiaobo Zhao, Tao Tao, Yingbang Yao, Shengguo Lu, Huazheng Yang, Bo Liang
Summary: The effect of a nano-honeycomb cathode on the performance of a microtubular solid oxide fuel cell is investigated. The nano-honeycomb cathodes with high unsealing pore porosity and high structural strength were prepared by freeze casting, which improved the adsorption and dissociation of oxygen. The cell performance of the nano-cell structure of the GDC-LSCF cathode is significantly improved compared to a traditional GDC-LSCF cathode with a spongy porous structure.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2023)
Article
Chemistry, Physical
Sea-Fue Wang, Yung-Fu Hsu, Yi-Le Liao, Shih-Ting Huang, Piotr Jasinski
Summary: The perovskite NdSrCo2O5+delta (NSCO) shows high electrical conductivity and is used as the cathode material for Ce0.8Gd0.2O2-delta (GDC)-supported microtubular solid oxide fuel cells (MT-SOFCs). By varying design parameters, the MT-SOFC with an outer tube diameter of 1.86 mm, an electrolyte thickness of 180 um, and a 5NSCO-5GDC composite cathode exhibits the best performance, with high power density and mechanical integrity. The results demonstrate the high electrochemical activity of the NSCO-GDC composite and exceed existing MT-SOFCs in terms of power density.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2021)
Article
Chemistry, Physical
Tolga Altan, Cigdem Timurkutluk, Bora Timurkutluk, Selahattin Celik
Summary: A new production technique combining tape casting and isostatic pressing is proposed for fabricating microtubular supports for solid oxide fuel cells. The results show that the supports fabricated using this method have good microstructural and mechanical properties, as well as reasonable electrochemical performance.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2022)
Article
Materials Science, Ceramics
Yinglong Liu, Hao Ye, Yue Ma, Chenpeng Wang, Jiawei Liu, Yingli Liu, Xiaoru Xu, Zhicong Chen, Bo Liang
Summary: In this study, a microtubular solid oxide fuel cell with an anode buffer layer was fabricated, which exhibited excellent stability and protected the performance of the fuel cell during long-term operation.
INTERNATIONAL JOURNAL OF APPLIED CERAMIC TECHNOLOGY
(2023)
Article
Chemistry, Physical
Cigdem Timurkutluk
Summary: This paper proposes a novel method for manufacturing functionally graded anode supports for microtubular solid oxide fuel cells using tape casting and isostatic pressing. By tape casting, six different anode support strips with various pore former contents are produced. Furthermore, three-layered anode supports composed of different combinations of these tapes are fabricated by isostatic pressing. The results show that both homogeneous and porosity graded anode supports can be successfully manufactured by this method. Moreover, the cell with a porosity graded anode support achieves the highest maximum performance of 0.645 Wcm(-2) at 800 degrees C under 0.3 NLmin(-1) hydrogen and stationary air.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2023)
Article
Chemistry, Physical
Tolga Altan, Cigdem Timurkutluk, Bora Timurkutluk
Summary: This paper presents the fabrication of anode support microtubes for microtubular solid oxide fuel cells (SOFCs) using tape casting and isostatic pressing. The experimental results show that adjusting the parameters of isostatic pressing can produce robust microtubular anode supports without structural defects, with good mechanical and electrochemical performance.
JOURNAL OF POWER SOURCES
(2022)
Article
Energy & Fuels
Hazrul Adzfar Shabri, Siti Norlaila Faeizah Mohd Rudin, Mohd Hafiz Dzarfan Othman, Siti Munira Jamil, Siti Nur Elida Aqmar Mohd Kamal, Suriani Abu Bakar, Nafisah Osman, Juhana Jaafar, Mukhlis A. Rahman, Ahmad Fauzi Ismail
Summary: Adding a copper metal layer on top of the anode of micro-tubular SOFC can significantly enhance conductivity by 10^10 times, while also reducing gas permeability by 10 times. The optimal Cu solution composition was found to be a 2:1:8 ratio of Cu: citric acid: ethylene glycol, with stability in metal layer thickness after 5 deposition cycles. Increasing micron-sized pore formers during anode fabrication can help alleviate the reduction in gas permeability caused by the copper coating.
INTERNATIONAL JOURNAL OF ENERGY RESEARCH
(2022)
Review
Energy & Fuels
Mohsen Fallah Vostakola, Bahman Amini Horri
Summary: Solid oxide fuel cells (SOFCs) are promising candidates for sustainable and efficient energy conversion, but face challenges with operating temperature. Low-temperature operation can increase losses and decrease overall performance. Material and fabrication advancements have been developed to address these challenges in recent years.
Article
Chemistry, Physical
Xiufu Sun, Yuliang Liu, Peter Vang Hendriksen, Ming Chen
Summary: The study tested three cells under different conditions to mimic gas flow series or parallel arrangements, finding that a gas-flow series arrangement led to reduced cell degradation by reducing the overall cell voltage degradation rate. This was attributed to the milder conditions and reduced polarization in the gas flow series case compared to the parallel flow case.
JOURNAL OF POWER SOURCES
(2021)
Article
Engineering, Environmental
Juntao Gao, Yingying Liu, Yuan Gao, Mengke Yuan, Zhe Wang, Zhe Lu, Qiang Li, Bo Wei
Summary: This study developed cobalt-free fluorine doped Bi0.7Sr0.3FeO3-6 oxides for energetic cathodes of low-temperature solid oxide fuel cells.
CHEMICAL ENGINEERING JOURNAL
(2023)
Review
Chemistry, Multidisciplinary
Yuzheng Lu, Youquan Mi, Junjiao Li, Fenghua Qi, Senlin Yan, Wenjing Dong
Summary: This review article discusses the recent progress in enhancing the ionic conductivity of SOFCs by using semiconductor-ionic conductor nanomaterials, highlighting the crucial role of nanomaterials in lowering the operating temperature of SOFCs. Furthermore, it explores the historical development and working mechanism of semiconductor-ionic membrane fuel cells (SIMFC).
Review
Chemistry, Physical
Idris Temitope Bello, Shuo Zhai, Qijiao He, Qidong Xu, Meng Ni
Summary: Solid oxide fuel cells (SOFCs) have the potential to replace conventional thermal power plants due to their high efficiency and low emission. The development of high-performance and durable cathode materials is essential for improving SOFC performance. Research in cathode development for intermediate to low-temperature SOFCs has shown significant growth since 2000, with about 29% of countries globally involved in the research.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2021)
Article
Chemistry, Physical
Fumihiko Kosaka, Toshiaki Yamaguchi, Yuji Ando, Takehisa Mochizuki, Hideyuki Takagi, Koichi Matsuoka, Koji Kuramoto
Summary: The study proposes a method to manage temperature distribution in CO2 methanation reactors by using gradient-distributed Ni-YSZ catalysts. The catalyst successfully prevents hotspot formation at the reactor inlet, resulting in high CH4 yields with minimal temperature differences in the reactor. This approach using gradient-distributed catalysts could be a potential method to achieve high CO2 conversion in compact reactors.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2021)
Article
Electrochemistry
Hiroyuki Shimada, Hirofumi Sumi, Yuki Yamaguchi, Yoshinobu Fujishiro
Summary: The study introduces a highly active GSC-GDC nanocomposite cathode for intermediate-temperature SOFCs, which achieves remarkably high power densities. The cathode features an extensive electrochemically active triple-phase boundary and electrically conductive networks formed with highly dispersed GSC and GDC crystallites.
ELECTROCHIMICA ACTA
(2021)
Article
Multidisciplinary Sciences
Hirofumi Sumi, Hiroyuki Shimada, Yuki Yamaguchi, Yasunobu Mizutani, Yuji Okuyama, Koji Amezawa
Summary: This study investigated the anode and cathode polarization resistances in protonic ceramic fuel cells (PCFCs) compared to solid oxide fuel cells (SOFCs), revealing differences in their characteristics.
SCIENTIFIC REPORTS
(2021)
Article
Materials Science, Ceramics
Hirofumi Sumi, Susumu Takahashi, Yuki Yamaguchi, Hiroyuki Shimada
Summary: The study found that using lanthanum-doped ceria (LDC) as an interlayer in solid oxide fuel cells can result in higher ionic conductivity and maximum power density compared to gadolinia-doped ceria (GDC). While the switch from GDC to LDC interlayers decreased the ohmic resistance, the polarization resistance for the oxygen reduction reaction slightly increased due to distribution of relaxation times. The gradual variation of chemical compositions between YSZ electrolyte and LDC interlayer influenced both ohmic and polarization resistances.
JOURNAL OF ASIAN CERAMIC SOCIETIES
(2021)
Article
Electrochemistry
Keigo Kumada, Kazuhisa Sato, Tatsuya Kawada, Hirofumi Sumi, Hiroyuki Shimada, Toshiyuki Hashida
Summary: This paper discusses the effects of through-thickness pinholes in an electrolyte on re-oxidation and mechanical damage of anode-supported solid oxide fuel cells. It was found that pinholes can cause oxygen leakage, accelerate oxidation reactions, and ultimately lead to mechanical damage. The correlation between oxygen leakage and mechanical damage highlights the importance of addressing pinhole issues in the electrolyte for the overall performance of solid oxide fuel cells.
Article
Electrochemistry
Hiroyuki Shimada, Yuki Yamaguchi, Matsuda Malik Ryuma, Hirofumi Sumi, Katsuhiro Nomura, Woosuck Shin, Yuichi Mikami, Kosuke Yamauchi, Yuki Nakata, Tomohiro Kuroha, Masashi Mori, Yasunobu Mizutani
Summary: The development of a bi-layered protonic ceramic fuel cell (PCFC) with a functional interlayer has been reported in this paper, showing improved electrochemical performance with higher power density and open-circuit voltage (OCV). The functional interlayer reduces cathode polarization resistance and suppresses current leakage in the PCFC, resulting in enhanced power density and OCV.
JOURNAL OF THE ELECTROCHEMICAL SOCIETY
(2021)
Article
Materials Science, Ceramics
Katsuhiro Nomura, Hiroyuki Shimada, Yuki Yamaguchi, Hirofumi Sumi, Yasunobu Mizutani, Yuji Okuyama, Woosuck Shin
Summary: Using various machine learning models, the space groups of Ba(Ce0.8-xZrx)Y0.2O3 (0 <= x <= 0.8) perovskite-type protonic conductors were predicted in a wide temperature range. The models were trained using data of chemical formulas, space groups obtained from high-temperature X-ray and neutron diffraction, and different datasets. The best accuracy and F1 score were achieved by the Random Forest model with a coordination number of 9 for oxygen of the A-site cation.
CERAMICS INTERNATIONAL
(2023)
Article
Chemistry, Physical
Hirofumi Sumi, Hiroyuki Shimada, Konosuke Watanabe, Yuki Yamaguchi, Katsuhiro Nomura, Yasunobu Mizutani, Yuji Okuyama
Summary: This study investigates the effect of polarization resistances on current leakage and the distribution of relaxation times (DRT) analysis of electrochemical impedance spectra (EIS) for solid oxide cells (SOCs) with GDC electrolyte and protonic ceramic cells (PCCs) with BZYb electrolyte. The results show that the polarization resistances increase with increasing current density in SOC with GDC electrolyte, but exhibit the opposite tendency in PCC with BZYb electrolyte. This suggests that the effect of current leakage on polarization resistance is related to the conductivity of the electrolyte.
ACS APPLIED ENERGY MATERIALS
(2023)
Article
Materials Science, Ceramics
Konosuke Watanabe, Katsuhiro Nomura, Yuki Yamaguchi, Hirofumi Sumi, Masashi Mori, Yasunobu Mizutani, Hiroyuki Shimada
Summary: This study compares the electrochemical performance of composite cathodes in anode-supported protonic ceramic fuel cells using La(0.6)Sr(0.4)CoxFe(1-x)O(3-delta) and BaZr0.8Yb0.2O3-delta (BZYb) sintered at different temperatures. The cathodes sintered at 1100 degrees C showed better performance due to increased proton conductive network paths. PCFCs with LSCF-BZYb, LSC-BZYb, and LSF-BZYb composite cathodes exhibited power densities of 0.25, 0.19, and 0.07 W cm(-2), respectively, at an operating temperature of 600 degrees C. The presence of Co was found to be important for high catalytic activity in cathode reactions.
CERAMICS INTERNATIONAL
(2023)
Article
Electrochemistry
Hirofumi Sumi, Hiroyuki Shimada, Yuki Yamaguchi, Katsuhiro Nomura, Kazuhisa Sato
Summary: Small-scale planar solid oxide fuel cells (SOFCs) called button cells or coin cells are widely used for fundamental research. The performance of large-scale cells is inferior to that of button cells, but the precise reason is unclear. In this study, electrochemical impedance spectroscopy (EIS) was performed on button cells with different cathode areas and varying fuel utilization, and distribution of relaxation times analysis was conducted to deconvolute the EIS. The power density decreased with increasing cathode diameter for the button cells, and the polarization resistances associated with the gas diffusion process increased for cells with large cathode areas and increasing fuel utilization. According to a simple simulation, the power density at 0.75 V was estimated to be 0.169 W/cm2 for a large-scale cell with dimensions of 10 x 10 cm2, smaller than that for a button cell with a cathode diameter of 6 mm (0.730 W/ cm2 at Uf = 0.04).
ELECTROCHIMICA ACTA
(2023)
Article
Chemistry, Physical
Hiroyuki Shimada, Hirofumi Sumi, Yuki Yamaguchi, Katsuhiro Nomura, Yasunobu Mizutani, Yoshinobu Fujishiro, Woosuck Shin
Summary: This study presents high-performance nanocomposite cathode and anode layers that greatly improve the power density of solid oxide fuel cells (SOFCs).
JOURNAL OF POWER SOURCES
(2023)
Article
Materials Science, Ceramics
Woosuck Shin, Yuki Yamaguchi, Mirano Horie, Hiroyuki Shimada, Katsuhiro Nomura, Hirofumi Sumi
Summary: This study investigates the application of porous metals in solid oxide fuel cells using machine learning methods. The process conditions for oxide layers and metal particles are examined, and it is found that random forest, a multi-output method, predicts the target variables with higher accuracy compared to neural network. Additionally, the relationship between the microstructure of metal supported cells and their power generation performance is discussed.
CERAMICS INTERNATIONAL
(2023)
Article
Chemistry, Physical
Hirofumi Sumi, Hiroyuki Shimada, Konosuke Watanabe, Yuki Yamaguchi, Katsuhiro Nomura, Yasunobu Mizutani, Ryuma Malik Matsuda, Masashi Mori, Keiji Yashiro, Takuto Araki, Yuji Okuyama
Summary: In this study, the overpotential of protonic ceramic fuel cells (PCFCs) was accurately estimated using distribution of relaxation times analysis and an equivalent circuit model. It was found that the activation overpotential in an open circuit state is not zero due to leakage current and interdiffusion of nickel and cobalt. In addition, intergranular cracks formed through nickel deposition increased the ohmic overpotential over time.
JOURNAL OF POWER SOURCES
(2023)
Article
Chemistry, Physical
Yuji Okuyama, Keita Kasuga, Masaki Shimomura, Yuichi Mikami, Kosuke Yamauchi, Tomohiro Kuroha, Hirofumi Sumi
Summary: This study investigates the elementary reactions occurring within the electrode impedance of proton-conducting ceramic fuel cells. By observing the change in components when the gas on the anode was switched from light hydrogen to heavy hydrogen during the power generation and shutdown phases of the fuel cell, impedance components attributable to the steam production reaction were identified.
JOURNAL OF POWER SOURCES
(2023)
