Article
Chemistry, Physical
Donglin Han, Xin Liu, Tor Svendsen Bjorheim, Tetsuya Uda
Summary: Increasing Ce content in Y-doped BaZrO3, BaCeO3, and their solid solutions stabilizes protons, increases oxide ion conductivity, and decreases hole conduction, thereby enhancing the ionic conduction of BZCY20 for improved performance in fuel cells and electrolysis cells.
ADVANCED ENERGY MATERIALS
(2021)
Article
Materials Science, Ceramics
D. Ciria, M. Jimenez-Melendo, V. Aubin, G. Dezanneau
Summary: The high-temperature mechanical properties of yttrium-doped barium zirconate obtained by two different routes are investigated in this study. The material shows a gradual transition from brittle-to-ductile behavior as temperature increases and/or strain rate decreases during compression tests.
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
(2021)
Article
Chemistry, Physical
Donglin Han, Lulu Jiang, Peng Zhong
Summary: This study improved the phase compatibility between BaZrO3-based electrolyte and NiO electrode substrate by adjusting the electrolyte composition and selecting proper dopants. However, high temperature heat treatment during co-sintering led to Ni diffusion into the electrolyte layer, negatively impacting performance.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2021)
Article
Chemistry, Physical
Xuejiao Li, Lei Zhang, Liuming Yan, Meilin Liu, Zhongfeng Tang
Summary: In this study, reactive molecular dynamics simulations were used to investigate the defect structures and ion transport mechanism of yttrium-doped barium zirconate (BZY) electrolyte. The study found that a slightly elongated O-O distance in the hydrated system promotes proton hopping and the weak interaction between dopants and protons facilitates proton diffusion in the dislocation system. The dopant concentration and proton concentration were identified as important factors affecting proton conduction.
ACS APPLIED ENERGY MATERIALS
(2022)
Article
Chemistry, Physical
Yifeng Li, Shihang Guo, Donglin Han
Summary: In this study, researchers found that there was good chemical compatibility between NiO and BaZr0.8Yb0.2O3 or BaZr0.8Tm0.2O3 at 1500 degrees Celsius. Additionally, BaZr0.8Y0.1Yb0.1O3 and BaZr0.8Y0.12Yb0.08O3 showed good chemical compatibility with NiO at 1350 and 1500 degrees Celsius. The co-doped BaZrzYxYb0.2-xO3 electrolyte exhibited higher conductivity compared to BaZr0.8Y0.2O3, with BaZr0.8Y0.1Yb0.1O3 showing the highest conductivity.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2023)
Review
Green & Sustainable Science & Technology
Arpan Kumar Nayak, Ananta Sasmal
Summary: Recently, Perovskite oxides have been widely used in electrochemical conversion devices like Proton conducting Ceramic Fuel Cells (PCFC). Among them, barium zirconate (BaZrO3) is considered as a promising PCFC electrolyte material due to its excellent chemical stability and rapid proton diffusion. By altering the synthesis parameters and conditions, various novel synthesis techniques have been employed to prepare barium zirconate (BaZrO3) with enhanced material properties. Doping with trivalent impurities improves proton mobility and increases proton conductivity at reduced temperature, thereby expanding the scope of PCFC application with optimized output performance.
JOURNAL OF CLEANER PRODUCTION
(2023)
Article
Chemistry, Physical
Tomohiro Kuroha, Yoshiki Niina, Mizuki Shudo, Go Sakai, Naoki Matsunaga, Takehito Goto, Kosuke Yamauchi, Yuichi Mikami, Yuji Okuyama
Summary: This study investigates ceramic tape-casting and anode electrolyte co-firing for large-scale manufacturing of protonic ceramic fuel cells. It confirms the reactivity of certain metal elements with the anode material and reveals that NiO doping decreases the proton conductivity of all materials. The research identifies the suitable material BZYb20 for this fabrication technique.
JOURNAL OF POWER SOURCES
(2021)
Article
Chemistry, Physical
Isabel Antunes, Domingo Perez-Coll, Narendar Nasani, Helena S. Soares, Glenn C. Mather, Jorge R. Frade, Duncan P. Fagg
Summary: Mechanosynthesis has been shown to be an efficient method to prepare Ba(Zr,Y)O3-δ materials, producing pure powders with good densification and grain growth, and high homogeneity. Comparisons with materials made by other processing routes demonstrate that the materials synthesized by mechanosynthesis exhibit good electrical properties and no phase separation.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2021)
Article
Chemistry, Physical
Sebastian Eisele, Fabian M. Draber, Steffen Grieshammer
Summary: This study investigates the thermodynamics of water uptake into yttrium-doped barium zirconate on a microscopic level, focusing on ionic defect interactions. Monte Carlo simulations based on first-principles energy calculations reveal that ionic defect interactions are the primary reason for non-ideality observed in experiments under varying conditions. Activity coefficient quotients obtained from mass action law provide a link between ideal and real models for data evaluation and theoretical calculations.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2021)
Article
Chemistry, Physical
Amir Masoud Dayaghi, Reidar Haugsrud, Marit Stange, Yngve Larring, Ragnar Strandbakke, Truls Norby
Summary: Proton conducting oxide electrolytes with increased thermal expansion coefficient by partially substituting Ba and Zr with Sr and Ce while maintaining a cubic structure and minor n-type conduction, have potential applications in proton ceramic electrochemical cells at intermediate temperatures.
SOLID STATE IONICS
(2021)
Article
Energy & Fuels
Junji Hyodo, Yoshihiro Yamazaki
Summary: Proton-conducting oxides have great potential in environmentally friendly electrochemical cells, and research has found that mechanical strain significantly affects proton conduction and diffusion rates.
JOURNAL OF PHYSICS-ENERGY
(2022)
Article
Materials Science, Ceramics
Celso Antonio Goulart, Lucia Adriana Villas Boas, Marcio Raymundo Morelli, Dulcina Pinatti Ferreira de Souza
Summary: The effects of Yttrium-doped Barium Zirconate (BZY) synthesis steps by solid-state reaction and the number of starting reactants on the characteristics of the synthesized ceramic powders were investigated in this study. It was found that utilizing residual reactants could improve densification during sintering. Additionally, the addition of low concentration ZnO as sintering aid led to different microstructural and electrical conductivity results compared to undoped samples.
CERAMICS INTERNATIONAL
(2021)
Article
Chemistry, Physical
Maria A. Gomez, Sophia Brooks-Randall, Gianna Cai, Juniper Glass-Klaiber, Yuxin Jiang, Sungeun Jo, Ziqing Lin, Shiyun Lin, Marsophia Marcellus, Hong Anh Nguyen, Trang Pham, Yujing Wang, Fangyi Zhai, Parikshita Gya, Samira Khan
Summary: Understanding the relationship between acceptor dopant size and proton conductivity in barium zirconate is crucial for optimizing efficiency in fuel cell materials. Different proton conduction pathways involving various dopant defects have been explored, with ScZr' defect pathways being a new area of study. BaSc0.125Zr0.875O3 exhibits an intermediate overall conduction barrier limited by trapping, which may be improved with increased oxygen vacancy concentration.
JOURNAL OF CHEMICAL PHYSICS
(2021)
Article
Chemistry, Multidisciplinary
Monica Susana Campos Covarrubias, Mantas Sriubas, Kristina Bockute, Aurelija Poskaite, Rokas Vazgys, Maria Gazda, Giedrius Laukaitis
Summary: This study investigated the formation of doped/undoped BCO and BZO thin films using e-beam vapor deposition and analyzed the influence of the formation parameters on the microstructural and crystallographic properties. The formed thin films were found to be highly dense and consisted of oriented columnar grains.
APPLIED SCIENCES-BASEL
(2022)
Article
Chemistry, Physical
Zhaoling Wei, Jinpeng Wang, Xinchao Yu, Zhongbiao Li, Yujun Zhao, Jinling Chai
Summary: The study prepared a new triple-conducting BFCY perovskite cathode using the Pechini sol-gel process and found that it has good thermal expansion coefficient and chemical compatibility. The construction of a BFCY-BCFY composite cathode with good cathode/electrolyte interface adhesion was successful, and the single cell achieved low polarization resistance and high peak power density at 700 degrees Celsius.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2021)
Article
Materials Science, Ceramics
Hiroyuki Shimada, Yuki Yamaguchi, Hirofumi Sumi, Yasunobu Mizutani
Summary: By modifying the cathode/electrolyte interface with a porous BZCYYb interlayer (PBI) in PCFCs, the cathode performance has been significantly improved, achieving high power density at lower temperatures. The use of this interlayer enhances the cathode/electrolyte interfacial structure and increases the triple-phase boundary, resulting in improved overall performance of the fuel cell.
CERAMICS INTERNATIONAL
(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
Materials Science, Ceramics
Hisashi Nakane, Hiroyuki Shimada, Kunimasa Sagata, Yuki Yamaguchi
Summary: The research finds that ceramic sealing agents exhibit stable sealing properties in a wide temperature range for high-temperature solid oxide cells, with the characteristics of low-temperature curing and optimized thermal expansion coefficient, making them suitable candidates for SOC sealing materials.
CERAMICS INTERNATIONAL
(2022)
Article
Electrochemistry
Katsuhiro Nomura, Hiroyuki Shimada, Yuki Yamaguchi, Woosuck Shin, Yuji Okuyama, Yasunobu Mizutani
Summary: The phase transitions, thermal expansions, chemical expansions, and CO2 resistances of two different compositions of perovskite materials were investigated. The results show that the composition of the materials plays an important role in determining their properties.
JOURNAL OF THE ELECTROCHEMICAL SOCIETY
(2022)
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
Thermodynamics
Kunpeng Li, Hiroyuki Shimada, Yasunobu Mizutani, Yuji Okuyama, Takuto Araki
Summary: By combining numerical methods with experiments, we developed high-performance and chemically stable Ce-free protonic ceramic fuel cells. This study can accurately predict the performance of cells under different conditions without the need for conducting additional experiments.
ENERGY CONVERSION AND MANAGEMENT
(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
Electrochemistry
Yuji Okuyama, Yoshiaki Harada, Yuichi Mikami, Kosuke Yamauchi, Tomohiro Kuroha, Hiroyuki Shimada, Yuki Yamaguchi, Yasunobu Mizutani
Summary: A proton current detector was developed using a proton conducting oxide to measure the proton current in a PCFC. An apparatus based on the electromotive force of an electrochemical cell was used to measure the amount of proton current flowing in the PCFC. The hydrogen ion current was determined by monitoring the water vapor pressure.
JOURNAL OF THE ELECTROCHEMICAL SOCIETY
(2023)
