Authorship：Lead author,　Corresponding author   Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1149/1945-7111/ac6392

Web of Science

researchmap

Authorship：Lead author,　Corresponding author   Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1149/1945-7111/abb565

Web of Science

researchmap

Authorship：Lead author,　Corresponding author   Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1016/j.ijhydene.2018.04.180

Web of Science

Scopus

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：Royal Society of Chemistry (RSC)  

This study demonstrated a Ba-diffusion-assisted sintering strategy that enables complete densification of BaCe0.4Zr0.4Y0.1Yb0.1O3−δ (BCZYYb4411) electrolytes at substantially reduced temperatures (1200–1400 °C) compared to conventional methods (≥1600 °C). By controlling barium carbonate (BaCO3) addition (0–6 wt%) in the anode layer, we facilitated natural diffusion of barium into the electrolyte during co-sintering, eliminating the need for external sintering aids or specialized processing techniques. Systematic microstructural analysis revealed that 2 wt% BaCO3 addition resulted in optimal densification, with grain size increasing from ∼1 μm at 1200 °C to ∼10 μm at 1400 °C. X-ray diffraction confirmed phase purity across all sintering temperatures, while electrochemical impedance spectroscopy demonstrated significantly enhanced proton conductivity (∼5 × 10−3 S cm−1 at 650 °C) and reduced activation energy (0.16 eV) for samples with 2 wt% BaCO3 sintered at 1400 °C. The calculated area-specific resistance values from proton conductivity measurements reached as low as 0.2 Ω cm2, representing a 67% reduction compared to reference samples without BaCO3 addition and comparable to previously reported values for PCFCs sintered at much higher temperatures (1450–1500 °C). This processing innovation addresses fundamental challenges in zirconium-rich proton conductors while preserving their intrinsic electrochemical properties, offering a practical pathway toward more efficient and cost-effective protonic ceramic fuel cell manufacturing.

DOI： 10.1039/d5ta06821e

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：American Chemical Society (ACS)  

Protonic ceramic fuel cells (PCFCs) have great potential to realize ultrahigh energy-conversion efficiency, but higher power density is required for future commercialization. The present work reports the effect of the electrolyte surface condition related to chemical composition such as stoichiometry and element distribution on cathode performance as a key for high-performance PCFCs. In our PCFCs, Ce-free Yb-doped BaZrO3 (BZYb20) electrolytes are prepared using two BZYb20 raw powder materials with different A/B ratios, i.e., Ba0.97Zr0.8Yb0.2O3−δ (Cell-97) and Ba0.99Zr0.8Yb0.2O3−δ (Cell-99). These PCFCs exhibit different element distributions on their BZYb20 electrolyte surfaces, namely, a heterogeneous element distribution with segregation of Yb2O3 for Cell-97 and a homogeneous distribution for Cell-99. The maximum power density of Cell-99 is higher than that of Cell-97 and reaches exceptionally high values, e.g., ∼1.3 W cm–2 at 600 °C and ∼0.7 W cm–2 at 500 °C, which are the highest attained for PCFCs with Ce-free BaZrO3-based electrolytes. The distribution of relaxation times and fitting analysis reveals that the cathode polarization resistance of Cell-99 is much lower than that of Cell-97 even when using the same cathode material. In conclusion, an optimal electrolyte surface condition significantly reduces cathode polarization resistance, leading to the achievement of high-performance PCFCs.

DOI： 10.1021/acsami.5c04806

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：Springer Science and Business Media LLC  

Protonic ceramic fuel cells (PCFCs) should exhibit high performance at intermediate temperatures in the range of 400–600 °C. To reduce the operating temperature, more active air electrodes (positrodes) are needed. In the present work, BaCo0.4Fe0.4Mg0.1Y0.1O3-δ (BCFMY) is investigated as a positrode material for application in PCFCs as well as solid oxide fuel cells (SOFCs). For SOFCs, the polarization resistance ascribed to the oxygen reduction reaction is proportional to pO2−1/4 (pO2: oxygen partial pressure), suggesting that the rate-determining process is the charge transfer on the mixed ionic-electronic conductors. For PCFCs, this polarization resistance is proportional to pO2−1/2, suggesting that the rate-determining process is the oxygen dissociation. The total polarization resistance for the PCFCs using the BCFMY positrode is 0.066 Ωcm2 at 600 °C, lower than that using the BaCo0.4Fe0.4Zr0.1Y0.1O3-δ (BCFZY) positrode. The higher oxygen nonstoichiometry of BCFMY promotes the oxygen dissociation process on the PCFC positrode surface.

DOI： 10.1038/s42004-025-01468-4

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：Elsevier BV  

This study explores Ba diffusion sintering as a novel method to enhance the densification and microstructural properties of BaZr_0.8Yb_0.2O_3–δ (BZYb20) electrolytes for proton-conducting fuel cells (PCFCs). By adding BaCO₃ to the anode and optimizing sintering conditions, significant improvements in electrolyte grain growth and densification are achieved. The sintering mechanism, driven by chemical potential gradients of Ba, Ni, and Yb, involves element migration toward the electrolyte surface and the formation of a Ba–Ni–O phase. Ba diffusion plays a central role, with Ni evaporation and reverse Ba migration contributing to improved microstructure, while Yb diffusion at elevated temperatures leads to porous structure formation. This approach enables the synthesis of dense electrolytes with a uniform grain size of 4–5 μm, doubling proton conductivity compared to BaCO₃–free samples. However, excessive anode densification reduces the H2 supply, which is mitigated by adjusting the NiO–BZYb ratio from 60:40 to 80:20, yielding a peak power density of 0.85 W cm⁻² at 600 °C. The findings highlight Ba diffusion's critical role in controlling microstructure and optimizing PCFC performance, providing a foundation for further sintering optimization.

DOI： 10.1016/j.jpowsour.2025.236198

researchmap

Authorship：Lead author,　Corresponding author   Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：Fuel Cell Development Information Center  

Protonic ceramic fuel cells (PCFCs) are expected to be commercialized as the next generation of fuel cells. For the practical application of PCFCs, high-performance cathode materials have been actively developed. To investigate the applicability of BaCo0.4Fe0.4Mg0.1Y0.1O3-δ (BCFMgY), which has been reported to have higher oxygen permeability than BaCo0.4Fe0.4Zr0.1Y0.1O3-δ (BCFZrY), the power generation characteristics of the PCFCs with BCFMgY cathodes were measured and compared with those of the PCFCs with BCFZrY cathodes. The PCFCs with BCFMgY cathodes exhibited lower electrode resistances and higher power densities than those of the PCFCs with BCFZrY cathodes. Therefore, BCFMgY is a candidate material for a PCFC cathode.

researchmap

Other Link： https://cir.nii.ac.jp/crid/1520021713767261568

Language：English   Publishing type：Research paper (scientific journal)   Publisher：American Chemical Society (ACS)  

Intercalation reactions are highly dependent on the electronic and structural relationships between host and guest materials. It is difficult for divalent ions, such as Mg, to undergo intercalation reactions compared with monovalent cations. However, further development of synthetic techniques for controlling divalent ions is strongly demanded to advance applied chemistry and fundamental physics. In this study, the cointercalation of Mg and H into the transition-metal chalcogenide TaS2 was utilized to obtain bulk polycrystalline MgxHyTaS2. Introduced H can be extracted via postannealing at approximately 400 °C without altering the crystal structure. This study clarified the relationship between superconducting properties and electronic carrier density from the perspectives of calculations and experiments, along with the advantages of using hydride as a multivalent intercalation reaction.

DOI： 10.1021/jacs.4c07294

researchmap

Language：English   Publishing type：Research paper (scientific journal)  

For producing hydrogen from renewable energy, a proton exchange membrane water electrolyzer (PEMWE) is an appealing method offering higher current density and purity of generated hydrogen than other electrolyzers. However, this technique should be further developed to have higher efficiency for utilization. The main issue on reducing the PEMWE performance is the management of generated oxygen bubbles near the reaction site. They persist near the reaction site, inhibit the water supply, and significantly reduce the reaction efficiency. Therefore, how oxygen bubbles are removed from the reaction site should be optimized, however, the mechanism of transport phenomena of oxygen bubbles through the porous transport layer (PTL) has not been clarified. Therefore, in this study, an original cell was developed which allowed us to observe bubble movements inside PTL with a high-speed camera, and the effects of PTL wettability on the oxygen bubble movement were investigated. The PTL wettability drastically affected the PEMWE performance and bubble movement, and hydrophobic PTL reduced the PEMWE performance. The oxygen bubbles tended to stay inside hydrophobic PTL, which might cause lower PEMWE performance.

DOI： 10.1016/j.ijhydene.2024.02.356

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：Elsevier BV  

Overpotential is frequently estimated from electrochemical impedance spectroscopy to evaluate the electrode performance of fuel cells. However, the overpotential of protonic ceramic fuel cells (PCFCs) is possibly underestimated because of hole conductivity in the electrolyte. In the present work, the overpotentials of PCFCs with BaZr0.8Yb0.2O3-δ (BZYb) and BaCe0.4Zr0.4Y0.1Yb0.1O3-δ (BCZYYb) electrolytes are accurately estimated using distribution of relaxation times analysis and an equivalent circuit model with considering a polarization resistance during durability tests. The activation overpotential in an open circuit state is not zero because leakage current flows in the PCFC electrolytes. The activation overpotential of the cell with the BCZYYb electrolyte is higher than that with the BZYb electrolyte because of the interdiffusion of nickel from the Ni-based anode to the cathode and cobalt from the La0.6Sr0.4Co0.2Fe0.8O3-δ cathode to the anode. The compressive internal stress in the electrolyte, determined by the cos α method using X-ray, decreases after discharging. Intergranular cracks formed at the grain boundary through nickel deposition, causing an increase in the ohmic overpotential with time for the both cells with BZYb and BCZYYb electrolytes. The interdiffusion of transition metals from the anode/cathode to the electrolyte in the manufacturing process should be prevented to improve the PCFC durability.

DOI： 10.1016/j.jpowsour.2023.233528

researchmap

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1021/acsaem.2c03733

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.5796/electrochemistry.22-00110

Web of Science

researchmap

Language：Japanese   Publishing type：Research paper, summary (national, other academic conference)  

J-GLOBAL

researchmap

Language：Japanese   Publishing type：Research paper, summary (national, other academic conference)  

J-GLOBAL

researchmap

Language：Japanese   Publishing type：Research paper, summary (national, other academic conference)  

J-GLOBAL

researchmap

Language：Japanese   Publishing type：Research paper, summary (national, other academic conference)  

J-GLOBAL

researchmap

Authorship：Lead author   Language：Japanese   Publishing type：Research paper, summary (national, other academic conference)  

J-GLOBAL

researchmap

Language：Japanese   Publishing type：Research paper, summary (national, other academic conference)  

J-GLOBAL

researchmap

Authorship：Lead author   Language：English   Publishing type：Research paper, summary (international conference)   Publisher：The Electrochemical Society  

In protonic ceramic fuel cells (PCFCs), the use of cobalt-free cathodes is expected to reduce manufacturing costs and improve durability performance. However, cobalt-free cathodes generally tend to have poor power generation performance due to their lower catalytic activity than cobalt-containing cathodes. Therefore, based on a previous study in which higher power generation performance was obtained with SOFCs using La_0.65Ca_0.35FeO_3−δ (LCaF) than with SOFCs using La_0.6Sr_0.4Co_0.2Fe_0.8O_3-δ (LSCF) containing cobalt, we focused on LCaF as a cobalt-free cathode. In this study, we attempted to apply cathodes with LCaF to anode-supported PCFCs using a BaZr_0.8Yb_0.2O_3-δ (BZYb) electrolyte in order to improve the power generation performance and durability of PCFCs.

The proton-conducting oxides used for composite cathodes were investigated. BZYb, which is the same as the electrolyte, was used, but the adhesion between the electrolyte and the cathode was poor. When, BaZr_0.1Ce_0.7Y_0.1Yb_0.1O_3-δ (BZCYYb), which has good sinterability compared with BZYb, was therefore used, reading to improvement in the adhesion. Moreover, process parameters such as composite ratio and sintering temperature were also optimized. As a result, a maximum power density of 0.4 W cm^-2 at an operating temperature of 600 °C was obtained for PCFCs using a composite cathode of LCaF and BZCYYb at a weight ratio of 6:4 sintered at 1100 °C, which is equivalent to PCFCs using a cathode with LSCF. In addition, the voltage drop rate of PCFCs using a composite cathode of LCaF and BZCYYb in the constant current durability test (0.26 A cm^-2) at an operating temperature of 600 °C was 4% per 1000 hours, less than 1/10 that of PCFCs using a cathode with LSCF. Based on these results, LCaF is one of the candidate materials of cobalt-free cathode for PCFCs.

Acknowledgements: This work is based on the results obtained from a project (JPNP20003) commissioned by the New Energy and Industrial Technology Development Organization (NEDO), Japan.

DOI： 10.1149/ma2023-015450mtgabs

researchmap

Authorship：Lead author   Language：Japanese   Publishing type：Research paper, summary (national, other academic conference)  

J-GLOBAL

researchmap

Language：Japanese   Publishing type：Research paper, summary (national, other academic conference)  

J-GLOBAL

researchmap

Authorship：Lead author   Language：Japanese   Publishing type：Research paper, summary (national, other academic conference)  

J-GLOBAL

researchmap

Authorship：Lead author   Language：Japanese   Publishing type：Research paper, summary (national, other academic conference)  

J-GLOBAL

researchmap

Language：Japanese   Publishing type：Research paper, summary (national, other academic conference)  

J-GLOBAL

researchmap

Language：Japanese   Publishing type：Research paper, summary (national, other academic conference)   Publisher：Japan Society of Mechanical Engineers  

In order to expand the practical application range of the proton exchange membrane water electrolyzers (PEMWE), it is necessary to reduce the mass transport loss due to oxygen at the anode. Oxygen transport near the catalyst layer (CL) is thought to have two transport mechanisms, gaseous oxygen and dissolved oxygen. However, as far as we know, there are no reports of experimental investigation of the presence of dissolved oxygen in PEMWE. In this study, the behavior of bubbles floating near CL was observed with a high-speed camera, and the bubble diameter was measured. Even after the bubbles left the CL surface, the bubble diameter continued to increase, confirming the presence of dissolved oxygen and the formation of an oxygen supersaturated region.

DOI： 10.1299/jsmepes.2022.26.d122

researchmap

Authorship：Lead author   Language：English   Publishing type：Research paper, summary (international conference)   Publisher：The Electrochemical Society  

Water electrolysis technology is expected to be essential to build a hydrogen energy system. In particular, proton exchange membrane water electrolyzer (PEMWE) has attracted much attention because of its advantages such as the ability to downsize the equipment and produce high-purity hydrogen [1]. Improving the electrolysis efficiency of PEMWE is needed for future commercialization. One of the serious problems to improve the electrolysis efficiency is the oxygen concentration overpotential [2]. The oxygen concentration overpotential is considered to be not only caused by the generated oxygen bubbles but also by the dissolved oxygen near the anode catalyst electrode. Therefore, it is necessary to investigate the concentration distribution of dissolved oxygen near the anode catalyst electrode and to clarify the mechanism of the oxygen concentration overpotential. Although there are some reports about oxygen bubbles in PEMWE [3], there are few reports which investigate the dissolved oxygen. In this study, due to investigate the existence of the dissolved oxygen, the oxygen bubble behavior near the anode catalyst electrode was observed by using a high-speed camera and measured the oxygen bubble size change.
A single cell with a 1 cm2 active area was used and a transparent acrylic plate was set to the side face of the cell for observing bubbles. Nafion-117 was used as the PEM, and IrOx and Pt/C were used as the anode and the cathode catalysts, respectively. A sintered Ti with Pt plating was used for the anode porous transport layer (PTL) and a carbon paper (TGP-H-060) was used for the cathode PTL. A high-speed camera (Photron, FASTCAM Mini AX100) and two LED lighting apparatuses (Hayashi-Repic, LA-HDF108DA) were used for visualizing. The resolution was 1024 × 1024 pixel, the pixel size was 3.2 μm, and the framerate was 4000 fps. An electrochemical measurement system (Bio-Logic, SP-300) was used for the power supply. Visualization was performed during electrolysis at 30 mA/cm2 with current control.
From the observation of oxygen bubble behavior, the diameter of oxygen bubbles continued to increase until the bubbles left a certain distance even after detached from the anode catalyst. It was considered that the generated oxygen dissolved into the water and there were oxygen supersaturated areas near the anode catalyst electrode.

Reference
[1] M. Carmo et al, Int. J. Hydrogen Energy, 38 (12), 4901-4934 (2013)
[2] J. Kai et al, J. Electrochem. Soc., 166 (4), F246-F254 (2019)
[3] P. J. Kim et al, J. Electrochem. Soc., 167, 124522 (2020)

Acknowledgments
This study was based on results obtained from a project (JPNP14021) commissioned by the New Energy and Industrial Technology Development Organization (NEDO) and also partly supported by JSPS KAKENHI Grant Number 19J20495.

DOI： 10.1149/ma2021-02411230mtgabs

researchmap

Authorship：Lead author   Language：English   Publishing type：Research paper, summary (international conference)   Publisher：The Electrochemical Society  

Proton exchange membrane water electrolysis (PEMWE) has attracted much attention because of its advantages such as the ability to downsize the equipment and produce high-purity hydrogen. For further improvement of the efficiency and durability of PEMWE, it is necessary to separate and examine polarizations. However, it is difficult to separate the anodic and cathodic polarizations by the AC impedance method. Also, it is difficult to separate resistance polarizations by using the reference poles with normal electrodes as shown in Figure 1 (a). Therefore, we are developing a device in which the electrode arrangement of both poles is deliberately shifted and a reference electrode is placed on each of the anode and cathode, as shown in Figure 1 (a) [1]. Since the phenomena in PEMWE are complicated due to the mutual influence of material/electric charge transport and reaction distribution, a multiphysical numerical analysis considering the potential distribution in the shifted electrode structure have been performed using COMSOL Multiphysics 5.4. Ohm's law was solved for the ionic charge transport in the electrolyte and the ionomer of the catalyst layer and also applied to the contact resistance between the electrode and the current collector. Butler-Volmer's equation was used for the activation overpotential at both poles. Figure 1(b) shows the electrolyte potential distribution when the electrode arrangement is shifted, and the potential distribution was completely changed from the (a). Figure 2 shows the relationship between the shift amount of electrode and the potential difference between both reference electrodes. The potential difference between both reference electrodes increases as the shift amount of electrode increases, and the rate of change of the potential difference decreases as the shift amount increases. Design and data processing based on these numerical results will lead to the development of devices that can perform more accurate separation of polarizations.

Reference
1) S. Mitsushima, H. Kashiwagi, K.Nagasawa, and Y. Kuroda, ECS Meet. Abstr., MA2019-02, 1715 (2019).

DOI： 10.1149/ma2020-02382484mtgabs

researchmap

Authorship：Lead author   Language：Japanese   Publishing type：Research paper, summary (national, other academic conference)  

J-GLOBAL

researchmap

Authorship：Lead author   Language：English   Publishing type：Research paper, summary (international conference)   Publisher：The Electrochemical Society  

Introduction
Recently, formic acid is expected as one of the energy career for renewable energy. Especially, direct formic acid fuel cells (DFAFCs) which use formic acid as fuel, have received considerable attention since they can generate higher power density than the other direct liquid fuel cells [1]. However, CO₂ gas is generated in the anode reaction when DFAFCs are operating. If CO₂ bubbles stay in the anode gas diffusion layer (GDL) the mass transport resistance in GDL increases and the power generation performance of DFAFCs decreases with the lapse of time.
In this study, we have investigated the effect of CO₂ bubble distribution on power generation performance by visualizing the CO₂ bubble distribution in DFAFCs during power generation using X-ray CT.

Experimental
A single cell with 1 cm² of active area was used. We used NR-212 as proton exchange membrane, PEM. Pd/C was used for anode catalyst and Pt/C was used for cathode catalyst. Moreover, two types of GDL with different structures of carbon paper and carbon cloth were used.
The voltage sweep was performed at a sweep rate of -5 mV / sec until the cell voltage turned from the open circuit voltage to 0 V, and the cell voltage and current density during the sweep were recorded.
A three-dimensional measurement X-ray CT apparatus (TDM-1000H-Ⅱ (2K), Yamato Scientific) was used for visualizing CO₂ bubble distribution in DFAFCs. It took 15 minutes to visualize and the spatial resolution was 2.7 μm.

Results and discussion
From the measurement of the power generation characteristics, it was found that the maximum current density is higher with carbon cloth GDL than with carbon paper GDL, despite the lower open circuit voltage. In addition, using carbon paper GDL, the gradient of polarization curve became steep in the high current density region. These phenomena are generally considered to be caused by mass transport, and in this experiment it is thought that this is probably due to the effect of bubbles in the anode GDL.
Therefore, in order to investigate the influence of bubbles in the anode GDL, visualization was performed. Fig. 1 shows the CO₂ bubble distribution in the anode GDL at high current density operation using each GDL. These figures are three-dimensional representation of the bubble distribution in the anode GDL averaged over 15 minutes of visualization time. Furthermore, these are top views seen from the vertically upward direction of the GDL plane, the white part indicates that bubbles exist.
As shown in Fig. 1, using carbon paper GDL, bubbles were present under most of the rib and also present under the channel, which was thought to cause the power generation performance degradation due to the mass transport. On the other hand, with the carbon cloth GDL, there were almost no bubbles under the channel, and bubbles and voids were concentrated under the rib. It is considered that in the carbon cloth, the bubbles were concentrated in part and the discharge path of the bubbles was formed, so that the bubbles were efficiently discharged and the power generation performance did not decrease even in the high current density region.

Reference
1) Y. Zhu, Z. Khan, R.I. Masel, Journal of Power Sources, 139, 15-20 (2005)

DOI： 10.1149/ma2019-02/33/1458

researchmap

Language：Japanese   Publishing type：Research paper, summary (national, other academic conference)   Publisher：Japan Society of Mechanical Engineers  

In order to construct a hydrogen energy system, water electrolysis technology for converting renewable energy into hydrogen has recently attracted attention. In particular, a proton exchange membrane (PEM) water electrolysis can be operated at high current density and can produce high purity hydrogen compared to other water electrolysis techniques. However, increasing th0e efficiency is indispensable for putting PEM water electrolysis into practical use in the future. One of the serious problems is that the staying of generated oxygen bubbles in the reaction site inhibits the water supply and significantly reduces the reaction efficiency. However, the mechanism of generation, growth and detachment of oxygen bubbles on the reaction site in the PEM electrolyzer has not been clarified. Therefore, in this research, in order to understand the two-phase flow phenomenon of this oxygen bubble, the behavior of the bubbles was observed using a visible light high-speed camera and a visualized electrolysis cell.

DOI： 10.1299/jsmepes.2019.24.c113

researchmap

Authorship：Lead author   Language：Japanese   Publishing type：Research paper, summary (national, other academic conference)   Publisher：日本伝熱学会  

J-GLOBAL

researchmap

Authorship：Lead author   Language：Japanese   Publishing type：Research paper, summary (national, other academic conference)   Publisher：Japan Society of Mechanical Engineers  

Recently, formic acid is expected as one of the energy career of renewable energy. Especially, A direct formic acid fuel cell, DFAFC, has received considerable attention since it can generate higher power density than the other direct liquid fuel cells and its power density is comparable to that of a polymer electrolyte fuel cell, PEFC, operated with hydrogen and oxygen at room temperature. However, CO2 gas is generated in the anode reaction when a DFAFC is operating. If CO2 bubbles stay in the anode gas diffusion layer, GDL, the mass transport resistance in a GDL increases and the generated power of a DFAFC decreases with the lapse of time. Furthermore, the gas-liquid two-phase flow behavior in a GDL, which is porous material, is not clear. In this study, we investigated the effect of Anode GDL configuration on power generation characteristics and bubbles behavior by visualizing CO2 bubbles distribution using Xray CT.

DOI： 10.1299/jsmepes.2018.23.c115

researchmap

Language：Japanese   Publishing type：Research paper, summary (national, other academic conference)   Publisher：日本伝熱学会  

J-GLOBAL

researchmap

Event date： 2019.10

Language：English   Presentation type：Oral presentation (general)  

Venue：Atlanta, GA   Country：United States  

researchmap

Event date： 2018.6

Language：English   Presentation type：Oral presentation (general)  

Venue：Yokohama   Country：Japan  

researchmap

Event date： 2026.3

Language：English   Presentation type：Poster presentation  

Venue：Kyoto   Country：Japan  

researchmap

Event date： 2026.3

Language：English   Presentation type：Oral presentation (general)  

Venue：Noda   Country：Japan  

researchmap

Event date： 2026.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：Kyoto   Country：Japan  

researchmap

Event date： 2025.11

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：Tokyo   Country：Japan  

researchmap

Event date： 2025.9

Language：English   Presentation type：Oral presentation (general)  

Venue：Tottori   Country：Japan  

researchmap

Event date： 2025.9

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：Tottori   Country：Japan  

researchmap

Event date： 2025.5

Language：English   Presentation type：Oral presentation (invited, special)  

Venue：Vancouver, BC   Country：Canada  

researchmap

Event date： 2025.5

Language：English   Presentation type：Oral presentation (invited, special)  

Venue：Vancouver, BC   Country：Canada  

researchmap

Event date： 2025.1

Language：English   Presentation type：Oral presentation (general)  

Venue：Daytona Beach, FL   Country：United States  

researchmap

Event date： 2024.12

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：Tokyo   Country：Japan  

researchmap

Event date： 2024.12

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：Tokyo   Country：Japan  

researchmap

Event date： 2024.12

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：Osaka   Country：Japan  

researchmap

Event date： 2024.12

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：Osaka   Country：Japan  

researchmap

Event date： 2024.10

Language：English   Presentation type：Oral presentation (general)  

Venue：Sapporo   Country：Japan  

researchmap

Event date： 2024.9

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：Nagoya   Country：Japan  

researchmap

Event date： 2024.9

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：Nagoya   Country：Japan  

researchmap

Event date： 2024.9

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：Nagoya   Country：Japan  

researchmap

Event date： 2024.6

Language：English   Presentation type：Oral presentation (keynote)  

Venue：Dijon   Country：France  

researchmap

Event date： 2024.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：Kumamoto   Country：Japan  

researchmap

Event date： 2024.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：Nagoya   Country：Japan  

researchmap

Event date： 2023.12

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：Tokyo   Country：Japan  

researchmap

Event date： 2023.11

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：Sapporo   Country：Japan  

researchmap

Event date： 2023.11

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：Hokkaido   Country：Japan  

researchmap

Event date： 2023.11

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：Hokkaido   Country：Japan  

researchmap

Event date： 2023.9

Language：English   Presentation type：Oral presentation (general)  

Venue：Fukuoka   Country：Japan  

researchmap

Event date： 2023.9

Language：English   Presentation type：Oral presentation (general)  

Venue：Fukuoka   Country：Japan  

researchmap

Event date： 2023.9

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：Kyoto   Country：Japan  

researchmap

Event date： 2023.9

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：Kyoto   Country：Japan  

researchmap

Event date： 2023.9

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：Kyoto   Country：Japan  

researchmap

Event date： 2023.8

Language：English   Presentation type：Poster presentation  

Venue：Yamagata   Country：Japan  

researchmap

Event date： 2023.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：Yokohama   Country：Japan  

researchmap

Event date： 2022.12

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：Tokyo   Country：Japan  

researchmap

Event date： 2022.12

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：Sendai   Country：Japan  

researchmap

Event date： 2022.12

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：Online   Country：Japan  

researchmap

Event date： 2022.9

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：Tokushima   Country：Japan  

researchmap

Event date： 2022.9

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：Tokushima   Country：Japan  

researchmap

Event date： 2022.9

Language：English   Presentation type：Oral presentation (general)  

Venue：Nagoya   Country：Japan  

researchmap

Event date： 2022.7

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：Saga   Country：Japan  

researchmap

Event date： 2022.3

Language：English   Presentation type：Oral presentation (general)  

Venue：Online   Country：China  

researchmap

Event date： 2021.10

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：Online   Country：Japan  

researchmap

Event date： 2020.6

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：Online   Country：Japan  

researchmap

Event date： 2019.6

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：Tokyo   Country：Japan  

researchmap

Event date： 2019.5

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：Tokushima   Country：Japan  

researchmap

Event date： 2018.11

Language：English   Presentation type：Poster presentation  

Venue：Baltimore, MD   Country：United States  

researchmap

Event date： 2018.6

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：Ube   Country：Japan  

Recently, formic acid is expected as one of the energy career of renewable energy. Especially, A direct formic acid fuel cell, DFAFC, has received considerable attention since it can generate higher power density than the other direct liquid fuel cells and its power density is comparable to that of a polymer electrolyte fuel cell, PEFC, operated with hydrogen and oxygen at room temperature. However, CO2 gas is generated in the anode reaction when a DFAFC is operating. If CO2 bubbles stay in the anode gas diffusion layer, GDL, the mass transport resistance in a GDL increases and the generated power of a DFAFC decreases with the lapse of time. Furthermore, the gas-liquid two-phase flow behavior in a GDL, which is porous material, is not clear. In this study, we investigated the effect of Anode GDL configuration on power generation characteristics and bubbles behavior by visualizing CO2 bubbles distribution using Xray CT.

researchmap

Event date： 2017.8

Language：English   Presentation type：Poster presentation  

Venue：Yokohama   Country：Japan  

researchmap

Event date： 2017.5

Language：Japanese   Presentation type：Poster presentation  

Venue：Omiya   Country：Japan  

researchmap