| 中島 裕典（なかじま ひろのり） | データ更新日：2024.04.18 |
助教 ／
工学研究院
機械工学部門
水素利用工学講座
| 1. | Hironori Nakajima, Mass Transfer - Advanced Aspects, 10.5772/1432, 2011.11. |
| 2. | Hironori Nakajima, Mass Transfer - Advances in Sustainable Energy and Environment Oriented Numerical Modeling, 10.5772/3372, 2013.07. |
| 3. | Yan Ming Hao, Hironori Nakajima, Akiko Inada, Kazunari Sasaki, Kohei Ito, Separation and Characterization of Overpotentials in Electrochemical Hydrogen Pump with a Reference Electrode, ECS Meeting Abstracts, 10.1149/MA2016-02/38/2371, {MA}2016-02, 38, 2371-2371, 2016.09. |
| 4. | Hua Li, Hironori Nakajima, Kohei Ito, Optimization of Annealing Catalyst Powder for High Temperature PEMWE, ECS Meeting Abstracts, 10.1149/MA2016-02/38/2420, {MA}2016-02, 38, 2420-2420, 2016.09. |
| 5. | Tatsuhiro Ochiai, Hironori Nakajima, Takahiro Karimata, Tatsumi Kitahara, Kohei Ito, Yusuke Ogura, Jun Shimano, In-Situ Analysis of the in-Plane Current Distributions in an Electrolyte-Supported Planar Solid Oxide Fuel Cell By Segmented Electrodes, ECS Meeting Abstracts, 10.1149/MA2016-02/53/4015, {MA}2016-02, 53, 4015-4015, 2016.09. |
| 6. | Tatsumi Kitahara, Hironori Nakajima, Kenta Ishikawa, Gas Diffusion Layer Coated with a Microporous Layer Containing Hydrophilic CNTs to Enhance PEFC Performance without Humidification Using Anode Gas Recirculation, ECS Meeting Abstracts, 10.1149/MA2016-02/38/2748, {MA}2016-02, 38, 2748-2748, 2016.09. |
| 7. | Kohei Ito, Kenji Terabaru, Hua Li, Akiko Inada, Hironori Nakajima, Challenging of Reducing Electrolysis Voltage by Superimposing Boiling on PEMWE–A Thermodynamic Coupling–, ECS Transactions, 10.1149/08008.1117ecst, 80, 8, 1117-1125, 2017.08. |
| 8. | Kohei Ito, Kenji Terabaru, Hua Li, Akiko Inada, Hironori Nakajima, Challenging of Reducing Electrolysis Voltage by Superimposing Boiling on PEMWE–A Thermodynamic Coupling–, ECS Meeting Abstracts, 10.1149/MA2017-02/37/1670, {MA}2017-02, 37, 1670-1670, 2017.09. |
| 9. | Tatsumi Kitahara, Hironori Nakajima, Gas Diffusion Media and NaCl Contamination of Polymer Electrolyte Fuel Cells for Marine Applications, ECS Meeting Abstracts, 10.1149/MA2018-02/42/1424, 2018.07. |
| 10. | Tatsumi Kitahara, Hironori Nakajima, Gas Diffusion Media and NaCl Contamination of Polymer Electrolyte Fuel Cells for Marine Applications, ECS Transactions, 10.1149/08613.0271ecst, 2018.07. |
| 11. | Kohei Sasaki, Hironori Nakajima, Tatsumi Kitahara, Influence of Carbon Deposition on the Current Distribution in an Anode-Supported Planar Solid Oxide Fuel Cell In-Situ Assessed by Segmented Electrodes, ECS Transactions, 10.1149/09101.0549ecst, 2019.07. |
| 12. | Yoshihiro Iwanaga, Hironori Nakajima, Kohei Ito, Electrolytic Performance of a Cathode-Supported Honeycomb Solid Oxide Electrolysis Cell, ECS Meeting Abstracts, 10.1149/MA2019-02/54/2334, {MA}2019-02, 54, 2334-2334, 2019.09. |
| 13. | Kohei Sasaki, Hironori Nakajima, Tatsumi Kitahara, Electrochemical Impedance Spectroscopy Analysis of Carbon Deposition in an Anode-Supported Planar Solid Oxide Fuel Cell By Segmented Electrodes, ECS Meeting Abstracts, 10.1149/MA2019-02/54/2340, {MA}2019-02, 54, 2340-2340, 2019.09. |
| 14. | Iwasaki Shintaro, Hironori Nakajima, Tatsumi Kitahara, Pore Network Modeling of Microporous Layers for Polymer Electrolyte Fuel Cells, ECS Meeting Abstracts, 10.1149/MA2020-02533841mtgabs, {MA}2020-02, 53, 3841-3841, 2020.11. |
| 15. | Tasuku Higa, Hironori Nakajima, Fabrication and Evaluation of an Anode-Supported Honeycomb SOFC with Built-in Catalytic Partial Oxidation Micro-Reformer, ECS Meeting Abstracts, 10.1149/MA2020-02533842mtgabs, {MA}2020-02, 53, 3842-3842, 2020.11. |
| 16. | Hironori Nakajima, Experimental and Numerical Analyses of Mass Transfer in Solid Oxide Cells, ECS Meeting Abstracts, 10.1149/MA2020-02402515mtgabs, {MA}2020-02, 40, 2515-2515, 2020.11. |
| 17. | Koichiro Otaguro, Ryo Saito, Hironori Nakajima, Kohei Ito, Analysis of Influence of Cathode Current Collector Wettability on Current Loss By Crossover Evaluation Both at Cathode and Anode Side, ECS Meeting Abstracts, 10.1149/MA2020-02382473mtgabs, {MA}2020-02, 38, 2473-2473, 2020.11. |
| 18. | Tasuku Higa, Hironori Nakajima, Evaluation of Three-Dimensional Placement of Built-in Catalytic Partial Oxidation Catalyst in an Anode-Supported Honeycomb SOFC, ECS Meeting Abstracts, 10.1149/MA2021-031252mtgabs, {MA}2021-03, 1, 252-252, 2021.07. |
| 19. | Manh Ngo, Kohei Ito, Hironori Nakajima, Takahiro Karimata, Tomoko Saitou, Visualization of Combustion in Polymer-Electrolyte-Membrane Fuel Cell - Mechanism on Abrupt Change from Moderate to Accidental Scale-, ECS Meeting Abstracts, 10.1149/MA2022-02391407mtgabs, 2022.10. |
| 20. | Peng Wang, Hironori Nakajima, Tatsumi Kitahara, (Digital Presentation) Effect of the Hydrophilic Layer in Double Microporous Layer Coated Gas Diffusion Layer on PEFC Performance, ECS Transactions, 10.1149/10909.0085ecst, 2022.09. |
| 21. | Peng Wang, Hironori Nakajima, Tatsumi Kitahara, (Digital Presentation) Effect of the Hydrophilic Layer in Double Microporous Layer Coated Gas Diffusion Layer on PEFC Performance, ECS Meeting Abstracts, 10.1149/MA2022-02391383mtgabs, 2022.10. |
| 22. | Hironori Nakajima, Henrik Ekström, Asuka Shima, Yoshitsugu Sone, Göran Lindbergh, Water Transport Modeling in a Microporous Layer for a Polymer Electrolyte Membrane Water Electrolyzer Having a Gas-Liquid Separating Interdigitated Flow Field, ECS Transactions, 10.1149/11204.0273ecst, 2023.09. |
| 23. | Linjun Li, Hironori Nakajima, Atsushi Moriyama, Kohei Ito, Theoretical analysis of the effect of boiling on the electrolysis voltage of a polymer electrolyte membrane water electrolyzer (PEMWE), Journal of Power Sources, 10.1016/j.jpowsour.2023.233143, 2023.08. |
| 24. | Hironori Nakajima, Jin Yamashita, Keiichi Okai, Takayuki Kojima, Numerical Modeling of a Pressurized Solid Oxide Fuel Cell for Electric Aircraft, ECS Meeting Abstracts, 10.1149/MA2023-01562726mtgabs, 2023.08. |
| 25. | Shunji Kubota, Hironori Nakajima, Motohiko Sato, Asuka Shima, Masato Sakurai, Yoshitsugu Sone, Liquid Water Permeability in a Hydrophobic Microporous Layer for the Anode Interdigitated Flow Field of a Gas-Liquid Separating Polymer Electrolyte Membrane Water Electrolyzer, ECS Transactions, 10.1149/11204.0207ecst, 2023.09. |
| 26. | Yoshitsugu Sone, Asuka Shima, Omar Samuel Mendoza-Hernandez, Hironori Nakajima, Hiroshige Matsumoto, Mitsuhiro Inoue, Takayuki Abe, Hybrid Reactor by the Combination of Water Electolyzer with Methanation Reactor Targeting the Space and Terrestrial Applications, ECS Meeting Abstracts, 10.1149/MA2023-02663198mtgabs, 2023.12. |
| 27. | Hua Li, Senrui Huang, Chao Guan, Huixuan Wang, Hironori Nakajima, Kohei Ito, Yulin Wang, Experimental optimization of the Nafion® ionomer content in the catalyst layer for polymer electrolyte membrane water electrolysis at high temperatures, Frontiers in Energy Research, 10.3389/fenrg.2023.1313451, 11, 2023.12, The polymer electrolyte membrane water electrolysis (PEMWE) performance is closely related to the Nafion® ionomer content in catalyst layers (CLs). This study experimentally investigates the impact of anode and cathode Nafion® ionomer contents on the PEMWE performance at high temperatures. The Nafion® ionomer content is 5–30 wt% on both anode and cathode sides, while the temperature and operating pressure change from 80°C to 120°C and 0.1 MPa to 0.3 MPa, respectively. Experimental results reveal that elevated temperature and operating pressure can remarkably promote the performance of PEMWE with a reasonable Nafion® ionomer content and without dehydrating the membrane at 120°C and 0.3 MPa. However, the PEMWE performance deteriorates as the Nafion® ionomer content is too low. The anode Nafion® ionomer content has a relatively great impact on ohmic resistance, concentration, and activation overpotential, especially the concentration overpotential. Nevertheless, the cathode Nafion® ionomer content only affects the ohmic resistance. Finally, under the operating conditions of 120°C and 0.3 MPa, employing a Nafion ionomer content of 10 wt% in the anode–cathode sides minimizes the electrolysis voltage to 2.18 V at 18 A/cm2.. |
| 28. | Peng Wang, Hironori Nakajima, Tatsumi Kitahara, Effect of Hydrophilic Layer in Double Microporous Layer Coated Gas Diffusion Layer on Performance of a Polymer Electrolyte Fuel Cell, Journal of The Electrochemical Society, 10.1149/1945-7111/ad13da, 2023.12. |
| 29. | Xuefeng Wang, Hironori Nakajima, Yoshihiro Iwanaga, Kohei Ito, Numerical and experimental investigation of a cathode-supported microtubular solid oxide electrolysis cell from current and temperature variations in-situ assessed with electrode-segmentation method, Journal of Energy Storage, 10.1016/j.est.2023.108459, 72, 108459-108459, 2023.11. |
| 30. | Yingtian Chi, Kentaro Yokoo, Hironori Nakajima, Kohei Ito, Jin Lin, Yonghua Song, Optimizing the homogeneity and efficiency of a solid oxide electrolysis cell based on multiphysics simulation and data-driven surrogate model, Journal of Power Sources, 10.1016/j.jpowsour.2023.232760, 562, 232760-232760, 2023.02. |
| 31. | Xuesong Wei, Takumi Kakimoto, Yutaro Umehara, Hironori Nakajima, Kohei Ito, Hiromitsu Inagaki, Shoji Mori, Improvement of the critical current density of alkaline water electrolysis based on the hydrodynamic similarity between boiling and water electrolysis, International Journal of Heat and Mass Transfer, 10.1016/j.ijheatmasstransfer.2023.124420, 214, 124420-124420, 2023.11. |
| 32. | Phi Manh Ngo, Hironori Nakajima, Takahiro Karimata, Tomoko Saitou, Kohei Ito, Investigation of in-situ catalytic combustion in polymer-electrolyte-membrane fuel cell during combined chemical and mechanical stress test, Journal of Power Sources, 10.1016/j.jpowsour.2022.231803, 542, 231803-231803, 2022.09. |
| 33. | Hironori Nakajima, Shintaro Iwasaki, Tatsumi Kitahara, Pore network modeling of a microporous layer for polymer electrolyte fuel cells under wet conditions, Journal of Power Sources, 10.1016/j.jpowsour.2023.232677, 560, 232677-232677, 2023.03. |
| 34. | Munekazu Motoyama, Makoto Ejiri, Hironori Nakajima, Yasutoshi Iriyama, Mechanical Failure of Cu Current Collector Films Affecting Li Plating/Stripping Cycles at Cu/LiPON Interfaces, Journal of The Electrochemical Society, 10.1149/1945-7111/aca79d, 170, 1, 012503-012503, 2023.01, Herein an electro-chemo-mechanical theory, which states that mechanical work to deform a Cu current collector (CC) film influences the nucleation overpotential (ηnc) for Li nucleation at the Cu CC film/lithium phosphorus oxynitride (LiPON) electrolyte interface, is examined. The finite element method (FEM) simulated the mechanical pressure that the CC film exerted on the Li nuclei at the Cu/LiPON interface, and the results agreed with the trends in our previous study. In situ scanning electron microscopy (SEM) observations for cycling of Li plating/stripping showed that Li repeatedly nucleated and grew at positions where the CC film was locally fractured, and ηnc decreased with repeated Li plating/stripping because the mechanical pressure to the Li nuclei was no longer applied at locations where the CC film was fractured. On the other hand, for thicker CC films that did not crack, ηnc exhibited nearly consistent values in the Li plating/stripping cycles. Consequently, the experimental results in this study supported our nucleation theory for a metal/solid-state-electrolyte interfacial system.. |
| 35. | E.M. Can, A. Mufundirwa, P. Wang, S. Iwasaki, T. Kitahara, H. Nakajima, M. Nishihara, K. Sasaki, S.M. Lyth, Superhydrophobic fluorinated carbon powders for improved water management in hydrogen fuel cells, Journal of Power Sources, 10.1016/j.jpowsour.2022.232098, 548, 232098-232098, 2022.11. |
| 36. | Hironori NAKAJIMA, Asuka SHIMA, Mitsuhiro INOUE, Takayuki ABE, Hiroshige MATSUMOTO, Omar Samuel, MENDOZA-HERNANDEZ, Yoshitsugu SONE, Three-Dimensional Numerical Modeling of a Low-Temperature Sabatier Reactor for a Tandem System of CO2 Methanation and Polymer Electrolyte Membrane Water Electrolysis, Electrochemistry, 10.5796/electrochemistry.22-00035, 90, 6, 067008, 2022.06. |
| 37. | Yuto Wakita, Yuya Tachikawa, Hironori Nakajima, Shigeru Hamada, Kohei Ito, Visualization and mechanical strength of glass seal in planar type solid oxide fuel cells, International Journal of Hydrogen Energy, 10.1016/j.ijhydene.2020.05.153, 45, 41, 21754-21766, 2020.08. |
| 38. | Hironori NAKAJIMA, Veeramani VEDIYAPPAN, Hiroshige MATSUMOTO, Motohiko SATO, Omar Samuel MENDOZA-HERNANDEZ, Asuka SHIMA, Yoshitsugu SONE, Water Transport Analysis in a Polymer Electrolyte Electrolysis Cell Comprised of Gas/Liquid Separating Interdigitated Flow Fields（宇宙・地上用気液分離型水電解）, Electrochemistry, 10.5796/electrochemistry.21-00097, 90, 1, 017002, 2021.10, [URL], PEM水電解，ガス拡散層、撥水MPL、毛管圧、飽和度、微小重力，空気再生，有人宇宙探査，PEM water electrolyzer, GDL, Hydrophobic MPL, Capillary pressure, Saturation, Microgravity, Manned space mission, Closed-loop air revitalization. |
| 39. | Wang Xuefeng, Hironori Nakajima, Kohei Ito, Spatial Current and Temperature Variations in a Microtubular Solid Oxide Electrolysis Cell In-Situ Analyzed with Electrode-Segmentation Method, ECS Transactions, 10.1149/10301.0643ecst, 103, 1, 643-651, 2021.07. |
| 40. | Shintaro Iwasaki, Hironori Nakajima, Tatsumi Kitahara, Pore Network Modeling of Hydrophilic / Hydrophobic Composite Microporous Layers for Polymer Electrolyte Fuel Cells, ECS Transactions, 10.1149/10408.0157ecst, 104, 8, 157-160, 2021.10, Liquid water accumulated in the catalyst layer (CL) and gas diffusion layer (GDL) of a polymer electrolyte fuel cell (PEFC, PEMFC) results in performance deterioration due to the inhibition of oxygen transport to the cathode CL (Flooding). To enhance the drainage in the GDL, a microporous layer (MPL) employed at the CL side of the GDL substrate is effective. Hydrophilic/hydrophobic composite MPLs in-house applied have mitigated the flooding, while the mechanism was not well clarified. A pore network model (PNM) of our in-house hydrophobic MPLs is modified for the analysis of the composite MPL.. |
| 41. | Hironori Nakajima, Shintaro Iwasaki, Tatsumi Kitahara, Mass Transfer in Microporous Layers for Polymer Electrolyte Fuel Cells Analyzed with Pore Network Modeling, ECS Transactions, 10.1149/10408.0129ecst, 104, 8, 129-135, 2021.10, Open PNM, Leverett function, Wetting liquid saturation, Concentration boundary layer, Relative permeability, FIB-SEM, Watershed. |
| 42. | Peng Wang, Hironori Nakajima, Tatsumi Kitahara, Hydrophilic and Hydrophobic Microporous Layer Coated Gas Diffusion Layer for Enhancing PEFC Performance, ECS Transactions, 10.1149/10408.0117ecst, 104, 8, 117-127, 2021.10, The hydrophobic microporous layer (MPL) coated on the gas diffusion layers (GDLs) have been commonly used to improve water management properties of polymer electrolyte fuel cells (PEFCs). An MPL coated GDL designed to prevent dehydration of the membrane electrode assembly (MEA) under low humidity conditions is generally inferior at reducing flooding under high humidity conditions. Thus, developing an MPL coated GDL to enhance the PEFC performance under low and high humidity conditions is crucial. One method to overcome the defects of pure hydrophobic MPL is to make double and triple MPLs, in which a thin hydrophilic layer coated on the hydrophobic MPL. Another method is a hydrophobic MPL containing hydrophilic carbon nanotubes (CNTs). Both methods effectively conserve membrane humidity and reduce flooding under high humidity conditions.. |
| 43. | 比嘉 資, 中島 裕典, Evaluation of Three-Dimensional Placement of Built-in Catalytic Partial Oxidation Catalyst in an Anode-Supported Honeycomb SOFC (Monolithic solid oxide fuel cell) アノード支持ハニカムSOFCにおける内蔵型マイクロ改質器の3次元配置評価（熱・燃料自立型燃料電池，小型，ポータブル，災害用）, ECS Transactions, 10.1149/10301.1991ecst, 103, 1, 1991-1996, 2021.07, [URL], Keywords: 燃料・熱自立型燃料電池，ポータブル電源，小型電源，災害用，非常用，メタン，ブタン，プロパン，カセットボンベ. |
| 44. | Mitsuhiro Inoue, Motohiko Sato, Asuka Shima, Hironori Nakajima, Yoshitsugu Sone, Takayuki Abe, Practical Application Study of Highly Active CO2 Methanation Catalysts Prepared Using the Polygonal Barrel-Sputtering Method: Immobilization of Catalyst Particles, Catalysis Letters, 10.1007/s10562-021-03623-7, 2021.04, [URL], Abstract: This study investigated immobilization (without binders and high-temperature heating) of highly active CO2 methanation catalyst particles, prepared by the polygonal barrel-sputtering method, onto porous Al2O3 plates. The catalyst particles were fixed uniformly and firmly on the plates and retained their high CO2 methanation performance. Graphic Abstract: [Figure not available: see fulltext.]. |
| 45. | 井上 光浩, 中島 裕典, 阿部 孝之, 多角バレルスパッタリング法で調製したRu/TiO2 触媒における熱自立CO2 メタン化反応の検討, 富山大学研究推進機構水素同位体科学研究センター研究報告, 39, 9-15, 2020.10. |
| 46. | Yoshitsugu SONE, Omar Samuel HERNANDEZ-MENDOZA, Asuka SHIMA, Motohiko SATO, Hironori NAKAJIMA, Hiroshige MATSUMOTO, Water Electrolysis by the Direct Water Supply to the Solid Polymer Electrolyte through the Interdigitated Structure of the Electrode, Electrochemistry, 10.5796/electrochemistry.20-00145, 89, 2, 138-140, 2020.12, © The Author(s) 2020. Water electrolysis cell in which the product gases was separated from liquid water on the surface of the electrode was developed. In order to realize the separation between gas and water, interdigitated diffusion layer (GDL) was designed, and the surface of the GDL was covered by catalyst to form electrode. When the pressurized water was supplied, the water directly made a contact to the proton conductive membrane. Due to the hydrophobic surface condition of the GDLs, gas/water separation along the surface of the electrode was completed.. |
| 47. | Yuto Wakita, Yuya Tachikawa, Hironori Nakajima, Shigeru Hamada, Kohei Ito, Visualization and mechanical strength of glass seal in planar type solid oxide fuel cells, International Journal of Hydrogen Energy, 10.1016/j.ijhydene.2020.05.153, 45, 41, 21754-21766, 2020.08, [URL], This study evaluated the mechanical reliability of glass seal in planar type solid oxide fuel cells and clarified the relationship between glass wettability and the mechanical reliability of glass seal. A visualization experiment was developed to observe a specific model seal in a furnace subjected to temperature variation and the relationship between the glass wettability and the seal shape was measured. The seal model consists of glass (G018-311, Schott, Germany) and interconnectors (Crofer 22 APU, VDM Metals GmbH, Germany). The visualization experiment and analysis were based on the sessile drop method to quantify glass surface tension and contact angle between glass and interconnector. The equation balance of forces with these surface properties succeeded to reproduce the seal shape observed in the visualization. Subsequently, the seal stress field was numerically solved, and the mechanical strength of the seal was quantitatively evaluated using the stress intensity factor. The analyses concluded that the stress intensity factor is 1.5 times higher than its minimum value as the contact angle raised from 90 to 130° and glass wettability decreased.. |
| 48. | Hironori Nakajima, Tatsumi Kitahara, Kenta Dan, Electrochemical Impedance Diagnosis of Abnormal Operational Conditions for Reliability of Polymer Electrolyte Fuel Cells in Marine Power Application-Sea Salt Contamination, ECS Transactions, 10.1149/09208.0341ecst, 92, 8, 341-349, 2019.07, [URL], Polymer electrolyte fuel cells (PEFCs) have attracted attention for marine vessels because of their potential to reduce pollutant emissions on the ocean. Electrochemical impedance spectroscopy (EIS) is suitable for real-time diagnosis for marine PEFCs. In this study, EIS is used to assess the impact of sea salt (NaCl) contamination in the cathode through the fast Fourier transform technique combined with a transmission line model including proton conduction in the ionomer/electrolyte membrane and the charge/mass transfer resistances with associated capacitances as diagnostic parameters. Variations in those resistances from the polarization losses in accelerated degradation tests with NaCl injection are revealed together with the capacitances. Five hours’ injection led to ca. 2.5 times larger mass transfer resistance possibly due to lowered hydrophobicity of the gas diffusion layer. Distilled water humidification after detecting the NaCl contamination at an early stage mitigates irreversible catalyst degradation indicated by transmission electron microscope observations. |
| 49. | Kohei Sasaki, Hironori Nakajima, Tatsumi Kitahara, Influence of carbon deposition on the current distribution in an anode-supported planar solid oxide fuel cell in-situ assessed by segmented electrodes, ECS Transactions, 10.1149/09101.0549ecst, 91, 1, 549-554, 2019.07, [URL], For solid oxide fuel cells (SOFCs), durability to carbon deposition is a common problem to use hydrocarbon fuels from the city gas and the biogas. Identification of degradation factors and locations leads to development of diagnosis method and optimized operation control for prevention of failure and accident. Electrochemical data by the degradation give useful parameters for health diagnosis. In this study, we are aiming to understand spatial degradation, so that we prepared an anode-supported planar cell in which the cathode layer was segmented to three parts. We fed dry methane gas to the anode as accelerated aging tests and measured the current distribution directly among the upstream, midstream and downstream parts along the anode flow channels. Electrochemical impedance spectroscopy analysis was carried out in each segment as well. Upstream part of the cell exhibited larger overpotentials with more enhanced carbon deposition than the other parts with the dry methane fuel.. |
| 50. | Y. Iwanaga, H. Nakajima, K. Ito, Fuel production by a cathode-supported honeycomb solid oxide electrolysis cell (Monolithic SOEC), ECS Transactions, 10.1149/09101.2707ecst, 91, 1, 2707-2712, 2019.07, [URL]. |
| 51. | Yang Ming Hao, Hironori Nakajima, Akiko Inada, Kazunari Sasaki, Kohei Ito, Overpotentials and reaction mechanism in electrochemical hydrogen pumps, Electrochimica Acta, 10.1016/j.electacta.2019.01.108, 301, 274-283, 2019.04, [URL], The overpotentials generated in an electrochemical hydrogen pump (EHP) are experimentally separated using a hydrogen reference electrode. An intentionally thick polymer electrolyte membrane and a low-Pt-catalyst-loaded layer are embedded in the EHP cell for high accuracy in separation. The results show that the non-ohmic overpotential of the cathode is larger than that of the anode. Electrochemical impedance spectroscopy (EIS) is employed to analyze the non-ohmic overpotential in detail, and different features are observed in the Nyquist plots for the anode and the cathode, where the cathode spectra exhibits charge transfer rate-limiting features and the anode spectra displays mass transfer rate-limiting features. These different characteristics are theoretically clarified by the classical Volmer–Heyrovsky–Tafel mechanism. The hydrogen evolution reaction (HER) in the cathode is dominated by the Volmer–Heyrovsky route, and the hydrogen oxidation reaction (HOR) in the anode is dominated by the Volmer–Tafel route. Due to the slow reaction rate imposed by the Volmer–Heyrovsky route, the cathode HER displays high non-ohmic overpotential. With increasing cathode pressure, the rate of HER is increased due to the increasing coverage of the hydrogen adsorbed on the surface of the catalyst.. |
| 52. | 壇 健太, 中島 裕典, 北原 辰巳, 舶用燃料電池の信頼性向上のためのインピーダンス異常診断法, 日本マリンエンジニアリング学会誌, 10.5988/jime.54.287, 54, 2, 287-297, 2019.03, [URL], 固体高分子形燃料電池，海水，塩分，触媒層，白金，劣化，補器故障，電気化学インピーダンス分光法，高速フーリエ変換. |
| 53. | Jyunya Kai, Ryo Saito, Kenji Terabaru, Hua Li, Hironori Nakajima, Kohei Ito, Effect of temperature on the performance of polymer electrolyte membranewater electrolysis Numerical analysis of electrolysis voltage considering gas/liquid two-phase flow, Journal of the Electrochemical Society, 10.1149/2.0521904jes, 166, 4, F246-F254, 2019.01, [URL], The numerical analysis conducted in this study proposes a guideline to maximize the higherature effect, which is expected to reduce the electrolysis voltage of the polymer electrolyte membrane water electrolyzer. Higherature operation is intuitively thought to reduce activation overvoltages. However, a further consideration predicts that high temperature, especially a temperature higher than the saturated temperature regulated in the operation pressure, decreases the liquid saturation and causes shortage of water, leading to a large increase in overvoltages. This high temperature problem is analyzed using the developed theoretical model, which considers gas/liquid behavior. The analysis suggests that, if the gas saturation in the anode catalyst layer is kept at or below 0.3 by increasing the pressure, liquid water in the catalyst layer is sufficient to OER catalytic ability regulated by exchange current density, demonstrating that the higherature effect works. According to this guideline, increasing the temperature with pressurization can monotonically reduce the anode activation overvoltage. For instance, raising the temperature from 100 to 120°C and raising the pressure from 0.13 to 0.22 MPa can prevent the gas saturation from increasing beyond 0.3 and allows the lower electrolysis voltage to vary from 1.57 to 1.51 V.. |
| 54. | Özgür Aydın, Tatsuhiro Ochiai, Hironori Nakajima, Tatsumi Kitahara, Kohei Ito, Yusuke Ogura, Jun Shimano, Mass transport limitation in inlet periphery of fuel cells: Studied on a planar Solid Oxide Fuel Cell, International Journal of Hydrogen Energy, 10.1016/j.ijhydene.2018.07.030, 43, 36, 17420-17430, 2018.09, [URL]. |
| 55. | Özgür Aydin, Hironori NAKAJIMA, Concentration Gradient of Reactants Extending from Reaction Sites Inward Inlet Periphery of Fuel Cells, Journal of the Electrochemical Society, 10.1149/2.0871805jes, 165, 5, F365-F374, 2018.06, [URL]. |
| 56. | Tatsumi Kitahara, Hironori Nakajima, Gas diffusion media and NaCl contamination of polymer electrolyte fuel cells for marine applications, ECS Transactions, 10.1149/08613.0271ecst, 271-279, 2018.07, [URL], The application of polymer electrolyte fuel cells (PEFCs) for marine vessels will be an effective means of reducing the environmental impact and solving energy crisis problems. The diagnosis of abnormal operational conditions is an important aspect of improving the reliability and durability of marine PEFCs, and helps to ensure long-term safe and stable operation. The present work investigates the effect of abnormal variations in the relative humidity of supplied gases on the resistance values in the equivalent circuit model using electrochemical impedance spectroscopy analysis. An appropriate microporous layer coated gas diffusion layer is evaluated to enhance the cell performance under both low and high humidity conditions. The effect of sea salt (NaCI) contamination in the cathode air on the cell performance is also evaluated. Injecting distilled water after the initial detection of performance degradation due to NaCI contamination is effective at recovering the cell performance.. |
| 57. | Tatsumi Kitahara, Hironori NAKAJIMA, Kenta Dan, Impedance Spectroscopy to Prevent Performance Degradation due to Sea Salt for Marine Polymer Electrolyte Fuel Cells, Marine Engineering, 10.5988/jime.53.417, 53, 3, 417-422, 2018.05, [URL]. |
| 58. | Hua Li, Hironori Nakajima, Akiko Inada, Kohei Ito, Effect of flow-field pattern and flow configuration on the performance of a polymer-electrolyte-membrane water electrolyzer at high temperature, International Journal of Hydrogen Energy, 10.1016/j.ijhydene.2018.02.171, 43, 18, 8600-8610, 2018.05, [URL], This study aimed to optimize the flow-field pattern and flow configuration of a polymer-electrolyte-membrane water electrolyzer, with a particular focus on high-temperature operation up to 120 °C. Three types of flow-field pattern (serpentine, parallel, and cascade) were tested in both the anode and cathode sides of a water electrolyzer cell, and the current-voltage characteristics and high-frequency resistance were measured to examine which overpotential components are impacted by the flow-field pattern. The experimental results revealed that the cathode flow-field pattern only affects the ohmic overpotential, while the anode flow-field pattern significantly affects the overpotential related to liquid water shortage at catalyst layer, and the flow configuration (counter- and co-flow) does not affect the electrolysis performance. Finally, under operating conditions of 120 °C and 0.3 MPa, we found that the optimized cell configuration consisted of cascade and serpentine flow-field patterns in the anode and cathode, respectively; this configuration produced the minimum electrolysis voltage of 1.69 V at 2 A/cm2.. |
| 59. | 中島 裕典, 村上 隼三郎, 北原 辰巳, 燃料極支持ハニカム固体酸化物形燃料電池のガス流路配置が発電性能におよぼす影響, 日本機械学会論文集(B編), 10.1299/transjsme.17-00419, 84, 859, 17-00419, 2018.04, [URL]. |
| 60. | Hironori NAKAJIMA, Tatsumi Kitahara, Real-Time Electrochemical Impedance Spectroscopy Diagnosis of the Solid Oxide Fuel Cell for Marine Power Applications, Heat and Mass Transfer, 10.1007/s00231-017-2215-0, 54, 8, 2551-2558, in press, 2017.11, [URL]. |
| 61. | Hironori NAKAJIMA, Shunzaburo Murakami, Sou Ikeda, Tatsumi Kitahara, Three-dimensional flow channel arrangements in an anode-supported honeycomb solid oxide fuel cell (Monolithic SOFC), Heat and Mass Transfer, 10.1007/s00231-017-2154-9, 54, 8, 2545-2550, 2017.10, [URL]. |
| 62. | Tatsuhiro Ochiai, Hironori NAKAJIMA, Takahiro Karimata, Tatsumi Kitahara, Kohei Ito, Yusuke Ogura, In-Situ Analysis of the in-Plane Current Distribution Difference between Electrolyte-Supported and Anode-Supported Planar Solid Oxide Fuel Cells by Segmented Electrodes, ECS Transactions, 10.1149/07801.2203ecst, 78, 1, 2203-2209, 2017.07, [URL]. |
| 63. | Özgür Aydın, Hironori NAKAJIMA, Tatsumi Kitahara, In Situ Measured Spatial Temperature Variations for Improving Reliability of Numerical SOFC Tools, ECS Transactions, 10.1149/07801.2191ecst, 78, 1, 2191-2201, 2017.07, [URL]. |
| 64. | Hironori NAKAJIMA, Tatsumi Kitahara, Eisaku Tduda, Segmented Electrode Analysis of an Anode-Supported Planar Solid Oxide Fuel Cell for the Diagnosis of Marine Power Applications, ECS Transactions, 10.1149/07801.2109ecst, 78, 1, 2109-2113, 2017.07, [URL]. |
| 65. | Yuto Wakita, Tachikawa Yuya, Hironori NAKAJIMA, Kohei Ito, Glass Shape Change during Firing for Improving the Seal of Planar SOFCs, ECS Transactions, 10.1149/07801.1731ecst, 78, 1, 1731-1737, 2017.07, [URL], Secure sealing is vital for planar type SOFCs to avoid the performance degradation and achieve long-term stable operation. Here we focus on the sheet type glass sealing which is produced by tape-casting method. High wettability of the glass is essential to avoid the stress concentration because low wettability increases the contact angle of the glass and makes the notch at the edge of glass sealing interface. We have evaluated the effect of temperature rising rate on the wettability of the sealing glass and the edge shape of it using the visualization test system. High temperature rising rate led to small contact angle of the sealing glass in some cases and can mitigate the stress concentration.. |
| 66. | Kohei Ito, Takuya Sakaguchi, Yuta Tsuchiya, Akiko Inada, Hironori NAKAJIMA, Ryo Saito, Gas Crossover Suppression by Controlling Wettability of Cathode Current Collector, ECS Transactions, 10.1149/07514.1107ecst, 75, 14, 1107-1112, 2017.01, [URL]. |
| 67. | Hua Li, Hironori NAKAJIMA, Kohei Ito, Optimization of Annealing Catalyst Powder for High Temperature PEMWE, ECS Transactions, 10.1149/07514.1095ecst, 75, 14, 1095-1105, 2017.01, [URL]. |
| 68. | Yan Ming Hao, Hironori NAKAJIMA, Akiko Inada, Kazunari SASAKI, Kohei Ito, Separation and Characterization of Overpotentials in Electrochemical Hydrogen Pump with a Reference Electrode, ECS Transactions, 10.1149/07514.1155ecst, 75, 14, 1155-1163, 2017.01, [URL]. |
| 69. | Tatsuhiro Ochiai, Hironori NAKAJIMA, Takahiro Karimata, Tatsumi Kitahara, Kohei Ito, Jun Shimano, Yusuke Ogura, In-Situ Analysis of the in-Plane Current Distributions in an Electrolyte-Supported Planar Solid Oxide Fuel Cell by Segmented Electrodes, ECS Transactions, 10.1149/07552.0091ecst, 75, 52, 91-98, 2017.01, [URL]. |
| 70. | Hironori NAKAJIMA, Akiko Inada, Tatsumi Kitahara, Yusaku Nagata, Impedance Spectra Associated with Metal Deposition at the Negative Electrode from Contaminating Metal Particles at the Positive Electrode in a Lithium Ion Battery, ECS Transactions, 10.1149/07523.0027ecst, 75, 23, 27-36, 2017.01, [URL], リチウムイオン電池，金属，ニッケル，銅，鉄，ステンレス，電析、析出，デンドライト、短絡，熱暴走，発火，インピーダンス分光法，診断，高速フーリエ変換，Metal, Ni, Cu, Fe, Stainless steel, Deposition, Dendrite, Short-circuiting, Thermal runaway, Electrochemical Impedance Spectroscopy, Fast Fourier transform, FFT, Safety. |
| 71. | Kohei Ito, K. Terabaru, H. Li, A. Inada, Hironori Nakajima, Challenging of reducing electrolysis voltage by superimposing boiling on PEMWE - A thermodynamic coupling, ECS Transactions, 10.1149/08008.1117ecst, 1117-1125, 2017.01, [URL], This study challenges to decrease water electrolysis voltage by thermodynamic coupling between boiling and water electrolysis. Boiling, once a system to cause boiling is given, spontaneously advances and causes entropy generation. When boiling is superimposed on an electrode where electrochemical reaction of water electrolysis progress, the entropy generation by the boiling possibly accelerates the reaction of water electrolysis, leading to reduction of electrolysis voltage. To confirm this new concept, electrolysis voltage for a unit cell of PEMWE is measured in the region from 80°C to 120°C under a condition that cell pressure and electrolysis current are kept constant. The measurement results showed that the electrolysis voltage abruptly decrease as cell temperature crosses boiling point and then turn to increase at a few degree higher than the point. These features in the measurement were reproduced in the theoretical analysis based on a mathematical model considering the thermodynamic coupling.. |
| 72. | Sou Ikeda, Hironori NAKAJIMA, Tatsumi Kitahara, Enhancement of fuel transfer in anode-supported honeycomb solid oxide fuel cells, Journal of Physics: Conference Series, 10.1088/1742-6596/745/3/032082, 745, 3, 032082, 2016.12, [URL]. |
| 73. | Hironori NAKAJIMA, Tatsumi Kitahara, Real-Time Electrochemical Impedance Spectroscopy Diagnosis of the Marine Solid Oxide Fuel Cell, Journal of Physics: Conference Series, 10.1088/1742-6596/745/3/032149, 745, 3, 032149, 2016.12, [URL]. |
| 74. | Tatsumi Kitahara, Hironori NAKAJIMA, Kenta Ishikawa, Microporous Layer-coated Gas Diffusion Layer for Performance Enhancement of Polymer Electrolyte Fuel Cells without Humidification Using Anode Gas Recirculation, Journal of the Electrochemical Society, 10.1149/2.0251613jes, 163, 13, F1366-F1372, 2016.12, [URL]. |
| 75. | Hua Li, Tsuyohiko Fujigaya, Hironori NAKAJIMA, Akiko Inada, Kohei Ito, Optimum structural properties for an anode current collector used in a polymer electrolyte membrane water electrolyzer operated at the boiling point of water, Journal of Power Sources, 10.1016/j.jpowsour.2016.09.086, 332, 16-23, 2016.11, [URL]. |
| 76. | Tatsumi Kitahara, Hironori NAKAJIMA, Kenta Ishikawa, Gas Diffusion Layer Coated with a Microporous Layer Containing Hydrophilic CNTs to Enhance PEFC Performance without Humidification Using Anode Gas Recirculation, ECS Transactions, 10.1149/07514.0209ecst, 75, 14, 209-217, 2016.10, [URL]. |
| 77. | Hironori NAKAJIMA, Daeho LEE, Ming-Tsang LEE, Costas P. GRIGOROPOULOS, Hydrogen Production with CuO/ZnO Nanowire Catalyst for a Nanocatalytic Solar Thermal Steam-Methanol Reformer - 光熱変換材料，ナノワイヤ触媒，ナノロッド，水蒸気改質，水素生成, International Journal of Hydrogen Energy, 10.1016/j.ijhydene.2016.07.039, 41, 38, 16927-16931, 2016.08, [URL], 光熱変換材料，触媒，水蒸気改質，水素生成. |
| 78. | Yan Ming Hao, Hironori Nakajima, Hiroshi Yoshizumi, Akiko Inada, Kazunari Sasaki, Kohei Ito, Characterization of an electrochemical hydrogen pump with internal humidifier and dead-end anode channel, International Journal of Hydrogen Energy, 10.1016/j.ijhydene.2016.05.160, 41, 32, 13879-13887, 2016.08, [URL], Electrochemical hydrogen pump (EHP) with an internal humidifier is reported. The internal humidifier contains liquid water stored in a vessel built in the cathode end plate, and the water directly wets a polymer electrolyte membrane (PEM). By using the internal humidifier, conductivity of the PEM is higher than that using a conventional vapor humidifier. A modeling of water transport is built to discuss the water balance in the membrane. Electrochemical impedance spectroscopy (EIS) is employed for analyzing the resistance components included in the EHP. In particular, the effects of compression ratio on resistance components are investigated.. |
| 79. | Özgür Aydın, Hironori NAKAJIMA, Tatsumi Kitahara, Reliability of the numerical SOFC models for estimating the spatial current and temperature variations, International Journal of Hydrogen Energy, 10.1016/j.ijhydene.2016.06.194, 41, 34, 15311-15324, 2016.07, [URL]. |
| 80. | YangMing Hao, Hironori NAKAJIMA, Hiroshi Yoshizumi, Akiko Inada, Kazunari SASAKI, Kohei Ito, Characterization of an electrochemical hydrogen pump with internal humidifier and dead-end anode channel, Journal of Power Sources, 10.1016/j.ijhydene.2016.05.160, 2016.06, [URL]. |
| 81. | Tatsumi Kitahara, Hironori NAKAJIMA, Microporous Layer-Coated Gas Diffusion Layer to Reduce Oxygen Transport Resistance in a Polymer Electrolyte Fuel Cell under High Humidity Conditions, International Journal of Hydrogen Energy, 10.1016/j.ijhydene.2016.04.117, 41, 22, 9547-9555, 2016.06, [URL]. |
| 82. | Hua Li, Akiko Inada, Tsuyohiko Fujigaya, Hironori NAKAJIMA, Kazunari SASAKI, Kohei Ito, Effects of operating conditions on performance of high-temperature polymer electrolyte water electrolyzer, Journal of Power Sources, 10.1016/j.jpowsour.2016.03.108, 318, 192-199, 2016.04, [URL]. |
| 83. | Hua Li, Akiko Inada, Hironori NAKAJIMA, Kohei Ito, Impact of Cathode Current Collector on High Temperature PEM Water Electrolysis, ECS Transactions, 10.1149/06918.0003ecst, 69, 18, 3-12, 2015.12, [URL]. |
| 84. | Özgür Aydın, Hironori NAKAJIMA, Tatsumi Kitahara, Processes Involving in the Temperature Variations in Solid Oxide Fuel Cells In-Situ Analyzed Through Electrode-Segmentation Method, Journal of the Electrochemical Society, 10.1149/2.0701603jes, 163, 3, F216-F224, 2015.12, [URL]. |
| 85. | Hiroshi Ito, Takuya Iwamura, Satoshi Someya, Tetsuo Munakata, Akihiro Nakano, Yun Heo, Masayoshi Ishida, Hironori NAKAJIMA, Tatsumi Kitahara, Effect of through-plane polytetrafluoroethylene distribution in gas diffusion layers on performance of proton exchange membrane fuel cells, Journal of Power Sources, 10.1016/j.jpowsour.2015.12.020, 306, 289-299, 2015.12, [URL]. |
| 86. | Hironori NAKAJIMA, Tatsumi Kitahara, Diagnosis Method to Detect the Incorporation of Metallic Particles in a Lithium Ion Battery, ECS Transactions, 10.1149/06802.0059ecst, 68, 2, 59-74, 2015.12, [URL], リチウムイオン電池，ニッケル、銅、鉄、ステンレス、電析、デンドライト，短絡，熱暴走，発火，診断，インピーダンス分光法，サイクリックボルタンメトリー，Nickel, Copper, Iron, Stainless steel, Deposition, Dendrite, Short-circuiting, Thermal runaway, Safety, Electrochemical impedance spectroscopy, Cyclic voltammetry. |
| 87. | Liqing He, LI Hai-Wen, Hironori NAKAJIMA, Nikolay Tumanov, Yaroslav Filinchuk, Son-Jong Hwang, Manish Sharma, Hans Hagemann, Etsuo Akiba, Synthesis of a Bimetallic Dodecaborate LiNaB12H12 with Outstanding Super Ionic Conductivity, Chemistry of Materials, 10.1021/acs.chemmater.5b01568, 27, 16, 5483-5486, 2015.08, [URL]. |
| 88. | Özgür Aydın, Hironori NAKAJIMA, Tatsumi Kitahara, Influence of Convective Heat Transfer by Air Flow on Local Current/Temperatures along Microtubular Solid Oxide Fuel Cells In-situ Identified by Electrode segmentation Method for Co- and Counter-flow Configurations, ECS Transactions, 10.1149/06801.2141ecst, 68, 1, 2141-2150, 2015.07, [URL]. |
| 89. | Özgür Aydın, Hironori NAKAJIMA, Tatsumi Kitahara, Current and Temperature Distributions In-situ Acquired by Electrode-Segmentation Along a Microtubular Solid Oxide Fuel Cell Operating with Syngas, Journal of Power Sources, 10.1016/j.jpowsour.2015.06.024, 293, 1053-1061, 2015.06, [URL]. |
| 90. | Takahiro KOSHIYAMA, Hironori NAKAJIMA, Takahiro KARIMATA, Tatsumi Kitahara, Kohei Ito, Soichiro MASUDA, Yusuke OGURA, Jun SHIMANO, Direct Current Distribution Measurement of an Electrolyte-Supported Planar Solid Oxide Fuel Cell under the Rib and Channel by Segmented Electrodes, ECS Transactions, 10.1149/06801.2217ecst, 68, 1, 2217-2226, 2015.06, [URL]. |
| 91. | Hironori NAKAJIMA, Tatsumi Kitahara, Yuta Higashinaka, Yusaku Nagata, Effect of Electrode Mixing Conditions on the Performance of Lithium-Ion Batteries Analyzed by Fast Fourier Transform Electrochemical Impedance Spectroscopy, ECS Transactions, 10.1149/06422.0087ecst, 64, 22, 87-95, 2015.05, [URL], リチウムイオン電池，合材電極、スラリー、導電助剤、アセチレンブラック、分散、ネットワーク、内部抵抗、電気化学インピーダンス分光法，高速フーリエ変換，Composite electrode, Slurry, Conductive material, Acetylene black, Dispersion, Network, Internal resistance, Electrochemical impedance spectroscopy, Fast Fourier transform, FFT. |
| 92. | Shota Kotake, Hironori NAKAJIMA, Tatsumi Kitahara, Mass Transfer in an Anode-Supported Honeycomb Solid Oxide Fuel Cell, ECS Transactions, 10.1149/06445.0135ecst, 64, 45, 135-142, 2015.05, [URL]. |
| 93. | Kohei Ito, Yusuke Maeda, Takuya Sakaguchi, Shigeru Tsukamoto, Yuta Tsuchiya, Akiko Inada, Hironori NAKAJIMA, Analysis and visualization of water flow impact on hydrogen production efficiency in solid polymer water electrolyzer under high-pressure condition, International Journal of Hydrogen Energy, 10.1016/j.ijhydene.2015.03.045, 40, 18, 5995-6003, 2015.04, [URL]. |
| 94. | Tatsumi Kitahara, Hironori NAKAJIMA, Kosuke OKAMURA, Gas Diffusion Layers Coated with a Microporous Layer Containing Hydrophilic Carbon Nanotubes for Performance Enhancement of Polymer Electrolyte Fuel Cells under both Low and High Humidity Conditions, Journal of Power Sources, 10.1016/j.jpowsour.2015.02.115, 283, 115-124, 2015.02, [URL]. |
| 95. | Özgür Aydın, Takahiro Koshiyama, Hironori NAKAJIMA, Tatsumi Kitahara, In-situ Diagnosis and Assessment of Longitudinal Current Variation by Electrode-Segmentation Method in Anode-Supported Microtubular Solid Oxide Fuel Cells, Journal of Power Sources, 10.1016/j.jpowsour.2014.12.156, 279, 218-223, 2015.01, [URL]. |
| 96. | 北原 辰巳, 中島 裕典, 津田 和人, PEFC無加湿運転時の発電性能向上のためのセル内部湿度交換システムに関する研究, 日本機械学会論文集（B編）, 10.1299/transjsme.2014tep0363, 80, 820, TEP0363-TEP0363, 2014.12, [URL], Polymer electrolyte fuel cells (PEFCs) generally have external humidifiers to supply humidified hydrogen and oxidant gases, preventing dehydration of the membrane electrode assembly (MEA). If a PEFC could be operated without humidification, external humidifiers may be removed, resulting in a very simplified PEFC system with increased total efficiency and reduced cost. One of most important issues to advance the commercial viability of PEFCs is to develop high performance PEFCs that can operate without humidification. In the present study, a water vapor exchange system installed in the cell was developed to enhance the PEFC performance without humidification. A gas diffusion layer coated with a hydrophilic microporous layer, which consists of carbon black and polyvinyl alcohol (PVA), used at the cathode exchange area increases water transport from the wet cathode outlet gas to the dry anode inlet gas. This prevents dehydration of the MEA, thereby reducing the IR (ohmic) overpotential. The exchange area using interdigitated flow channels is effective to achieve further enhancement of water transport from the cathode to the anode, which significantly enhances the ability to prevent dehydration of the MEA. This results in a much higher output power density compared with that for a PEFC without the water vapor exchange area.. |
| 97. | 水谷 千晶, 北原 辰巳, 中島 裕典, 佐々木 一成, 伊藤 衡平, 極細熱電対群を用いたPEFC内部の3次元温度分布計測と水挙動の解析, 日本機械学会論文集（B編）, 10.1299/transjsme.2014tep0364, 80, 820, TEP0364-TEP0364, 2014.12, [URL], Local water behaviors in a PEFC was analyzed by equivalent electric circuit and the temperature distribution with an ultra-fine thermocouples. The thermocouple is tailor-made: thermocouple elements in 50 μm diameter are welded, and electrically insulated with polyimide coating, resulting in the ultra-fine thermocouple. The temperature distribution, which was measured by the thermocouple placed in array configuration, reveals that the cathode catalyst layer shows the highest temperature in the through-plane direction due to the activation over-potential in cathode. Under low humidification condition, however, the anode catalyst layer has the highest temperature triggered by dried polymer electrolyte membrane and increased IR loss. Along gas flow direction, upstream has the highest temperature, because water droplets accumulate in downstream resulting that load current and heat production concentrates in the upstream. In comparison of the temperature in the adjacent channels direction, the tendency of liquid water accumulation under rib makes the temperature under the channel higher.. |
| 98. | Martin Andersson, Hironori NAKAJIMA, Tatsumi Kitahara, Akira Shimizu, Takahiro Koshiyama, Hedvig Paradis, Jinliang Yuan, Bengt Sunden, Comparison of Humidified Hydrogen and Partly Pre-Reformed Natural Gas as Fuel for Solid Oxide Fuel Cells applying Computational Fluid Dynamics, International Journal of Heat and Mass Transfer, 10.1016/j.ijheatmasstransfer.2014.06.033, 77, 1008-1022, 2014.10, [URL]. |
| 99. | Tatsumi Kitahara, Hironori NAKAJIMA, Kosuke OKAMURA, Influence of GDL Coated with MPL Containing CNTs on PEFC Performance under Low and High Humidity Conditions, ECS Transactions, 10.1149/06403.0477ecst, 64, 3, 477-483, 2014.10, [URL]. |
| 100. | Hironori NAKAJIMA, Performance of an Anode-Supported Honeycomb Solid Oxide Fuel Cell, Materials Science Forum, 10.4028/www.scientific.net/MSF.783-786.1698, 783 - 786, 1698-1703, 2014.05, [URL]. |
| 101. | Tatsumi Kitahara, Hironori NAKAJIMA, Masaoki Inamoto, Kosuke Shinto, Triple Microporous Layer Coated Gas Diffusion Layer for Performance Enhancement of Polymer Electrolyte Fuel Cells under both Low and High Humidity Conditions, Journal of Power Sources, 10.1016/j.jpowsour.2013.10.009, 248, 1256-1263, 2014.02, [URL]. |
| 102. | Hiroshi Ito, Katsuya Abe, Masayoshi Ishida, Akihiro Nakano, Tetsuhiko Maeda, Tetsuo Munakata, Hironori NAKAJIMA, Tatsumi Kitahara, Effect of through-plane distribution of polytetrafluoroethylene in carbon paper on in-plane gas permeability, Journal of Power Sources, 10.1016/j.jpowsour.2013.10.009, 248, 822-830, 2014.02, [URL]. |
| 103. | 高園康隼, 清水慧, 中島 裕典, 北原 辰巳, サーペンタインハイブリッド形流路を有するPEFCに関する研究（第5報 電気化学インピーダンス分光法による内部抵抗解析）, 日本機械学会論文集（B編）, 10.1299/kikaib.79.2774, 79, 808, 2774-2785, 2013.12, [URL], The development of a polymer electrolyte fuel cell (PEFC) without external humidification is one of the most important issues to increase total efficiency and reduce cost. We have so far developed hybrid pattern gas flow channels consisting of interdigitated and serpentine gas flow channels for PEFCs without external humidification. The PEFC performance was improved when using the serpentine hybrid flow channels compared with the conventional flow channels. For further study, we have analyzed resistances of the cells with electrochemical impedance spectroscopy in the present study. The proton transfer resistance through the ionomer at the catalyst layer is dominant and its value for the hybrid flow channel is less than half that for the serpentine flow channel. The smaller resistance is possibly ascribed to the interdigitated design that can uniformly distributed reactant gas to each flow channel. The oxygen partial pressure is thereby relatively uniform at the active area. Thus, the interdigitated design can provide uniform current and water distribution. In addition, the hybrid flow channel has a low-pressure serpentine flow channel that helps the catalyst layer to hydrate. Un-reacted gas that contains modest water vapor flows through the channel and supplies water to the catalyst layer.. |
| 104. | Hironori NAKAJIMA, Tatsumi Kitahara, Kazuto TSUDA, Water Vapor Exchange Flow Channels to Enhance the Performance of Polymer Electrolyte Fuel Cells Without Cathode Humidification, ECS Transactions, 10.1149/05801.1799ecst, 58, 1, 1799-1805, 2013.10, [URL]. |
| 105. | Tatsumi Kitahara, Hironori NAKAJIMA, Masaoki Inamoto, Kosuke Shinto, Influence of Triple MPL Coated GDL on the PEFC Performance under Low and High Humidity, ECS Transactions, 10.1149/05801.1401ecst, 58, 1, 1401-1408, 2013.10, [URL]. |
| 106. | Kohei Ito, Yang Ming Hao, Hironori NAKAJIMA, Hiroshi Yoshizumi, Kazunari SASAKI, Electrochemical characterization of hydrogen pump with internal humidifier and dead-end anode channel, ECS Transactions, 10.1149/05801.0681ecst, 58, 1, 681-691, 2013.10, [URL]. |
| 107. | Shota Kotake, Hironori NAKAJIMA, Tatsumi Kitahara, Flow Channel Configurations of an Anode-Supported Honeycomb Solid Oxide Fuel Cell (Monolithic SOFC), ECS Transactions, 10.1149/05701.0815ecst, 57, 1, 815-822, 2013.10, [URL]. |
| 108. | Akira Shimizu, Hironori NAKAJIMA, Tatsumi Kitahara, Current Distribution Measurement of a Microtubular Solid Oxide Fuel Cell, ECS Transactions, 10.1149/05701.0727ecst, 57, 1, 727-732, 2013.10, [URL]. |
| 109. | Yusuke Shiratori, Mio Sakamoto, Yutaro Takahashi, Yuto Wakita, Masaru Takada, Teppei Ogura, Hironori NAKAJIMA, Kazunari SASAKI, Development of Direct Internal Reforming SOFC Integrated with Paper-Structured Catalyst Fuelled by Biofuels, ECS Transactions, 10.1149/05701.2997ecst, 57, 1, 2997-3004, 2013.10, [URL]. |
| 110. | Yusuke Shiratori, Teppei Ogura, Hironori NAKAJIMA, Mio Sakamoto, Yutaro Takahashi, Yuto Wakita, Takuya Kitaoka, Kazunari SASAKI, Study on paper-structured catalyst for direct internal reforming SOFC fueled by the mixture of CH4 and CO2, International Journal of Hydrogen Energy, 10.1016/j.ijhydene.2013.06.046, 38, 25, 10542-10551, 2013.07, [URL]. |
| 111. | Tatsumi Kitahara, Hironori Nakajima, Masaoki Inamoto, Masashi Morishita, Novel Hydrophilic and Hydrophobic Double Microporous Layer Coated Gas Diffusion Layer to Enhance Performance of Polymer Electrolyte Fuel Cells under both Low and High Humidity, Journal of Power Sources, 10.1016/j.jpowsour.2013.01.150, 234, 129-138, 2013.07, [URL]. |
| 112. | Akira Fukushima, Hironori NAKAJIMA, Tatsumi Kitahara, Performance Evaluation of an Anode-supported Honeycomb Solid Oxide Fuel Cell (Monolithic SOFC), ECS Transactions, 10.1149/05048.0071ecst, 50, 48, 71-75, 2013.05, [URL], An anode-supported honeycomb SOFC that can achieve high power density and enhanced durability was developed. Electrolyte layer of 8YSZ (8 mol% yittria stabilized zirconia) is employed by dip-coating an anode honeycomb substrate of Ni/YSZ, followed by being coated with cathode layer of La0.7Sr0.3MnO3. Current-voltage and current-power density characteristics of the cells having different anode and cathode flow channel configurations at 850℃ were measured. The results show promising performances of the cell as a starting point to develop stacks composed of multiple honeycomb cells.. |
| 113. | 北原辰巳, 中島裕典, 稲本昌興, PEFCの耐ドライアップ性と耐フラッディング性向上のための親水・撥水複合マイクロポーラス層付きガス拡散層に関する研究, 日本機械学会論文集(B編), 10.1299/kikaib.78.1849, 78, 794, 1849-1859, 78巻794号,pp.1849-1859, 2012.10., 2012.10, Gas diffusion layers (GDLs) coated with a hydrophobic microporous layer (MPL) have been commonly used to improve water management properties of polymer electrolyte fuel cells (PEFCs). In the present study, a novel hydrophilic and hydrophobic double MPL coated GDL was developed to achieve further enhancement of the PEFC performance under both low and high humidity conditions. Under low humidity conditions, a thin hydrophilic layer using titanium dioxide coated on the hydrophobic MPL is effective to conserve the humidity of the membrane electrode assembly (MEA), while a hydrophobic intermediate MPL between the hydrophilic layer and the carbon paper substrate prevents removal of water in the hydrophilic layer. This results in a significant enhancement of the ability of the MPL to prevent drying-up of the MEA. Under high humidity conditions, the double MPL coated GDL with appropriate pore diameter, thickness, and hydrophilic and hydrophobic properties is also effective to reduce flooding on the cathode catalyst layer, resulting in the higher PEFC performance compared with that for a hydrophobic MPL coated GDL.. |
| 114. | Hironori NAKAJIMA, Tatsumi Kitahara, Yasutaka Takazono, Satoshi Miyahara, Akira Shimizu, In-plane Liquid Water Distribution at the Interface Between the Gas Diffusion Layer and Catalyst Layer in the Cathode of a Polymer Electrolyte Fuel Cell with a Hybrid Pattern Flow Field, ECS Transactions, 50, 2, 593-601, 2012.10, [URL]. |
| 115. | Tatsumi Kitahara, Hironori Nakajima, Kyohei Mori, Masaoki Inamoto, Influence of Hydrophilic and Hydrophobic Double MPL Coated GDL on PEFC Performance, ECS Transactions, 50, 2, 437-444, 2012.10. |
| 116. | Tatsumi Kitahara, Hironori NAKAJIMA, Kyohei Mori, Hydrophilic and Hydrophobic double MPL Coated Gas Diffusion Layer for Enhanced Performance of Polymer Electrolyte Fuel Cells under No-Humidification at the Cathode, Journal of Power Sources, 10.1016/j.jpowsour.2011.10.002, 199, 29-36, 2012.02, [URL], Gas diffusion layers (GDLs) coated with a hydrophobic microporous layer (MPL) have been commonly used to improve the water management properties of polymer electrolyte fuel cells (PEFCs). In the present study, a new hydrophilic and hydrophobic double MPL coated GDL was developed to achieve further enhancement of PEFC performance under no-humidification at the cathode. The hydrophobic MPL, which consists of carbon black and polytetrafluoroethylene (PTFE), was coated on the carbon paper substrate. The hydrophilic layer, which consists of carbon black and polyvinyl alcohol (PVA), was also coated on the hydrophobic MPL. The hydrophilic layer is effective for conserving humidity at the catalyst layer, while the hydrophobic intermediate layer between the hydrophilic layer and the substrate prevents the removal of water in the hydrophilic layer via dry air in the substrate. Both decrease in the hydrophilic layer thickness to 5 μm and appropriate enhancement of hydrophilicity by increasing the PVA content to 5 mass% are effective for enhancing PEFC performance. Reducing the maximum pore diameter of hydrophobic intermediate layer to 20 μm is also effective for enhancing PEFC performance. However, when the pore diameter of the hydrophobic layer becomes too small, concentration overpotential tends to increase, thereby lowering PEFC performance.. |
| 117. | Tatsumi Kitahara, Hironori Nakajima, Kyohei Mori, Hydrophilic and Hydrophobic Double MPL Coated GDL to enhance PEFC Performance under Low and High Humidity Conditions, ECS Transactions, 10.1149/1.3635592, 41, 1, 593-601, 2011.10, [URL]. |
| 118. | Yasutaka Takazono, Hironori Nakajima, Tatsumi Kitahara, Effect of Gas Flow Channel without Cathode Humidification Analyzed with Electrochemical Impedance Spectroscopy, 4th World Hydrogen Technologies Convention, 0080, 2011.09. |
| 119. | 津田和人, 髙園康隼, 北原 辰巳, 中島 裕典, サーペンタインハイブリッド形流路を有するPEFC に関する研究 （第４報 両極無加湿運転における発電特性）, 日本機械学会論文集(B編), 10.1299/kikaib.77.1138, 77, 776, 1138-1146, 2011.04, [URL], The development of a polymer electrolyte fuel cell (PEFC) without external humidification is one of the most important issues to increase total efficiency and reduce cost. In the present study, we have developed hybrid pattern gas channels consisting of interdigitated and serpentine gas flow channels for PEFCs. The effects of gas flow channels at the anode and cathode on PEFC performance without external humidification were investigated. The PEFC performance was significantly deteriorated when a conventional triple serpentine channel was used at both the anode and cathode. However, when using the serpentine hybrid flow channel in the cathode, the performance was improved because of preventing the water from exhausting from the cathode. Moreover, the gas which flowed through the low pressure serpentine flow channel in the serpentine hybrid flow channel possibly promoted spreading water vapor over the whole active area. The triple serpentine flow channel in the anode was indicated to enhance spreading the water to whole of active area. Accordingly, IR overpotential was decreased and thereby PEFC performance was enhanced.. |
| 120. | Hironori Nakajima, Tatsumi Kitahara, Current Distribution Analysis of a Microtubular Solid Oxide Fuel Cell with Surface Temperature Measurements, ECS Transactions, 10.1149/1.3570089, 35 (1), pp. 1087-1096, 2011.05, [URL], Electrochemical single electrode Peltier heat, Transported entropy, Endothermic, Electrochemical impedance spectroscopy, Integration, Overpotential. |
| 121. | KITAHARA Tatsumi, KONOMI Toshiaki, NAKAJIMA Hironori, KAZAMA Masato, Influences of Microporous Layer Design Parameters for Gas Diffusion Layer on Permeability and PEFC Performance, Journal of Environment and Engineering, 10.1299/jee.6.17, 6, 1, 17-27, Volume 6, No. 1, 17-27, 2011.01, [URL], Gas diffusion layers (GDLs) coated with a microporous layer (MPL) have been commonly used to improve water management properties of polymer electrolyte fuel cells (PEFCs). However, the appropriate pore diameter, thickness and hydrophobicity of the MPL remain unclear. In the present study, the influences of MPL design parameters on permeability and PEFC performance were evaluated. A decrease in the pore diameter of the MPL reduces through-plane permeability significantly, but reduces in-plane permeability only slightly. Under high-humidity conditions, a decrease in the MPL pore diameter is effective for preventing flooding, enhancing PEFC performance. However, when the pore diameter becomes too small, PEFC performance tends to decrease. Reducing the MPL thickness improves in-plane permeability, enhancing the ability of the MPL to avoid flooding. Under low-humidity conditions, a decrease in the MPL pore diameter is effective for preventing drying-out of the MEA. Increasing the MPL thickness is also effective for maintaining the humidity of the MEA. However, when the MPL thickness becomes too large, the transport of oxygen to the electrode through the GDL is deteriorated, lowering PEFC performance.. |
| 122. | 北原辰巳, 許斐敏明, 中島裕典, 白石純一郎, PEFCの耐ドライアップ性向上のための親水・撥水複合マイクロポーラス層付きガス拡散層に関する研究, 日本機械学会論文集(B編), 10.1299/kikaib.76.772_2218, 76, 772, 2218-2226, 76巻772号, 2010.12, Gas diffusion layers (GDLs) coated with a hydrophobic microporous layer (MPL) have been commonly used to improve the water management property of polymer electrolyte fuel cells (PEFCs). In the present study, the influence of a hydrophilic and hydrophobic double MPL on PEFC performance under no-humidification at the cathode was evaluated. The hydrophobic MPL using a PTFE (polytetrafluoroethylene) binder and the hydrophilic MPL using a PVA (polyvinyl alcohol) binder were coated on the carbon paper GDL substrate. The thin hydrophilic layer coated on the conventional hydrophobic MPL enhances the ability to prevent drying-up of the MEA, thereby enhancing PEFC performance. The hydrophilic layer is effective for conserving membrane humidity. The hydrophobic intermediate layer between the hydrophilic layer and the GDL substrate prevents removing the water in the hydrophilic layer via dry air in the substrate. Reducing the hydrophilic layer thickness to 5μm is effective for enhancing PEFC performance. Appropriate enhancement of hydrophilicity by increasing the PVA content to 5mass% is also effective for enhancing PEFC performance.. |
| 123. | 北原辰巳, 許斐敏明, 中島裕典, 瀬口雄士, アノードガス再循環によるPEFC無加湿運転時の発電性能に及ぼすガス拡散層の影響, 日本機械学会論文集(B編), 10.1299/kikaib.76.771_1956, 76, 771, 1956-1963, 76巻771号, 2010.11, Polymer electrolyte fuel cells (PEFCs) generally have external humidifiers to supply humidified hydrogen and oxidant gases. If a PEFC could be operated under no-humidification, humidifiers may be removed, resulting in a simplified PEFC system with increased total efficiency and reduced cost. The present study was carried out to clarify the influence of gas diffusion layers (GDLs) on PEFC performance under no-humidification using anode gas recirculation. For the anode GDL, it is important to increase water transport between the anode gas and the membrane electrode assembly (MEA). The anode GDL without a microporous layer (MPL) is effective for enhancing PEFC performance. For the cathode GDL, it is important to maintain humidity and prevent drying-up of the MEA. A double hydrophobic MPL coated on both sides of the GDL is effective for reducing gas permeability, thereby preventing removing the water in the MEA through the GDL via dry air at the cathode. The hydrophilic layer coated on the double MPL enhances the ability of the GDL to prevent drying-up. Appropriate hydrophilic layer thickness of 40μm is effective for enhancing PEFC performance. Reducing the pore diameter of the hydrophobic intermediate layer between the hydrophilic layer and the substrate is also effective for enhancing PEFC performance.. |
| 124. | Hironori NAKAJIMA, Tatsumi Kitahara, toshiaki konomi, Electrochemical Impedance Spectroscopy Analysis of an Anode-Supported Microtubular Solid Oxide Fuel Cell, Journal of the Electrochemical Society, 10.1149/1.3486805, 157, 11, B1686-B1692, 2010.09, [URL]. |
| 125. | Yasutaka Takazono, Kazuto Tsuda, Tatsumi Kitahara, Hironori Nakajima, Toshiaki Konomi, Development of a PEFC with Serpentine-Interdigitated Hybrid Pattern Gas Channels, ECS Transactions, 10.1149/1.3484586, 33, 1, 927-935, Volume 33(1), pp. 927-935, 2010.10, [URL]. |
| 126. | Tatsumi Kitahara, Hironori Nakajima, and Toshiaki Konomi, Influence of Hydrophilic and Hydrophobic Double MPL Coated GDL on PEFC Performance without Cathode Humidification, ECS Transactions, 10.1149/1.3484602, 33, 1, 1089-1097, Volume 33(1), pp. 1089-1097, 2010.10, [URL]. |
| 127. | Hironori Nakajima, Tatsumi Kitahara, and Toshiaki Konomi, Effect of Flow Field Pattern and Microporous Layer on Gas Purge of a Polymer Electrolyte Fuel Cell, ECS Transactions, 10.1149/1.3484587, 33, 1, 937-944, Volume 33(1), pp. 937-944, 2010.10, [URL]. |
| 128. | 高園康隼, 津田和人, 許斐 敏明, 北原 辰巳, 中島 裕典, サーペンタインハイブリッド形流路を有するPEFCの開発研究（第3報，並行流，対向流が出力電圧の安定性に与える影響）, 日本機械学会論文集(B編), 10.1299/kikaib.76.767_1011, 76, 767, 1011-1018, 2010.07, [URL], In our previous study, we have developed a hybrid pattern gas flow channel design, where a serpentine flow channel is placed between interdigitated flow channels for polymer electrolyte fuel cells (PEFCs). In the present paper, using this flow channel design, we investigate the effects of gas flow direction on the output voltage under non-humidified cathode condition. As a result, we find a gas flow pattern that causes partial flooding by product water accumulation due to the gravity. Moreover, counter flow in the serpentine channel is found to increase the water content in the membrane, so that the fluctuation of the output voltages is suppressed. On the other hand, when the cathode outlet is downside, the above partial flooding is prevented. In addition to choosing this outlet, the counter flow of the serpentine and interdigitated flows is found to be effective to increase average output voltage and to suppress the fluctuation of the output voltage. In this case, the cathode outlet faces the inlet of the anode serpentine channel, where flow velocity is the highest in the anode flow channels. This gas flow pattern leads to sufficient supply of the product water at the cathode outlet to the anode side channels by the back-diffusion. Thus, the fluctuation of the output voltage is also minimized.. |
| 129. | Tatsumi KITAHARA, toshiaki konomi, Hironori NAKAJIMA, Microporous Layer Coated Gas Diffusion Layers for Enhanced Performance of Polymer Electrolyte Fuel Cells, Journal of Power Sources, 10.1016/j.jpowsour.2009.10.089, 195, 8, 2202-2211, 2010.04, [URL]. |
| 130. | 北原辰巳, 許斐敏明, 中島裕典, 瀬口雄士, 固体高分子形燃料電池のアノードガス再循環がカソード無加湿時の発電特性に及ぼす影響, 日本機械学会論文集(B編), 76巻761号, pp.95-100, 2010.01. |
| 131. | 北原辰巳, 許斐敏明, 中島裕典, 白石純一郎, マイクロポーラス層付きガス拡散層のPTFE量が撥水性とPEFC性能に及ぼす影響, 日本機械学会論文集（B編）, 76巻761号, pp.101-107, 2009.12. |
| 132. | 中島 裕典, 許斐 敏明, 北原 辰巳, 池田 丈典, サイクリックボルタンメトリー法による固体高分子形燃料電池の発電状態カソード有効触媒面積の解析, 日本機械学会論文集（B編）, 75巻758号, pp.2068-2075, 2009.10, [URL]. |
| 133. | Hironori Nakajima, Toshiaki Konomi, Tatsumi Kitahara, Thermal Analysis of a Microtubular Solid Oxide Fuel Cell Using Electrochemical Impedance Spectroscopy, ECS Transactions, 10.1149/1.3205544, 25, 2, 359-368, Volume 25 (2), pp. 359 - 368, 2009.12, [URL], Electrochemical Peltier heat, Single electrode, Transported entropy, Irreversible thermodynamics, Non-equilibrium thermodynamics, Overpotential, Integration, Impedance, Endothermic. |
| 134. | Tatsumi Kitahara, Toshiaki Konomi, Hironori Nakajima, Influence of Gas Diffusion Layers with Microporous Layer on the Performance of Polymer Electrolyte Fuel Cells, ECS Transactions, Volume 25 (1), pp. 1735-1744, 2009.09, [URL]. |
| 135. | Tatsumi KITAHARA, Toshiaki KONOMI, Hironori NAKAJIMA and Makoto MURATA, Effects of Design Parameters in Paper Type Gas Diffusion Layer on the Performance of Polymer Electrolyte Fuel Cells (Measures to Prevent Flooding and Drying-Up), Journal of Environment and Engineering, Vol. 4, No. 2, pp. 338-345 (2009) , 2009.09, [URL]. |
| 136. | 北原 辰巳, 許斐 敏明, 中島 裕典, 風間 雅仁, マイクロポーラス層付き拡散層の設計諸元が空気透過性とPEFC性能に及ぼす影響, 日本機械学会論文集（B編）, 10.1299/kikaib.75.755_1524, 75, 755, 1524-1531, 75巻755号, pp. 1524-1531, 2009.07, Gas diffusion layers (GDLs) coated with a microporous layer (MPL) have been commonly used to improve water management properties of polymer electrolyte fuel cells (PEFCs). However, the appropriate pore diameter, thickness and hydrophobicity of the MPL remain unclear. In the present study, the influences of MPL design parameters on permeability and PEFC performance were evaluated. A decrease in the pore diameter of the MPL reduces through-plane permeability significantly, but reduces in-plane permeability only slightly. Under high-humidity conditions, a decrease in the MPL pore diameter is effective for preventing flooding, enhancing the PEFC performance. However, when the pore diameter becomes too small, the PEFC performance tends to decrease. Reducing the MPL thickness improves in-plane permeability, enhancing the ability of the MPL to avoid flooding. Under low-humidity conditions, a decrease in the MPL pore diameter is effective for preventing drying-out of the MEA. Increasing the MPL thickness is also effective for maintaining the humidity of the MEA. However, when the MPL thickness becomes too large, the transport of oxygen to the electrode through the GDL is deteriorated, lowering the PEFC performance.. |
| 137. | 中島 裕典, 許斐 敏明, 北原 辰巳, 伊賀上 聡, 円筒型マイクロ固体酸化物形燃料電池のインピーダンス解析 (第２報 アノード・カソード過電圧分離解析）, 日本機械学会論文集（B編）, 10.1299/kikaib.75.755_1510, 75, 755, 1510-1516, 75巻755号，pp.1517-1523, 2009.07, [URL], The present paper addresses a separate overpotential analysis of the anode and cathode of a practical solid oxide fuel cell (SOFC). Electrochemical impedance spectroscopy with two-electrode set-up is used for the analysis of a micro tubular SOFC having anode-supported electrolyte. This cell is composed of an Ni/(ZrO_2)_(Y_2O_3)_ cermet anode, an La_Sr_Ga_Mg_O_ electrolyte, and an La_Sr_(Co_Fe_)O_3 cathode. Measurements are carried out for the cell operated at 700℃ with varying flow rate and composition of H_2-N_2 mixture gas fed in the anode. In our previous study, the anode and cathode impedances have been found to appear in low and high frequency regions, respectively. Therein, the Ohmic resistance, and the charge and mass transfer resistances at the anode and cathode were evaluated. In the present study, the Ohmic, activation and concnetration overpotentials are then evaluated by integration of those resistances. The anode and cathode activation overpotentials are found to be separated using the Butler-Volmer equation. Thereby the concentration overpotential of the anode is also found to be separated by subtracting the anode activation overpotential from the anode overpotential, while the cathode concentration overpotential is found to be negligible. The separation of the overpotentials is successfully confirmed by the observation of the variation of the overpotentials in conjunction with the variation of the anode gas flow rate and composition, giving the exchange current densities. The analysis shows that decreases in the anode activation overpotential and concentration overpotential including the Nernst loss imporove the cell performance.. |
| 138. | 中島 裕典, 許斐 敏明, 北原 辰巳, 伊賀上 聡, 円筒型マイクロ固体酸化物形燃料電池のインピーダンス解析(第1報 アノード・カソードインピーダンス分離解析）, 日本機械学会論文集（B編）, 10.1299/kikaib.75.755_1510, 75, 755, 1510-1516, 75巻755号，pp. 1510-1516, 2009.07, [URL], A separate analysis of the anode and cathode impedances of a practical solid oxide fuel cell (SOFC) has been performed. Electrochemical impedance spectroscopy is used for the analysis of a micro tubular SOFC havig anode-supported electrolyte with two-electrode set-up. This cell is composed of an Ni/(ZrO_2)_(Y_2O_3)_ cermet anode, an La_Sr_Ga_Mg_O_ electrolyte, and an La_Sr_(Co_Fe_)O_3 cathode. Measurements are carried out for the cell operated at 700℃ with varying flow rate and composition of H_2-N_2 mixture gas fed into the anode and those of air-O_2 mixture gas fed into the cathode. The anode and cathode impedances are thereby found to appear in low and high frequency regions, respectively. A common equivalent circuit model is applied for the complex nonlinear least squares curve fitting of impedance spectra to acquire the resistances and capacitances of the charge and mass transfers at the anode and cathode, and the cell Ohmic resistance. Then variation of those parameters of the equivalent circuit in accordance with anode gas feed conditions are obtained for the practical SOFC. They are useful parameters for health diagnosis of SOFCs.. |
| 139. | 許斐敏明, 北原辰巳, 中島裕典, トレーサEDXマッピングによるPEFC生成水排出過程に関する研究, 日本機械学会論文集（B編）, 10.1299/kikaib.75.753_1119, 75, 753, 1119-1126, 75巻753号,pp.1119-1126, 2009.05, The present work addresses the clarification of the exhaust process of the product water in the polymer electrolyte fuel cell using a tracer. Magnesium acetate tetrahydrate and a surfactant (polyoxyethylene di-styrenated phenyl ether) are dissolved into distilled water to prepare the tracer. The magnesium tracer is painted on the separator or electrode (catalyst layer) side of gas diffusion layers (GDLs) and dried. After operating a cell with these GDLs, magnesium at the surface and cross-section of the GDLs is captured ex-situ by energy dispersive X-ray spectroscopy (EDX) mapping on scanning electron microscope (SEM) images. In the case of the GDL having microporous layer (MPL), water produced at the rib part electrode of the cathode is found to be transported to the interspace between the channel part MPL and electrode in liquid phase. A part of the water is possibly transported through the MPL to the channel in gas phase. The water accumulated at the interspace is also found to be exhausted through the MPL to the channel in gas phase. Moreover, the suppression mechanism of the flooding by the MPL is shown as follows. The MPL repels condensed water in the GDL substrate, preventing transport of the liquid water to the electrode, so that the water accumulates in the GDL substrate.. |
| 140. | 高園康隼, 許斐 敏明, 北原 辰巳, 中島 裕典, サーペンタインハイブリッド形流路を有するPEFCの開発研究（第2報，低圧流路流速がPEFC性能に与える影響）, 日本機械学会論文集（B編）, 10.1299/kikaib.75.752_577, 75, 752, 577-584, 2009.04, [URL], We have developed hybrid pattern gas channels consisting of high and low pressure channels for polymer electrolyte fuel cells (PEFCs). The pressure difference between them gives rise to in-plane flow in the gas diffusion layer (GDL) under the rib. The high pressure channel is an interdigitated gas channel and the low pressure channel is a serpentine gas channel having smaller cross-sectional area than that in the 1st report of this work. An in-house separator is used for the cathode to vary the air flow velocity in the low pressure channel. By taking advantage of the hybrid pattern gas channels, maximum current density and stability of the cell voltage are significantly improved by an increase in the flow velocity in the low pressure channel. In contrast, a decrease in the flow velocity in the low pressure channel leads to a decrease in the current density at which sudden rise of IR overpotential due to the drying of the membrane electrode assembly occurs.. |
| 141. | 許斐 敏明, 北原 辰巳, 中島 裕典, 田代匡憲, 高園康隼, サーペンタインハイブリッド形流路を有するPEFCの開発研究（第1報，流路の設計と発電特性）, 日本機械学会論文集（B編）, 10.1299/kikaib.75.752_569, 75, 752, 569-576, 2009.04, [URL], We have developed hybrid pattern gas channel consisting of high and low pressure gas channels for polymer electrolyte fuel cells (PEFCs). The pressure difference between them gives rise to inplane flow in the gas diffusion layer (GDL) under the rib. This hybrid pattern gas channel allows to configure both parallel and serpentine gas channels for the high pressure channels. The low pressure channel is a serpentine gas channel to improve water exhaust ability by its large flow velocity. By taking advantage of the hybrid pattern gas channels, stability of the cell voltage is improved by increase in the flow velocity of the high pressure gas channel when it is switched to the serpentine gas channel. Moreover, atmospheric air introduced into the low pressure gas channel without humidification can dry and exhaust product water extruded to the GDL under the low pressure gas channel. However, flow rate of this air should be optimized to avoid output voltage drop due to the drying of the membrane electrode assembly.. |
| 142. | 許斐敏明, 北原辰巳, 中島裕典, 田中祐哉, PEFC電極面における発電分布の解析(第4報，熱圧着拡散層の発電分布解析), 日本機械学会論文集（B編）, 75巻 749号, pp.170-175, 2009.01, [URL]. |
| 143. | 許斐敏明，北原辰巳，中島裕典，田中祐哉, PEFC電極面における発電分布の解析(第3報，部分電極法による発電分布解析), 日本機械学会論文集（B編）, 10.1299/kikaib.75.749_164, 75, 749, 164-169, 2009.01, [URL], Analysis of Electric Generation Distribution on a PEFC Electrode : 3rd Report, Electric Generation Distribution in a PEFC Analyzed by Partial Electrode Method, Toshiaki KONOMI, Tatsumi KITAHARA, Hironori NAKAJIMA, Yuya TANAKA, 2009, Volume 75, Issue 749, Pages 164-169. Keywords: PEMFC, Local current density, In-situ, Current distribution, Rib, Land, Channel, CCM, MEA partially coated with catalyst layer, Partially-catalyzed membrane. |
| 144. | 許斐敏明, 北原辰巳, 中島裕典, PEFC過渡運転時の水バランス解析（ガス拡散層諸元がサーペンタイン形流路PEFCの摸擬起動運転時の濃度過電圧に与える影響）, 日本機械学会論文集（B編）, 74, 748, 2648-2655, 74巻 748号, pp．2648-2655, 2008.12, We have analyzed the dependence of the concentration overpotentials on the properties of gas diffusion layers (GDLs) of a polymer electrolyte fuel cell (PEFC) using dual serpentine flow fields during a start-up operation. Moreover, we directly and separately analyze such dependence of the amount of the water accumulated at each component of a cell by measuring the weight of adherent water. As a result, the hydrophobic treatment with micro porous layer addition to a GDL substrate is found to be effective to improve the cell performance by suppressing the water accumulation at the electrode (catalyst layer) which increases the concentration overpotential. Suppressed water accumulation at the electrode also increases cumulative current that represents the power generation and calorific power important for warm-up. Besides, increase in the coarseness of the GDL substrate is not so effective for decreasing the concentration overpotential and increasing the cumulative current for the case of the serpentine flow field. Increase in the thickness of the GDL substrate increases the concentration overpotential and decreases the cumulative current. These results will offer proper design parameters of GDLs for improving the performance of PEFCs, in particular during start-up.. |
| 145. | Hironori NAKAJIMA, Toshiaki KONOMI, Tatsumi KITAHARA, Hideaki TACHIBANA, Electrochemical Impedance Parameters for the Diagnosis of a Polymer Electrolyte Fuel Cell Poisoned by Carbon Monoxide in Reformed Hydrogen Fuel, Transactions of the ASME, Journal of Fuel Cell Science and Technology, 10.1115/1.2931462, 5, 5, 041013, 2008.11, [URL]. |
| 146. | 北原辰巳, 許斐敏明, 中島裕典, 立石吉忍, ガス拡散層の空気透過性がPEFC性能に及ぼす影響, 日本機械学会論文集（B編）, 74巻746号, pp.2221-2228, 2008.10. |
| 147. | Takuya Hoshiko, Hironori Nakajima, Toshiaki Konomi, Tatsumi Kitahara, and Shoichiro Kita, Estimation of Water Layer Thickness Adjacent to the Cathode Catalyst Layer of a PEFC (Analysis Using Electrochemical Impedance Spectroscopy), ECS Transactions, Volume 16, Issue 2, pp. 2117-2123, 2008.10, [URL]. |
| 148. | Tatsumi Kitahara, Toshiaki Konomi, Hironori Nakajima, Yoshinobu Tateishi, Makoto Murata, Nico Haak, Peter Wilde, Best combination of gas diffusion layers for polymer electrolyte fuel cell under cathode condition of very low humidity, ECS Transactions, 10.1149/1.2982000, 16, 2, 1603-1613, Volume 16, Issue 2, pp. 1603-1613, 2008.10, [URL]. |
| 149. | 星子 琢也, 中島 裕典, 許斐 敏明, 北原 辰巳, 固体高分子形燃料電池の拡散インピーダンス解析によるカソード電極触媒表面の水膜厚さの推定, 日本機械学会論文集(B編), 第74巻第741号, pp.1176-1182., 2008.06, [URL], We have analysed the diffusion impedance of a polymer electrolyte fuel cell (PEFC) by electrochemical impedance spectroscopy (EIS). As a result, we derive oxygen diffusion distance d adjacent to the cathode electrode (catalyst layer) assuming planar oxygen diffusion in a thin water layer unlike the conventional flooded-agglomerate model and gas phase diffusion model in a gas diffusion layer. The experimental results and their analyses show that δ agrees with a value reported from our previous ex-situ measurement. Moreover, δ gives reasonable concentration overpotentials. Increasing current density and gas humidification brings about the growth of S. It supports that δ corresponds to the thickness of the accumulated product water in liquid state at the cathode electrode. Thus EIS analysis of the diffusion impedance can be used to diagnose the water accumulation at the cathode electrode. This result enables the prediction of the flooding and drying-up of PEFCs and assures their stable operation.. |
| 150. | 許斐 敏明, 北原 辰巳, 中島 裕典, 田代 匡憲, 高園 康隼, パラレルハイブリッド形流路を有するPEFCの開発研究 (第3報 拡散層の設計諸元が対向櫛形流路の性能に与える影響), 日本機械学會論文集（B編）, 第74巻第741号, pp.1010-1017, 2008.06. |
| 151. | 許斐 敏明, 北原 辰巳, 中島 裕典, 田代 匡憲, 高園 康隼, パラレルハイブリッド形流路を有するPEFCの開発研究 (第2報 対向櫛形流路の性能とリブ部フラッデング), 日本機械学會論文集(B編), 第74巻第741号, pp.1003-1009, 2008.06. |
| 152. | 許斐 敏明, 北原 辰巳, 中島裕典, 田代匡憲, パラレルハイブリッド形流路を有するPEFCの開発研究 (第1報 流路の設計と基本特性), 日本機械学會論文集(B編), 第74巻第741号, pp.995-1002., 2008.06. |
| 153. | 許斐敏明, 北原辰巳, 中島裕典, 村上寛樹, PEFC電極面における発電分布の解析(第2報，リブ・溝幅ピッチが2mmのPEFCにおける発電分布), 日本機械学会論文集(B編), 第74巻第739号, pp.678-683, 2008.03. |
| 154. | 村田誠, 北原辰巳, 許斐敏明, 中島裕典, ペーパー形拡散層の設計諸元がPEFC性能に与える影響（フラッディングとドライアップの防止策）, 日本機械学会論文集(B編), 74, 737, 183-189, 74巻737号, p.183-189, 2008.01, The experiments to understand the dependency of the gas diffusion layer (GDL) design parameters on the performance of polymer electrolyte fuel cells (PEFCs) were carried out using the test apparatus in which the clamp pressure of the cell could be controlled. The behavior of the PEFC performance was highly influenced by the humidity of the supplied gas. Under high-humidity conditions, the hydrophobic treatment to the GDL substrate improved the PEFC performance with reducing the flooding magnitude, resulting in decreasing concentration overpotential. Much higher effect to prevent the flooding was achieved with putting a microporous layer (MPL). Under low-humidity conditions, both of the hydrophobic treatment and the MPL worked to prevent drying-up of the MEA, resulting in minimizing IR, activation and concentration overpotentials. The MPL coating substrate with larger air permeability was better to prevent the flooding, and the substrate with the smaller air permeability was better to prevent the drying-up.. |
| 155. | Hironori NAKAJIMA, Toshiaki Konomi, Tatsumi KITAHARA, Direct water balance analysis on a polymer electrolyte fuel cell (PEFC): Effects of hydrophobic treatment and micro porous layer addition to the gas diffusion layer of a PEFC on its performance during a simulated start-up operation, Journal of Power Sources, 10.1016/j.jpowsour.2007.06.004, 171, 2, 457-463, 2007.09, [URL]. |
| 156. | Koji Nitta, Shinji Inazawa, Kazunori Okada, Hironori Nakajima, Toshiyuki Nohira, Rika Hagiwara, Analysis of tungsten film electrodeposited from a ZnCl2–NaCl–KCl melt, Electrochimica Acta, 10.1016/j.electacta.2007.01.032, 53, 1, 53(1), pp. 20-23, 2007.09, [URL]. |
| 157. | Hironori Nakajima, Toshiyuki Nohira, Rika Hagiwara, Koji Nitta, Shinji Inazawa, Kazunori Okada, Electrodeposition of metallic tungsten films in ZnCl2–NaCl–KCl–KF–WO3 melt at 250 C, Electrochimica Acta, 10.1016/j.electacta.2007.04.082, 53, 1, 24-27, 53(1), pp. 24-27 , 2007.11, [URL]. |
| 158. | 許斐 敏明，北原 辰巳，中島 裕典，村上 寛樹, PEFC電極面における発電分布の解析(第1報, 1mmリブ幅セルのリブ部とガス流路部の発電分布), 日本機械学会論文集(B編), 10.1299/kikaib.73.631, 73, 726, 631-637, 2007.02, [URL], Toshiaki KONOMI, Tatsumi KITAHARA, Hironori NAKAJIMA, and Hiroki MURAKAMI, Analysis of Electric Generation Distribution on PEFC Electrode (1st Report, Electric Generation Distribution under Rib and Gas Channel), Transactions of the Japan Society of Mechanical Engineers, Series B, Vol.73, No.726 (2007-2), p.631-637. Keywords: PEMFC, Local current density, In-situ, Rib, Land, Channel, partial gas diffusion layer (GDL), Microporous layer (MPL). |
| 159. | Toshiyuki Nohira, Hironori Nakajima, Kan Kitagawa, Rika Hagiwara, Kouji Nitta, Shinji Inazawa, and Kazunori Okada, Electrodeposition of Refractory Metals from Some ZnCl2 Based Molten Salts at 150-250C, Molten Salts 15, in Memory of Robert Osteryoung, ECS Transactions, 3(35), pp. 333-340, 2007.09, [URL]. |
| 160. | Hironori Nakajima, Toshiyuki Nohira, Rika Hagiwara, Electrodeposition of metallic molybdenum films in ZnCl2–NaCl–KCl–MoCl3 systems at 250°C - 高融点金属の低温電析，めっき, Electrochimica Acta, 10.1016/j.electacta.2005.10.041, 51, 18, 3776-3780, 51, 3776-3780, 2006.05, [URL]. |
| 161. | Hironori Nakajima, Toshiyuki Nohira, Yasuhiko Ito, Signe Kjelstrup, Dick Bedeaux, The Surface Adsorption of Hydride Ions and Hydrogen Atoms on Zn Studied by Electrochemical Impedance Spectroscopy with a Non-Equilibrium Thermodynamic Formulation, Journal of Non-Equilibrium Thermodynamics, 10.1515/JNETDY.2006.011, 31, 231-255, Vol. 31, pp. 231-255, 2006.10, [URL]. |
| 162. | Hironori NAKAJIMA, Toshiyuki Nohira, Rika Hagiwara, Electrodeposition of Refractory Metals in Medium-Temperature Molten Salts, Molten Salts XIV, The Electrochemical Society Proceedings Series, PV 2004-24, 945-954, 2006.01. |
| 163. | Katsutoshi Kobayashi, Hironori Nakajima, Takuya Goto, Yasuhiko Ito, Thermodynamics of the N2/N3-Redox Couple in a LiBr−KBr−CsBr Melt, The Journal of Physical Chemistry B, 10.1021/jp053920i, 109, 50, 23972-23975, 109, 23972-23975, 2005.12, [URL], Lithium Bromide, Eutectic melt, Nitride ion, Nitride formation, Ammonia production. |
| 164. | Hironori NAKAJIMA, Toshiyuki Nohira, Rika Hgiwara, Koji Nitta, Shinji Inazawa, Kazunori Okada, Electrodeposition of metallic molybdenum films in molten ZnCl2-NaCl-KCl-MoCl5 systems at 250°C, Journal of Rare Earths, 23, SUPPL. 1, 23, 16-20, 2005.10. |
| 165. | Hironori NAKAJIMA, Toshiyuki Nohira, Rika Hagiwara, Electrodeposition of Metallic Tungsten in ZnCl2-NaCl-KCl-WCl4 Melt at 250゜C, Electrochemical and Solid-State Letters, 8, C91-C94, 2005.08, [URL]. |
| 166. | Katsutoshi Kobayashi, Hironori Nakajima, Takuya Goto and Yasuhiko Ito, Thermodynamic Investigations of Nitrogen Electrode Reaction in a Molten LiCl-KCl-CsCl-Li3N System, Journal of the Electrochemical Society, 152, E207-E211, 2005.05, [URL]. |
| 167. | Hironori Nakajima, Toshiyuki Nohira, Yasuhiko Ito, Electrochemical Impedance Spectroscopy Study of a Hydrogen Electrode Reaction at a Zn Electrode in a Molten LiCl−KCl−LiH System, The Journal of Physical Chemistry B, 10.1021/jp044477z, 109, 19, 9645-9650, 109, 9645-9650, 2005.05, [URL]. |
| 168. | 中島 裕典, 野平 俊之, 伊藤 靖彦, 溶融LiCl-KCl中への水素の溶解, 電気化学および工業物理化学 : denki kagaku, 10.5796/electrochemistry.73.733, 73, 8, 733-735, 73, 733-735, 2005.08. |
| 169. | Hironori Nakajima, Toshiyuki Nohira, Yasuhiko Ito, Infrared Spectroscopy of Molten LiCl−KCl under Hydrogen Gas Atmosphere, The Journal of Physical Chemistry A, 10.1021/jp049490y, 108, 21, 4567-4569, 108, 4567-4569, 2004.05, [URL]. |
| 170. | Hironori NAKAJIMA, Toshiyuki Nohira, Yasuhiko Ito, Thermodynamic Investigations of Hydrogen Electrode Reaction in a Molten LiCl-KCl-LiH System, Electrochemical and Solid-State Letters, 10.1149/1.1462876, 5, E17-E22, 2002.05, [URL], Keywords: Molten chloride, Eutectic melt, Regenerative fuel cell, Silane production, SiH4, Isotope separation, Molten salt reactor, Thorium cycle, MSBR, Standard state, Standard potential, Activity coefficient, Hydride ion, Ionic liquid. |
| 171. | Hironori Nakajima, Toshiyuki Nohira, Yasuhiko Ito, The single electrode Peltier heats of Li+/Li, H2/H− and Li+/Pd–Li couples in molten LiCl–KCl systems - ハイドライドイオン（ヒドリドイオン）／水素ガス電極系の非平衡熱力学（熱収支，輸率）, Electrochimica Acta, 10.1016/j.electacta.2004.06.014, 49, 27, 4987-4991, 2004.10, [URL]. |
| 172. | Hironori NAKAJIMA, Toshiyuki Nohira, Yasuhiko Ito, Infrared Spectroscopy of Molten LiCl-KCl-LiH, Electrochemical and Solid-State Letters, 7, E27-E29, 2004.07, [URL]. |
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