Details of a Researcher - OKAWA Hirokazu

With the aim of investigating the deposition of Au/Pd core-shell nanoparticles (NPs) on cathode materials to decrease charge transfer resistance, Au/Pd core-shell NPs were successfully synthesized and deposited on LiFePO4 coated with carbon (LiFePO4/C) using ultrasound irradiation. Transmission electron microscopy observation confirmed that dispersed Au/Pd NPs with an average particle size of 7.2 nm were deposited on LiFePO4/C. An X-ray diffraction measurement evidenced a peak shifting from 38.2° to 39.1° upon calcination at 400 °C in Ar atmosphere, which can be attributed to the phase transition of the Au/Pd NPs from core-shell to alloy.

DOI

Utilization of tertiary amine solutions and ultrasound irradiation for CO<inf>2</inf> desorption at low temperature in a CCS process

Okawa H.

Japanese Journal of Applied Physics ( Japanese Journal of Applied Physics ) 60 ( SD ) 2021.07 [Refereed]

Research paper (journal) Domestic Co-author

This study used three tertiary amine solutions as a CO absorbent. Ultrasound can desorb CO from CO (aq) and H CO species at low temperature. Tertiary amine solution with lower pKa created CO adsorption equilibrium at lower pH related to a higher CO desorption amount using 28 kHz ultrasound because the lower pH environment would increase the existence ratio of CO (aq). Triethanolamine (TEA) with lowest pKa (7.85) showed the highest CO desorption ratio of 48% for 30 min irradiation at 25 °C. The CO absorption-desorption capacity of TEA by reuse was evaluated and found to keep the first capacity for three cycles. 2 2 2 2 3 2 2 2 2 2

DOI

Desorption of carbon dioxide from monoethanolamine solution via calcium chloride addition under ultrasound irradiation and evaluation of the characteristics of generated calcium carbonate

Kitamura Y.

Japanese Journal of Applied Physics ( Japanese Journal of Applied Physics ) 60 2021.07 [Refereed]

Research paper (journal) Domestic Co-author

We report the desorption of carbon dioxide [CO2(g)] from monoethanolamine (MEA) solution via the addition of calcium chloride (CaCl2) into a CO2-Absorbed MEA solution (0.2 M, pH 8.2) under ultrasound treatment (28 kHz, 200 kHz) and stirring (1500 rpm). Ultrasound at 28 kHz had a higher CO2(g) desorption ratio than either ultrasound at 200 kHz or stirring after 1 min [9.2% (28 kHz), 6.2% (stirring), and 5.8% (200 kHz)]. Treatment with ultrasound at 28 kHz resulted in the highest Ca recovery ratio, 89.1%, at 1 min treatment time. The desorption of CO2(g) from the MEA solution using 28 kHz ultrasound started immediately after the initiation of CaCO3 formation. Furthermore, it was found that the average particle size of CaCO3 obtained by ultrasound treatment at 28 kHz and a treatment time of 1 min was 0.91 μm, with a narrow particle size distribution.

DOI

Utilization of tertiary amine solutions and ultrasound irradiation for CO2 desorption at low temperature in a CCS process

Hirokazu Okawa, Hiroyasu Ito, Tatsuo Fujiwara, Yuya Kitamura, Takahiro Kato and Katsuyasu Sugawara

Japanese Journal of Applied Physics 60 SDDD01-1 - SDDD01-4 2021.02 [Refereed]

Research paper (journal) Domestic Co-author

Preparation of fine copper particles by a wet chemical method

Takahiro Kato, Yuri Takada, Hirokazu Okawa and Katsuyasu Sugawara

Journal of Chemical Engineering of Japan 54 ( 3 ) 103 - 109 2021.01 [Refereed]

Research paper (journal) Domestic Co-author

Enhancement of bitumen recovery from the oil sand in an alkaline solution using ultrasound irradiation and carbon dioxide

irokazu Okawa, Tomonao Saito, Shohei Yasuda, Youhei Kawamura, Takahiro Kato, Katsuyasu Sugawara and Tayfun Babadagli

Japanese Journal of Applied Physics ( The Japan Society of Applied Physics ) 59 ( SK ) 2020.07 [Refereed]

Research paper (journal) International Co-author

Herein, we demonstrated the enhancement of bitumen recovery from the oil sand in a concentrated alkaline solution using ultrasound irradiation and carbon dioxide. The alkaline solution allowed the separation of bitumen and sand; however, it was difficult to collect bitumen via aeration. CO2 exhibited a high contact angle for bitumen even at a high pH. Therefore, we attempted to use CO2 for bitumen recovery under ultrasound irradiation, increasing the number of collisions between bitumen and the CO2 bubbles; thus, the bitumen recovery ratio exhibited a high value of approximately 70% even at a low CO2 injection rate of 20 ml min(-1). (C) 2020 The Japan Society of Applied Physics

DOI

Enhancement of desorption amount of carbon dioxide gas from monoethanolamine solution using ultrasound and calcium chloride

Kitamura Y.

Japanese Journal of Applied Physics ( The Japan Society of Applied Physics ) 59 ( SK ) 2020.07 [Refereed]

Research paper (journal) Domestic Co-author

DOI

Mercury forms contained in desulfurization gypsums

Kosuke Sakusabe, Takahiro Kato, Hirokazu Okawa and Katsuyasu Sugawara

Journal of Chemical Engineering of Japan ( Journal of Chemical Engineering of Japan ) 53 ( 7 ) 359 - 365 2020.07 [Refereed]

Research paper (journal)

We analyzed mercury forms in desulfurization gypsum generated at a coal-fired power plant via temperature-programmed desorption (TPD) and cold vapor atomic absorption. The gypsum used as samples was obtained from double contact flow and jet bubbling desulfurization equipment. There were three types of gypsum samples for each type of desulfurization equipment, and six types of samples in all. The total mercury in these samples was 0.36–1.85 ppm. For model samples, we prepared and analyzed carbon with mercury that was adsorbed onto unburned carbon particles separated from fly ash or onto bituminous coal-based activated carbon. The desorption temperature varied depending on the carbon species; as the amount of adsorption increased, the peak width also increased. The TPD behavior of desulfurization gypsum was simulated with a linear combination of TPD curves from model samples. Mercury was found in carbon contained in all desulfurization gypsum analyzed in the present study. Mercury in carbon in the desulfurization gypsum obtained from the double contact flow desulfurization equipment could be simulated with model samples for unburned carbon with adsorbed mercury alone. Further, desulfurization gypsum obtained from jet bubbling desulfurization equipment could be simulated using unburned carbon with adsorbed mercury and activated carbon with adsorbed mercury. With the jet bubbling type of equipment, the abundance ratios of HgO, HgS, and HgSO4·2HgO were higher than those in double contact flow equipment, showing that depending on the type of desulfurization equipment, not only the type of mercury in carbon but also mercury forms in gypsum vary notably.

DOI

Recovery of rare metals from spent denitrification catalysts in coal-fired power plants

Kosuke Sakusabe, Yuuki Mochizuki, Takahiro Kato, Hirokazu Okawa and Katsuyasu Sugawara

Journal of Chemical Engineering of Japan ( Journal of Chemical Engineering of Japan ) 53 ( 7 ) 351 - 358 2020.07 [Refereed]

Research paper (journal) Domestic Co-author

A process for selectively recovering titanium, vanadium, and tungsten from spent denitrification catalysts generated in coal-fired power plants was developed in this study. Carbon was added as a reducing agent and the chloride volatilization behavior of rare metals under a chlorine gas flow was subsequently tracked. This demonstrated that the chloride volatilization reaction is promoted by the addition of carbon. In addition, if the spent catalyst is heat-treated in methanol vapor to deposit solid carbon on the catalyst surface, the chloride volatilization promotion is particularly high. After carbon was added by this method, heating to 400°C under a chlorine gas flow selectively released rare metals without releasing coexisting elements such as iron and aluminum. In addition, the released rare metals were converted into chlorides upon cooling and were completely recovered in solid or liquid form.

DOI

Removal of arsenite from aqueous solutions using ultrasonic irradiation in the presence of a lead electrode

Miyaki Ohta, Hirokazu Okawa, Takahiro Kato and Katsuyasu Sugawara

Japanese Journal of Applied Physics ( The Japan Society of Applied Physics ) 59 ( SK ) 2020.07 [Refereed]

Research paper (journal) Domestic Co-author

DOI

Separation of trace magnesium from metallic bismuth by chlorination

Takahiro Kato, Hirokazu Okawa, Katsuyasu Sugawara, Risehiro Nonaka and Masashi Tsuda

Journal of Chemical Engineering of Japan ( Journal of Chemical Engineering of Japan ) 53 ( 7 ) 366 - 374 2020.07 [Refereed]

Research paper (journal) Domestic Co-author

Open-cell porous silicon is gaining attention for use as a negative electrode to increase the theoretical capacity of lithium-ion batteries. Open-cell porous silicon is prepared by eluting Mg from Mg–Si alloy in molten Bi. To reuse the expensive Bi, separation of trace Mg from Bi is indispensable. Although metallic Mg and Bi form a uniform melting state, MgCl2 floats on the Bi melt. To separate Mg from Mg–Si alloy, effects of different types of chlorinating agents, reaction temperatures, and reaction times on chlorination behavior of Mg and Bi were investigated in this study. When the alloy was heated at 600°C for 21 h, as accumulated reaction time under the decomposition of NH4Cl gas, the Mg content in the sample decreased from the initial 0.9 to 0.1% and 90% of Bi was recovered as melt.

DOI

Adsorption and Desorption Mechanisms of Rare Earth Elements (REEs) by Layered Double Hydroxide(LDH) Modified with Chelating Agents

Shuang Zhang, Naoki Kano, Kenji Mishima, Hirokazu Okawa

Applied science 9 4805-1 - 4805-16 2019.11 [Refereed]

Research paper (journal) International Co-author

DOI

Mercury Forms in By-Products from Coal-Fired Power Plant

Kosuke Sakusabe, Takahiro Kato, Hirokazu Okawa and Katsuyasu Sugawara

Journal of Chemical Engineering of Japan 52 ( 11 ) 859 - 865 2019.11 [Refereed]

Research paper (journal) Domestic Co-author

Mercury forms in by-products from coal-fired power plant

Kosuke Sakusabe, Takahiro Kato, Hirokazu Okawa, Katsuyasu Sugawara

Journal of Chemical Engineering of Japan ( 公益社団法人化学工学会 ) 52 ( 11 ) 859 - 865 2019.11 [Refereed]

Research paper (journal) Domestic Co-author

An analysis of the chemical form of mercury in the by-products produced from a coal-fired power plant was performed by a combining temperature programmed desorption (TPD) method and cold vapor atomic absorption. The TPD curve of the model sample for each mercury compound showed a unique peak temperature, and the chemical form of mercury was identified by comparing the peak temperature with that of the by-product sample. A linear combination of the TPD curve of each model sample was curve-fitted to that of the by-product sample. The ratio of each form of mercury present in the by-products was calculated from the area ratio of the TPD curve of the model sample used in the analysis. The mercury in the fly ash used in this study mainly existed in a form bound to sulfur, and the mercury that adsorbed on carbon was not found despite the very high unburned carbon content. In contrast, the study found that the mercury adsorbed to carbon was the main form of mercury in desulfurization gypsum. These findings suggested that mercury-adsorbed carbon was formed when the mercury that transitioned into the liquid phase in a desulfurization equipment was adsorbed onto the unburned carbon.

DOI CiNii Research

Distribution of Sulfur during Solvent Extraction of Coals and Desulfurization of Extracted Product

Katsuyasu Sugawara, Takahiro Kato, Hirokazu Okawa, Nakorn Worasuwannarak

Journal of Chemical Engineerig of Japan 52 ( 7 ) 610 - 615 2019.07 [Refereed]

Research paper (journal) Domestic Co-author

Removal of Arsenic from a Denitration Catalyst by Reduction Using Methanol as Carbon Source

Takahiro Kato, Kosuke Sakusabe, Yuki Mochizuki, Hirokazu Okawa, KatsuyasuSugawara

Reaction Chemistry & Engineering 4 1208 - 1215 2019.07 [Refereed]

Research paper (journal) Domestic Co-author

DOI

Synthesis of porous γ-Fe<inf>2</inf>O<inf>3</inf> via alkaline treatment of size controlled scorodite particles synthesized using ultrasound irradiation and its evaluation as a cathode for lithium-ion battery

Yuya Kitamura, Hirokazu Okawa, Kozo Shinoda, Takahiro Kato, Katsuyasu Sugawara, Shigeru Suzuki

Japanese Journal of Applied Physics 58 ( SG ) 2019.07 [Refereed]

Research paper (journal) Domestic Co-author

Herein, we synthesized scorodite particles using ultrasound irradiation in a strong sulfuric acidic solution (pH 0.5) and investigated the scorodite particles' size and morphology. The highest crystallinity of scorodite (96%) was synthesized using 200 kHz ultrasonic treatment, and maximum yield of scorodite was obtained in three conditions: 200, 28 kHz, and stirrer. The oxidant generated through 200 kHz ultrasound irradiation enhanced Fe(II) oxidation in the solution resulting in crystal nuclei formation. The crystal nuclei were transformed to scorodite by oxidation with a supply of solute [Fe(III)] from the solution and ostwald ripening. Clustered scorodite (4 μm in size) was obtained via synthesis using 200 kHz ultrasound (pH 0.5). Arsenic could be separated from the clustered scorodite via alkaline treatment; scorodite was changed to porous γ-Fe O comprising nanosized particles. Porous γ-Fe O was evaluated as a cathode in a lithium-ion battery, which showed a 149 mAh g discharge capacity with a 0.5 C rate. 2 3 2 3 -1

DOI

Effect of Ultrasound Irradiationon Deposition of Au nanoparticles on Carbon-coated cathode material

Yasuyuki Tanaka, Hirokazu Okawa, Yuki Ono, Turtogtokh Enkhtuya, Tsermaa Galya, Takahiro Kato, Katsuyasu Sugawara

JapaneseJournal of Applied Physics 58 SGGD17-1 - SGGD17-6 2019.06 [Refereed]

Research paper (journal) Domestic Co-author

Synthesis of Porous γ-Fe₂O₃ via Alkaline Treatment of Size Controlled Scorodite Particles Synthesized Using Ultrasound Irradiation and Its Evaluation as a Cathode for Lithium-Ion Battery₂

Yuya Kitamura, Hirokazu Okawa, Kozo Shinoda, Takahiro Kato, Katsuyasu Sugawara, and Shigeru Suzuki

JapaneseJournal of Applied Physics 58 SGGD03-1 - SGGD03-7 2019.06 [Refereed]

Research paper (journal) Domestic Co-author

Separation and Desulfurization of Bitumen from Oil Sand Using Oxidation Combined with Ultrasound

Hirokazu Okawa, Nobuyuki Akazawa, Takahiro Kato, and Katsuyasu Sugawara

JapaneseJournal of Applied Physics, 58, SGGD01-1-3 (2019) 58 SGGD01-1 - SGGD01-3 2019.05 [Refereed]

Research paper (journal) Domestic Co-author

Sonochemical Synthesis of Au Nanoparticles on LiFePO4/C and the Evaluation of Its Battery Performance

Okawa Hirokazu, Ono Yuki, Tanaka Yasuyuki, Kato Takahiro, Sugawara Katsuyasu

Journal of the Society of Powder Technology, Japan ( The Society of Powder Technology, Japan ) 56 ( 3 ) 117 - 122 2019.03 [Refereed]

Research paper (journal) Domestic Co-author

LiFePO4 has attracted attention as a promising cathode material for lithium ion battery, because it consists of abundant elements. However, the battery performance of this material is limited by its low electron conductivity and low lithium ion diffusion rate. Coating its surface with an electronically conductive material, such as carbon, is one of the major methods to overcome this issue. In this study, we tried to synthesize Au nanoparticles (NPs) on the surface of carbon-coated LiFePO4 (LiFePO4/C) using sonochemical reaction to further enhance the electron conductivity. The size of Au NPs deposited on the surface of LiFePO4/C changed in relation to the concentration of Au ions. The battery performance of the Au NPs-deposited LiFePO4/C, as evaluated at a high constant current rate of 20 C, showed an improvement in the polarization and discharge capacity of LiFePO4/C.

DOI CiNii Research

Recovery of gold and silver from an incinerated spent printed circuit board using chlorination

Kosuke Sakusabe, Takahiro Kato, Hirokazu Okawa, Katsuyasu Sugawara

Journal of Chemical Engineering of Japan ( Journal of Chemical Engineering of Japan ) 51 ( 8 ) 704 - 710 2018.08 [Refereed]

Research paper (journal) Domestic Co-author

We studied an efficient recovery process for precious metals from secondary resources. The release behaviors of gold and silver were investigated during the heat treatment of an incinerated spent circuit board in a stream of chlorine gas. When the incinerated ash alone was heated in a stream of chlorine, a temperature of 1000°C was required to completely volatilize the gold and silver in the sample. However, the temperature required for the initial release of gold and silver decreased when a mixture of the incinerated spent printed circuit board and carbon particles was heated in a stream of chlorine, and fractions of these metals were captured by the carbon particles. The amounts of gold and silver captured by the carbon particles decreased when the temperature increased above 800°C. To completely volatilize the gold and silver from the sample and to ensure their capture by the carbon particles, the sample was heated to 1000°C in chlorine gas, and the volatilized chlorides were passed through a bed of carbon particles, which was maintained at 800°C. The total amounts of gold and silver from the incinerated printed circuit board were successfully recovered by adjusting the temperature and thickness of the bed of carbon particles.

DOI

Simultaneous recovery and desulfurization of bitumen from oil sand using ultrasound irradiation

Okawa H.

Japanese Journal of Applied Physics ( Japanese Journal of Applied Physics ) 57 ( 7 ) 2018.07 [Refereed]

Research paper (journal)

DOI

Utilization of carbon dioxide to synthesize large scorodite particles under ultrasound irradiation

Yuya Kitamura, Hirokazu Okawa, Takahiro Kato, Katsuyasu Sugawara

Japanese Journal of Applied Physics 57 07LB15-1 - 07LB15-5 2018.06 [Refereed]

Research paper (journal) Domestic Co-author

Performance analysis of ZigBee network topologies for underground space monitoring and communication systems

Moridi, M.A.Email Author, Kawamura, Y., Sharifzadeh, M., Chanda, E.K., Wagner, M., Okawa, H.

Tunnelling and Underground Space Technology ( Tunnelling and Underground Space Technology ) 71 201 - 209 2018.01 [Refereed]

Research paper (journal) International Co-author

The advancement in tunnelling and underground space technologies and the need for large scale monitoring and communication systems for safe and efficient operations has triggered the era of wireless sensor networks (WSNs). The progress of WSNs have been associated with the innovation of sensor nodes with the more significant features of smaller size, more cost-effectiveness, lower latency and powerful antenna coverage. The sensor nodes arrangement in dense industrial WSNs is one of the crucial issues for a better quality of service and a reliable message transmission through the network. In this study, we investigate various sensor node arrangements of ZigBee networks for underground space monitoring and communication systems. The performance of ZigBee topologies are analysed in 12, 20, 30, 40 and 50-node scenarios for stationary node deployment in underground environments. The metrics used for the performance evaluation include throughput, packet delivery ratio (PDR), end-to-end delay, energy consumption and packet delivery security. The results evaluation confirms the mesh topology is prioritised in WSNs design considering higher throughput, packet delivery ratio and network security, while the cluster-tree topology is preferred in case of lower end-to-end delay and lower energy consumption. The analyses show that the mesh topology creates a more reliable monitoring and communication network with an adequate quality of service in underground spaces and tunnels. Therefore, greater end-to-end delay and energy consumption could not be major concerns for the mesh topology in underground mine applications based on the acceptable data latency and using mine power.

DOI

Utilization of ultrasonic atomization for dust control in underground mining

Hirokazu Okawa, Kentaro Nishi, Youhei Kawamura, Takahiro Kato, Katsuyasu Sugawara

Jpn. J. Appl. Phys 56 7JE10-1 - 07JE10-6 2017.06 [Refereed]

Research paper (journal) Domestic Co-author

Ultrasound-assisted oxidative desulfurization of bitumen

Wan Mohamad Ikhwan bin Wan Kamal, Hirokazu Okawa, Takahiro Kato, Katsuyasu Sugawara

Jpn. J. Appl. Phys. 56 07JE03-1 - 07JE03-3 2017.06 [Refereed]

Research paper (journal) Domestic Co-author

Effect of reaction temperature on the size and morphology of scorodite synthesized using ultrasound irradiation

Yuya Kitamura, Hirokazu Okawa, Takahiro Kato, Katsuyasu Sugawara

Ultrasonics Sonochemistry 35 ( PartB ) 598 - 604 2016.04 [Refereed]

Research paper (journal) Domestic Co-author

DOI

Recovery of Valuable Elements from Spent Printed Circuit

Takahiro Kato, Katsuyasu Sugawara and Takashi Nakamura

Journal of Chemical Engineering of Japan 49 ( 1 ) 60 - 67 2016.01 [Refereed]

Research paper (journal) Domestic Co-author

Desorption of CO2 from low concentration monoethanolamine solutions using calcium chloride and ultrasound irradiation

Kosuke Tanaka, Hirokazu Okawa, Tatsuo Fujiwara, Takahiro Kato, Katsuyasu Sugawara

Japanese Journal of Applied Physics 54 07HE08 - 07HE08 2015.07 [Refereed]

Research paper (journal) Domestic Co-author

Ultrasound Irradiation for Desorption of Carbon Dioxide Gas from Aqueous Solutions of Monoethanolamine

Kosuke Tanaka, Tatsuo Fujiwara, Hirokazu Okawa, Takahiro Kato, Katsuyasu Sugawara

Japanese Journal of Applied Physics 53 ( 7S ) 07KE14-1 - 07KE14-5 2014.07 [Refereed]

Research paper (journal) Domestic Co-author

Recovery of Bitumen from Oil Sand by Sonication in Aqueous Hydrogen Peroxide

Hirokazu Okawa, Tomonao Saito, Ryota Hosokawa, Takashi Nakamura, Youhei Kawamura, and Shinobu Koda

Jpn. J. Appl. Phys. 2011.01

Research paper (journal)

Effect of Ultrasound Irradiation on Arsenic Adsorption from Aqueous Solution into Iron Compound

Ryota Hosokawa,Tomonao Saito,and Hirokazu Okawa

Jpn. J. Appl. Phys. 2011.01

Research paper (journal)

Effects of different ultrasound irradiation frequencies and water temperatures on extraction rate of bitumen from oil sand

Hirokazu Okawa, Tomonao Saito, Ryota Hosokawa, Takashi Nakamura, Youhei Kawamura, and Katsuyasu Sugawara

Jpn. J. Appl. Phys. 49 ( 2 ) 07HE12 - 1 2010.01

Research paper (journal)

The application of sonication for purifying soil contaminated with microorganism

Takashi Nakamura, Hirokazu Okawa, Ryota Hosokawa, Tomonao Saito, Youhei Kawamura, and Katsuyasu Sugawara

Jpn. J. Appl. Phys. 49 ( 7 ) 07HE11 - 1 2010.01

Research paper (journal)

Solid-liquid separation by sonochemistry: a new approach for the separation of mineral suspensions

Takashi Nakamura, Hirokazu Okawa, Youhei Kawamura, and Katsuyasu Sugawara

Ultrasonics Sonochemistry 2010.01

Research paper (journal)

Structure and luminescence of sodium and lanthanide(III) coordination polymers with pyridine-2,6-dicarboxylic acid

Taoyun Zhu, Kazuya Ikarashi, Tadashi Ishigaki, Kazuyoshi Uematsu, Kenji Toda, Hirokazu Okawa, Mineo Sato&0d0a;

Inorganica Chimica Acta 362 ( 10 ) 3407 - 3414 2009.01

Research paper (journal)

One-dimensional coordination polymers of praseodymium(III)–vanadium(V) complexes with pyridine-2,6-dicarboxylic acid

Taoyun Zhu, Koichi Murokawa, Kazuyoshi Uematsu, Tadashi Ishigaki, Kenji Toda, Hirokazu Okawa, Mineo Sato&0d0a;

Polyhedron 28 ( 11 ) 2196 - 2200 2009.01

Research paper (journal)

Underground Imaging Method Using Magnified Cross-Correlation Analysis&0d0a;

Ha, E., Kawamura, Y., Mizutani, K., Kamohara, A., Okawa, H.

Japanese Journal of Applied Physics 47 ( 7 ) 3946 - 3951 2008.01

Research paper (journal)

A Method of &0d0a;Underground Imaging Using Value of Elliptic Orbit Brightness for Detecting Underground Piping

Kawamura, Y., Takanari, T., Kamohara, A., Okawa

Journal of MMIJ 124 801 - 807 2008.01

Research paper (journal)

Detection of Underground Concrete Block using Giant-Magnetostriciton Vibrator applying Magnified Cross-Correlation Analysis

E.Ha, Y.Kawamura, K.Mizutani, H.Okawa, M.Asaka

Japanese Journal of Applied Physics 46 ( 7 ) 4500 - 4503 2007.01

Research paper (journal)

Synthesis of Fine Particles of LiFePO4 Cathode Material for Lithium-Ion Battery using a Hydrothermal Method

2004 ECS Joint International Meeting(Honolulu Hawaii) Abs.#297 2004.01

Research paper (journal)

Fine Particles Synthesis Process of LiFePO4 Cathode Material for Lithium ion Battery

Proc.International Workshop on Resource Science and Engineering of Rare Metals(Akita, Japan) Paper373-375 2004.01

Research paper (journal)

Improvement of Cycle Performance of Fe2(SO4)3 Cathode for Lithium Ion Battery

2000 ECS Joint International Meeting(Honolulu Hawaii) Abs.#6-27 2000.01

Research paper (journal)

Enhancement of Discharge capacity of Li3V2(PO4)3 by stabilizing the orthorhombic phase at room temperature

Solid State Ionics Vol.135 pp.137-142 2000.01

Research paper (journal)

Improvement of Discharge Capacity of β- Fe2(SO4)3-Type Li3V2(PO4)3 by Stabilizing High Temperature Orthorhombic Phase at Room Temperature

Chemistry letters pp.1017－1018 1999.01

Research paper (journal)

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<OKAWA Hirokazu>

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