著者

Akira KOTANI Hikaru YANAI Takashi MATSUMOTO Hideki HAKAMATA

出版者

The Electrochemical Society of Japan

雑誌

Electrochemistry (ISSN:13443542)

巻号頁・発行日

pp.20-65154, (Released:2021-01-13)

被引用文献数

5

著者

Takao ESAKA Salmie Suhana Binti Che Abdullah

出版者

The Electrochemical Society of Japan

雑誌

Electrochemistry (ISSN:13443542)

巻号頁・発行日

vol.78, no.11, pp.907-911, 2010-11-05 (Released:2012-03-26)

参考文献数

26

被引用文献数

2 4

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In order to find a new type of oxide ion conductor, the electrical conduction was measured in the substituted perovskite-type oxides. In the present case, LaYO3 was used as a based material with an orthorhombic and comparatively large unit cell, and a novel substitution method was introduced to intend to increase the concentration of oxide ions, e.g., LaY1−xZrxO3+x/2. As a result, the LaYO3-based perovskite-type solid solution was found to be formed, where the enhanced oxide ion conduction was observed as compared with that of the based material. A typical sample was LaY0.95Zr0.05O3.025, the ionic conduction of which was 1.2×10−2 S cm−1 at 1000°C. Another substitution method of La1−xZrxYO3+x/2 resulted in the analogous result. Considering these results and the further structural and density measurements, the charge carriers in these phases were expected to be due to interstitial oxide ions.

著者

Noriko KASAI Ryota FUJISHIMA Naoya ISHIDA Naoto KITAMURA Yasushi IDEMOTO

出版者

The Electrochemical Society of Japan

雑誌

Electrochemistry (ISSN:13443542)

巻号頁・発行日

pp.20-00126, (Released:2020-11-21)

参考文献数

28

被引用文献数

1

---

We studied the average crystal structural change during charging and discharging of a 0.4Li2MnO3-0.6LiMn1/3Ni1/3Co1/3O2 battery cathode in combination with a Li-metal anode, graphite anodes, and three types of separators. Prelithiation of the graphite anode enabled stable charge and discharge of the cathode. The average structure of the cathode after the 5th discharge did not change significantly due to the difference in the anodes and separators. However, after the 55th discharge, the difference in the electron density distribution and the distortion of the M-O6 octahedra for the different separators increased. The findings suggest that the changes in the crystal structure of a cathode over a long-term cycle should be studied with the anodes and separators used in actual batteries rather than Li-metal anodes and conventional separators.

著者

Isao SHITANDA Kengo KUMAGAI Chihomi TAKAMI Yoshinao HOSHI Masayuki ITAGAKI

出版者

The Electrochemical Society of Japan

雑誌

Electrochemistry (ISSN:13443542)

巻号頁・発行日

vol.89, no.1, pp.54-58, 2021-01-05 (Released:2021-01-05)

参考文献数

22

被引用文献数

1 2

---

Tin-plated copper tubes have been widely used in cold and hot water service systems. However, leakage accidents caused by pitting corrosion can occur in such tubes; therefore, it is necessary to evaluate the effects of major environmental factors on the occurrence of local corrosion to ultimately suppress this corrosion. In the present study, the anodic polarization curves of a tin-coated copper electrode were measured in simulated freshwater containing Cl−, SO42−, and HCO3−. The anodic current increased suddenly and sharply due to the breakdown of the passive layer and the initiation and growth of pitting generation at the pitting potential. The pitting potential shifted to a more negative direction with increasing Cl− and SO42− concentrations. In contrast, the pitting potential shifted to more noble potentials upon increasing the HCO3− concentration, indicating that HCO3− has an inhibitory effect on pitting attack by Cl− and SO42−. The quantitative relationship between each anion concentration and the pitting potential was determined by multiple regression analysis. A plot of the pitting potential predicted from the created regression equation and the measured values of the pitting potential showed a positive linear relationship.

著者

Shigenori MITSUSHIMA Yuki KOIZUMI Ken-ichiro OTA Nobuyuki KAMIYA

出版者

The Electrochemical Society of Japan

雑誌

Electrochemistry (ISSN:13443542)

巻号頁・発行日

vol.75, no.2, pp.155-158, 2007-02-05 (Released:2012-03-20)

参考文献数

19

被引用文献数

7 13

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Platinum depositions have been observed in the electrolyte membrane of polymer electrolyte fuel cells (PEFCs) as in other types of fuel cells; PEFCs, MCFCs. The platinum solubility in the membrane must be a key issue to improve and guarantee the durability of PEFCs. In this basic study, the platinum solubility has been determined in an acidic medium as a function of temperature, pH, and potential which was controlled by the oxygen partial pressure. The solubility was 3.0×10−6 mol dm−3 at 23°C in 1 mol dm−3 H2SO4 under air, and increased with temperature and the decrease in pH. The platinum solubility slightly increased with the oxygen partial pressure in oxygen–nitrogen mixtures. However, the solubility in nitrogen was much smaller than the mixtures. Based on these results, the dissolution of platinum in an acidic medium would follow the acidic dissolution mechanism.

著者

Kasumi NAKAGAWA Michiki TAKEUCHI Mayu KIKUCHI Suzuna KIYOFUJI Masami KUGO Takaiku SAKAMOTO Kenji KANO Jun OGAWA Eiji SAKURADANI

出版者

The Electrochemical Society of Japan

雑誌

Electrochemistry (ISSN:13443542)

巻号頁・発行日

pp.20-00123, (Released:2020-10-15)

参考文献数

29

被引用文献数

15

---

Indigo is one of the oldest natural blue dyes. Microorganisms and their enzymatic activities are deeply involved in the traditional indigo staining procedure. To elucidate the mechanism of the microbial indigo reduction, we directly performed cyclic voltammetry on alkaline fermenting dye suspensions. A pair of characteristic redox peaks of leuco-indigo was observed in a supernatant fluid of the fermenting dye suspension. On the other hand, it was found that the indigo/leuco-indigo redox couple mediated two-way microbially catalyzed oxidation and reduction in a sediment-rich suspension of the fermenting suspension. Acetaldehyde was supposed to be the electron donor and acceptor of the catalytic reactions. In order to verify the bioelectrocatalytic reaction, we isolated indigo-reducing bacterium K2-3′ from the fermenting suspension, and the two-way bioelectrocatalysis was successfully restaged in a model system containing K2-3′ and methyl viologen (as a soluble mediator instead of indigo) as well as acetaldehyde at pH 10.

著者

德島 高

出版者

The Electrochemical Society of Japan

雑誌

Electrochemistry (ISSN:13443542)

巻号頁・発行日

vol.82, no.9, pp.756-761, 2014-09-05 (Released:2014-09-05)

参考文献数

46

被引用文献数

1

著者

杉本 渉 白石 壮志

出版者

公益社団法人 電気化学会

雑誌

Electrochemistry (ISSN:13443542)

巻号頁・発行日

vol.76, no.1, pp.74-79, 2008-01-05 (Released:2012-03-22)

参考文献数

15

被引用文献数

1 2

著者

片山 靖

出版者

公益社団法人 電気化学会

雑誌

Electrochemistry (ISSN:13443542)

巻号頁・発行日

vol.79, no.12, pp.969-973, 2011 (Released:2012-03-30)

参考文献数

5

被引用文献数

1

著者

Tetsuya TOBA Kouji YASUDA Toshiyuki NOHIRA Xiao YANG Rika HAGIWARA Koki ICHITSUBO Kenta MASUDA Takayuki HOMMA

出版者

The Electrochemical Society of Japan

雑誌

Electrochemistry (ISSN:13443542)

巻号頁・発行日

vol.81, no.7, pp.559-565, 2013-07-05 (Released:2013-07-05)

参考文献数

56

被引用文献数

19 31

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Direct electrolytic reduction of SiO2 was investigated in molten CaCl2 at 1123 K as a fundamental study to develop a continuous process for solar-grade Si production. Several different types of SiO2 granules, as well as SiO2 pellets, were successfully reduced to Si on the bottom cathode of a Si plate. Three parameters were varied in the reduction of SiO2 granules: electrode potential, layer thickness of the SiO2 granules, and SiO2 particle size. The reduction rate was evaluated by the magnitude of the reduction current. The main factor determining the reduction rate was the diffusion of O2− ions inside the reduced porous Si layer filled with the electrolyte. Another factor which influenced the reduction rate was the contact resistance between Si granules.

著者

山木 準一 江頭 港 岡田 重人

出版者

公益社団法人 電気化学会

雑誌

Electrochemistry (ISSN:13443542)

巻号頁・発行日

vol.69, no.9, pp.664-669, 2001-09-05 (Released:2019-09-25)

参考文献数

9

被引用文献数

1

---

Lithium intercalation materials are widely used in lithium ion cells as cathode and anode active materials. Lithium intercalation materials show sometimes phase separation as a function of the amount of inserted Li+. The thermodynamic criterion of the phase separation of binary mixtures is already known using Gibbs free energy. The criterion of the phase separation was applied to that of lithium intercalation materials. We demonstrated the phase separation condition of the Li cathode for the cases of Gas Model and Coulomb Potential Model. By using Gas Model, the cathode potential is written as E = E0 + Ky + (RT/F) ln [(1−y)/y], where E is the cathode potential (V vs. Li), y is Li occupancy. In this case, two phase area is exp (−KF/2RT)<y<1−exp (−KF/2RT) and the potential is E0 + K/2. We have been considering the contribution of the internal energy change to the cell voltage (E vs. Li/Li+) assuming that the cathode material was completely ionic and only the Coulomb potential was effective in terms of changing the internal energy. From this model, we calculated E0 = 3.879 V and K = 1.020 V for LixNiO2 where y = 4 x (0<x<0.25). In this case, two phase area is 2.396 × 10−9 < y < 1 − 2.396 × 10−9 and the potential is 4.384 V.

著者

Shu ZHANG Waheed MIRAN Divya NARADASU Siyi GUO Akihiro OKAMOTO

出版者

The Electrochemical Society of Japan

雑誌

Electrochemistry (ISSN:13443542)

巻号頁・発行日

pp.20-00021, (Released:2020-04-21)

参考文献数

34

被引用文献数

9

---

Microbial extracellular electron transfer (EET) in diverse environments has gained increasing attention. However, the EET capability of oral pathogens and associated mechanisms has been scarcely studied. Here, our results suggest that the Capnocytophaga ochracea, an etiological human pathogen showed current production and demonstrated a rate enhancement of electron transport at a high cell-density. C. ochracea produced ∼10-fold more current at an OD600 of 0.5 associated with twice a higher glucose consumption rate per cell, compared to 0.1, measured in a three-electrode electrochemical system by single-potential amperometry at +0.2 V (vs Ag/AgCl [sat. KCl]). During current production, the accumulation of the redox molecules on the electrode was observed at high OD600 compared to low OD600. Apart from cell released redox active product, externally added redox active additives enhanced the electron transport, suggesting the EET capability of C. ochracea via electron mediator. A higher metabolic activity via single-cell assay (based on anabolic incorporation of 15NH4+) in cells that did not attach to the electrode strongly suggests the EET rate enhancement through an electron mediator. As bacterial populations play a role in the pathogenesis of human infections such as periodontitis, our results suggest that population-induced EET mechanisms may facilitate in-vivo colonization of C. ochracea.

著者

北折 典之 吉岡 眞由子 関戸 広太 大西 則彦 前田 菜花 松石 早矢

出版者

The Electrochemical Society of Japan

雑誌

Electrochemistry (ISSN:13443542)

巻号頁・発行日

vol.81, no.8, pp.627-633, 2013-08-05 (Released:2013-08-05)

参考文献数

22

被引用文献数

1 3

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Two kinds of small-sized electrolyzed water generator to be driven with a dry cell were investigated for sterilization in homes. These generation devices were able to produce the electrolyzed water which was weak acidic electrolyzed water or ozonated water. The weak acidic electrolyzed water was manufactured with the electrolysis of mixed solution of sodium chloride and citric acid, and ozonated water was formed by SPE (Solid Polymer Electrolyte) electrolysis of pure water. In this paper, it was reported about ability of weak acidic electrolyzed water and ozonated water for generation, sterilizing property and safety as performance of generator.

著者

Shinichi KOMABA

出版者

The Electrochemical Society of Japan

雑誌

Electrochemistry (ISSN:13443542)

巻号頁・発行日

vol.87, no.6, pp.312-320, 2019-11-05 (Released:2019-11-05)

参考文献数

108

被引用文献数

12

---

Rechargeable batteries are capable of storing electric energy on the basis of pairing electrochemical redox reactions to realize sustainable energy society in our future. Since lithium-ion batteries with the highest specific energy among all the practical batteries were commercialized in 1991, many studies on lithium insertion materials and their electrochemical characterization have been reported to achieve even higher energy density, longer cycle life, and safer lithium-ion battery technologies. It is quite fortunate that the author had an opportunity to contribute to the research and development of lithium battery materials since 1997. In particular, studies on the influence of dissolved metallic ions like Mn2+, Co2+, Ni2+, Na+, and K+ ions in electrolyte solution on graphite negative electrodes in lithium-ion batteries motivated the author to extend the research scope to electrochemical sodium insertion chemistry. Furthermore, the author’s research experiences as a postdoctoral fellow in Dr. Delmas’ group in FY 2003 and a remarkable oral presentation on alpha-NaFeO2 electrode properties given by Professor Okada’s group in 2004 provided motivations and opened up new avenue toward the successful demonstration of non-aqueous sodium-ion batteries later in the career. Since 2009, the author’s research group has successfully demonstrated 3-volt class charge and discharge of a sodium-ion battery of a NaNi1/2Mn1/2O2 // hard carbon cell and a brand-new potassium-ion battery of a K2Mn[Fe(CN)6] // graphite cell. The systematic studies of three different alkali-metal insertion systems synergistically induce deeper understanding and faster development of new materials for the next-generation rechargeable batteries.

著者

橋本 秀樹 柳 和宏

出版者

公益社団法人 電気化学会

雑誌

Electrochemistry (ISSN:13443542)

巻号頁・発行日

vol.71, no.11, pp.960-965, 2003-11-05 (Released:2019-08-30)

参考文献数

24

被引用文献数

1 1

著者

南眞 一量 神垣 良昭

出版者

公益社団法人 電気化学会

雑誌

Electrochemistry (ISSN:13443542)

巻号頁・発行日

vol.72, no.7, pp.520, 2004-07-05 (Released:2019-06-08)

被引用文献数

1 1

著者

芦原 聡

出版者

The Electrochemical Society of Japan

雑誌

Electrochemistry (ISSN:13443542)

巻号頁・発行日

vol.82, no.9, pp.762-765, 2014-09-05 (Released:2014-09-05)

参考文献数

21

著者

石川 敏功

出版者

公益社団法人 電気化学会

雑誌

Electrochemistry (ISSN:13443542)

巻号頁・発行日

vol.68, no.1, pp.46-47, 2000-01-05 (Released:2019-11-10)

著者

垣内 隆

出版者

公益社団法人 電気化学会

雑誌

Electrochemistry (ISSN:13443542)

巻号頁・発行日

vol.81, no.12, pp.1006-1011, 2013-12-05 (Released:2013-12-05)

参考文献数

14

被引用文献数

2 5

著者

佐藤 祐一 大澤 康彦

出版者

The Electrochemical Society of Japan

雑誌

Electrochemistry (ISSN:13443542)

巻号頁・発行日

vol.82, no.9, pp.782-786, 2014-09-05 (Released:2014-09-05)

参考文献数

3