- 著者
- Masaki YAMAGATA Kohei TANAKA Yoshihiro TSURUDA Yoshitsugu SONE Seisuke FUKUDA Shinichi NAKASUKA Michiyuki KONO Masashi ISHIKAWA
- 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.83, no.10, pp.918-924, 2015-10-05 (Released:2015-10-05)
- 参考文献数
- 51
- 被引用文献数
- 4 35
A prototype lithium-ion battery with a bis(fluorosulfonyl)imide (FSI)-based ionic liquid electrolyte was developed. The prototype was mounted on a demonstration module of the “Hodoyoshi-3” microsatellite, which was successfully launched on June 20, 2014. Qualification tests for space application, including radiation tolerance and vacuum tests, revealed negligible degradation of the ionic liquid-based lithium-ion battery (IL-LIB) cell. According to the flight data, the IL-LIB cell can exist stably in an ultra-high vacuum environment despite its thin and flexible pouch casing without any rigid anti-vacuum reinforcements. Furthermore, the power unit showed the same charge–discharge performance as that predicted by the charge–discharge behavior of an identical cell on the ground, suggesting that the IL-LIB cell maintains performance in high vacuum a microgravity environment. These results prove that LIB cells with FSI-based ionic liquids can be used as a power source for space applications.
- 著者
- Sota OKABE Satoshi UCHIDA Yukiko MATSUI Masaki YAMAGATA Masashi ISHIKAWA
- 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.85, no.10, pp.671-674, 2017-10-05 (Released:2017-10-05)
- 参考文献数
- 13
- 被引用文献数
- 6
We prepared activated carbon (AC) and sulfur (S) composite cathodes. The present AC has developed micropores and a large pore volume. The composite could successfully include a large amount of S and exhibited stable cycle performance in a glyme-based electrolyte. An oxidation treatment of the AC with a concentrated nitric acid solution at 120°C was found to improve S utilization in charge-discharge cycling. A cathode with the oxidized AC including S showed stable cycle performance with a high capacity in not only the glyme-based electrolyte but also a carbonate-based electrolyte.
- 著者
- Shinya USUKI Satoshi UCHIDA Yukiko MATSUI Masaki YAMAGATA Hidenori HINAGO Masashi ISHIKAWA
- 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.85, no.10, pp.650-655, 2017-10-05 (Released:2017-10-05)
- 参考文献数
- 22
- 被引用文献数
- 10
Micropore-rich activated carbon with high surface area and pore volume was prepared by alkali activation of azulmic carbon (AZC) precursor as nitrogen-doped carbon; AZC was a carbonized product from azulmic acid. We successfully loaded a large amount of sulfur (S) into micropores of the activated AZC. Our two kinds of activated AZC (BET surface area: 1,747 and 2,319 m2 g−1) can include S up to 55 and 62 wt%, respectively. The former activated AZC including S can be charged and discharged with lithium (Li) ion transfer stably and reversibly in glyme-based and carbonate-based electrolytes. The latter activated AZC can be charged and discharged in a glyme-based electrolyte. These different characteristics are due to a difference in fine pore structure between them. Our microporous activated AZC with high S loading is promising material as positive S electrode for rechargeable Li-S batteries.
- 著者
- Masaki YAMAGATA Masaya HIRAYAMA Satoshi NISHISHITA Daisuke HORIKAWA Masashi ISHIKAWA
- 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.10, pp.857-862, 2013-10-05 (Released:2013-10-05)
- 参考文献数
- 34
- 被引用文献数
- 3 7
The charge-discharge behavior of electric double-layer capacitors (EDLCs) composed of several ionic liquids and their lithium solutions were evaluated. The model EDLC cell with a Li+-containing ionic liquid electrolyte, LiTFSI/EMImFSI (LiTFSI = lithium bis(trifluoromethylsulfonyl)imide, EMImFSI = 1-ethyl-3-methylimidazolium bis(fluorosulfonyl)imide), exhibited a higher discharge capacitance than the cell containing EMImFSI, whereas the discharge capacitance of the cell with LiTFSI/EMImTFSI was lower than that of the cell containing EMImTFSI. In addition, the cells composed of EMImBF4-based electrolytes displayed similar charge-discharge characteristics irrespective of the presence of the corresponding lithium salts. The distinctive results for the EDLCs with lithium-containing ionic liquid electrolytes are also discussed based on the application of the electrochemical impedance technique to model carbon electrodes in ionic liquids. According to the obtained differential capacitance of the model glassy carbon electrode in each ionic liquid electrolyte, the electric double-layer (compact layer) structure at the electrode/electrolyte interface depends on the component anion species of the ionic liquid and the co-existence of the anion and Li+.
- 著者
- Kazunari SOEDA Masaki YAMAGATA Shigeaki YAMAZAKI Masashi ISHIKAWA
- 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.10, pp.867-872, 2013-10-05 (Released:2013-10-05)
- 参考文献数
- 21
- 被引用文献数
- 12
Chitosan-based gel electrolytes with ionic liquids (Chi/IL) were prepared and investigated for use in electric double-layer capacitors (EDLCs). The voltage drop for the test cell with Chi/EMImBF4 (EMImBF4 = 1-ethyl-3-methylimidazolium tetrafluoroborate) or Chi/DEMEBF4 (DEMEBF4 = N,N-diethyl-N-methyl-N-2-methoxyethylammonium tetrafluoroborate) and activated carbon fiber cloth electrodes (ACFCs) was smaller than that with the corresponding ionic liquid electrolyte. To clarify the effect of the presence of Chi in contact with the carbon electrode, we also prepared the Chi-containing ACFC electrode (Chi+ACFC) and evaluated its charge-discharge characteristics in EMImBF4. The results proved that the presence of Chi on the active materials reduces the internal resistances of the cell and plays an important role in the improvement of the EDLC performance. In addition, the high-voltage operation of the test cells with Chi-based gel electrolytes was investigated. These results suggest that the Chi is suitable for use in practical high-performance and safe EDLCs.