- 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
- Mika FUKUNISHI Tatsuo HORIBA Mouad DAHBI Kei KUBOTA Satoshi YASUNO Shinichi KOMABA
- 出版者
- The Electrochemical Society of Japan
- 雑誌
- Electrochemistry (ISSN:13443542)
- 巻号頁・発行日
- vol.87, no.1, pp.70-77, 2019-01-05 (Released:2019-01-05)
- 参考文献数
- 24
- 被引用文献数
- 4
A nanometer-sized Sn (nano-Sn) powder composite electrode with polyacrylate binder delivers a discharge capacity of 600 mAh g−1 with a good capacity retention for 100 cycles in non-aqueous Na cells, however, a micrometer-sized Sn (micro-Sn) composite electrode exhibits an insufficient cycle performance under the same condition. Although surface analysis of cycled electrodes reveals no apparent difference in solid electrolyte interphase layer formed on the nano- and micro-Sn electrodes, we found that in the case of nano-Sn electrodes the moderately porous composite layers and thin binder coating on Sn particles are responsible for a favorable cycle performance. On the other hand, the dense and less-porous micro-Sn electrode having a relatively thicker coating of binder on micro-Sn particles deteriorates the reversibility of sodium alloying reaction. Therefore, we optimize the electrode preparation process to introduce the suitable porosity and properly thin binder coating in the micro-Sn composite electrodes. The optimization enables the micro-Sn electrode to demonstrate high reversible sodiation capacity of 676–470 mAh g−1 with much improved capacity retention over 100 cycles.