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空間電荷測定法を用いた蓄積電荷の可視化と電気二重層キャパシタの大容量化へ向けた検討
http://hdl.handle.net/10458/1339
http://hdl.handle.net/10458/133994bc85bc-ea95-4e77-90e1-94191e0f322c
| 名前 / ファイル | ライセンス | アクション |
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Doctoral_thesis.pdf (3.3 MB)
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| Item type | 学位論文 / Thesis or Dissertation(1) | |||||
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| 公開日 | 2008-03-11 | |||||
| タイトル | ||||||
| タイトル | 空間電荷測定法を用いた蓄積電荷の可視化と電気二重層キャパシタの大容量化へ向けた検討 | |||||
| 言語 | ja | |||||
| タイトル | ||||||
| タイトル | Direct Observation of Stored Charge using Space Charge Measurement and Concerning for Large Capacitance of Electric Double Layer Capacitor | |||||
| 言語 | en | |||||
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| 言語 | jpn | |||||
| 資源タイプ | ||||||
| 資源タイプ識別子 | http://purl.org/coar/resource_type/c_46ec | |||||
| 資源タイプ | thesis | |||||
| 著者 |
田島, 大輔
× 田島, 大輔 |
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| 抄録 | ||||||
| 内容記述タイプ | Abstract | |||||
| 内容記述 | Electric double layer capacitor (EDLC), a type of physical battery, has attracted much attention from the viewpoint of preventing global warming and energy problems. High power density and very good cyclability make EDLC useful in power electronic systems and have very promising applications in many other fields of technology. Recently, the characteristics of EDLC have been remarkably improved due to many studies; however, some of them still need enhancement, such as the specific energy density and capacitance. EDLC utilizes the double-layer formed at the interface between nanoporous carbonaceous electrode and nonaqueous electrolyte solution. The activated carbons have been used as the material of EDLC because of their relatively low cost and very high specific surface area; however, capacitance of EDLC based on carbon materials was lower than anticipated one. The charge storage process in EDLC, which is not dominated by chemical reactions, is closely related to the charge behavior. This is one of important consideration for EDLC performance. The charge behavior, which reflects the electrical capacitance, is strongly affected by many factors such as surface morphology, and additives and impurities of EDLC electrodes. Therefore, information on charge behavior during charge and discharge is prerequisite for any rational approach to the understanding of the charge storage process in EDLC. Until now, measurements of the capacitance of EDLC have been chiefly performed using several electrochemical methods, and no research on direct as conducting filler. Moreover, N2 adsorption-desorption isotherm as well as Transmission Electron Microscope (TEM) observation revealed that ketjen black used in this study has different pore structures compared to acetylene black. The capacitance of prepared EDLC was evaluated through discharge characteristics. It was found that the ketjen black containing EDLC showed very high capacitance compared to acetylene black one. Especially, 8 wt% ketjen black containing EDLC showed the highest capacitance among the prepared samples. The specific capacitance of the best one was evaluated as 59.2 F/g. It was also found that the 8 wt% ketjen black containing EDLC exhibited very stable capacitance at elevated temperature from temperature dependence of capacitance for 10 wt% acetylene black containing EDLC and 8 wt% ketjen black one. Furthermore, carbonaceous materials were modified in order to improve capacitance and charge density in EDLC. Optimal conditions for plasma surface treatment of activated carbon have been examined for times from 10 min to 1 h at 150 ℃ . The plasma source was a high-frequency glow discharge in N2. The operating gas pressure was 13.3 Pa. The electrode was set up so that the EDLC sample was covered with the glow discharge. As the results, space charge density was improved by the plasma surface treatment of carbon materials. Moreover, an activated carbon sheet was modified, to improve capacitance and energy density of EDLC. The plasma surface treatments were carried out for 1, 5, 10, 20, and 30 min. The plasma source was a DC glow discharge in argon gas. The pressure was 20 Pa and the distance between positive and negative electrodes was 20 mm. DC power was 70 W. The activated carbon sheets were set up to cover the sheets with the DC glow discharge. As the results of plasma surface treatment, EDLC single cells with the activated carbon sheets became more marked at higher discharge rate because the BET surface area of activated carbon sheet increased with argon plasma etching. In addition, capacitance of EDLC single cells can be improved by the plasma surface treatment. Capacitance of the EDLC cells with the activated carbon sheets after 1 min plasma surface treatment was increased 2 % compared to EDLC cells with the original activated carbon sheet at a high discharge rate. |
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| 言語 | en | |||||
| 内容記述 | ||||||
| 宮崎大学大学院工学研究科博士論文(平成19年度) | ||||||
| 内容記述 | ||||||
| ja | ||||||
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| 出版タイプ | AM | |||||
| 出版タイプResource | http://purl.org/coar/version/c_ab4af688f83e57aa | |||||
