Project/Area Number |
07454183
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Research Category |
Grant-in-Aid for Scientific Research (B)
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Allocation Type | Single-year Grants |
Section | 一般 |
Research Field |
機能・物性・材料
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Research Institution | Tokyo Institute of Technology |
Principal Investigator |
OKADA Isao Tokyo Institute of Technology, Department of Electronic Chemistry, Professor, 大学院・総合理工学研究科, 教授 (60011582)
|
Co-Investigator(Kenkyū-buntansha) |
HABASAKI Junko Tokyo Institute of Technology, Department of Electronic Chemistry, Research asso, 大学院・総合理工学研究科, 助手 (10133331)
|
Project Period (FY) |
1995 – 1997
|
Project Status |
Completed (Fiscal Year 1997)
|
Budget Amount *help |
¥7,100,000 (Direct Cost: ¥7,100,000)
Fiscal Year 1997: ¥1,500,000 (Direct Cost: ¥1,500,000)
Fiscal Year 1996: ¥1,700,000 (Direct Cost: ¥1,700,000)
Fiscal Year 1995: ¥3,900,000 (Direct Cost: ¥3,900,000)
|
Keywords | Molten carbonate / Lithium carbonate / Sodium carbonate / Internal mobility / Countercurrent electromigration / Polarized Raman spectroscopy / Rotational relaxation / Dynamic dissociation model / 共融混合物 / 溶融炭酸リチウム / 溶融炭酸ナトリウム / 溶融炭酸塩燃料電池 / 向流電気泳動法 / 電気伝導機構 / 振動・回転緩和 / 溶融塩 / 銀イオン / タリウムイオン / 鎮静効果 / 扇動効果 / 希土類イオン / 同位体効果 |
Research Abstract |
The molten binary systems (Li, K)_2CO_3 and (Li, Na)_2CO_3 at their eutectic compositions are the candidates for the electrolytes for the molten carbonate fuel cells (MCFC). The internal mobilities in the system (Li, Na)_2CO_3 have been measured by countercurrent electromigration ; those in the system (Li, Na)_2CO_3 at were previously measured In the former system the mobility of Na^+ is somewhat greater than that of Li^+ at all the investigated range of composition and temperature. The internal mobilities of Li^+, u_<Li>, in these two systems are well expressed by the empirical equation : u_<Li>=[A/ (V_m-V_0)] exp (-E/RT), where V_m is the molar volume of the mixture ; V_0, A and E are constants nearly independent of the second cation. The mobilities in the ternary system (Li, Na, K)_2CO_3 at the eutectic composition (43.5-21.5-25.0 mol%) have also been measured. The order of the mobilities of these cations is as follows : u_<Li>-u_K<u_<Na> (at 500゚C), u_<Li><u_<Na>-u_K (at 600゚C) and u_<Li><u_<Na>-u_K (at 750゚C). These results can be interpreted in terms of the dynamic dissociation model previously presented by us. This suggests that the internal mobilities of other cations could be semi-quantitatively predicted by this model. Polarized Raman spectroscopy has been applied for systems (Li, Na)_2CO_3 to investigate the rotational relaxation of the C_<3V> axis of the CO_3^<2-> ion. No appreciable relation has been found between the mobility and the rotationa motion.
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