2007 Fiscal Year Final Research Report Summary
Lithium ion conductivity of halides with a defect spinel structure
| Project/Area Number |
18550127
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Functional materials chemistry
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| Research Institution | Nihon University |
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Principal Investigator |
YAMADA Koji Nihon University, College of Industrial Technology, Professor (10166704)
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| Project Period (FY) |
2006 – 2007
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| Keywords | Lithium bromide / Indium / Rock salt structure / Spinel structure / Ionic conductivity / Rietveld analysis / 7Li NMR / 115In NMR |
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| Research Abstract |
Ionic conductivity is one of the functional properties of material. The preparation of the new materials having high ionic conductivity is a key technology for the development of fuel cell or secondary battery. In this research, solid electrolytes having the formula LiInBr_4 and Li_3InBr_6 were prepared and their structures and conduction mechanisms were investigated on the basis of high resolution X-ray diffraction and solid state NMR.
Both of these structures could be regarded as a rock salt type in which three Li^+ is replaced by one In^<3+> and two vacancies. Although cubic LiInBr_4 belongs to a defect spinel structure, its structure can be regarded as a defect rock salt type because tetrahedral site is empty. Since the positional disorder of In^<3+> was commonly observed at the superionic state, this disorder plays an important role for the Li^+ conduction. Furthermore, a continuous solid solution Li_<1-x>,In_<x/3>Br, between LiBr and InBr_3 was suggested at least below x<0.2.
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