2007 Fiscal Year Final Research Report Summary
Preparation and evaluation of lithium secondary batteries by using thin film technology
| Project/Area Number |
16560272
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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 |
Electronic materials/Electric materials
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| Research Institution | Shizuoka University |
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Principal Investigator |
ISAI Masaaki Shizuoka University, Faculty of Engineering, Professor (80022317)
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| Project Period (FY) |
2004 – 2007
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| Keywords | LiMN_2O_4 / Li secondary batteries / Manganese oxide films / Magnetron Sputtering / Reactive Evaporation / Rapid Thermal Annealing |
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| Research Abstract |
The preparation procedure of manganese oxide films have been investigated from 2005 through 2006. Before starting this research, it was found that manganese oxide (Mn_3O_4) films for lithium secondary batteries have been prepared using a reactive evaporation method. The metallic Mn in the crucible suffers oxidation since it is evaporated in the oxygen atmosphere. So the deposition rate is deteriorated with increasing deposition run.
This research shows a technique which keeps off the Mn evaporant from oxygen atmosphere during the reactive evaporation process. Three types of separators have been developed through our studies: a Mo separator, a stainless steel cell (SUS cell), and a quartz ampoule. They have been installed in the bottom of the Mn crucible. The Mn_3O_4 films could be prepared with high reproducibility with these devices.
During the evaluation of Mn_3O_4 films, it was found that manganese oxide films which involve Li have to be prepared. Preparation of LiMn_2O_4 thin films using a sputtering method was started on 2006. It was found that LiMn_2O_4 thin films could be prepared even at the substrate temperature of room temperature (R.T.) by this method. This material is superior to other materials in the cost performance as well as non-toxic. The crystal properties could be improved after a rapid thermal annealing (RTA) process. The preparation procedure has been sophisticated through this study. The study is now under way.
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