2014 Fiscal Year Annual Research Report
| Project/Area Number |
13F03371
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| Research Institution | Hokkaido University |
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Principal Investigator |
忠永 清治 北海道大学, 工学(系)研究科(研究院), 教授 (90244657)
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| Co-Investigator(Kenkyū-buntansha) |
ROSERO-NAVARRO Nataly Carolina 北海道大学, 工学(系)研究科(研究院), 外国人特別研究員
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| Project Period (FY) |
2013-04-01 – 2016-03-31
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| Keywords | 固体電解質 / リチウムイオン電池 / ゾル－ゲル法 / 低温合成 |
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| Outline of Annual Research Achievements |
Li7La3(Zr2-xNbx)O12 (LLZNbO, x=0-1.5) was prepared by sol-gel process at low temperatures. Additives (LiBO2 and Li3BO3) were used to improve the sintering of the ceramic electrolyte at low temperatures. XRD patterns of the calcined powder displayed the formation of cubic garnet phase between 600 - 700oC in composition with higher Nb content (LLZNbO, x>0.5). The density of composites with additives sintered at 900oC achieves 90%. In the composites sintered with LiBO2, the presence of La2Zr2O7 was detected, while single cubic phase was obtained for the composites sintered with Li3BO3. The ion conductivity attained was 7 x 10-5 S/cm at 30oC using 6.5 wt.% Li3BO3 (900oC), enhancement more than 2 orders of magnitude than the material without additive. Improvements of Li ion conductivity can be interpreted by the enhanced relative density as a result of the rearrangement of the particles produced by adequate concentration of the additive.
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| Current Status of Research Progress |
Current Status of Research Progress
2: Research has progressed on the whole more than it was originally planned.
Reason
Li7La3(Zr2-xNbx)O12 with high ionic conductivity was obtained with low sintering temperature of 900 degree C. A paper on this topic is already submitted for publication.
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| Strategy for Future Research Activity |
Effect of glass additives, such as Li2O-B2O3-SiO2 and BaO-B2O3-SiO2 glasses, on the performance of Lithium garnet-type oxides Li7-xLa3Zr2-xNbxO12 (LLZNbO, x=0-1) solid electrolyte will be studied.
LiCoO2, typical cathode material for Li battery, is prepared by a solution process, and composite electrodes with LiCoO2 and lithium ion conductive oxide materials will be prepared by co-sintering. The composite electrode will be applied to all-solid state battery.
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