成果報告書詳細
管理番号20140000000204
タイトル*平成25年度中間年報 革新型蓄電池先端科学基礎研究事業 革新型蓄電池先端科学基礎研究開発 (7)
公開日2014/5/17
報告書年度2013 - 2013
委託先名国立大学法人東北大学
プロジェクト番号P09012
部署名スマートコミュニティ部
和文要約
英文要約1) Development of advanced techniques with X-ray synchrotron radiation sources
We have developed in-situ two dimensional XAS technique with the spatial resolution of mm square and within 1 minute measuring time. With this technique, we have evaluated the formation behavior of the reaction distribution in a composite electrode during high-rate charge conditions. To evaluate the effect of slow ionic diffusion in liquid electrolyte on the reaction distribution, the laminated electrode was prepared by setting the kapton film on the LiCoO2 composite layer. Ionic diffusion can proceeds only through the edge to inside of the laminated electrode. The state of charge at a certain position was evaluated from the peak top position of the Co K-edge XANES spectra. Non-uniform charged area was formed from the edge to 60 mm inside of the electrode under the high rate charge condition. This suggests that the reaction distribution due to ionic diffusion can be formed even in practical electrode under high rate charge/discharge conditions. The highly advanced measuring technique was successfully established, which can contribute to the development of the practical batteries and next-generation rechargeable batteries.
2) Development of advanced analysis techniques with nuclear magnetic resonance and differential interference contrast microscope (LCM-DIM)
Transport phenomena of lithium containing polymer electrolyte was studied by in-situ 7Li NMR imaging. Direct measurement clarified surface reaction and motion of the lithium ion. From numerical analysis, dynamic parameters such as diffusion measurements and transport number were refined. In addition to the NMR imaging, we have developed diffusion measurement of lithium ion containing electrolyte in separators or composite cathode materials by PFG-NMR. Diffusion coefficients were strongly dependent on diffusion time, which was characteristic behavior of diffusion in inhomogeneous structure. It was analyzed by the theory of anomalous diffusion in restricted area. We have successfully achieved to quantify averaged pore size and tortuosity factor of the inhomogeneous media by PFG-NMR.
To understand surface reaction in battery system, we have developed an exciting optical microscopy which can resolve single atomic steps of metal electrodes such as Au, Pt, and Si in solutions. Single atomic height of 0.24 nm on Au (111) can be seen. Many electrochemical reactions such as dissolution and deposition processes can be followed by the differential interference contrast microscope (LCM-DIM). We are now working on Zn electrodes for a new battery. Dendrite formation should be avoided for this battery. The main goal of our work is to find experimental conditions to avoid the formation of dendrite. We have found few molecules which may exist on Zn play an important role for the formation of dendrites. LCM-DIM can be also used for evaluate many reactions involved in batteries with atomic layer resolution.
ダウンロード成果報告書データベース(ユーザ登録必須)から、ダウンロードしてください。

▲トップに戻る