成果報告書詳細
管理番号20150000000227
タイトル*平成26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 (3)
公開日2015/5/26
報告書年度2014 - 2014
委託先名学校法人立命館大学
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Development of innovative analytical methods for secondary batteries using soft X-ray synchrotron radiation

In the SR center of Ritsumeikan University, two soft X-ray XAFS beamlines (BL-2 and 10) and three hard X-ray XAFS beamlines (BL-3, 4 and 5) are devoted to the studies of secondary batteries. In addition, two beamline (BL-11 and 13) for soft X-ray spectroscopy have been newly developed and constructed for soft X-ray XAFS experiments. Several developments and improvements have been performed in the fiscal year, 2014.

(1) Direct observation of reversible charge compensation by O ion in Li-rich Mn layered oxide positive electrode material

The depth-profiling XAFS method was applied to study the charge compensation mechanism of Li rich Mn layered oxide cathode, Li_{1.16}Ni_{0.15}Co_{0.19}Mn_{0.50}O_{2. O}.O K-XAFS spectra of the charged state shows significant pre-edge enhancement compared with that of the discharged state, indicating the peroxide ion formation. This is a direct evidence of reversible charge compensation by O ions.

(2) Development of a compact high resolution soft X-ray double crystal monochromator beamline

By adopting a unique optical design, a compact double crystal monochromator beamline for soft X-ray region has been constructed. The diverging SR beam is converted to a pseudo-parallel beam with a toroidal mirror and is delivered in the double crystal monochromator. The monochromatized parallel beam is focused by another toroidal mirror onto the sample position with a beam size of 2mm H x 1mmV apart from the source
point by 7 m. The performance test revealed that higher energy resolution with higher intensity can be obtained than that of the conventional one (BL-10). This beamline will be exclusively used for the battery project.

(3) Development of a vertically dispersive XAFS method and its application to the battery reactions

A vertically wavelength-dispersive XAFS method was newly designed and constructed, which enables us quick 1D imaging XAFS. This method was successfully applied to trace the charging process of the LiFePO_{4} electrode. It is confirmed that the charging reaction takes place inhomogeneously and the reaction mechanism at delayed parts cannot be explained by a simple kinetics.

(4) Development of a double dispersive XAFS method for simultaneous measurements of two elements

With two curved crystals, both focusing into a same sample position, a double dispersive XAFS method can be achieved. This enables us to obtain dispersive XAFS spectra for two elements simultaneously. This method must be useful for the study of reaction dynamics involving two elements, such as battery electrodes. The experimental set up has been completed and the performance test will be performed soon.
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