実験報告書様式（一般利用課題・成果公開利用）

MLF Experimental Report

提出日 Date of Report
30th July, 2011

課題番号 Project No.

装置責任者 Name of responsible person

2010B0083

Professor Dr. Toru Ishigaki

実験課題名 Title of experiment

装置名 Name of Instrument/（BL No.）

Crystal structure analysis of Li2CuO2 Cathode Material for Lithium

i-MATERIA/BL-20- ion Batteries

実施日 Date of Experiment

実験責任者名 Name of principal investigator

10-11th December, 2010

Yoshinori ARACHI

10-12th February, 2011

所属 Affiliation
Kansai University
試料、実験方法、利用の結果得られた主なデータ、考察、結論等を、記述して下さい。（適宜、図表添付のこと）
Please report your samples, experimental method and results, discussion and conclusions. Please add figures andtables for better explanation.
1. 試料 Name of sample(s) and chemical formula, or compositions including physical form.
Samples:
Li2CuO2 and Li2-xCuO2. Chemical analysis showed that average valence state of Cu was 1.97 by iodometry
and ICP analysis and chemical composition was nearly stoichiometric Li2.02Cu1.00O2.00.
Synthesis of samples:
The conventional solid-state reaction was used. Starting materials were chemical grade Li2CO3 and CuO.
They were calcined at 1023 K for 24 h and sintered at 1073 K for 24 h in air.

Samples for Li2-xCuO2 wereprepared electrochemically using lithium cells with a coin-type configuration.

2. 実験方法及び結果 （実験がうまくいかなかった場合、その理由を記述してください。）
Experimental method and results.

If you failed to conduct experiment as planned, please describe reasons.

Experimental method
Neutron diffraction data were collected at room temperature on the time-of-flight (TOF) neutron powder
diffractometer installed in BL-20, i-MATERIA with pulsed spallation neutron source at Japan Photon Accelerator
Research Complex (J-PARC).

The specimen (ca. 1 g) was contained in a cylindrical vanadium cell having aradius 6 mm and height 60 mm. The structural parameters were refined by Rietveld analysis using the computer
program Z-Rietveld.
Experimental results
Fig. 1 shows the one of representative results of Rietveld analysis for neutron diffraction pattern of Li2CuO2
obtained from back surface bank at room temperature. The measurement time was for 35 minutes and thesamples weight was 1.74 g.

The intensity was sufficient for the following further analysis.

a relatively good fitting by using the structure model, S.G. Immm.

The obtained lattice parameters fororthorhombic were a = 3.65423(11)Å, b = 2.86078(9) Å and c = 9.38862(27) Å.
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Refinement yields

2. 実験方法及び結果（つづき） Experimental method and results (continued)
However, some additional peaks are clearly shown in the pattern and some of those correspond to CuO phase,
which was not detected by X-ray diffraction in our laboratory.

However, the magnetic property of the sample,

Li2CuO2 confirmed that an anti-ferromagnetic behavior with Néel temperature, TN = 10 K.

It can therefore be

presumed that here the stability is involved.
Then, analysis using a mixed model composed of Li2CuO2 and CuO are under investigation and for anothersamples including different Li content as well.
due to CuO phase increased.

With lithium-removing, LiCuO2 phase appeared and the peaks

At the present the Rietveld refinement doesn’t progress satisfactory.

reason is due to the structure model of CuO phase.
effect of CuO on the electrochemical activity.

The mainHowever, this CuO phase is a key to understand the uniqueIn this experiment, the main object is to clarify the crystal

structure change of Li2-xCuO2 related to the electrochemical reaction, while focusing on changes in distributionof Li and oxygen.

The further analysis should be needed.

Fig.1 Observed and calculated diffraction profiles for
Rietveld refinement using TOF neutron data.

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