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
2011/6/30

課題番号 Project No.

装置責任者 Name of responsible person

2010B0065

Touru Ishigaki

実験課題名 Title of experiment

装置名 Name of Instrument/（BL No.）

Crystal structure analysis of lithium-excess layered material

iMateria (BL No.20)

Li1+xMO2 (M=Ni, Co, Mn) - New cathode material for lithium

実施日 Date of Experimentbatteries

2011/3/9 - 3/10

実験責任者名 Name of principal investigator
Ryoji Kanno
所属 Affiliation
Tokyo Institute of Technology
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.

Powdered Li1.6Ni0.3Co0.2Mn0.3O2 and Li1.7Ni0.3Co0.2Mn0.3O2 in the lithium excess LixM0.8O2(M=Ni, Co, Mn) system were synthesized by a high-pressure synthesis method.

We confirmed acontinuous lattice expansion with increasing lithium compositions from 1.4 to 1.7 using X-ray
diffraction measurements, but lithium positions have not been clarified.

These compounds show

an excellent charge/discharge characteristic as a cathode material for lithium batteries.

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.

Neutron diffraction data of Li1.6Ni0.3Co0.2Mn0.3O2 and Li1.7Ni0.3Co0.2Mn0.3O2 were taken at room
temperature on a time-of-flight (TOF) neutron powder diffractometer at iMATERIA (BL20) using
the BS (Back Scattering) bank. The specimen of ca. 1.5 cc is contained in a cylindrical vanadiumcell of dimensious 10 mm inradius, 20 mm in height. The data were analyzed by the Rietveld
method using the Z-Rietveld program.
Figure 1 shows a preliminary Rietveld analysis result using neutron diffraction data of
Li1.7Ni0.3Co0.2Mn0.3O2.

Structural parameters are summarized in Table 1.

The structure wasrefined based on the structure model with a layered rocksalt structure investigated by the X-ray
Rietveld analysis. The present refined structure cannot explain positions of the excess lithium inthe layered structure.

The detailed structure is under analyzing to clarify (i) extent of disordering
12. 実験方法及び結果（つづき） Experimental method and results (continued)

at the lithium layer, (ii) stacking disorder perpendicular to the two-dimensional lithium layer, (iii)
distribution of transition metals, Mn, Ni, and Co. These parameters that are variable and controllable
by changing synthesis conditions affect significantly for its lithium storage capacity, and it isnecessary to clarify the charge-discharge mechanism, which provides extremely high capacity for ournew material.

Fig. 1

Observed (plus marks), calculated (solid line), and difference (bottom) patterns for the Rietveld refinementfrom neutron diffraction data of Li1.7Mn0.3Co0.2Ni0.3O2.

The short vertical lines below the profiles mark the peak

positions of all the possible Bragg reflections.
Table 1

Rietveld refinement results for Li1.7Mn0.3Co0.2Ni0.3O2.

AtomSitegxyz

B / Å2Li1

3a0.8393(7)

0001

Li2

3b0.1992(6)

000.5

0.5

Ni13b0.3002(1)

000.5

0.5

Mn13b0.2996(3)

000.5

0.5

Co13b0.2007(5)

000.5

0.5

O16c

1000.24286(2)

0.8

Ni2

3a0.1607(7)0001Li36c0.022(1)000.125

12a = 2.895711(4) Å, c = 14.31221(5) Å, Rwp = 5.18%, Rp = 3.95%, Re = 2.16%, S = 5.731, RB= 7.15%, RF = 2.17%

2