サイエンス記事
リチウムイオン電池正極材料の平均・局所構造と電池特性
キーワード:
Crystal structure,
Li ion battery,
Cathode material,
Local structure,
Pair distribution function method
2013 年 23 巻 4 号 p. 272-277
詳細
2013 年 23 巻 4 号 p. 272-277
In the present study, we performed ex-situ measurements of the change in the crystal structure of the cathode material subjected to a charge - discharge cycle in a coin type cell fabricated for this purpose. The results of this study demonstrate that it is possible to perform ex-situ structural analysis by neutron diffraction of only 8.5 mg of an active material in a cathode together with the cathode fabrication materials. Moreover, the average, local and electronic structures of LiMn1/3Ni1/3Co1/3O2 prepared by various methods was investigated. In order to clarify how the preparation processes affected on the crystal structures in detail, local structure, i.e. cation mixing and transition-metal ordering, in the samples were analyzed by Pair Distribution Function (PDF) method using a neutron source and X-ray absorption fine structure measurements. From this analysis, it was found that the local structure in LiMn1/3Ni1/3Co1/3O2 depended on the preparation process. Such a difference in the local structures may result in different cathode properties among the samples synthesized.
