Hydrothermal Syntheses of Layered Lithium Nickel Manganese Oxides from Mixed Layered Ni(OH)2-Manganese Oxides
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- 作者：Yaohua Xu ; Qi Feng ; Koji Kajiyoshi ; Kazumichi Yanagisawa ; Xiaojing Yang ; Yoji Makita ; Shuji Kasaishi ; and Kenta Ooi
- 刊名：Chemistry of Materials
- 出版年：2002
- 出版时间：September 2002
- 年：2002
- 卷：14
- 期：9
- 页码：3844 - 3851
- 全文大小：174K
- 年卷期：v.14,no.9(September 2002)
- ISSN：1520-5002
文摘
A series of mixed layered Ni(OH)2-manganese oxides with Ni/Mn molar ratios up to near1 were prepared by using a novel exfoliation-restacking hydrothermal method and ahydrothermal intercalation method. A series of lithium nickel manganese oxides withhexagonal layered structure (space group R
m) can be obtained by hydrothermal treatmentof the mixed layered Ni(OH)2-manganese oxides in a concentrated LiOH solution at 200
C. Another type of lithium nickel manganese oxide with an 
-LiFeO2-like cubic structurecan be obtained by using NiMnO3 as precursor under similar hydrothermal conditions. Thesynthesis reactions and the products were investigated by XRD, TEM, TG-DTA, and XPSstudies. The mixed layered structure of Ni(OH)2-manganese oxides can be described bytwo sublattices having different hexagonal unit-cell parameters in the ab plane but a commonperiodicity perpendicular to them along c. The layered lithium nickel manganese oxides canbe expressed by a general formula of {Lix}[LiyNinMnm]O2 (x 
1, y 1/3, (y + n + m) 1).The cubic phase of lithium nickel manganese oxide is metastable, which transforms to thehexagonal layered phase after heating at 500 C in air.
m) can be obtained by hydrothermal treatmentof the mixed layered Ni(OH)2-manganese oxides in a concentrated LiOH solution at 200C. Another type of lithium nickel manganese oxide with an -LiFeO2-like cubic structurecan be obtained by using NiMnO3 as precursor under similar hydrothermal conditions. Thesynthesis reactions and the products were investigated by XRD, TEM, TG-DTA, and XPSstudies. The mixed layered structure of Ni(OH)2-manganese oxides can be described bytwo sublattices having different hexagonal unit-cell parameters in the ab plane but a commonperiodicity perpendicular to them along c. The layered lithium nickel manganese oxides canbe expressed by a general formula of {Lix}[LiyNinMnm]O2 (x 1, y 1/3, (y + n + m) 1).The cubic phase of lithium nickel manganese oxide is metastable, which transforms to thehexagonal layered phase after heating at 500 C in air.