Reaction mechanisms for 0.5Li2MnO3·0.5LiMn0.5Ni0.5O2 precursor prepared by low-heating solid state reaction

• Published in: International journal of minerals, metallurgy and materials metallurgy and materials, 2012-09, Vol.19 (9), p.856-862
• Main Authors: Li, Dong, Lian, Fang, Hou, Xin-mei, Chou, Kuo-chih
• Format: Article
• Language: English
• Subjects: Calorimetry; Ceramics; Characterization and Evaluation of Materials; Chemical synthesis; Chemistry and Materials Science; Composites; Corrosion and Coatings; Decomposition reactions; Diffraction patterns; Emission analysis; FESEM; Field emission microscopy; Fourier transforms; Glass; Heating; Infrared spectroscopy; Lithium; Manganese; Materials Science; Metallic Materials; Natural Materials; Precursors; Reaction mechanisms; Solid state; Surfaces and Interfaces; Thermogravimetric analysis; Thin Films; Tribology; X-ray diffraction; X-射线衍射; 低热固相反应; 傅里叶变换红外光谱; 前驱物; 反应机制; 场发射扫描电子显微镜; 差示扫描量热法
• ISSN: 1674-4799; 1869-103X
• DOI: 10.1007/s12613-012-0639-6

Lithium-excess manganese layered oxides, which are commonly described in chemical formula 0.5Li2MnO3·0.5LiMn0.5Ni0.5O2, were prepared by low-heating solid state reaction. The reaction mechanisms of synthesizing precursors, the decomposition mechanism, and intermediate materials in calcination were investigated by means of Fourier transform infrared spectroscopy （FT-IR）, X-ray diffraction （XRD）, field emission scanning electron microscopy （FESEM）, thermogravimetric analysis （TGA）, and differential scanning calorimetry （DSC）. The major diffraction patterns of 0.5Li2MnO3·0.5LiMn0.5Ni0.5O2 powder calcinated at 720℃ for 15 h are indexed to the hexagonal structure with a space group of R3m, and the clear splits of doublets at （006）/（102） and （108）/（110） indicate that the sample adopts a well-layered structure. FESEM images show that the size of the agglomerated particles of the sample ranges from 100 to 300 nm.