Synthesis of orthorhombic LiMnO2 by solid-phase reaction under steam atmosphere and a study of its heat and acid-treated phases
Synthesis of orthorhombic LiMnO2 by solid-phase reaction under steam atmosphere and a study of its heat and acid-treated phases
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DOI：
10.1016/s0022-4596(02)00018-x
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发表时间：
2002-11-15
影响因子：
3.3
通讯作者：
Ooi, K
中科院分区：
文献类型：
--
作者：
Chitrakar, R;Sakane, K;Ooi, K
通过γ-MnOOH或Mn 2 O3与LiOH反应合成了低晶型正交晶系LiMnO 2（o-LiMnO 2）。在120 ℃的蒸汽气氛下，固相中的H2O。在封闭系统中，LiOH产生的蒸气。H2O可以增强LiOH在MnOOH或Mn 2 O3颗粒表面的反应性，这可以使得Li+离子能够缓慢扩散形成LiMnO 2。将这些样品与在700 ℃氮气中通过固态反应法制备的晶体o-LiMnO 2进行了比较。低结晶度样品在空气中400 ℃加热后的粉末X射线衍射图显示形成了立方Li1.6Mn1.6O4的单相，但结晶样品在空气中400 ℃加热后显示出o-LiMnO 2和LiMn 2 O 4的混合相。Li+/H+交换在Li1.6Mn1.6O4样品中进行拓扑，同时保持前体的晶体结构和形貌。但热处理后的晶态o-LiMnO_2表现出Mn ~（2+）离子溶解的分解反应。(C)2002 Elsevier Science（美国）。All rights reserved.
Low crystalline orthorhombic LiMnO2 (o-LiMnO2) samples were synthesized by reacting either gamma-MnOOH or Mn2O3 with LiOH . H2O in the solid phase under steam atmosphere at 120degreesC. In the closed system, the vapor arising from LiOH . H2O may strengthen the reactivity of LiOH at the surface of MnOOH or Mn2O3 particles, which may enable slow diffusion of Li+ ions forming LiMnO2. These samples were compared with crystalline o-LiMnO2 prepared by a solid-state reaction method at 700degreesC in nitrogen gas. The powder X-ray diffraction patterns of low crystalline samples after heating at 400degreesC in air revealed the formation of a single phase of cubic Li1.6Mn1.6O4, but the crystalline sample revealed a mixed phase of o-LiMnO2 and LiMn2O4 after heating at 400degreesC in air. The Li+/H+ exchange in the Li1.6Mn1.6O4 sample progressed topotactically, while maintaining the crystal structure and morphology of the precursor. But heat-treated crystalline o-LiMnO2 showed a disproportionation reaction with dissolution of Mn2+ ions. (C) 2002 Elsevier Science (USA). All rights reserved.