关键词: 水热合成, 原位氧化还原沉淀, 尖晶石, Li_xMn₂O

Abstract: Li_xMn₂O₄ spinels were prepared by in-situ redox precipitation hydrothermal synthesis method, and characterized by XRD, BET, TGA, TEMand SEMetc. , and the effects of many factors on the properties of as-prepared Li_xMn₂O₄ samples were investigated. The results demonstrated that Li_xMn₂O₄ spinels can be synthesized under milder conditions by in-situ redox precipitation hydrothermal synthesis method. Li_xMn₂O₄ spinels are cubic and symmetrical, and have a better stability at less than 700℃, their surface areas and particle sizes were strongly affected by crystallization temperature and time, pH value, calcination temperature and time. The optimal conditions of Li_xMn₂O₄ synthesis were determined as follows: the alkalinity(pHvalue) was 9; the crystallization temperature and time were more than 240 ℃ and 48 h, respectively; the calcination temperature and time were between 700-750 ℃ and 6-12 h, respectively; the molar ratio of Li to Mn was less than 1.2/2.

Key words: Hydrothermal synthesis, in-situ redox precipitation, Spinel, Li_xMn₂O₄