Li x Mn 2O 4 spinels were prepared by in situ redox precipitation hydrothermal synthesis method, and characterized by XRD, BET, TGA, TEM and SEM etc. , and the effects of many factors on the properties of as prepared ...Li x Mn 2O 4 spinels were prepared by in situ redox precipitation hydrothermal synthesis method, and characterized by XRD, BET, TGA, TEM and SEM etc. , and the effects of many factors on the properties of as prepared Li x Mn 2O 4 samples were investigated. The results demonstrated that Li x Mn 2O 4 spinels can be synthesized under milder conditions by in situ redox precipitation hydrothermal synthesis method. Li x Mn 2O 4 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 x Mn 2O 4 synthesis were determined as follows: the alkalinity(pH value) 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.展开更多
文摘Li x Mn 2O 4 spinels were prepared by in situ redox precipitation hydrothermal synthesis method, and characterized by XRD, BET, TGA, TEM and SEM etc. , and the effects of many factors on the properties of as prepared Li x Mn 2O 4 samples were investigated. The results demonstrated that Li x Mn 2O 4 spinels can be synthesized under milder conditions by in situ redox precipitation hydrothermal synthesis method. Li x Mn 2O 4 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 x Mn 2O 4 synthesis were determined as follows: the alkalinity(pH value) 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.
