Using water soluble organic compound as matrix, Carbon-coated LiMn2O4 was synthesized successfully. Co-doped LiMn2O4 was also synthesized. Physical and electrochemical performances were investigated by XRD, IR, SEM an...Using water soluble organic compound as matrix, Carbon-coated LiMn2O4 was synthesized successfully. Co-doped LiMn2O4 was also synthesized. Physical and electrochemical performances were investigated by XRD, IR, SEM and electrochemical testing. The results showed that due to a better conductivity and stabilization of Co-doped LiMn2O4, the electrochemical performances of LiMn2O4 were improved. And Carbon-coated LiMn2O4 also showed a good property because of the reduction of Mn dissolution. Comparatively speaking, Carbon-coated LiMn2O4 showed a more stable electrochemical performance.展开更多
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
The LiMn2O4 spinel was prepared by wet method using Li2CO3, Mn(CH3COO)2·4H2O and CO2 as raw materials. The products were measured by TG/DTA, XRD, IR. The results Showed that the sample calcined at 800℃for 10h wa...The LiMn2O4 spinel was prepared by wet method using Li2CO3, Mn(CH3COO)2·4H2O and CO2 as raw materials. The products were measured by TG/DTA, XRD, IR. The results Showed that the sample calcined at 800℃for 10h was well crystallized monophase product. The contents of Mn?and Mn?of LiMn2O4 spinel were determined simultaneously by spectrophotometric analysis with pyrophosphoric acid.展开更多
文摘Using water soluble organic compound as matrix, Carbon-coated LiMn2O4 was synthesized successfully. Co-doped LiMn2O4 was also synthesized. Physical and electrochemical performances were investigated by XRD, IR, SEM and electrochemical testing. The results showed that due to a better conductivity and stabilization of Co-doped LiMn2O4, the electrochemical performances of LiMn2O4 were improved. And Carbon-coated LiMn2O4 also showed a good property because of the reduction of Mn dissolution. Comparatively speaking, Carbon-coated LiMn2O4 showed a more stable electrochemical performance.
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.
文摘The LiMn2O4 spinel was prepared by wet method using Li2CO3, Mn(CH3COO)2·4H2O and CO2 as raw materials. The products were measured by TG/DTA, XRD, IR. The results Showed that the sample calcined at 800℃for 10h was well crystallized monophase product. The contents of Mn?and Mn?of LiMn2O4 spinel were determined simultaneously by spectrophotometric analysis with pyrophosphoric acid.
