A simple hydrothermal process followed by heat treatment was applied to the preparation of spinel Li1.05Mn1.95O4. In this process, electrolytic manganese dioxide(EMD) and LiOH·H2O were used as starting materials....A simple hydrothermal process followed by heat treatment was applied to the preparation of spinel Li1.05Mn1.95O4. In this process, electrolytic manganese dioxide(EMD) and LiOH·H2O were used as starting materials. The physiochemical properties of the synthesized samples were investigated by thermogravimetry-differential scanning calorimetry(TG-DSC), X-ray diffractometry(XRD), and scanning electronic microscopy(SEM). The results show that the hydrothermally synthesized precursor is an essential amorphous. The precursor can be easily transferred to spinel powders with a homogeneous structure and a regularly-shaped morphology by heat treatment. Li1.05Mn1.95O4 powder obtained by heat treating the precursor at 430 °C for 12 h and then calcining at 800 °C for 12 h shows an excellent cycling performance with an initial charge capacity of 118.2 mA·h·g-1 obtained at 0.5C rate and 93.8% of its original value retained after 100 cycles.展开更多
LiNi0. 45 Co0. 10 Mn0. 4sO2 was synthesized from Li2CO3 and a triple oxide of nickel, cobalt and manganese at 950 ℃ in air. The structures and characteristics of LiNi0. 45 Co0.10 Mn0. 45 O2, LiCoO2 and LiMn2 O4 were ...LiNi0. 45 Co0. 10 Mn0. 4sO2 was synthesized from Li2CO3 and a triple oxide of nickel, cobalt and manganese at 950 ℃ in air. The structures and characteristics of LiNi0. 45 Co0.10 Mn0. 45 O2, LiCoO2 and LiMn2 O4 were investigated by XRD, SEM and electrochemical measurements. The results show that LiNi0.4s Co0.10 Mn0. 45 O2 has a layered structure with hexagonal lattice. The commercial LicoO2 has sphere-like appearance and smooth surfaces, while the LiMn2 O4 and LiNi0.45 Co0. 10 Mn0. 45 O2 consist of cornered and uneven particles. LiNi0. 45 Co0.10 Mn0. 45 O2 has a large disLiMn2 O4 and LiCoO2, respectively. LiCoO2 and LiMn2 O4 have higher discharge voltage and better rate-capability than LiNi0. 45Co0.10 Mn0. 45 O2. All the three cathodes have excellent cycling performance with capacity retention of above 89.3 % at the 250th cycle. Batteries with LiMn2 O4 or LiNi0.45 Co0.10 Mn0. 45 O2 cathodes show better safety performance under abusive conditions than those with LiCoO2 cathodes.展开更多
Modified lithium manganese oxides were prepared by using LiMn 2 O 4 and LiCoO 2 as precursors by solid state reaction.A study has been carried out by TG - DSC,XRD and FTIR to analyze the reaction process and structura...Modified lithium manganese oxides were prepared by using LiMn 2 O 4 and LiCoO 2 as precursors by solid state reaction.A study has been carried out by TG - DSC,XRD and FTIR to analyze the reaction process and structural characterization of products.The results showed that the LiMn 2 O 4 reacted chemically with LiCoO 2 at high temper - ature.Li and Co atom could insert into the LiMn 2 O 4 crystal lattice and obtained the Cobalt - Doped spinel com - pound.The results of constant - current cyclic test showed that the cyclic stability of the products are increased with the amount of doped LiCoO 2 ,while their initial capacity is decreased.展开更多
基金Project(50174058)supported by the National Natural Science Foundation of ChinaProject(2011A025)supported by the Glorious Laurel Scholar Program of Guangxi Zhuang Autonomous Region,China
文摘A simple hydrothermal process followed by heat treatment was applied to the preparation of spinel Li1.05Mn1.95O4. In this process, electrolytic manganese dioxide(EMD) and LiOH·H2O were used as starting materials. The physiochemical properties of the synthesized samples were investigated by thermogravimetry-differential scanning calorimetry(TG-DSC), X-ray diffractometry(XRD), and scanning electronic microscopy(SEM). The results show that the hydrothermally synthesized precursor is an essential amorphous. The precursor can be easily transferred to spinel powders with a homogeneous structure and a regularly-shaped morphology by heat treatment. Li1.05Mn1.95O4 powder obtained by heat treating the precursor at 430 °C for 12 h and then calcining at 800 °C for 12 h shows an excellent cycling performance with an initial charge capacity of 118.2 mA·h·g-1 obtained at 0.5C rate and 93.8% of its original value retained after 100 cycles.
基金Project(50302016) supported by the National Natural Science Foundation of China Project(2005037698) supported by the Postdoctoral Science Foundation of China
文摘LiNi0. 45 Co0. 10 Mn0. 4sO2 was synthesized from Li2CO3 and a triple oxide of nickel, cobalt and manganese at 950 ℃ in air. The structures and characteristics of LiNi0. 45 Co0.10 Mn0. 45 O2, LiCoO2 and LiMn2 O4 were investigated by XRD, SEM and electrochemical measurements. The results show that LiNi0.4s Co0.10 Mn0. 45 O2 has a layered structure with hexagonal lattice. The commercial LicoO2 has sphere-like appearance and smooth surfaces, while the LiMn2 O4 and LiNi0.45 Co0. 10 Mn0. 45 O2 consist of cornered and uneven particles. LiNi0. 45 Co0.10 Mn0. 45 O2 has a large disLiMn2 O4 and LiCoO2, respectively. LiCoO2 and LiMn2 O4 have higher discharge voltage and better rate-capability than LiNi0. 45Co0.10 Mn0. 45 O2. All the three cathodes have excellent cycling performance with capacity retention of above 89.3 % at the 250th cycle. Batteries with LiMn2 O4 or LiNi0.45 Co0.10 Mn0. 45 O2 cathodes show better safety performance under abusive conditions than those with LiCoO2 cathodes.
文摘Modified lithium manganese oxides were prepared by using LiMn 2 O 4 and LiCoO 2 as precursors by solid state reaction.A study has been carried out by TG - DSC,XRD and FTIR to analyze the reaction process and structural characterization of products.The results showed that the LiMn 2 O 4 reacted chemically with LiCoO 2 at high temper - ature.Li and Co atom could insert into the LiMn 2 O 4 crystal lattice and obtained the Cobalt - Doped spinel com - pound.The results of constant - current cyclic test showed that the cyclic stability of the products are increased with the amount of doped LiCoO 2 ,while their initial capacity is decreased.
