Monoclinic Li0.5MnO2 was synthesized by solid state reaction and the spectral and magnetic properties were studied in comparison with those of spinel LiMn2O4. The XRD pattern and Raman spectrum of Li0.5MnO2 are differ...Monoclinic Li0.5MnO2 was synthesized by solid state reaction and the spectral and magnetic properties were studied in comparison with those of spinel LiMn2O4. The XRD pattern and Raman spectrum of Li0.5MnO2 are different from those of LiMn2O4, which indicate the different long-range and short-range crystal structure. XPS result shows the binding energies of 2p3/2 and 2p1/2 in Li0.5MnO2 are located at 642.3 and 653.6 eV, respectively. Through fitting the XPS spectra, the valence state of Mn ion in Li0.5MnO2 coincides with that in LiMn2O4. The high-temperature susceptibility of Li0.5MnO2 can be fitted by Curie-Weiss law whose Curie and Weiss constants are 33 A·m^2.K/（mol·T） and -277（6） K, respectively. Although Li0.5MnO2 shows spin glass ground state, the transition temperature of Li0.5MnO2 is about 9 K lower than that of LiMn2O4.展开更多
分别采用氢氧化物共沉淀、碳酸盐共沉淀、喷雾干燥的方法合成了层状α-Na Fe O2结构的富锂正极材料0.5Li2Mn O3·0.5Li(Ni1/3Co1/3Mn1/3)O2,通过X射线衍射分析(XRD)、扫描电子显微镜(SEM)和电化学性能测试对不同合成方法所得的样品...分别采用氢氧化物共沉淀、碳酸盐共沉淀、喷雾干燥的方法合成了层状α-Na Fe O2结构的富锂正极材料0.5Li2Mn O3·0.5Li(Ni1/3Co1/3Mn1/3)O2,通过X射线衍射分析(XRD)、扫描电子显微镜(SEM)和电化学性能测试对不同合成方法所得的样品进行了表征。实验结果表明:氢氧化物共沉淀合成的前驱体所制备的正极材料0.5Li2Mn O3·0.5Li(Ni1/3Co1/3Mn1/3)O2具有良好的电化学性能,0.05C倍率下首次放电容量可达247.1 m A·h/g,0.2C倍率条件下经过50次循环,容量保持率为98.7%。展开更多
基金Supported by the National Natural Science Foundation of China(No.50672031)the Special Funds for Major State Basic Research Project of China(No.2009CB220104)+1 种基金Program for Changjiang Scholar and Innovative Research Team in Universities of China(No.IRT0625)Jilin Province Project of Research and Development,China(Nos.20060511 and 20075007)
文摘Monoclinic Li0.5MnO2 was synthesized by solid state reaction and the spectral and magnetic properties were studied in comparison with those of spinel LiMn2O4. The XRD pattern and Raman spectrum of Li0.5MnO2 are different from those of LiMn2O4, which indicate the different long-range and short-range crystal structure. XPS result shows the binding energies of 2p3/2 and 2p1/2 in Li0.5MnO2 are located at 642.3 and 653.6 eV, respectively. Through fitting the XPS spectra, the valence state of Mn ion in Li0.5MnO2 coincides with that in LiMn2O4. The high-temperature susceptibility of Li0.5MnO2 can be fitted by Curie-Weiss law whose Curie and Weiss constants are 33 A·m^2.K/（mol·T） and -277（6） K, respectively. Although Li0.5MnO2 shows spin glass ground state, the transition temperature of Li0.5MnO2 is about 9 K lower than that of LiMn2O4.
文摘分别采用氢氧化物共沉淀、碳酸盐共沉淀、喷雾干燥的方法合成了层状α-Na Fe O2结构的富锂正极材料0.5Li2Mn O3·0.5Li(Ni1/3Co1/3Mn1/3)O2,通过X射线衍射分析(XRD)、扫描电子显微镜(SEM)和电化学性能测试对不同合成方法所得的样品进行了表征。实验结果表明:氢氧化物共沉淀合成的前驱体所制备的正极材料0.5Li2Mn O3·0.5Li(Ni1/3Co1/3Mn1/3)O2具有良好的电化学性能,0.05C倍率下首次放电容量可达247.1 m A·h/g,0.2C倍率条件下经过50次循环,容量保持率为98.7%。
