Spinel lithium manganese oxides doped with rare earth elements in forms of LiM 0.02 Mn 1.98 O 4 (M=La, Pr and Sm) were prepared and their electrochemical properties for lithium ion intercalation reaction were investigated. The materials were prepared by solid state reaction using electrolytic MnO 2, Li 2CO 3 with Pr 2O 3, Sm 2O 3 or La(NO 3) 3·H 2O. From the voltammetry test it was found that the reversibility of lithium intercalation reaction could be improved by doping with Sm or Pr into spinel lithium manganese oxides. Although the first discharge capacity was decreased by about 10% for LiPr 0.02 Mn 1.98 O 4 and LiSm 0.02 Mn 1.98 O 4 compounds compared with undoped LiMn 2O 4, but their cycling properties were improved, obviously.
A novel disulfide-containing aniline, 8-dihydro-1H,4H-2,3,6,7-tetrathia-anthracen-9-ylamine (5) was synthesized.The single-crystal X-ray analysis of 4 indicates that the molecular has a non-planar structure, with its four sulfur atoms out of the plane of benzene ting. The designed molecular has the advantage of high theoretic specific capacity and reversibility,[1,2] when it is to be polymerized and used as the cathode material of the secondary lithium batteries.……
Nanosized spinel LiMn 2O 4 was prepared by a sol-gel method. The preparation process was monitored by XRD, BET, DTA, TGA and TEM observations. It is found that at temperature higher than 350 ℃ the spinel phase of the samples could be detected by XRD, which is lower than that temperature in common solid-state preparation. The diameters of the samples calculated by Sherrer equation were increased with the temperature of calcination.
