Rare Earth And Zirconium Doped Spinel Of Limn <sub> 2 </ Sub> O <sub> 4 </ Sub>

With the advance of science and technology, energy and environmental are becoming worse. People have paid close attention to the Li-ion batteries as its favorable advantages of high voltage, big specific capacity life and non-pollution. The cathode material of the spinel LiMn₂O₄ have a good prospect in application because of its abundant resources, low cost, easy to synthesis, and environment friendly. But the problems of poor cyclybility and low capacity prevent it from wide application. It is an effective method using rare earth to improve the capabilities of spinel LiMn₂O₄. It is important to find new application for rare earth because of its abundance. For as much as the unique physical chemistry characters of rare earth and the application on other cell, there is an optimism foreground for doping rare earth into spinel LiMn₂O₄. Aiming at the merits and defects, we use the rare earth to improve the electro-character of spinel LiMn₂O₄.In the work, summarize the development of Li-ion batteries and every part of batteries. Based on summarizing and comparing the advantages and shortcoming of the cathode materials, the spinel LiMn₂O₄ are demand.Following, introducing the characters of zirconium and rare earth, and the researches of these doped in the spinel LiMn₂O₄. The work adopting the two steps of solid phase synthesis method, research the effect of zirconium and rare earth doped the Li-ion batteries cathode material spinel LiMn₂O₄. Analyze the mechanism and reaction of materials carrying through the analysis of TG-DTG, then consider the effect of rising temperature speed on the grain of material, to insure the technology route of experimentation.Then the cathode materials are assembled into batteries to study the effect of zirconium and rare earth doped in spinel LiMn₂O₄. From the dates of test, the material doped ZrO₂ 0.02, Ce doped 0.03, Nd doped 0.005, Ho doped 0.01, and Lu doped 0.01 are best and the capabilities of diferent materials are 119mAh/g, 122mAh/g, 118mAh/g, 112mAh/g and 113mAh/g.The cathode material LiMn_1.98Zr_0.02O₄, LiMn_1.97Ce_0.03O₄ and LiMn_1.995Nd_0.005O₄ have excellent reversibilities and cyclybilities at room temperature(25℃) and high temperature(55℃). Then explain the performance of the cathode materials through the tests of XRD, SEM-EDS and XPS.In this paper, we synthesize LiMn_1.98Zr_0.02O_3.5F_0.5 and LiMn_1.995Nd_0.005O_3.5F_0.5, but a little Mn₂O₃ exist through XRD, so the performance is not very good.To sum up, the structure of material doped zirconium is stabilization. Rare earth have optimism foreground in altering the performance of materials on account of the special characters of rare earth, the application in other cells and the outstanding performance in this work, especial to improve the performance of batteries at high temperature.For the future, the research on using cation and antion to dop together need more study.