Preparation And Study Of Lithium Manganese Oxide

With the rapid development of today's technologies, information and network, peoplehave made high demands on the low price and long life-term batteries. Low cost, highenergy density, high-voltage, light and long cycle life, safety and good performances of thenew green power-lithium ion rechargeable batteries become a hot spot, now have beenwidely used in all kinds of lightweight, small size of portable electronic equipments andmobile electrical devices. In the next few years, the commercialize cathode material will beLiCoO₂, the capacity of LiCoO₂ generally is restricted in 125mAh/g. The high price andtoxic of Co, also with cheap and high performance cathode materials for studying in depth,the using of LiCoO₂ will gradually reduce. Although LiNiO₂ has high capacity (180mAh/g),raw materials wide adaptability, it is poor thermal stability and Synthesis difficulties. Thatimpedes the commercialization process of LiNiO₂. The spinel of LiMn₂O₄ has high voltage,high security, low cost, clean and other characteristics which are expected to be the nextgeneration to replace lithium ion battery cathode material of the LiCoO₂.This paper summarized the lithium ion battery principle, the development process andthe advantages of green power, described and compared several lithium-ion battery cathodematerials of the situation. With many researchers having came to the conclusion that thespinel LiMn₂O₄ is considered to be the most promising as a lithium-ion battery cathodematerial substitute of LiCoO₂, which is as a research direction in the paper. We analyzedthe research of spinel LiMn₂O₄, including the advantages and shortcomings of the spinelLiMn₂O₄ as a cathode material. Theoretical analyze the causes of defect and giveimprovement measures; Summary of lithium manganese oxide synthesis of the many waysand comparison of the advantages and disadvantages of the various methods, the use ofmechanical activation wet-section as a solid-phase method. Based on the shortcomings ofthe spinel LiMn₂O₄ take doping measures, doping of specific cation doping Co, aniondoping F and anion and cation Co, the F-doped. According to many workers on the latestresearch findings and the needs of industrial production, based on the traditionalsolid-phase synthesis, on the basis of raw materials used ball mill for wet milling machineactivation,consider wet milling-section method of solid-phase spinel LiMn₂O₄ cathode material as a research priority. By XRD, TEM, SEM to detect and electrochemical analysisof the combination studied the properties. Through a series of tests found thatLi_1.05Mn_2-xM_xO₄ cation-doped compounds (M=Co) in the charge-discharge process havepresence: with the increasing of doping, the capacity of materials gradually reduced and thecycle performance tends to be stable. The ion doping experiment was found thatLi_1.05Mn₂O₄ lithium-rich spinel stability of the cycle was better than the stoichiometricLiMn₂O₄. The Co doping 0.2 is the best doping. In Anion and cation-doped study,Li_1.05Mn_1.8M_0.2O_3.9F_0.1 synthetic material (M=Co) capacity was higher than separatedoping cation.Generally speaking, although the cation doping in certain extent reduced the capacity,it could improve the recycling performances of materials properties; and the F-dopingmaterials will enhance the capacity, but the cycle performance will become worse. Dopingon the composite material properties of the mechanism needs further in-depth study.