Studies On The Preparation And Modification Of Molybdenum Iron Lithium Oxide Cathode Material For Lithium-ion Battery

Since we entered the new century,the rapid development of economy has urged the rapid rise of energy storage equipment.Traditional LiCoO2 cathode material,because of its high cost and low capacity, can not meet the needs of modern society. At present, the research on the cathode materials of lithium ion batteries is mainly focused on some kinds of excessive metal elements in the fourth periodic table of elements and their doping modification. But they have their own shortcomings:for example, the production process of nickel materials is complex and the structure is not stable;low bulk density and poor chemical stability of lithium iron phosphate and so on.So the study of new cathode materials for lithium-ion battery development is particularly critical. To this end, we explore a new type of cathode material——molybdenum lithium oxide. The optimum synthesis conditions and the ratio of its synthesis were explored by high temperature solid state method. Then we use Cr to modify it and improve it.It is found that there is a significant improvement in the cycle performance and the capacity. Specific operations are as follows:Synthesis of Li2MoFe0.1Ox by high temperature solid state method. With MoO3 and Fe(NO3)3 as raw materials, adding nitric acid, stirring evenly, sinter to get precursor.After 750℃ reduction,add lithium salt and calcination to get the cathode material Li2MoFe0.1Ox. The first charge capacity of Li2MoFe0.1Ox cathode material is 113.4mA h/g. the efficiency of the first time in coulomb is 94.8%. The retention rate of the first 20 cycles is 80.2%. Capacity and cycle performance remains to be improved.The material Li2MoFe0.1Ox is doped with Cr,and the method is used as alloying method. The specific steps will be that making certain proportion of MoO3, Fe(NO3)3 and Cr (NO3)3 mixed evenly, adding nitric acid, sinter to get the precursor. Then in the atmosphere furnace with H2 to restore,reducing temperature is 1150 ℃.Oxidated in the muffle furnace. The material Li2MoFe0.1Cr0.02Ox will be obtained after 750℃ low temperature reduction and adding lithium salt to calcinate in the atmosphere furnace. Material Li2MoFe0.1Cr0.02Ox for the first time charging capacity is up to 136.6mAh/g. For the first time,the coulomb efficiency is 95.7%. The capacity retention rate for the first 20 times cycle is 92.4%, and it is 68.2% after 40 times cycle. Although the material in terms of capacity and cycle performance are to be improved, but also show the potential of the material as a cathode material for lithium ion batteries.