Study On Industrialization Process Of Ternary Cathode Material For Lithium Ion Batteries

LIB?lithium ion battery? is one of the most important methods to solve the problem of energy sources. As an important part of LIB, the performance of cathode material may affect the performance of LIB. The researching for the new kind of cathode material with high performance and low cost is always the purpose of lithium-ion battery. As a cathode material for LIB, layered three element material LiNi_l/3Co_1/3Mn_l/3O₂ provides attractive advantages including large reversible capacity, better cycle performance, excellent safety and low cost. This kind of material is regarded as the most promising and new cathode material to substitute LiCoO2. At present, this kind of cathode material is introducing into the market gradually, especially, in the field of electric vehicle?EV? and hybrid electric vehicle?HEV?, and it still has very large space to develop.Co-precipitation method was chosen as the optimal synthetic method for layered LiNi_l/3Co_1/3Mn_l/3O₂. The precursor Ni1/3Co1/3Mn1/3?OH?2 was prepared by chemical co-precipitation process in this paper, and Li Nil/3Co1/3Mnl/3O2 was synthesized by solid state reaction method. Taking LiNi_l/3Co_1/3Mn_l/3O₂ as researching object, the effect of different synthesis method on physical and electrochemical performance of product was studied. The particle morphology, lattice structure and electrochemical performance were studied by X-ray diffraction?XRD? analysis, scanning electron microscope?SEM? analysis, TG-DTA analysis, and galvanostatic charge/discharge testing method.During the process of making Ni1/3Co1/3Mn1/3?OH?2 precursor by chemical coprecipitation method, the effects of pH value, metal ion concentration, precipitator concentration and complexing agent on precursor were investigated. As a result, when the range of p H value is about 10.5, metal ion concentration is 2 mol/L, precipitator concentration is 4 mol/L, and complexing agent is 3 mol/L, Ni1/3Co1/3Mn1/3?OH?2 precursor has a narrow particle distribution, and moreover, the particles are ball-like.During the process of synthesizing Li Nil/3Co1/3Mnl/3O2 by solid state reaction method, the effects of calcination temperatures, sinter time, different Li/?Ni+Co+Mn? mole ratio on product were researched. The test results show that when the mole ratio of Li/M?Ni+Co+Mn? is 1.05/1 and the mixed materials are calcined at 900? for 12 h, Li Nil/3Co1/3Mnl/3O2 can be successfully synthesized. The initial discharge specific capacity is 154.50mAh/g in 2.75⁴.3V at 0.2C and after 20 cycles, the capacity retention is 92.91%.