Preparation And Modification Of LiNi_0.5Co_0.2Mn_0.3O₂ Of The Lithium Ion Battery

With the prosperity and development of the 3C industry,the higher requirements for mobile power supply,and lithium ion batteries become the focus of new high-energy green battery.Currently commercialized main cathode material has the high cost of LiCoO₂,cheap and good stability LiMn2O4 but its energy density is low,LiNiO₂ has high theoretical specific capacity but excess lithium that the embedded leads to structural damage,and cause capacity sharply attenuation and safety problems.Therefore,the three-element positive material LiNixCoyMn1-x-yO₂,which combines the advantages of LiCoO₂,LiMn2O4 and LiNiO₂.It has been the focus of this year's research because of its low cost,high relative capacity and safety performance.This paper adopted commercially finished goods precursor and homemade by NaOH co-precipitation Ni_0.5Co_0.2Mn_0.3OH spherical ternary precursor,this paper studies the lithium technology,sintering temperature and finished product material surface modification,research it on the material surface morphology,microstructure and electrochemical properties of the lattice.The morphology of the synthesized samples was characterized by powder X-ray diffraction?XRD?and scanning electron microscope?SEM?.Assemble the button battery and test the electrochemical properties of the material through the electrochemical workstation.The experimental results show that when the precursors of commercial products are mixed with Li₂CO₃ in the proportion of Li/M= 1.04,and the solid phase sintering is carried out,the comprehensive performance of the materials is the best.When using a homemade precursor,eventually when the sintering temperature of 850? and Ag5%surface modification,the ternary material has the highest specific capacity and good cycle performance.It also has good electrochemical properties.Using NaOH co-precipitation preparation LiNi_0.5Co_0.2Mn_0.3O₂ cathode material,and by using the X-ray powder diffraction?XRD?,scanning electron microscope?SEM?,Gamry electrochemical workstation?CV and EIS?and electrochemical test,etc.,on the material particle surface morphology and microscopic crystal structure of the morphology and the electrochemical properties were characterized.The experimental results show that the LiNi_0.5Co_0.2Mn_0.3O₂ XRD spectrum analysis on the anode material,it has R3m space group structure.Button cell charge-discharge test results show that when the Li/M = 1.04,the highest calcination temperature is 850? and surface modification Ag5%,the first charge and discharge specific capacity of 206.67mAh/g,1 C ratio in circulation discharge capacity is 50 times 159.1mAh/g,given a rate of 92.5%.When the high ratio of the battery test is high,the 5C still retains a ratio of 105.2mAh/g,and the decrease is obvious.With homemade precursor,therefore,according to Li/M = 1.04,the highest calcination temperature is 850? and surface modification Ag5%ternary positive pole material preparation,they can greatly change the anode material LiNi_0.5Co_0.2Mn_0.3O₂ cycle life and high rate performance.