Preparation Of Lithium Manganate As Cathode For Lithium Ion Battery

Lithium-ion batteries have attracted more and more attention because of their excellent performance.The electrochemical characteristics of lithium-ion batteries are mainly determined by electrode materials.The mass ratio of positive to negative for commercial lithium-ion battery is usually about 3:1.So the cathode material is a important part of lithium-ion battery.Among them,LiMn₂O₄ has become a promising cathode material for lithium-ion batteries due to its great performance and cycle stability,price moderate and environmental protection.In this paper,several kinds of LiMn₂O₄ cathode materials were prepared by electrospinning and template methods,respectively.The morphology and structure of the materials were compared by scanning electron microscope?SEM?and X-ray diffraction?XRD?.The results show that the electrospinning method can effectively improve the crystallinity of LiMn₂O₄.The improvement of crystallinity of LiMn₂O₄ cathode material indicates that the material will show more excellent electrochemical performance.The results show that the initial discharge capacity of LiMn₂O₄ prepared by electrospinning is in the range of 110 mAh g^-1at 1C current density,and the capacity retention rate is 80%after a long cycle period of 900 cycles.At a low current density of 0.5 C,the capacity retention is82%after 400 cycles of the same long cycle.At the current density of 5C,the first discharge capacity of 100 mAh g^-1 was obtained,and the capacity retention was 87%after 1600 cycles.It has excellent cycle stability and rate performance.This is related to the better crystallinity of LiMn₂O₄ prepared by electrospinning.The influence of radius of secondary spherical lithium manganate on electrochemical performance of lithium manganate was studied by template method.The results show that when x in Li(Y_xMn_1-x)₂O₄ is 0.005,LiMn₂O₄ exhibits the best performance.At 1C current density,the discharge capacity is up to 120 mAh g^-1,when the amount of yttrium is 0.005.At the current density of 0.5C,the discharge capacity can reach 130 mAh g^-1,and after 100cycles,the capacity retention is 93%.It has very good cycle stability.It was found that the addition of lithium salt had a certain effect on the properties of LiMn₂O₄,so the experiment was carried out with different amount of lithium.Finally,it was found that when the amount of lithium was 1.2 times of the original stoichiometric ratio,the amount of lithium added was 1.2 times that of the original stoichiometric ratio.The prepared lithium manganate exhibits excellent cyclic stability,with a capacity retention rate of 92%for 500 cycles at 1C current density and 100%for 100 cycles at 0.5C current density.