Experimental Studies On Dispersion Of High Specific Surface Conductive Additives And Its ALD Coating Optimization

Since the atomic layer deposition(ALD)successfully prepared high quality coatings,this technology had been successfully applied to the surface coating of semiconductor devices and modified powder materials in recent years.At present,ALD had attracted many researchers in energy,environment,and catalyst.Low cost,long life,high rate current and large energy density became the trend of the development of the lithium-ion battery.It was development trend to improve the energy density of lithium-ion battery with high rate current.Conductive additive as an important component of lithium-ion batteries plays a role in high conductivity.Compared with the low specific surface area,the conductive additive with high specific surface area can greatly reduce proportion of the conductive additive in the positive electrode and increase the content of the active material in the electrode.This can improve the utilization of the active material,thereby improving the energy density and the coulomb efficiency of the lithium-ion battery.Therefore,it was a very interesting subject to study the dispersion of the high specific surface area of the conductive additives in the positive electrode slurry and to reduce side reaction of the lithium-ion battery used in the conductive additive with high specific surface area under high voltage.Our experimental results were:(1)The process of preparing active materials and binder grinding,change the process flow of addition and ultrasonic dispersion was intended to make the active material and conductive additives mixed completely,which increase the adhesion between the binder,the active substance,and the conductive additive in the NMP;(2)The results of the lithium-ion battery tested show that the rate performance of conductive additives D with high specific surface was higher than that of the acetylene conductive additives C at a high voltage of 4.45 V.The CB/PVDF weight ratio 2:5 and the 32 ml NMP is found the best proportion of Lithium-ion cathode;(3)Atomic layer deposition technology coated conductive material can improvethe lithium-ion battery coulomb efficiency and high rate performance;(4)Atomic Layer Deposition coating showed a nanometer order of magnitude film grown on the surface of conductive additives particle material,and the film can be completely coated on the surface of conductive additives materials with high specific surface area;(5)During ALD coating,it was found the deposition rate of the film is related to the specific surface area of the base-material,and the higher the specific surface area of conductive additives,the lower the material growth rate.