Lithium Ion Batteries Ternary Cathode Material Preparation And Electrochemical Performance Of The Research

Lithium-ion battery as a clean and efficient energy storage device has been widely used in cameras, mobile phones, notebook computers and other portable devices. LiCoO2has been widely used as a cathode material in commercial lithium-ion battery production, but researchers have been devoting to find substitutable materials of low cost and excellent properties for LiCoO2due to high price of Co and security of LiCoO2.We will study the Li-Co-Mn-Ni-O compound, and hope to find a way to get the cathode with a better performance. As a new generation cathode material, LiCoi/3Mn1/3Ni1/3O2cathode material has great potential for being a new kind of cathode candidate for its excellent electrochemical performance and low cost, and showing an attractive prospect at monotype-portable electric sources and large scale power supplies. For these reasons, LiCo1/3Mni/3Nii/3O2has been studied intensively as a cathode material to replace the presently used LiCoO2.The LiCo1/3Mn1/3Ni1/3O2cathode materials for lithium-ion batteries were synthesized by mechanical activation-high temperature solid-state method. The relations between the electrochemical properties and crystal structure of LiCo1/3Mn1/3Nii/3O2and ball milling effects, ball milling time, synthesis temperature, synthesis time and Li/M have been investigated systematically. The main factor that influence the structure and electrochemical properties of materials is synthesis temperature, synthesis time and Li/M. Based on single factor experiment, a L8(27) orthogonal experiment is carried out to determine optimum process condition. Experimental were studied on anode slurry ratio too. The morphology, crystal structure and electrochemical properties of LiCo1/3Mn1/3Ni1/3O2are also studied by X-ray(XRD), scanning electron microscopy(SEM), the battery test system, electrochemical workstation and other test means.The optimum process condition for LiCo1/3Mn1/3Ni1/3O2preparation by mechanical activation-high temperature solid-state method is ball milling time=6h, pre synthesis temperature=500℃, pre synthesis time>4h, synthesis temperature=900℃, synthesis time≥4h, Li/M=1.11, m(C)%=10%, m(PVDF)=5%。The results of electrochemical performance tests show that the first discharge specific capacity of obtained under optimum conditions can reach183.1mAh-g-1at0.2C in voltages of2.7～4.4V, and the capacity maintenance rate is94.5% after50charge-discharge circles.