Synthesis And Electrochemical Properties Research Of LiNi_0.8Co_0.15Al_0.05O₂ Cathode Materials For Lithium-ion Batteries

Among the nickel-rich LiNi02-based cathode materials for lithium-ion batteries,LiNi0.8Co0.15Al0.05O2 has been considered as the substitution for LiCoO2 in that it owns the advantages of LiNi02,LiCoO2 and LiAlO2,such as high capacity,good thermal stability,low cost and low toxicity.The synthesis of Ni0.8Co0.15Al0.05(OH)2.05 precursor and LiNi0.8Co0.15Al0.05O2 cathode materials and the electrochemical properties of LiNi0.8Co0.15Al0.05O2 were explored systematically in this paper.This experiment prepares Ni0.8Co0.15Al0.05(OH)2.05 precursor by control crystallization method and finds the optimal process of preparing Ni0.8Co0.15Al0.05(OH)2.05.The optimal process of preparing Ni0.8Co0.15Al0.05(OH)2.05 are reaction temperature:55?,reaction time:40h,Al element concentration:0.05mol/L,Ammonia concentration:0.75mol/L,pH:11±0.3 and Stirring speed:500r/min.The Ni0.8Co0.15Al0.05(OH)2.05 precursor components prepared by this process are accurate.The surfaces of Ni0.8Co0.15Al0.05(OH)2.05 precursor particles are petals like folds and the petals are good for the electrochemical performance of LiNi0.8Co0.15Al0.05O2 cathode material.This experiment prepares LiNi0.8Co0.15Al0.05O2 cathode material by oxidation process and finds the optimal process of preparing LiNi0.8Co0.15Al0.05O2.The optimal process of preparing LiNi0.8Co0.15Al0.05O2 are roast temperature 675?,Lithium ratio 1:1.075 and roasting time 8h.The electrochemical performance of LiNi0.8Co0.15Al0.05O2 is better when the median diameter of LiNi0.8Co0.15Al0.05O2 is 7-9?m.In the range of 2.8-4.3V potential and the charge discharge of 0.05C,the the first discharge capacity of LiNi0.8Co0.15Al0.05O2 is 179.4mAh/g.In the charge discharge of 0.1C,the average discharge capacity of the 20 cycles is 154.6 mAh/g.This experiment find that the incorporation of Co and Al enhances the structural stability and charge discharge of LiNiO2 cathode materials,through the cyclic voltammetry test of LiNi0.8Co0.15Al0.05O2 cathode material.