Preparation And Properties Of Cathode Material LiNi_0.8Co_0.15Al_0.05O₂ For Lithium Ion Battery

LiNi0.8Co0.15Al0.05O2(NCA),as the most valuable and promising three electrode material for high nickel alloys,has attracted wide attention due to its high specific capacity and low cost.In order to further improve the performance of NCA,it has better cycle stability and higher capacity,so as to better commercialization,the synthesis of NCA cathode materials with layered structure by the solid state method,study the different preparation process on the phase structure,morphology and electrochemical properties of materials.In the preparation of solid phase,NCA was first prepared by using nickel nitrate and cobalt aluminum salt.It is found that the pure phase NCA samples with lamellar structure are obtained by calcining 24h at 840 ? by calcination at 8h,and the particles are well dispersed and uniform in size.Under the 0.1C condition,the specific capacity of the first constant discharge is 149.6mAh/g,and the capacity retention rate of 20 cycles is 85%.The method uses nitrate as the raw material,and has high heat release rate at the high temperature,and the diffusion of atoms is accelerated by the tabletting process,which saves time and energy compared with the traditional solid phase method.In order to better control the morphology,this paper further uses the cheaper nickel sulfate cobalt aluminum salt as the raw material.Firstly,the precursor with controllable morphology is prepared by coprecipitation method,and then NCA is prepared by solid phase sintering.It is found that when 20%24h is added to the base solution,the pH value is controlled at 11.5?800r/min speed,and the spherical precursor with uniform size can be obtained.The above precursor is calcined 10h at Li/(Ni+Co+Al)value to obtain a good layered structure NCA material at 1.15 and 760?.V2O5 coating was also studied in this paper.The coating was verified by TEM and the coating thickness was about 10?15nm.It was found that the specific capacity of the first constant current discharge of the coated sample under 0.1C was 121.3mAh/g,and that the capacity of the 50 cycle cycle showed no decay and showed good electrochemical performance.