Modification Of Nickel-rich Ternary Cathode Material NCA For Lithium-ion Battery

As one of nickel-rich ternary cathode cathode material for the lithium-ion battery,NCA (LiNi0.8Co0.15Al0.05O2) has many advantages, such as high discharge capacity,better thermal stability and low cost. It is considered as one of the most promising cathode material which is substitute for lithium cobalt oxide, and is expected to occupy one place in the field of power lithium-ion batteries. Although NCA has been used for some of automobiles lithium-ion batteries, according to the cycling stability performance, Widely using in the power lithium-ion battery is probably not enough.Material modifications to extend the cycle life of the NCA material was studied in this paper.Adding F can improve the stability of the material NCA, and extend its cycle-life.When the doping amount of F is 0.05, the temperature of the high temperature treatment is 450 ? and being calcined in air atmosphere, the cycling stability performance of the synth material is best. When charged and discharged for 100 cycles at 1C, the capacity retention rate of the material is 96.17%, increased by 6%compared to undoped material NCA. The four metal compound are used in the coating modification experiments, Li2O·2B2O3,aluminum-doped zinc oxide,Al2O3 and BaF2. Surface by coated lwt% Li2O·2B2O3, the cycling stability of NCA can be improved, but the capacity is decreased. Under the optimum synthesis condition, the cycling capacity retention rate of LBO-NCA by charged and discharged for 100 cycles at 1C, is 97.63%, significantly higher than the raw material. Aluminum-doped zinc oxide coating modification can significantly improve the electrochemical properties of NCA. When charged and discharged for 500 cycles at 1C, the cycling capacity retention rate of the modified material by synthesized under the optimum experimental conditions is 80.64%(NCA, 61.88%). The electrochemical properties of NCA modified by Al2O3-coated can be improved greatly. Under the optimum synthesis condition, the cycling capacity retention rate of AO-NCA of charged and discharged at 1C after 100 cycles is 96.5%,which is higher than the raw material. And the discharge capacity is slightly higher than that of the raw material. The cycling stability of NCA coated BaF2 by dry coating can improved. Though the initial discharge capacity and the coulombic efficiency are slightly decreased,the cycling capacity retention rate of BF-NCA by charged and discharged at 1C after 100 cycles,is 94.87%, increasing by 4%, compared with NCA.According to the experimental results, by coated 1wt% aluminum doped zinc oxide or alumina oxide, the cycle stability of NCA material has been improved signifiantly.