摘要

Layered Ni-rich LiNi0.8Co0.15Al0.05O2 (LNCA) cathode material is successfully synthesized with the precursor of Ni0.8Co0.15Al0.05(OH)(2) (NCA) prepared from an improved continuous co-precipitation method, in which a new chelating agent, EDTA is firstly adapted in the synthesis process instead of the traditional NH3 center dot H2O. X-ray diffraction (XRD) measurement indicates that the as-prepared sample is a hexagonal phase which adopts R_3m space group. The morphology of the samples is characterized by scanning electron microscope (SEM) analysis, which shows that both the precursor and LNCA present similar spherical shape. Energy dispersive spectrometer (EDS) elemental mapping results show that the elements Ni, Co and Al are uniformly distributed on the surface of the particles. Crystal lattice fringe arranged along the (003) axis is found clearly in transmission electron microscope (TEM) analysis. The obtained LiNi0.8Co0.15Al0.05O2 materials show excellent electrochemical performance with an initial discharge capacity of 192.3 mAh g(-1) at 0.1C and a capacity retention of 90.24% after 100 cycles when cycled at 1C between 2.8 and 4.3 V.