Lithium-Rich Nanoscale Li sub(1.2)Mn sub(0.54)Ni sub(0.13)Co sub(0.13)O sub(2) Cathode Material Prepared by Co-Precipitation Combined Freeze Drying (CP-FD) for Lithium-Ion Batteries

Nanoscale Li-rich Li sub(1.2)Mn sub(0.54)Ni sub(0.13)Co sub(0.13)O sub(2) material is synthesized by a co-precipitation combined freeze drying (CP-FD) method, and compared with a conventional co-precipitation method combined vacuum drying (CP-VD). With the combination of X-ray diffraction (XRD) and scanning electron microscopy (SEM), it is found that the sample from CP-FD method consists of a pure phase with good crystallinity and small, homogenous particles (100-300nm) with uniform particle size distribution. Inductively coupled plasma spectroscopy (ICP) shows that the sample has a stoichiometric ratio of n sub((Li)):n sub((Mn)):n sub((Ni)):n sub((Co))=9:4:1:1; and its Brunauer-Emmett-Teller (BET) specific surface area is 5.749m super(2)g super(-1). This sample achieves excellent electrochemical properties: its initial discharge capacities are 298.9mAhg super(-1) at 0.1C (20mAg super(-1)), 246.1mAhg super(-1) at 0.5C, 215.8mAhg super(-1) at 1C, and 154.2mAhg super(-1) at 5C (5C charge and 5C discharge), as well as good cycling performance. In addition, the Li super(+) chemical diffusion coefficient of Li sub(1.2)Mn sub(0.54)Ni sub(0.13)Co sub(0.13)O sub(2) material prepared by the CP-FD method is 4.5910 super(-11)cm super(2 )s super(-1), which is higher than that of the Li sub(1.2)Mn sub(0.54)Ni sub(0.13)Co sub(0.13)O sub(2) material prepared by CP-VD. This phenomenon illustrates the potential for Li sub(1.2)Mn sub(0.54)Ni sub(0.13)Co sub(0.13)O sub(2) with good rate performance synthesized by CP-FD method. Freeze-dried batteries: Nanoscale Li-rich Li sub(1.2)Mn sub(0.54)Ni sub(0.13)Co sub(0.13)O sub(2) material is synthesized by a co-precipitation combined freeze drying (CP-FD) method and compared with a conventional co-precipitation method combined vacuum drying (CP-VD). The new CP-FD achieves excellent electrochemical properties as well as a good rate performance after 50cycles.