文摘
LiNi1/3Co1/3Mn1/3O2 cathode materials were synthesized by molten salt method. The preparation was performed by sintering the mixture of Ni1/3Co1/3Mn1/3(OH) 2 and the eutectic molten salts 0.76LiOH路H2O-0.24Li2CO3 at 750-900 掳C for 2-11 h. The prepared particles were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and galvanostatic charge-discharge test. XRD analysis shows the molten salt method can enhance the ordering degree of the layered structure and reduce the cation mixing of LiNi1/3Co1/3Mn1/3O2 compounds. The sample prepared at 850 掳C for 5 h exhibits an excellent electrochemical performance. It can deliver an initial discharge capacity of 175.6 mAh g鈭? at a current density of 16 mA g鈭? between 2.8 and 4.4 V, and a capacity of 156.7 mAh g鈭? is retained after 2, 10, 20 and 20 cycles at the corresponding current density of 16 mA g鈭?, 32 mA g鈭?, 80 mA g鈭? and 160 mA g鈭?, respectively. At a current density of 320 mA g鈭? followingly, it still exhibits a capacity of 150.5 mAh g鈭? after 20 cycles. The electrochemical impedance shows the charge-discharge process of electrode is controlled by the lithium ion diffusion. It is concluded that the molten salt synthesis can substantially reduce the calcination temperature and shorten the soaking time.
