LiNi_(1/3)Co_(1/3)Mn_(1/3)O_2的制备及电化学性能

Synthesis of cathode material LiNi_(1/3)Co_(1/3)Mn_(1/3)O_2 and its electrochemical performances

首次采用流变相反应法合成了锂镍钴锰复合氧化物LiNi1/3Co1/3Mn1/3O2。考察了Li/(Ni+Co+Mn)比值、焙烧温度和焙烧时间对其电化学性能的影响。在此基础上成功的合成了LiNi1/3Co1/3Mn1/3O2样品,X射线试验结果发现,预焙烧得到的前驱体具有和LiNi1/3Co1/3Mn1/3O2相似的结构。扫描电子显微镜法(SEM)显示,其粒径小于1mm。充放电结果显示,当电流密度为0.20mA/cm2时,在3.0～4.4V区间内,其首次放电比容量达到146.30mAh/g,循环20次后,仍能保持在136.00mAh/g。

The lithium-nickel-cobalt-manganese complex oxide LiNi1/3Co1/3Mn1/3O2 was firstly successfully prepared by rheological phase reaction method. The effect of Li/ （Ni＋Co＋Mn） ratios, calcination temperature and calcination time on performances of LiNi1/3Co1/3Mn1/3O2 were studied. Based on the optimized conditions, LiNi1/3Co1/3Mn1/3O2 cathode material was readily synthesized. The X-ray diffraction pattems show that the structure of precursor sintered beforehand is similar to that of LiNi1/3Co1/3Mn1/3O2.The SEM results reveal that the particle size of LiNi1/3Co1/3Mn1/3O2 is smaller than 1 μm.The charge-discharge testing results demonstrate that the LiNi1/3Co1/3Mn1/3O2 compound has better electrochemical properties. The initial discharge specific capacity reached 146.30 mAh/g with a discharge current density of 0.20 mA/cm^2 and the discharge specific capacity maintained 136.00 mAh/g after twenty cycles with the same discharge current density.