工业化LiNi_(0.5)Co_(0.2)Mn_(0.3)O_2阴极材料精细合成条件研究

Refining synthesis condition of industrial LiNi_(0.5)Co_(0.2)Mn_(0.3)O_2 cathode material

通过高温固相法合成了层状三元LiNi0.5Co0.2Mn0.3O2阴极材料,考察了烧结温度和锂过量的微小差别对电极性能的影响。扫描电子显微镜实验证实当烧结温度高于980℃时,合成的样品棱角分明,而在950℃以下合成的样品主要是球形。随着循环的进行,对于在900和930℃合成的样品,放电容量几乎成线性降低;当合成温度高于980℃时,随着循环的进行放电容量呈S型变化。900℃合成的样品初始比容量为170 mAh/g左右（循环窗口3.0~4.3 V）,100次以后比容量为140 mAh/g。锂过量6%（摩尔分数）时综合性能较好。

The ternary layered LiNi0.5Co0.2Mn0.3O2 was synthesized by high-temperature solid state reaction method. The effect of the tiny difference of the sintering temperature and Li excess content on the electrode performance was investigated. The SEM measurements show that the samples synthesized at the temperatures of more than 980 ℃ have obvious edges and comers, while the samples synthesized at the temperature of less than 950℃ are composite of spherical particles. During the cycle, the discharge capacity linearly decreases for the samples synthesized at 900 and 930 ℃. The samples synthesized at the temperatures of more than 980 ℃ exhibit a S-shaped cycling discharge capacity curve. The sample synthesized at 900℃exhibits a initial discharge capacity of about 170 mAh/g and about 140 mAh/g after 100 cycles in the operation potential range of 3.0-4.3 V. In addition, the Li excess content in the precursor should be more than 6mol%.