高性能LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2)正极材料的合成及其电化学性能  

Investigations on synthesis and electrochemical performance of high performance LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2) cathode material

作　　者：蔡厚雪 袁安 冯茹茜 邓颜 汤昊 谭龙 孙润光 CAI Houxue;YUAN An;FENG Ruxi;DENG Yan;TANG Hao;TAN Long;SUN Runguang(School of Materials Science and Engineering,Nanchang University,Nanchang 330031,China)

机构地区：[1]南昌大学材料科学与工程学院,南昌330031

出　　处：《复合材料学报》2021年第6期1882-1889,共8页Acta Materiae Compositae Sinica

基　　金：江西省科技厅青年科学基金(20192BAB216010)。

摘　　要：通过改变煅烧过程中的气氛条件,以简单的固相法合成工艺获得了优异性能的LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2)(NCM811)材料,并探究了不同O_(2)流量对样品的结构和电化学性能的影响。结果表明,当O_(2)流量为0.1 L/min时,所合成的LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2)样品具有最低的阳离子混乱程度和较大的晶面间距。该样品在1 C、4.3 V下循环100次后的放电容量为174 mA·h·g^(-1),容量保持率高达98.3%;在更高的2 C倍率下循环100次后的保持率也达96.8%,并在高截止电压条件下表现良好。从实验结果还可得出,过低的O_(2)流量不利于Ni^(2+)转化为Ni^(3+),从而造成较高的阳离子混排度,而过高的O_(2)流量则会使所合成LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2)材料的晶胞体积减小,不利于Li+的脱嵌。A facie solid-state route has been employed to synthesize LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2) material with superior electrochemical performance by varying the oxygen flow rate during the calcination process, and the effect of different oxygen flow rates on the structure and electrochemical performance of LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2) has also been investigated. It reveals that the LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2) material synthesized under a flow rate of 0.1 L/min has the lowest degree of cation mixing among all samples and large d-space. The 0.1 L/min sample shows a discharge capacity of174 mA·h·g^(-1) after 100 cycles at 1 C, corresponding to the capacity retention rate of 98.3%. A retention rate as high as96.8% is achieved at 2 C, and good performance is also obtained in high cut-off votage test. Moreover, we confirm that low oxygen-flow rate can lead to high degree of cation mixing because of high content of Ni^(2+), and high oxygenflow rate can decrease the d-spacing of LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2) material, thereby being harmful for the Li+ intercalation/deintercalation.

关 键 词：锂离子电池 正极材料 LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2) O_(2)气氛 阳离子混排 

分 类 号：TB34[一般工业技术—材料科学与工程] TM911[电气工程—电力电子与电力传动]