(中南大学 冶金科学与工程学院,长沙 410083)
摘 要: 将液相共沉淀法制备的Ni0.8Co0.1Mn0.1(OH)2与LiOH·H2O混合,固相烧结合成微米级的LiNi0.8Co0.1Mn0.1O2 正极材料。XRD谱表明,合成的LiNi0.8Co0.1Mn0.1O2 正极材料为典型的α-NaFeO2层状结构,无杂质峰;从SEM像可以看出,产物颗粒为类球形,分散性好,由一次粒子紧密堆积而成,平均粒径为3 μm;电化学测试结果表明,在2.8~4.3 V电压范围内,750 ℃焙烧15 h合成的LiNi0.8Co0.1Mn0.1O2材料的电化学性能最优,0.1 C 时,其首次放电容量为186.748 mA·h/g,分别高于700和800 ℃时的首次放电容量172.947和180.235 mA·h/g。材料在0.5和2 C时循环40次后,容量保持率分别为98.32%和88.72%,循环性能良好。
关键字: LiNi0.8Co0.1Mn0.1O2;正极材料;共沉淀法;电化学性能
micro-size LiNi0.8Co0.1Mn0.1O2 cathode material
(School of Metallurgical Science and Engineering, Central South University, Changsha 410083, China)
Abstract:The micro-size LiNi0.8Co0.1Mn0.1O2 cathode material was synthesized by mixing Ni0.8Co0.1Mn0.1(OH)2 and LiOH·H2O via solid state reaction followed by heating to elevated temperatures. X-ray diffraction (XRD) patterns show that all samples exhibit typical α-NaFeO2 structure without any other impurities. The scanning electron microscopy (SEM) reveals that the primary particles agglomerate to form secondary particles with an average size of 3 μm, and the particles are near-spherical and well distributed. In the voltage range of 2.8−4.3 V, LiNi0.8Co0.1Mn0.1O2 synthesized at 750 ℃ for 15 h exhibits a higher initial discharge capacity of 186.748 mA·h/g at 0.1 C compared with those of LiNi0.8Co0.1Mn0.1O2 synthesized at 700 and 800 ℃ (172.947 and 180.235 mA·h/g, respectively). The material has excellent cycling performance, in which the capacity retention at the rates of 0.5 and 2 C are 98.32% and 88.72%, respectively, after 40 cycles.
Key words: LiNi0.8Co0.1Mn0.1O2; cathode material; co-precipitation; electrochemical performance