摘要
采用尿素燃烧法制备多孔的Li[Li0.2Mn0.56Ni0.16Co0.08]O2微球,再利用化学沉淀法对微球进行Li2O-2B2O3表面包覆,研究不同Li2O-2B2O3包覆量对材料电化学性能的影响。采用X-射线衍射（XRD）、X-射线光电子能谱（XPS）和扫描电子显微镜（SEM）对材料的微观组织结构及表面特性进行了表征,结果表明：Li2O-2B2O3被均匀包覆在微球表面,包覆层没有改变材料的晶格结构。电化学测试结果表明：3.0 wt%Li2O-2B2O3包覆量大大提高了材料的首次库伦效率和高倍率性能,相比于未包覆样品,在0.1 C倍率和2.0-4.7V电压区间下,材料的首次库伦效率由81.17%提高到84.14%;在5 C倍率下,材料的放电比容量由66.30 mAh/g提高到81.56 mAh/g。
Li[Li0.2Mn0.56Ni0.16Co0.08]O2 porous microspheres were synthesized using urea combustion method, and the microspheres were coated with Li2O- 2B2O3 by a chemical precipitation method. The influence on electrochemical properties of different coating amount of Li2O - 2B2O3 was investigated. The microstructure and surface properties of materials were characterized by using X- ray diffraction （XRD） , X- ray photoelectron spectroscopy （XPS） and scanning electron microscopy （SEM）. The results show that Li2O - 2B2O3 is uniformly coated on the surface of the microspheres, and the coated layers do not change the lattice structure of the material. The electrochemical testing results show that the initial columbic efficiency and high rate performance are greatly improved when the coating amount of Li2O - 2B2O3 is 3.0 wt%. Compared to the original samples, the initial columbic efficiency increases from 81.17% to 84.14% at 0.1 C rate and 2.0- 4.7 V voltage range, and the discharge capacity increases from 66.30 mAh/g to 81.56 mAh/g at 5 C rate .
作者
兰青
谢清亮
刘开宇
LAN Qing XIE Qingliang LIU Kaiyu(Central South University, Changsha, Hunan 410083, China)
出处
《龙岩学院学报》
2016年第5期8-15,共8页
Journal of Longyan University
