锂含量对富锂正极材料Li_(1+x)[Ni_(0.5)Co_(0.2)Mn_(0.3)]_(1-x)O_2(x=0.091,0.115,0.138)结构、形貌及电化学性能的影响  

Influences of Lithium Content on Structure,Morphology and Electrochemical Behavior of Li_(1+x)[Ni_(0.5)Co_(0.2)Mn_(0.3)]_(1-x)O_2(x=0.091,0.115,0.138)

作　　者：王先友[1] 白艳松[1] 杨秀康[1] 舒洪波[1] 吴强[1] 

机构地区：[1]湘潭大学化学学院环境友好化学与应用教育部重点实验室,湖南湘潭411105

出　　处：《湘潭大学自然科学学报》2012年第3期48-54,共7页Natural Science Journal of Xiangtan University

基　　金：国家自然科学基金项目(20871101);科技部科技计划项目(2009GJD20021);湖南省科技厅计划项目(2010WK4007);湖南省自然科学市州联合基金重点项目(09JJ8001)

摘　　要：通过共沉淀方法制备了不同锂含量的球形富锂正极材料Li1+x[Ni0.5Co0.2Mn0.3]1-xO2(x=0.091,0.115,0.138).采用XRD、SEM和电池充放电测试仪研究了不同锂含量对于球形富锂正极材料结构、形貌及电化学性能的影响.结果表明:增加锂含量不会改变富锂正极材料Li1+x[Ni0.5Co0.2Mn0.3]1-xO2的晶体结构,但是随着锂含量的增加,球形粒子中一次粒子粒径逐渐增大.当x=0.115时,球形Li1.115[Ni0.5Co0.2Mn0.3]0.885O2粒子的一次粒子大小适中,并且材料具有最佳的电化学性能.在2.0～4.8V范围内,0.1C倍率对材料进行活化,放电比容量高达230mAhg-1.在2.0～4.6V范围内,0.2C循环50次后容量的保持率为84%.0.2C,1C,2C不同倍率下的放电容量分别为209.3mAhg-1,156.1mAhg-1和113.0mAhg-1.The spherical lithium-rich transition metal oxides were prepared by co-precipitation method. The samples of Lil＋,[Ni0.5C00.2Mn0.3]1-xO2 （x = 0. 091, 0. 115, 0. 138 ） were characterized by XRD and SEM, and the influences of lithium content on structure and the morphology of lithium-rich transition metal oxides were studied. The results demonstrated that the structure of Lil＋,[Ni0.5C00.2Mn0.3]1-xO2 （x-= 0. 091, 0. 115, 0. 138） was not altered witb. Li content. However, the size of primary particle increased with the increase of Li content. It has been found that the material has better electrochemical behavior when x is equal to 0. 115, and the discharge capacity is as high as 230 mAhg-1 when the material is activated at 0.1 C in the voltage range of 2.0-4.8 V. The capacity retention of the material after 50 cycles is 84% at 0.2 C in the voltage range of 2.0-4.6 V. The discharge capacities of the material at 0.2 C, 1 C, 2 C are 209.3 mAhg-1 , 156.1 mAhg-1, 113.0 mAhg-1, respectively

关 键 词：锂离子电池 富锂过渡金属氧化物 放电容量 电化学性能 

分 类 号：TM910.4[电气工程—电力电子与电力传动]