摘要
采用共沉淀法制备前驱体,高温固相合成正极材料Li(Ni_(0.6)Co_(0.2)Mn_(0.2))_(1-x)Cu_xO_2(x=0、0.01、0.015和0.02),通过X射线衍射、SEM和电池测试系统及电化学工作站测试,对其结构、形貌和电化学性能进行表征.结果表明,掺杂少量的Cu,样品均具有α-NaFeO2型结构,没有出现杂相;样品(108)/(110)峰分裂明显,材料有着良好的层状结构;随着Cu掺杂量的增加,c和c/a增大,层间距增大,Li+脱嵌通道增大,改善导电性.Cu掺杂1%和1.5%的I(003)/I(104)比值分别为1.467、1.438,比0%的1.431值大,减小了阳离子混排.首次放电比容量依次为170.6 mAh/g、164.1 mAh/g、163.6 mAh/g和162.4 mAh/g,当x为0,1%,2%经过100次循环,保持率为87.1%、98.7%、和87.7%; x为1.5%,比容量从161.8 mAh/g增加到173.9 mAh/g,性能较优.
The precursor was prepared by co-precipitation and Li （Ni0.6Co0.2Mn0.2）1-xCuxO2 （x=0, 0.01, 0.015 and 0.02） was synthesized by high temperature solid-state reaction. In this study, the structure, morphology and electrochemical properties of Li （Ni0.6Co0.2MnO2）1-xCuxO2 were characterized by X-ray diffraction （XRD）, scanning electron microscope （SEM）, battery test system （BTS） and electrochemical workstation. The results showed that, with a small amount of Cu, α-NaFeO2type structure was formed in all the samples with no impurities; the peak splitting of the sample （108）/（110） was obvious with a good layered structure; then, with the increase of Cu, c and c/a, interlayer distance and the deintercalation channels of Li＋ all increased, so the conductivity improved. The ratios of I（003）/I（004） were 1.467 and 1.438, respectively, with 1% Cu and 1.5% Cu, higher than the ratio of 1.431 without any addition of Cu and at the same time reducing cation mixing. The specific discharge capacities for the first time were 170.6, 164.1, 163.6 and 162.4 mAh/g, respectively. When x was 0, 1%, 2 % a fter 100 cycles, the retention rates were 87.1%, 98.7 %, and 87.7 %, respectively; when x was 1.5 %, the specific capacity increasing from 161.8 to 173.9 mAh/g, Li（Ni0.6Co0.2Mn0.2）1-xCuxO2 obtained its best electrochemical performance.
作者
邱世涛
钟盛文
李婷婷
杨金猛
田丰
QIU Shitao;ZHONG Shengwen;LI Tingting;YANG Jinmeng;TIAN Feng(School of Materials Science and Engineering;Jiangxi Key Laboratory of Power Battery and Materials,Jiangxi University of Science and Technology,Ganzhou 341000,China)
出处
《有色金属科学与工程》
CAS
2018年第5期21-25,共5页
Nonferrous Metals Science and Engineering
基金
江西省科技计划资助项目(20151BBE50106)
