摘要
采用草酸盐共沉淀法合成一系列的Li(Ni1/3Co1/3Mn1/3)1-xCrxO2正极材料(0≤x≤0.1),用X射线衍射仪(XRD)和扫描电子显微镜(SEM)分析合成产物的晶体结构及表面形貌;利用充放电仪测定了产物的电化学性能.结果表明,合成的Li(Ni1/3Co1/3Mn1/3)1-xCrxO2(x=0.01,0.03,0.05,0.07)均保持α-2NaFeO2层状结构相,属于空间R3m点群.Li(Ni1/3Co1/3Mn1/3)0.95Cr0.05O2的电化学性能最佳,首次放电容量达158.6 mAh/g,在2.5～4.5 V区间30次循环后比容量衰竭率仅为3.92%.Li(Ni1/3Co1/3Mn1/3)0.95Cr0.05O2和Li(Ni1/3Co1/3Mn1/3)CrO2的电极阻抗变化不同,进而影响其电化学性能.
A series of Li(Ni1/3Co1/3Mn1/3)1-xCrxO2(0≤x≤0.1) samples were prepared as anode materials of lithium-ion battery by using oxalate co-precipitation method.The crystal structure and surface morphologies of the products were analyzed by means of X-ray diffraction(XRD)and scanning electron microscopy(SEM) methods.The electrochemical performance of Li(Ni1/3Co1/3Mn1/3)1-xCrxO2 was evaluated by charge/discharge tests.Results show that Li(Ni1/3Co1/3Mn1/3)1-xCrxO2(x=0.01,0.03,0.05,0.07) keeps bedded structure of α-2NaFeO2 and have cubic structure of phase R3m,The Li(Ni1/3Co1/3Mn1/3)0.95Cr0.05O2 has the best electrochemical performance,an initial discharge capacity of 158.6 mAh/g and the capacity fade is only 3.92 % after 30 cycles of charge-discharge within 2.5～4.5 V.The electrochemical circulation mechanism of the products was analyzed by means of ac impedance methods.Besides,Li(Ni1/3Co1/3Mn1/3)0.95Cr0.05O2 and Li(Ni1/3Co1/3Mn1/3)CrO2 electrodes had different changes of impedance,leading to different effects on the electrochemical performance.
出处
《吉首大学学报（自然科学版）》
CAS
2011年第1期88-92,共5页
Journal of Jishou University(Natural Sciences Edition)
基金
国家自然科学基金资助项目(20873054)
国家高技术研究发展计划(863计划)重点项目子课题(2010AA065205)
湖南省教育厅科学研究项目(10A098)
生态旅游应用技术湖南省重点实验室开放基金项目(10stlvzd06)
吉首大学林产化工工程湖南省重点实验室开放基金项目资助(JDZ200907)
吉首大学大学生研究性学习和创新性实验计划项目资助(JSU-CX-2010-55)
