Li与Ni＋Co＋Mn摩尔比对LixNi1／3Co1／3Mn1／3O2结构和性能的影响

Effect of molar ratio of n (Li)∶n (Ni+Co+Mn) on the structure and performance of Li_xNi_(1/3)Co_(1/3)Mn_(1/3)O_2

采用氢氧化物共沉淀前驱体高温固相反应制备了层状LixNi1/3Co1/3Mn1/3O2(0.95≤x≤1.14)正极材料,应用ICP-OES、AAS对材料进行了成分分析,并采用X射线衍射光谱法(XRD)、晶格精修、扫描电子显微镜法(SEM)、差示扫描量热法(DSC)以及充放电测试表征了n(Li)∶n(Ni+Co+Mn)对材料结构和性能的影响。结果表明:x≥1.00时,随x值的增大,峰I003/I004的比值R、首次放电比容量及DSC峰值温度均呈现先增后减的趋势,并在x=1.05附近具有极大值;晶格精修表明阳离子混排率呈现先减后增的趋势,在x=1.08附近具有最小混排率。

The layered cathode material LixNI1/3Co1/3Mn1/3O2（0.95 ≤ x≤1.14） was prepared by using the co-precipitated Ni1/3Co1/3Mn1/3 （OH）2 and Li2CO3 through solid reaction, ICP-OES and AAS were applied to analyze their compositions;XRD, Rietveld refinement, SEM, DSC and charge-discharge test were employed to characterize LixNi1/3- Co1/3Mn1/3O2＇s structure and performances. The results show that the ratio of /003/004, the first discharge capacity and the highest peak temperature of DSC curves are all increasing firstly and then decreasing when 1.00 ≤x≤ 1.14 and get their maximal values around x=1.05. Rietveld refinement shows that the ratio of cation mixing decreases firstly and then increases as 1.00≤x≤ 1.14, and possesses the minimal value around x=1.08.