LiNi_(1/3)Co_(1/3)Mn_(1/3)O_2粉体的类共沉淀制备及性能

Quasi-coprecipitation method preparation and electrochemical properties of LiNi_(1/3)Co_(1/3)Mn_(1/3)O_2 powders

在含有Li＋、Co2＋、Ni2＋、Mn2＋离子的混合溶液中加入（NH4）2CO3作沉淀剂，通过一步共沉淀反应得到含有四种金属离子的混合沉淀前驱体。前驱体经烘干，研磨后在不同温度（700～1000℃）及不同时间（6～24 h）条件下进行烧结，即得到LiNi1/3Co1/3Mn1/3O2粉体。分别通过X射线衍射（XRD）、扫描电镜（SEM）及循环伏安（CV）、交流阻抗对制备粉体的微结构进行表征和对样品的电化学性能进行测试。结果表明：获得的LiNi1/3Co1/3Mn1/3O2粉体为α-NaFeO2层状结构，颗粒分布均匀，放电比电容高，阻抗小。其中在900℃下烧结12 h所得的LiNi1/3Co1/3Mn1/3O2粉体电化学性能最优。当电压窗口在（0～1.4）Vvs.SCE、扫描速度为5 mV＆#183;s-1、电解液为1 mol＆#183;L-1 Li2SO4溶液时，其比容量可达399.46 F＆#183;g-1；并且其阻抗也最小。

（NH4）2CO3 was added into mixed solution contained Li ＋, Co2＋, Ni2＋ and Mn2＋ ions as a precipitant. The mixing precipitation precursors were prepared by one-step co-precipitation reaction. After being dried and ground, the precursors were sintered under different sintering temperatures（700-1 000℃） and different sintering times （6 -24 h）, and then LiNi1/3Co1/3Mn1/3O2 powders were obtained. The microstructures and electrochemical properties of the as-prepared powders were examined using X-ray diffraction （XRD）, scanning electron microscopy （SEM）, cyclic voltammetry （CV） and electrochemical impedance. The results show that the obtained LiNi1/3Co1/3Mn1/3O2 powders are pure α-NaFeO2 layered structure;the powders are uniform and exhibit excellent discharge specific capacitance and lower impedance. After sintered at 900℃ for 12 h, the obtained LiNi1/3Co1/3Mn1/3O2 powder exhibits the optimum electrochemical performance. The specific capacitance of the LiNi1/3Co1/3Mn1/3O2 powders can reach 399.46 F＆#183;g-1 within potential range of （0-1.4） V at a scanning rate of 5 mV＆#183;s-1 in 1 mol＆#183;L-1 Li2SO4 solution.And the powders also have the lowest impedance.