正极材料Li(Ni1/3Co1/3Mn1/3)1-xCrxO2的合成与表征

采用草酸盐共沉淀法合成一系列的Li(Ni_1/3Co_1/3Mn_1/3)_1-xCr_xO₂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(Ni_1/3Co_1/3Mn_1/3)_1-xCr_xO₂( 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(Ni_1/3Co_1/3Mn_1/3)_0.95Cr_0.05O₂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(Ni_1/3Co_1/3Mn_1/3)_0.95Cr_0.05O₂和Li(Ni_1/3Co_1/3Mn_1/3)CrO₂ 的电极阻抗变化不同，进而影响其电化学性能.

Synthesis and Performance of Li(Ni1/3 Co1/3 Mn1/3)1-xCrxO2 Anode Materials of Lithium-Ion Battery

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.