LiNi0.8Co0.2-xAlxO2正极材料的合成与电化学性能研究

以共沉淀法合成了锂离子电池正极材料LiNi0.8Co0.2-xAlxO2（x=0，0．03，0．05）。对合成的层状材料采用X射线衍射（XRD）、扫描电镜（SEM）和差示扫描量热分析-热重分析（DSC-TG）进行了结构、形貌和热分析，对LiNi0.8Co0.2-xAlxO2材料以0．2C倍率进行充放电测试，用循环伏安法分析充放电过程中的相变。实验结果表明，掺杂Al后材料的放电容量下降15mAh／g，但相变得到抑制，材料的稳定性和循环性能提高。

Synthesis and Characterization of LiNi0.8Co0.2-xAlxO2 as Cathode Materials for Lithiun-ion Battery

Co-precipitation method was employed to synthesis of LiNi_(0.8)Co_(0.2_x)Al_xO_2(x=0,0.03,0.05) cathode materials for lithium-ion batteries.The composition,structure,thermal analysis and surface morphlogy of the obtained layered materials are characterized by means of X-ray diffraction(XRD), Differential scanning calorimetry-thermal gravimetric analysis(DSC-TG) and scanning electron microscopy(SEM).The electrochemical properties of LiNi_(0.8)Co_(0.2_x)-Al_xO_2 are examined by charge-discharge test at 0.2 C rate and phase transition during the charge-discharge processes were studied by cyclic voltammetry(CV).Results show that dopping Al decreases the discharge capacity about 15 mAh/g,but restrains the phase transition and enhances the material stability and cycling performance.