层状化合物LiNi0.5Co0.5O2材料的模板法合成及性能

以聚丙烯酰胺(PAM)为模板剂用微波-固相复合加热技术合成了层状锂离子蓄电池正极材料LiNi0.5Co0.5O2,并与直接高温固相法合成的该材料进行比较。通过扫描电子显微镜(SEM)、激光粒度分析和X-射线粉末衍射(XRD)分析等技术对材料的微观形貌、粒度分布和相结构进行了表征。恒电流充放电循环测试表明:在3.0～4.3V电压范围内充放电倍率为0.2C时,采用微波法合成的材料放电比容量高达154mAh/g,且有良好的循环性能。同时,计时电量和电化学交流阻抗测试表明前者有较小的内阻,且在循环过程中Li 有较强的扩散能力。

Preparation and performances of layered cathode material LiNi0.5Co0.5O2

Layered cathode materials LiNi0.5Co0.5O2 were prepared by microwave-solid calcined method for lithium ion batteries using ployacrylamide(PAM) as template. They were compared with the materials synthesized by solid state method. The prepared materials were characterized for their morphologies, particle size and phase purity using SEM,particle size analyzer and X-ray diffraction (XRD) techniques. The results of the charge-discharge test show that the discharge capacity is up to 154 mAh/g in the voltage range 3.0-4.3 V at a C /5 rate, and the materials exhibit excellent cyclic reversibility. The measurements of chronocoulometry and electrochemical impedance spectroscopy indicate that the resistance of the former is lower, and the diffusion coefficient of Li is higher than that in the later.