采用冷冻干燥技术成功合成了层状锂离子电池正极材料LiNi0.8Co0.2O2,研究了不同煅烧温度对产物结构、微观形貌以及性能的影响。利用TG—DTA分析、X射线衍射(XRD)、场发射扫描电镜(FESEM)和激光粒度分析仪对前驱体和煅烧样品的热反应、晶体结构、微观形貌和粒度分布等进行了表征。结果表明,煅烧温度对LiNi0.8Co0.2O2晶体结构及材料性能有较大影响。750℃×5h的煅烧条件下制得的LiNi0.8Co0.2O2粉具有纳米级尺寸和窄的粒度分布,该样品的(003)晶面衍射峰强度与(104)晶面衍射峰的强度比J(003)/J(104)为1.51。晶格参数显示制得的LiNi0.8Co0.2O2样品用作锂离子电池的电极,可能会显示出良好的电化学性能。
Layered LiNi0. 8Co0. 2O2 powder, cathode material of lithium ion batteries, was successfully synthesized by a freeze,drying method. The calcination conditions were studied, which influence the material structure, morphology and characters. The thermal reaction, crystal structure, morphology and particle size distribution of the freeze-dried precursor and the powders heated to various temperatures for 5h were investigated by TG-DTA, XRD, FESEM and laser particle size analyzer. The results show the calcining temperature has a remarkable effect on the structure and characters of the samples. The sample LiNi0.8Co0.2O2 material calcined at 750℃ for 5h has the nanosized and narrow particle size distribution. And, the ratio of the (003) to (104) peaks for the sample is 1.51. Lattice parameters showed that the LiNi0.8Co0.2O2 samples synthesized by the method in the present investigation have potential to exhibit good electrochemical performance when used as electrodes in lithium ion batteries.