以PEG为模板剂和碳源制备Li_4Ti_5O_(12)/C复合材料

Synthesis of Li_4Ti_5O_(12)/C composite materials using PEG as template and carbon sources

采用聚乙二醇作为模板剂和碳源制备Li4Ti5O12/C复合材料。利用粉末X射线衍射(XRD)和扫描电镜(SEM)等测试手段研究了模板剂的用量对材料结构和形貌的影响。不同PEG用量时,所制备的样品均为尖晶石型纯相结构,随着PEG用量的增加,材料颗粒粒径逐渐减小,形貌趋于类球形。在1.0～2.5 V的电压范围内测试了材料的恒流充放电性能及倍率循环性能,结果显示,模板剂的用量为8%时,制备的Li4Ti5O12/C复合材料具有最佳的电化学性能。0.2 C时充放电比容量分别是153.5 mAh/g和154.5 mAh/g,在5 C条件下循环40次,复合材料的容量保留率为95.2%。

Li4Ti5O12/C composite materials were synthesized using PEG as template and carbon sources.The crystal structure and morphology of Li4Ti5O12/C composite materials with different amount of PEG were analyzed by powder X-ray diffraction（XRD）,and scanning electron microscope（SEM）.The electrochemical behavior of the Li4Ti5O12/C composite material was examined by galvanostatic charge-discharge instrument.The cyclic behavior of the the Li4Ti5O12/C composite materials were investigated at 0.2 C and 5 C rate with the cut-off voltages of 1.0-2.5 V.The charge and discharge specific capacity of Li4Ti5O12/C composite material synthesized with 8% PEG are 153.5 mAh/g and 154.5 mAh/g,respectivily.And the retention of capacity is 95.2% after 40 cycle at 5 C.