以有机气凝胶RC-500为原料,采用低质量比KOH(KOH：有机气凝胶=3：1)活化的方法,900℃炭化活化,制备出一种具有层次孔结构的活性炭气凝胶ACA-500-3。将其作为硫载体,与单质硫在155℃熔融复合后制备出含硫量达66.2%的锂硫电池正极复合材料( ACA-500-3-S)。通过N2吸附、SEM、TEM、XRD和XPS等测试手段考察ACA-500-3和ACA-500-3-S的结构和形貌,并利用循环伏安、恒流充放电和交流阻抗等方法研究ACA-500-3-S的电化学性能。 ACA-500-3-S在0.2 C(1 C=1675 mA·g-1)电流密度下,初始放电比容量高达1287 mAh·g-1,200圈后比容量保持在643 mAh·g -1,并表现出良好的倍率性能,明显优于单质硫电极。
An activated carbon aerogel with a hierarchical pore structure was prepared through KOH activation with a KOH/organ-ic aerogel with mass ratio 3:1, followed by carbonization at 900 ℃ for 3 h. The activated carbon aerogel was used as a conductive host of elemental sulfur to prepare a composite by a melt-infiltration method. Nitrogen adsorption, SEM, TEM, XRD and XPS were used to characterize the structure and morphology of the samples before and after the sulfur infiltration. Cyclic voltammetry, galvanostatic charge-discharge and electrochemical impedance spectroscopy were used to evaluate the electrochemical performance of the composite as a cathode in lithium ion batteries. It is found that the composite has a sulfur content of up to 66. 2%, a high initial discharge capacity of 1 287 mAh·g-1 at a current density of 0. 2 C and a retained capacity of 643 mAh·g-1 after 200 cycles, which are much higher than those of a sulfur cathode without the carbon host. The composite also exhibits excellent rate capability.
参考文献
- 下载量()
- 访问量()
- 您的评分：
-
10%
-
20%
-
30%
-
40%
-
50%