层次孔活性炭气凝胶/硫复合正极材料的制备及其电化学性能  

Preparation and electrochemical performance of a hierarchically porous activated carbon aerogel/sulfur cathode for lithium-sulfur batteries

作　　者：唐志伟[1] 徐飞[1] 梁业如[1] 吴丁财[1] 符若文[1] 

机构地区：[1]中山大学化学与化学工程学院材料科学研究所,教育部聚合物复合材料及功能材料重点实验室,广东广州510275

出　　处：《新型炭材料》2015年第4期319-326,共8页New Carbon Materials

摘　　要：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=1 675 m A·g-1)电流密度下,初始放电比容量高达1 287 m Ah·g-1,200圈后比容量保持在643 m Ah·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 / organic 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 m Ah·g^-1 at a current density of 0. 2 C and a retained capacity of 643 m Ah·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.

关 键 词：锂硫电池 活性炭气凝胶 KOH活化 复合材料 电化学性能 

分 类 号：O611.4[理学—无机化学] TM912[理学—化学]