硫/碳纤维复合膜的制备及电化学性能  

Preparation and Electrochemical Performance of Composite Film of Sulfur and Carbon Fibers

作　　者：杨学兵[1] 王传新[1] 汪建华[1] 谢秋实[1] 谢海鸥[1] 

机构地区：[1]武汉工程大学湖北省等离子体化学与新材料重点实验室,武汉430073

出　　处：《无机化学学报》2011年第12期2431-2436,共6页Chinese Journal of Inorganic Chemistry

基　　金：国家重点基础研究发展计划(No.2011CB201600);湖北省自然科学基金(No.2007ABA006);湖北省教育厅重点项目(2007)资助项目

摘　　要：采用热丝化学气相沉积法先在铁箔上沉积了致密的碳纤维膜,后通过加热渗硫法制得硫/碳纤维复合膜,并将其用作锂硫电池正极材料。通过扫描电子显微镜和X射线衍射表征膜的形貌和结构,采用恒流充放电法和阻抗测量法测试复合膜的电化学性能。结果表明,随热丝与铁箔基底间距减小,碳纤维膜致密度先升高后降低;随H2与(Ar+C3H6O)的体积流量比减小,碳纤维膜致密度升高。当丝基距为6 mm,流量比为30/40时,铁箔上沉积了厚度为50μm的致密碳纤维膜,其中碳纤维有良好的垂直取向性和较高结晶度。在硫/碳纤维复合膜正极中,密集的碳纤维形成均匀分布且垂直取向性良好的导电骨架,当电流密度为0.4 mA.cm-2时,硫/碳纤维复合膜正极的初次放电比容量为1 128 mAh.g-1,50次循环后的放电比容量为811 mAh.g-1。Dense carbon fiber film was deposited on iron foil at first by hot filament chemical vapor deposition.Then the film was sulfurized by heating to form composite film of sulfur and carbon fibers,which was then used as cathode materials of lithium/sulfur battery.Morphology and structure of films were characterized by scanning electron microscopy and X-ray diffraction.Electrochemical performance of the composite film was tested by methods of constant current charge-discharge and measurement of impedance.Results indicate that as distance between filament and substrate of iron foil decreases,the density of carbon fiber film increases firstly and decreases afterward.And the density increases with the diminishing volume flow ratio between H2 and（Ar＋C3H6O）.When the distance between filament and substrate is 6 mm and the volume flow ratio is 30/40,dense carbon fiber film with thickness of 50 μm is deposited on iron foil.Those carbon fibers are mainly vertically oriented and have relative high degree of crystalline.In the composite film of sulfur and carbon fibers,dense carbon fibers form evenly distributed electrically conductive framework with vertical orientation.When current density is 0.4 mA·cm-2,initial discharge specific capacity of the composite film is 1 128 mAh·g-1 and the discharge specific capacity is 811 mAh·g-1 after 50 cycles.

关 键 词：热丝化学气相沉积 碳纤维膜 锂硫电池 正极材料 

分 类 号：TQ342[化学工程—化纤工业] TM912.9[电气工程—电力电子与电力传动]