Dry-spun Carbon Nanotube(CNT)fibers were surface-modified by atmospheric pressure oxygen plasma functionalization using a well controlled and continuous process.The fibers were characterized by scanning electron micro...Dry-spun Carbon Nanotube(CNT)fibers were surface-modified by atmospheric pressure oxygen plasma functionalization using a well controlled and continuous process.The fibers were characterized by scanning electron microscopy(SEM),Raman spectroscopy,and X-ray Photoelectron Spectroscopy(XPS).It was found from the conducted electrochemical measurements that the functionalized fibers showed a 132.8% increase in specific capacitance compared to non-functionalized fibers.Dye-adsorption test and the obtained Randles-Sevcik plot demonstrated that the oxygen plasma functionalized fibers exhibited increased surface area.It was further established by Brunauer-Emmett-Teller(BET)measurements that the surface area of the CNT fibers was increased from 168.22 m^2/g to 208.01 m^2/g after plasma functionalization.The pore size distribution of the fibers was also altered by this processing.The improved electrochemical data was attributed to enhanced wettability,increased surface area,and the presence of oxygen functional groups,which promoted the capacitance of the fibers.Fiber supercapacitors were fabricated from the oxygen plasma functionalized CNT fiber electrodes using different electrolyte systems.The devices with functionalized electrodes exhibited excellent cyclic stability(93.2% after 4000 cycles),flexibility,bendability,and good energy densities.At 0.5 m A/cm^2,the EMIMBF4 device revealed a specific capacitance,which is 27% and 65%greater than the specific capacitances of devices using EMIMTFSI and H2SO4 electrolytes,respectively.The practiced in this work plasma surface processing can be employed in other applications where fibers,yarns,ribbons,and sheets need to be chemically modified.展开更多
研究了以碳纳米管（CNTs）和碳纤维（CF）作为复合导电剂的导电纸。通过高速剪切的方法将分散好的导电剂和纸浆纤维素在水溶液中复合,经真空抽滤法沉积得到导电纸。纤维状的导电剂与纸浆纤维搭建成三维导电网络,表现出了良好的柔韧性、...研究了以碳纳米管（CNTs）和碳纤维（CF）作为复合导电剂的导电纸。通过高速剪切的方法将分散好的导电剂和纸浆纤维素在水溶液中复合,经真空抽滤法沉积得到导电纸。纤维状的导电剂与纸浆纤维搭建成三维导电网络,表现出了良好的柔韧性、导电性和电磁屏蔽性能。采用扫描电子显微镜、四探针电阻仪、矢量网络分析仪对其进行表征。研究表明,当碳纤维和碳纳米管以1∶1比例添加作为复合导电剂时,碳纤维-碳纳米管复合纸的导电性能和电磁屏蔽性能较碳纤维或碳纳米管单一导电剂提高明显。复合导电纸的电导率达到280.1 S/m,在175-1600MHz频段电磁屏蔽效能达到37-44 d B,较碳纤维纸提高2 d B,较碳纳米管纸提高10 d B。展开更多
研究了一种由碳纳米管和纸纤维制备的新型导电纸。以纸纤维为基本骨架,碳纳米管为导电填充剂,通过真空抽滤法制备导电纸,对比了石墨化碳纳米管和未石墨化碳纳米管分别作为导电填料导电纸的性能。通过扫描电子显微镜、透射电镜、四探针...研究了一种由碳纳米管和纸纤维制备的新型导电纸。以纸纤维为基本骨架,碳纳米管为导电填充剂,通过真空抽滤法制备导电纸,对比了石墨化碳纳米管和未石墨化碳纳米管分别作为导电填料导电纸的性能。通过扫描电子显微镜、透射电镜、四探针电阻仪、XRD衍射、Raman光谱等进行性能表征。导电纸裁切为负极极片并组装成半电池,通过CT-3008W-5V5m A-S4电池放电柜检测电池电化学性能。研究表明:碳纳米管经高温石墨化处理后作为负极,在0.1 C条件下电池稳定放电比容量为266 m Ah/g,相比于改性前的142 m Ah/g,提高了87.3%。展开更多
基金funded by a NASA Grant NNX13AF46Apartly by the National Institute for Occupational Safety and Health through the UC Pilot Research Project Training Program ERC Grant #T42OH008432
文摘Dry-spun Carbon Nanotube(CNT)fibers were surface-modified by atmospheric pressure oxygen plasma functionalization using a well controlled and continuous process.The fibers were characterized by scanning electron microscopy(SEM),Raman spectroscopy,and X-ray Photoelectron Spectroscopy(XPS).It was found from the conducted electrochemical measurements that the functionalized fibers showed a 132.8% increase in specific capacitance compared to non-functionalized fibers.Dye-adsorption test and the obtained Randles-Sevcik plot demonstrated that the oxygen plasma functionalized fibers exhibited increased surface area.It was further established by Brunauer-Emmett-Teller(BET)measurements that the surface area of the CNT fibers was increased from 168.22 m^2/g to 208.01 m^2/g after plasma functionalization.The pore size distribution of the fibers was also altered by this processing.The improved electrochemical data was attributed to enhanced wettability,increased surface area,and the presence of oxygen functional groups,which promoted the capacitance of the fibers.Fiber supercapacitors were fabricated from the oxygen plasma functionalized CNT fiber electrodes using different electrolyte systems.The devices with functionalized electrodes exhibited excellent cyclic stability(93.2% after 4000 cycles),flexibility,bendability,and good energy densities.At 0.5 m A/cm^2,the EMIMBF4 device revealed a specific capacitance,which is 27% and 65%greater than the specific capacitances of devices using EMIMTFSI and H2SO4 electrolytes,respectively.The practiced in this work plasma surface processing can be employed in other applications where fibers,yarns,ribbons,and sheets need to be chemically modified.
文摘研究了以碳纳米管（CNTs）和碳纤维（CF）作为复合导电剂的导电纸。通过高速剪切的方法将分散好的导电剂和纸浆纤维素在水溶液中复合,经真空抽滤法沉积得到导电纸。纤维状的导电剂与纸浆纤维搭建成三维导电网络,表现出了良好的柔韧性、导电性和电磁屏蔽性能。采用扫描电子显微镜、四探针电阻仪、矢量网络分析仪对其进行表征。研究表明,当碳纤维和碳纳米管以1∶1比例添加作为复合导电剂时,碳纤维-碳纳米管复合纸的导电性能和电磁屏蔽性能较碳纤维或碳纳米管单一导电剂提高明显。复合导电纸的电导率达到280.1 S/m,在175-1600MHz频段电磁屏蔽效能达到37-44 d B,较碳纤维纸提高2 d B,较碳纳米管纸提高10 d B。
文摘研究了一种由碳纳米管和纸纤维制备的新型导电纸。以纸纤维为基本骨架,碳纳米管为导电填充剂,通过真空抽滤法制备导电纸,对比了石墨化碳纳米管和未石墨化碳纳米管分别作为导电填料导电纸的性能。通过扫描电子显微镜、透射电镜、四探针电阻仪、XRD衍射、Raman光谱等进行性能表征。导电纸裁切为负极极片并组装成半电池,通过CT-3008W-5V5m A-S4电池放电柜检测电池电化学性能。研究表明:碳纳米管经高温石墨化处理后作为负极,在0.1 C条件下电池稳定放电比容量为266 m Ah/g,相比于改性前的142 m Ah/g,提高了87.3%。
