Free-standing Ni-microfiber-supported carbon nanotube aerogel hybrid electrodes in 3D for high-performance supercapacitors
Free-standing Ni-microfiber-supported carbon nanotube aerogel hybrid electrodes in 3D for high-performance supercapacitors
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DOI：
10.1039/c2ra20271a
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发表时间：
2012-07
期刊：
影响因子：
3.9
通讯作者：
Y. Fang;Fangting Jiang;H. Liu;Xiaoming Wu;Yong Lu
中科院分区：
文献类型：
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作者：
Y. Fang;Fangting Jiang;H. Liu;Xiaoming Wu;Yong Lu
宏观镍微纤维支撑的碳纳米管气凝胶（CNAG）已被开发并显示出作为超级电容器电极的巨大潜力。采用催化化学气相沉积法，通过在由5 vol% 8 μm Ni纤维组成的烧结锁定微纤维结构（SMF）上生长碳纳米管（CNTs），可控地制备了宏观碳纳米管。通过浸渍/聚合方法将聚酰亚胺涂覆到植根于SMF-Ni上的CNT上，随后通过热解将其包覆以产生自支撑CNAG/SMF-Ni复合电极，其中Ni纤维网络充当集流体，并且在Ni纤维上生长的CNT充当纳米导线以连接电荷存储碳气凝胶（CAG）颗粒。这种新方法允许期望的大面积制造，并提供了高CNAG负载（高达71.0重量%; CAG/CNT：1.44重量/重量）、无粘合剂特征、优异的导电性、大表面积、宏观/介观/微米尺寸的分级多孔结构和高渗透性的独特组合。由68.5重量%的CNAG（CAG/CNT：1.17重量/重量）组成的典型混合物不仅提供良好的电容（例如，359 F/g CAG），而且具有优异的长循环寿命（300次循环伏安图循环后损失5%，然后在1000次循环中几乎不变）。
Macroscopic Ni-microfiber-supported carbon nanotube aerogels (CNAGs) have been developed and demonstrate great potential as supercapacitor electrodes. The macroscopic carbon nanotubes (CNTs) are controllably prepared by a catalytic chemical vapour deposition method through CNT growth on a sinter-locked microfibrous structure (SMF) consisting of 5 vol% 8 μm Ni fibers. Polyimide is coated onto the CNTs rooted on the SMF-Ni by an impregnation/polymerization method and is subsequently carbonized by pyrolysis to create self-supporting CNAGs/SMF-Ni composite electrodes, wherein the Ni-fiber network serves as current collector and the CNTs grown on the Ni fiber act as nano conducting wires to link the charge-storage carbon aerogel (CAG) particles. This novel approach permits desirable large-area fabrication and provides a unique combination of high CNAG-loading (up to 71.0 wt%; CAG/CNT: 1.44 wt/wt), binder-free feature, excellent electrical conductivity, large surface area, macro-/meso-/micro-sized hierarchical porous structure and high permeability. A typical hybrid consisting of 68.5 wt% CNAG (CAG/CNT: 1.17 wt/wt) delivers not only a good capacitance (e.g., 359 F per gram CAG) at high rates but also excellent long-cycle life (5% loss after 300 cyclic voltammogram cycles and then almost unchanged through 1000 cycles).