多孔CNTs@PANI修饰CNT纤维的制备及电化学性能

Fabrication and electrochemical performances of porous carbon nanotubes/polyaniline-modified carbon nanotube fiber

通过低电压电泳沉积的方法在碳纳米管纤维(CNF)表面沉积多孔碳纳米管(CNTs),然后在其表面电化学沉积一层聚苯胺(PANI),得到CNTs@PANI三维多孔网络结构修饰的核-鞘型纤维电极材料。通过扫描电镜、透射电镜和拉曼光谱表征电极材料表面形貌和微观结构,并利用电化学工作站测试电化学性能,研究结果表明,沉积的多孔CNTs结构可以为PANI提供更多的氧化还原反应活性位点,而PANI也具有固定CNTs的作用,在电流密度为1 mA/cm^2时,CNTs和PANI修饰的电极面积比电容达77.28 mF/cm^2。以聚二甲基硅氧烷薄膜为基底、PVA-H_3PO_4为电解质制备的对称型固态柔性超级电容器在电流密度为0.25mA/cm^2时,面积比电容为61.25 mF/cm^2,恒流充放电4000次后,电容值仍维持在80%,并且串联两个电容器可以点亮电压为1.8 V的LED灯泡。

A porous carbon nanotube （CNT） network was deposited on the surface of carbon nanotube fibers （CNF） by low-potential electrophoretic deposition, and then a layer of polyaniline （PANI） was electrochemically deposited on the surface of the CNT-decorated carbon nanotube fiber to form a core-sheathed structure of three-dimensional porous CNF/CNT/PANI fiber electrode material. Scanning electron microscopy （SEM）, transmission electron microscopy （TEM） and Raman spectroscopy were used to characterize the morphology and microstructure of the electrode material surface. An electrochemical workstation was used to measure the electrochemical performances. The experiment results showed the porous CNTs framework provided more active sites for the redox reaction of PANI, while the PANI can immobilize the pre-deposited CNTs structure. The areal specific capacitance of the electrode modified with CNTs and PANI reached 77.28 mF.cm-2 at the current density of 1 mA.cm 2. Besides, a symmetrical all-solid-state flexible supercapacitor was prepared by using polydimethylsiloxane （PDMS） thin film as the substrate and PVA-H3PO4 as the electrolyte, and the areal specific capacitance achieved 61.25 mF.cm 2 at the current density of 0.25 mA.cm 2. After 4000 cycles of charge/discharge, the capacitance value remains 80%, and two capacitors in series can light up a 1.8 V LED bulb.