定向加压过滤法制备碳纳米管/聚苯胺纸基复合电极材料及其电化学性能

Preparation of carbon nanotubes/polyaniline buckypaper composite electrode by directional pressure filtration and its electrochemical properties

采用定向加压过滤技术获得直径约为120 mm、厚度约为10μm的碳纳米管/聚苯胺(CNT/PANI)自支撑纸基柔性电极。在电极中CNT均匀弥散分布,PANI均匀地嵌入CNT网络中。PANI为纳米至亚微米级球形颗粒,其负载量最高为2.7 mg·cm^(-2)。PANI负载量为2.2 mg·cm^(-2)的电极的孔隙率为70.33%,密度为0.4 g·cm^(-3),孔面积为67.31 m^(2)·g^(-1)。该电极可紧绕直径为4 mm的玻璃棒数圈而无损伤。该电极在4 mA·cm^(-2)的电流密度条件下,单电极比电容为1.88 F·cm^(-2);在充放电1200次循环过程中,比电容先下降后增大,至900次循环时比电容达到2.41 F·cm^(-2),1200次循环时容量保持率为125.78%;经180°弯折500次后,容量保持率为78.43%。该电极所组装的对称三明治结构超级电容器在5 mA·cm^(-2)的电流密度条件下比电容为0.48 F·cm^(-2),经1000次充放电循环容量保持率为94.3%,能量密度和功率密度分别为213.75 mW·h·cm^(-3)和2163.22 mW·cm^(-3)。

Carbon nanotubes/polyaniline(CNT/PANI)buckypaper self-supporting flexible electrodes with a diameter of about 120 mm and a thickness of about 10μm were obtained by directional pressure filtration technology.CNTs distributed uniformly and dispersed in the electrode,and PANI was uniformly embedded in the CNT network.PANI was spherical particles of nanometer to submicron size,with a maximum loading capacity of2.7 mg·cm^(-2).The electrode with PANI loading of 2.2 mg·cm^(-2) has a porosity of 70.33%,a density of 0.4 g·cm^(-3) and a total pore area of 67.31 m^(2)·g^(-1).The electrode can be wound several times around the glass rod with diameter of4 mm without damage.At the current density of 4 mA·cm^(-2),the specific capacitance of the electrode is 1.88 F·cm^(-2).In the process of 1200 charging-discharging cycles,the specific capacitance decreases first and then increases,and reaches 2.41 F·cm^(-2) at the 900 th cycle,and the capacity retention rate is 125.78%at the 1200 th cycle.After 500 times of bending at 180°angle,the retention rate of capacity is 78.43%.The symmetrical sandwich structure supercapacitor assembled by this electrode has a capacitance of 0.48 F·cm^(-2) at a current density of 5 mA·cm^(-2).Its capacity retention rate after 1000 charge-discharge cycles is 94.3%.Its energy density and power density are 213.75 mW·h·cm^(-3) and 2163.22 mW·cm^(-3),respectively.