Preparation And Charge Storage Performance Of Nanocomposites Based On Electrospun Graphitized Fiber Films

Three types of three-dimensional (3D) nanomaterials with hierarchical porousstructure were prepared by using electrospun graphitized fiber films (EGFF) assubstrate and followingly growing nanowires with electrochemical capacitanceperformance on them. The special hierarchical porous structure was composed bymicronsized pores among graphitized fibers (GF) and nanoscale pores amongnanowires. The nanocomposites retain the3D web-like self-supporting structure ofEGFF. Due to their unique structure, the preparation of electrodes was simplified,utilization ratio of active material was improved, rapid charge-discharge ability andstability were also enhanced. Electrochemical tests show that these kinds of materialshave good electrochemical capacitance performance and they are good electrodematerials for supercapacitors.This thesis mainly includes the following three aspects:1. A series of polyaniline/graphitized fiber nanocomposites (PANI/GF) wereprepared by growing polyaniline (PANI) nanowires via in-situ chemicalpolymerization on the surface of GF. Experiment results show that, PANI/GF-3prepared with concentration ratio between aniline and ammonium persulfate0.03Mto0.0075M has the best morphology structure and electrochemical capacitanceperformance. The specific capacitance reaches its highest value976.5F/g at thecharge-discharge current density of0.4A/g, and still retains50.9%(497.4F/g) evenwhen the charge-discharge current density reaches50A/g. After1000cycles at10A/g,its specific capacitance only decreases by10.8%.2. A series of carbon/carbon nanomaterials were prepared by carbonizingPANI/GF-3at different temperature. The results showed that all the electrodes basedon carbonized samples showed typical double layer capacitance performance andimproved rapid charge-discharge performance. Among the carbonized samples, C700which was carbonized at700℃shows the best electrochemical capacitanceperformance. The specific capacitance reaches its highest value106.2F/g at thecharge-discharge current density of0.5A/g, and still keeps53.2%(56.5F/g) evenwhen the charge-discharge current density reaches100A/g.3. Activated carbon nanocomposites were prepared by immersing C700in KOH(aq) and then activated at different temperature. The results showed that0.1M KOH (aq) was the best activator and the resulted samples prepared by activated at differenttemperature all showed improved performance. Among the activated samples, AC600which was activated at600℃shows the best electrochemical capacitanceperformance. The specific capacitance reaches its highest value176.5F/g at thecharge-discharge current density of0.5A/g and still retains66.6%(117.6F/g) evenwhen the charge-discharge current density reaches100A/g, which is increased by108.1%.