Perparation And Electrochemistry Performance Of Polyaniline/Activated Carbon Composite Materials

In this dissertation, Polyaniline (PANI) and Polyaniline/Activated Carbon composite material (PANI/AC) were synthesized by electropolymerization. The materials were characterized using scanning electron microscopy and infrared spectrum, and the electrochemical characterisation of the materials were carried out by means of cyclic voltammetry, galvanostatic charge-discharge experiments, electrochemical impedance spectroscopy (EIS) and simulation with equivalent circuit. A series of experiments were conducted to research on preparation techniques of electrodes, optimization of electrolytes, assembly technology of capacitor. Rusults came as follows:1. Perparation and Electrochemistry Performance of Polyaniline MaterialsPolyaniline was fabricated by cyclic voltammetry (CV) on the surface of Pt electrode in organic solvent. The eleetrode exhibited typical capacitive behavior in 1M LiClO4 acetonitrile. The specific capacitance of the PANI electrode was up to 320.8F/g at a discharging current density of 1mA/cm2, and droped to 260.0F/g at 10 mA/cm². Cyclic life test of PANI electrode was measured by CV for 500 cycles. The result showed excellent cyclic life.2. Perparation and Performance of Activated Carbon electrodePreparation and electrochemistry property of AC electrode was investigated. The experiment results demonstrated that, the potential-time curves of AC electrode was linear in LiClO₄ acetonitrile solution, and the pecific capacitance was 103.3F/g. AC electrodes has the capacitance about 94.0F/g at the 1000th cycle, about 85% of early stage of cycling, and Coulomb effect of AC electrode was 96%. The ESR was 13.8Ωtested by EIS.3. Study of PANI/AC electrode prepared by electrochemical polymerization methodCyclic voltammetry methods were used to prepare PANI/AC composite electrode by coating polyaniline on the surface of AC electrode. The composite electrode had a specific capacitance of 290.7F/g, higher than AC electrode and had obvious faradaic pseudo-capacitance, and ESR was about 6.5Ω. The capacitance of PANI/AC composite electrode droped by about 15.7% after 1000 cycles. The specific capacitance of PANI/AC composite electrode prepareed by potentiostatic methods was 290.7F/g, and ESR was about 11.1Ω.The hybrid capacitor using PANI/AC anode and AC cathode was prepared and its electrochemical behavior materials was investigated in organic electrolyte. The specific capacitance and specific energy were 99.6F/g and 53.0Wh/kg separately, discharging from 2.0V to 0V, in comparison with values of 33.9F/g and 18.8Wh/kg for the AC capacitor. Both capacitor had better performances of self-discharge.