| Electrochemical capacitor is a new kind of energy storage device and have several advantages compared to the secondary battery, for example their long cycle life, simple principle and mode of construction, short charging-time, safety, and high power density. For this reason, electrochemical capacitor has been the important part of study of power source. This thesis consists of four parts. The next section is the content of very part.The purpose of the first chapter is to survey the fundamental principles, characterizations and applications of supercapacitors, especially the recent progress of researches on supercapacitors using carbon, transition-metal oxide and conducting polymer as electrode materials and the study of all solid sate supercapacitors. Based on these information I put forward my purposes and researches to solve existed questions.The second chapter shows the electrochemical capacitance performance of PAN film synthesized by electrochemical method. This chapter is divided into two parts. The electrochemical polymerization of aniline via cyclic voltammetry was performed in 1mol/L HCl and 0.2 mol/L aniline solutions with various concentration of NiCl2. The electrochemical tests indicated that the presence of Ni2+ ions can improve the density of nucleation, which made the more compact. It can also prove that presence of proper Ni2+ can improve the electrochemical capacitance performance of PAN film.The electrochemical polymerizaiton of aniline via cyclic voltammetry (CV) was performed in 1M HCl and 0.2M aniline solutions with various concentrations of anionic surfactant SDS (sodium dodecylsulphate). The electrochemical tests indicated that the rate of polymerization strongly depends on the concentration of concentration of SDS, and the presence of proper Ni2+ can improve the electrochemical performance of PAN film.The third chapter shows the electrochemical capacitance performance of all solid state supercapacitor. This chapter is divided into two parts. The proton-conducting composite phsopbotugstic acid (PTA)/ Al2(SO4).18H2O was used as the electrolyte of symmetric supercapacitor based on PAN. The optimum weight ratio of PTA/ Al2(SO4).18H2O for using in this supercapacitor was also reported. Electrochemical tests prove that the supercapacitor using this kind of composite as electrolyte has high capacitance performance.The gel polymer electrolyte PVA-H3PO4-H2O was prepared and its electrochemical characters were also examined by electrochemical methods. A totally solid state symmetric supercapacitor based on polymer polyaniline (PAN) has been fabricated by using this kind of gel polymer as electrolyte. Electrochemical tests prove that this symmetric supercapacitor has good electrochemical capacitance performance.The third chapter shows the electrochemical capacitance performance of composites based on TiO2 nanotubes. This chapter is divided into three parts.1. The aniline was polymerized by chemical oxidation in H2SO4 aqueous solution containing various amounts of TiO2 nanotubes. The results of electrochemical test show that the three dimensional nanotube network of TiO2 offers a solid support structure for active materials polyaniline (PAN), allows the active material to be readily accessible (available) for electrochemical reactions, and improves the efficiency of the active materials. 2. RuO2 / TiO2 nanotubes composites were synthesized by loading various amounts of RuO2 on TiO2 nanotubes. The results of electrochemical tests show that the three dimensional nanotube network of TiO2 offers a solid support structure for active materials RuO2, allows the active material to be readily accessible (available) for electrochemical reactions, and improves the efficiency of the active materials.3. In this paper, NiO/TiO2 nanotubes composites were synthesized by loading various amount of NiO on TiO2 nanotubes. The results of electrochemial tests prove that the three dimensional nanotube network of TiO2 offers a solid support structure for the active materials NiO, allows the a...
|
PDF Full Text Request