Preparation And Electrochemical Capacitance Performance Of PPy/inorganic Nanocomposite

Supercapacitor, often called electrochemical capacitors, is a new energy storage devicecapacitors between battery and conventional capacitors. Compared with traditional capacitors,supercapacitors have the advantages of high power density, environment-friendly, low cost, fastcharge-discharge, and long service life. They have attracted much attention in many fields such asregenerative braking in hybrid vehicles, cold engine starting. Currently scientists have focused onthe electrode material for the supercapacitors. PPy/inorganic nanocomposite materials because ofits advantages have been a research hotspot. This thesis is divided into the following four parts tointroduce.The purpose of first chapter is to describe the energy storage mechanism characteristics,classification, and application range of supercapacitor; and to introduce the research progress ofthe carbon material, metal oxide hydroxide material, conductive polymer materials and hybridcapacitor. At the same time, the preparation method of conductive polymer/inorganicnanocomposite is summarized. Finally, the research idea, purpose and method about theelectrode materials of supercapacitor are put forward.The second chapter introduces the preparation and electrochemical capacitive behaviors ofMoO₃/PPy composite. This chapter is divided into two parts:1. MoO₃/PPy nanocomposites were prepared by in-situ in the chemical oxidativepolymerization of pyrrole, which the MoO₃was matrix. MoO₃/PPy composite with the highspecific surface area possessed the best electrochemical activity due to the special core-shellstructure. A maximum capacitance of450.8F·g-1was obtained at the current density of1A·g-1.2. H-MoO₃/PPy composite material was prepared. The composite material is mainlypresented in one-dimensional structures. And when the mass ratio of H-MoO₃and PPy was2:1,the material exhibits excellent electrochemical performance.The third chapter shows the preparation and electrochemical capacitive behaviors ofPPy/metal oxide/CNTs composites, and is divided into three parts: 1. PPy/MnO₂/CNTs composite was prepared by in situ of pyrrole in the host of inorganicmatrix of MnO₂and CNTs. All the results indicate that PPy/MnO₂/CNTs composite possesses thetypical tube-in-tube nanostructures: the inner tubules are CNTs and the outer tubules aretemplate-synthesized PPy. MnO₂nanoparticles may either sandwich the space between the innerand outer tubules or directly latch onto the wall of the PPy tubes. The composite yields a goodelectrochemical reversibility through1000cycles’ CV test in the potential range of0.6to0.4Vand its specific capacitance was up to402.7F·g-1with a specific current density of1A·g-1.2. PPy/V2O5/CNTs composite was prepared by in situ polymerization. It is found that thecomposite in the potential range of-0.4～0.6V and-0.6～0.4V has good electrochemicalproperties.3. MoO₃/CNTs, MoO₃/PPy/CNTs were prepared by ultrasonic dispersion method andin-situ polymerization. The electrochemical test results showed that performance ofMoO₃/PPy/CNTs was better than MoO₃/CNTs in acidic electrolyte.The fourth chapter displays synthesis and electrochemical capacitance of the PPy/twometal oxide composites, this chapter is divided into two parts:1. MnO₂/TiO₂/PPy composite was prepared by using two methods. It was foundcomposite possessed good electrochemical performance when MnO₂/TiO₂was synthesized firstlyunder hydrothermal condition and then combined with PPy.2. V2O5/SnO₂/PPy composites were prepared by in situ by MO/FeCl3as template agent,it was noted that composite had good performance when the proportion of component was1:1:1.