Study On Preparation And Electrochemical Properties Of Polyaniline-based Composite

Supercapacitors are new clean power source devices between traditional capacitors andbatteries, with many advantages, such as high energy density, high power density, long life,low maintenance cost and enviromental friendly. Conducting polyaniline (PANI) is one ofimportant electrode materials, for large specific capacitance (Cs), extensive raw material, easyto prepare and good enviromental stability.First of all, PANI nanofibers were prepared via interfacial polymerization, graphene(GR)was used to modify PANI, PANI/GR nanocomposite was prepared by two different methods,Then carbon nanotubes (CNTs) and GR were used to modify PANI at the same time, toprepare PANI/CNTs/GR nanocomposite. The chemical structures and morphology of productswere analysed by flourier transform infrared (FTIR), UV-Vis spectra, X-ray diffraction (XRD),scanning electron microscope (SEM) together with transmission electron microscope (TEM).Conductivity tester, cyclic voltammogram (CV) and galvanostatic charge-discharge werefurther used to test the conductity properties and electrochemical properties, which wereproved to be improved remarkably after modified.The length-diameter ratio of PANI nanofibers was larger prepared in hydrochloric acidsolution, and the structure became more homogeneous with the decreasing of aniline (An)concentration, the products had better crystallinity and conductivity; showing faradaypseudocapacitance charateristics and higher electrochemical activity in electrochemical tests,the Csof PANI reached196F/g at a current density of0.5A/g for the first charge-dischargemeasurement, and after500continuous charge-discharge cycles, the Csretained67.2%.Using graphene oxide (GO) as template, PANI/GO nanocomposite was prepared byinterfacial polymerization, after deoxidated by hydrazin hydrate and reoxidized throughammonium persulfate (APS), the PANI/GR nanocomposite was obtained. When the massratio of An:GO was100:1, the product has higher Cs, reached up to306F/g at a currentdensity of0.5A/g, the PANI/GR nanocomposite maintained86.5%of the capacitance after500consecutive cycles; The GO was modified by An (the product named as GO-An), andthen GO-An was used as template to get PANI/GR nanocomposite, the product showed loosesyructure, with larger length-diameter ratio and uniform size, and exhibited goodelectrochemical capacitive properties.CNTs and GR were used to improve the performance of PANI simultaneously,PANI/CNTs nanocomposite was prapered via in situ polymerization, CNTs were covered withPANI was observed by electron microscope, to form loose and uniform structure, and theproduct embodied high conductivity. When the feeding ratio of An:CNTs was100:1, theproduct had higher Cs. Then the PANI/CNTs was dispersed in GO solution, after deoxidatedby hydrazin hydrate and reoxidized, the PANI/CNTs/GR nanocomposite was obtained, with good conductivity, higher Csand outstanting cycling stability. The Csof product reached350F/g at a current density of0.5A/g, and retained90.1%after500charge-discharge cycles,exhibiting excellent electrochemical capacitive properties, making it promising application insupercapacitors and other power source system.