Preparation And Capacitance Performance Of Condcuting Polymers Nanocomposites

Supercapacitors have been extensively studied as one type of the most promisingcandidates for next generation energy storage systems. Compared with electrostaticsupercapacitors or batteries, electrochemistry supercapacitors have several advantages,such as a large specific capacitance, a high power density, a long cycle life and rapidcharging-discharging rates. An electrode material is one of the key factors that affectthe electrochemical properties of the supercapacitor. The researches in the electrodematerials are mainly the following three types: the electrical double layer capacitance,such as carbon materials; and pseudo-capacitance, for example, transition metaloxides and conducting polymers.Among the electrode material, the conducting polymer based supercapacitor hasattracted much attention because of its high energy density, low cost, easy synthesis,and environmental friendliness. However, it has a relatively poor cycling stability andtemperature dependence, because the redox sites in the polymer backbone are notsufficiently stable and the backbone of polymer can be destroyed within a limitednumber of charge/discharge cycles. Therefore, it is often hybridized with inorganicmaterials （carbon materials, metal oxides） or organic materials to prepare a compositeand used in supercapacitors with better cycleability, specific capacitance andmechanical stability. We prepared a conductive polymer composite electrode material,the structure, morphology and electrochemical properties of the materials arecharacterized in detail. The main contents are as follows:1. Polyaniline/sodium carboxymethyl cellulose （PANI/CMC） nanorods have beensynthesized via in-situ oxidation polymerization of aniline in the presence of sodiumcarboxymethyl cellulose as a polymerization template. The structure and morphologyof the nanorods are characterized by TEM, FE-SEM and XRD. The size and shape ofthe composite nanorods are uniform with a diameter of100nm. Their electrochemicalproperties are also investigated using cyclic voltammetry and galvanostatic charge/discharge measurement. The specific capacitance of PANI/CMC nanorods preparedwith20wt%CMC can be as high as451.3F g^-1. Its capacitance remains higher than300F g^-1after1000cycles at a current density of1A g^-1. These novel nanorods aredesirable for applications in supercapacitor devides. 2. We report a facile strategy to synthesize of polypyrrole/molybdenum disulfide（PPy/MoS₂） nanocomposite as an advanced electrode material for high-performancesupercapacitors applications. Flowerlike MoS₂with graphene-like subunits structureis prepared using a hydrothermal method, and the nanocomposite PPy are embeddedin MoS₂nanosheets is prepared by in situ oxidation polymerization of pyrrole in thepresence of MoS₂suspension. Structural and morphological characterizations of thenanocomposite are investigated by XRD, FE-SEM and TEM measurements. Theirelectrochemical properties are also investigated using cyclic voltammetry, andgalvanostatic charge/discharge. The PPy/MoS₂nanocomposite exhibit high specificcapacitance of553.7F g^-1and its capacitance can still remain90%after500cycles ata current density of1A g^-1.3. We report a facile strategy to synthesize of polypyrrole coated copper sulfide（CuS@PPy） nanocomposite as an advanced electrode material for high-performancesupercapacitor applications. Novel sphere-like CuS with intertwined sheet-likesubunits structures are fabricated by solvothermal approach without any surfactantand template. And the PPy are filling in sheet-like subunits of sphere-like CuS formpolypyrrole coated copper sulfide nanostructures are prepared by in situ oxidationpolymerization of pyrrole in the presence of CuS suspension. Structural andmorphological characterizations of the nanocomposite are investigated by XRD,FE-SEM and TEM measurements. Their electrochemical properties are alsoinvestigated using cyclic voltammetry, and galvanostatic charge/discharge. TheCuS@PPy nanocomposite exhibit high specific capacitance of427F g^-1and itscapacitance can still remain90%after500cycles at a current density of1A g^-1.