Preparation Of Flexible Polyaniline Composite Electrodes And Application In Supercapacitors

Due to the high electrical conductivity,easy synthesis,low cost,polyaniline(PANI)and its derivatives were applied to many fields,such as electrochemical devices(sensors,capacitors,displays),batteries(solar cells,fuel cell,secondary cell),anticorrosive coating and electromagnetic shielding.However,its rigid chain and strength interaction between the chains of PANI made it difficult to be molded,and the support materials were needed,which restricted its practice applications.Therefore,to improve the workability of PANI materials,PANI has been modified by physical or chemical approaches,such as preparing PANI/thermoplastic polymer composites,introducing flexible alkyl chains or copolymerization.In this paper,we fabricated firstly the film substrates by spreading on glass panes.Then the PANI-based composite electrodes were prepared deposited or grafted on the surface via in-situ chemical oxidative polymerization of aniline,as free-standing electrode materials for supercapacitors.We selected polyvinyl chloride films with the low density and easy molding and glass fiber accompanying the large specific surface area as flexible substrates.And effect of polymerization conditions on properties of composites was studied,with the optimal synthesis procedures.Firstly,polyvinyl chloride films were fabricated by casting method.Then the flexible polyaniline composite film electrodes were prepared via in-situ chemical oxidative polymerization of aniline.The result showed that the polyvinyl chloride-g-polyaniline composite electrodes were best by rapid-mixing chemical oxidative polymerization.The specific capacitance was 645.2 F/g at the current density of 1 A/g.the rate property was nice,which the specific capacitance retained 95% of its original value at 2 A/g.the cyclic stability was excellent with the retention of 96% after 1000 cycles.In addition,the specific capacitance retained 80.3% under 8.7 MPa for 5 min.And it was 61.2% for 1 h.Thus,the composite electrodes exhibited the outstanding flexibility and tolerance to tensile.Secondly,the amino-functionalized glass fiber filter paper/polyaniline composite electrodes were prepared modified by silane coupling agent,via the conventional chemical oxidative polymerization and rapid-mixing chemical oxidative polymerization.The specific capacitance was 490.6 F/g via rapid-mixing chemical oxidative polymerization.The rate property was good retaining 64.8% of its original value at 10 A/g.The specific capacitance retained 106.8% after 2000 cycles of cyclic voltammetry,stating a good cyclic stability.In addition,the composites had excellent flexibility and tolerance to tensile,retaining 90.0% under 0.71 MPa for 5 min and 72.6% for 1 h.From SEM images,silane coupling agent played a role as the bridge for connecting the PANI and glass fiber,and formed a unique PANI coating,leading to a better electrochemical performance.Thirdly,the electrical conductive polyvinyl chloride/multi-walled carbon nanotubes films were fabricated,blending with multi-walled carbon nanotubes as conducting filler.Then,the polyaniline/polyvinyl chloride/ multi-walled carbon nanotubes composite film electrodes were prepared on the surface,via the chemical oxidative polymerization.The specific capacitance was 801.1 F/g via rapid-mixing chemical oxidative polymerization.The specific capacitance retained 66.6% at 10 A/g,with a good rate property.The specific capacitance retained 90.6% after 2000 cycles of cyclic voltammetry.In addition,the composites had excellent flexibility and tolerance to tensile,retaining 80.4% under 8.1 MPa for 5 min and 71.8% for 1 h.From SEM images,surface of composites via conventional chemical oxidative polymerization was loose and porous.Yet,the PANI nanofibers appeared with the length of 1 um,via rapid-mixing chemical oxidative polymerization.Fourthly,the porous polyvinyl chloride films were obtained by introducing zinc oxide and polyethylene glycol.Then,the porous polyaniline/polyvinyl chloride composite film electrodes were prepared via the in-situ chemical oxidative polymerization.The specific capacitance was 533.7 F/g introducing zinc oxide via rapid-mixing chemical oxidative polymerization.The specific capacitance retained 63.3% at 10 A/g.The specific capcacitance retained 95.0% after 2000 cycles of cyclic voltammetry.In addition,the specific capacitance retained 76.8% under 9.5 MPa for 5 min and 57.2% for 1 h,presenting a good comprehensive performance.