Preparation And Capacitance Performance Of Polyaniline/graphene Nanocomposite Electrode Materials Chemical Technology

As one of the important members in the new chemical energy family,supercapacitors(SCs)with high power density,high energy density and long cycle life have become a new type of green energy storage device.Generally,the electrode materials of SCs can be divided into three types:conductive polymers,carbon materials and metal oxides.The composite electrode materials possess excellent capacitive performances as that it reveals advantages of the different materials at the same time.Thus the composite electrode materials attract more and more attention by researchers in the electrode field.In this paper,controllable preparation of polyaniline/graphene oxide composite with different morphologies of polyaniline were realized through the electrostatic interaction between 3-aminopropyltriethoxysilane,(APTES)treated polyaniline(positive change)and graphene oxide(negative charge).In addition,capacitance behaviors of various polyaniline/graphene oxide electrodes were investigated.(1)Polyaniline nanospheres/graphene oxide composite electrode materials preparation and the performance.In this paper,polyaniline nanospheres were prepared by a hydrothermal method.The morphology of polyaniline nanospheres was controlled by changing the dosage of oxidant(H2O2)and catalyst(FeCl3).The diameter of prepared polyaniline nanospheres is 450-500nm,when the content of 30%H2O2 and O.lmol/L FeCl3 is 1 mmol and 2 mmol,respectively.The test results show that the capacitance retention rate is increased from 75%to 95%and the specific capacitance of the composite material is increased from 183 F/g to 445 F/g(with 143%improvement)when the current density is 1 A/g and the mass ratio of PANI-S:GO is 0.1:1.(2)Polyaniline nanofibers/graphene oxide composite electrode material preparation and the performance.One-dimensional polyaniline nanofiber with high specific surface area and large length to diameter ratio is beneficial for the formation of conductive network in the electrode materials matrix and improving the capacitive performance method.In this paper,polyaniline nanofibers were prepared by an interfacial polymerization and graphene oxide was prepared by improved Hummers method.The effects of different reaction time and aniline concentration on the morphologies and electrochemical properties of polyaniline nanofibers were explored.The performance can be obtained optimal when the reaction time is 5 min and the aniline concentration is 0.32 mol/L.The effect of graphene oxide content onthe capacitive properties of composite electrode materials was studied thought combining polyaniline nanofibers with different amount of graphene oxide.The result reveals that the capacity retention rate can be increased from 87%to 94%and the specific capacitance of the composite material is also improved from 450 F/g to 610 F/g(with 41%improvement),when the current density is 1 A/g and the mass ratio of PANI-F:GO is 0.1:1.(1)Polyaniline nanotube/graphene oxide composite electrode materials preparation and the performance.Polyaniline nanotubes with large specific surface area and abundant mesoporous structure will promote the ion transport process and improve the electrochemical performance of the electrode materials.In this paper,polyaniline nanotubes were prepared by a fast mixing method.The effects of different reaction time on the morphology and capacitance of polyaniline nanotubes were explored.The result revel that the optimum reaction time is 1.5 h and the diameter of the polyaniline nanotube is 15?20 nm.Electrochemical testing shows that the retention of capacitance is increased from 88%to 97%when the mass ratio of PANI-T:GO is 0.1:1.The capacitance is also improved from 510 F/g to 1071 F/g(with 110%improvement).Through investigating the relationship between the specific surface area and the capacitance of polyaniline with different morphologies,we found that polyaniline with larger surface area has higher specific capacitance,meanwhile,polyaniline nanotubes have the specific highest capacitance.The polyaniline nanofibers has moderate capacitance and polyaniline nanospheres has poorest capacitance.