| As the energy supply of functional wearable devices,flexible wearable energy storage device ensures its high efficiency.Electrode materials are the main factors that affect the performance and cost of supercapacitors.In the research process of supercapacitor,the emphasis is on the research and development of electrode materials with high specific capacitance and high specific energy.Conductive polyaniline has attracted much attention in the field of supercapacitors due to its simple preparation,low cost and high capacitance.Graphene has ideal electrochemical capacitance characteristics,which can be greatly improve the stability of charge discharge cycle of capacitor,and is also considered as an ideal candidate material for supercapacitor.However,there are still some problems in the research of Polyaniline and reduced graphene oxide used in supercapacitors,such as low area specific capacitance,difficult combination of active materials and flexible substrate,poor mechanical flexibility and so on.For fully flexible and wearable electronic devices,how to ensure their excellent energy storage performance(high area capacitance,high rate performance and high stability)and excellent flexibility is the key problem to be solved.Therefore,in this paper,using silk fabric as flexible substrate,polyaniline and reduced graphene oxide as active materials,polyaniline silk fabric electrode,reduced graphene oxide silk fabric electrode and reduced graphene oxide/polyaniline silk fabric electrode were prepared by optimizing different preparation processes and experimental conditions.The main research contents and results are as follows:1.Preparation and properties of polyaniline silk electrode(PANI@silk fabric)The silk fabric was treated with ternary solvent(calcium chloride/ethanol/water)at different temperatures,and then the polyaniline silk fabric electrode was obtained by in situ polymerization with aniline of different concentration as monomer.The optimum experimental technology and condition parameters were optimized,which were the pretreatment temperature of ternary solvent 40?and aniline monomer concentration of 2.03 mol L-1.The morphology and structure of the fabric electrodes were characterized by scanning electron microscope,infrared spectrometer,X-ray diffraction and energy spectrometer.The conductivity,capacitance,charge-discharge cycle performance,deformation response,sensing performance,mechanical durability and flexibility were tested and analyzed by using multimeter,square resistance meter and electrochemical workstation.The results showed that the surface area of silk fabric was increased and the loading capacity of active substances was increased by the ternary solvent pretreatment compared with that without the ternary solvent pretreatment.The higher loading capacity and better morphology of active materials make PANI@TS-silk fabric have a higher area capacitance(4091.43 m F cm-2),which is 125.87%higher than PANI@WTS-silk fabric(1811.43 m F cm-2).The area capacitance of PANI@TS-silk fabric is higher than the area capacitance reported in most literatures.The strong interaction between the reactive group of silk fabric and polyaniline makes the fabric electrode have excellent capacitance retention of 99.54%under 3000 charge-discharge cycles.2000 mechanical deformation tests show that the fabric electrode has good flexibility and durability.PANI makes the silk fabric electrode have excellent antibacterial and UV resistance(UPF>50),and improves the flame retardancy of silk fabric.PANI-silk fabric electrode is expected to be used as a multifunctional flexible wearable supercapacitor with antibacterial,anti ultraviolet and flame retardant properties.It can also be used as a flexible sensor to monitor the large and small movements of human body.The bending and twisting of2000 times show that the electrode of polyaniline fabric has excellent robustness.2.Preparation and properties of reduced graphene silk fabric electrodeGraphene oxide silk fabric was prepared by different finishing technology and experimental conditions,and then reduced to graphite oxide silk fabric electrode by ascorbic acid.Based on the conductivity and capacitance properties,the best experimental process and parameters were optimized as follows:the silk fabric was pretreated with ternary solvent,and then ultrasonically cycled and dried for 20 times.The morphology and structure of the fabric electrode were characterized by scanning electron microscope,infrared spectrometer,Raman spectrum and X-ray photoelectron spectroscopy.The conductivity,capacitance,charge-discharge cycle performance,deformation response,sensing performance,mechanical durability and flexibility were tested and analyzed by using multimeter,square resistance meter and electrochemical workstation.The results show that ultrasonic and cyclic drying methods have the greatest influence on the performance of the fabric electrode,and the reduction of graphene oxide has no effect on the secondary structure of silk fabric.The area specific capacitance of 20-RGO-silk fabric is the highest,reaching 1480.63m F cm-2,but the capacitance retention of 15-RGO-silk fabric is 39.66%.The capacitance retention of the reduced graphene oxide silk fabric electrode is 148%under 10000 charge-discharge cycles.The bending test of 2000 times shows that the fabric electrode has excellent flexibility and durability.The reduced graphene silk fabric also has excellent UV resistance(UPF value up to 2182.63),conductivity(107.4?/sq)and deformation response.It can also be used as a flexible sensor,and it has excellent robustness and flexibility under 2000 mechanical deformation.3.Preparation and properties of reduced graphene/polyaniline silk fabric electrodeUsing polyaniline(PANI)and reduced graphene oxide(RGO)as active materials and silk fabric as flexible substrate,reduced graphene oxide/polyaniline silk fabric electrode(RGO-PANI-SF)was prepared by different experimental processes and parameters.Taking the electrochemical performance as the optimization index,the optimal experimental conditions were as follows:first finishing RGO,then polymerizing aniline monomer,and then padding PANI by padding-dring for 10 times.The morphology and structure of the fabric electrodes were characterized by scanning electron microscope,infrared spectrometer,Raman spectrum and X-ray diffraction.The conductivity,capacitance and sensing properties were tested and analyzed by multimeter,square resistance meter and electrochemical workstation.The results show that the maximum area capacitance of RGO-PANI-SF in three electrode system is 7324.29 m F cm-2,and the capacitance retention rate is 65.38%.The comprehensive performance of RGO-PANI composite fabric electrode is much higher than that of RGO fabric electrode and PANI fabric electrode,and higher than that of polyaniline reduced graphene oxide electrode reported in the literature.The two electrode test shows that the maximum area capacitance of RGO-PANI fabric electrode is 6531.52m F cm-2,the maximum area specific energy density is 580.58?wh cm-2,the maximum area specific power density is 10546.60?w cm-2,and the capacitance retention rate can still reach 72.8%after 4000 charge-discharge cycles.RGO-PANI-SF electrode can also be used as a flexible sensor to detect various human behaviors. |
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