Synthesis And Properties Of Graphene/polyaniline-based Polymers Composites Used In Supercapacitor

Facing the challenges of global warming,environmental pollution,and fast depletion of fossil fuels,researchers have paid intensive attention to renewable sources of energy,as well as new technologies about their production and storage.In this field,supercapacitors which have high power density,excellent cycling stability,and low maintenance cost play a more important role in the transmittance and storage systems of energy over dielectric capacitors and batteries.Carbon materials forming electrical double-layer capacitance and conducting polymers forming pseudocapacitance are two main kinds of materials used in electrode materials for supercapacitors.Carbon materials always have excellent cycling stability,good power density,howveer,they usually suffer from a limited specific capacitance and thus a low energy density when used independently in supercapacitors.Conducting polymers always have excellent energy density,however,they usually suffer from poor cycling stability.Therefore,fabricating electrode materials with both high specific capacitance and excellent cycling stability is the key for designing and application of supercapacitors.Appropriate combination of carbon materials and conducting polymers is a potential breakthrough for fabricating supercapacitors with both high energy density and excellent cycling stability.In this paper,we prepared a kind of carbon materials,namely amine-terminated graphene oxide?GO-NH₂?.And then a new type of nanocomposites of GO-NH₂ and copolymers of 2,2'-dithiodianiline?DTDA?and aniline?P?DTDA-co-Ani?-g-GO?was prepared.Another new kinds of nanocomposites of GO-NH₂ and copolymers of 1,5-diaminoanthraquinone?DAAQ?and aniline?P?DAAQ-co-Ani?-g-GO?was also prepared.The main contents and results of this thesis are as follows:1.Graphene nanopalates?GNP?was used to prepared graphene oxide?GO?through the classic Hummmer's method;GO was modified with 1,4-phenylene diisocyanate?PPDI?to prepared isocyanate functionalized graphene oxide?iGO?;iGO was finally modified with H₂ O to prepared GO-NH₂.2.P?DTDA-co-Ani?-g-GO was prepared through in situ copolymerization of DTDA and aniline in the presence of GO-NH₂.Electrochemical tests including cyclic voltammetry?CV?,galvanostatic charge-discharge?GCD?,and electrochemical impedance spectroscopy?EIS?were used to explore the electrochemical performance of P?DTDA-co-Ani?-g-GO.Electrochemical tests of the P?DTDA-co-Ani?-g-GO nanocomposite containing 5 wt % GO-NH₂?P?DTDA-co-Ani?-g-5GO?demonstrated efficient capacitance of about 432 F·g-1 with a capacity retention of 82% of its initial capacitance even after 1000 charge-discharge cycles at a current density of 0.3 A·g-1,suggesting its potential for supercapacitors.3.P?DAAQ-co-Ani?-g-GO was also synthetised through in situ copolymerization of DAAQ and aniline in the presence of GO-NH₂.CV and GCD were also adopted to investigate the electrochemical performance of P?DAAQ-co-Ani?-g-GO.Electrochemical tests of P?DAAQ-co-Ani?-g-GO nanocomposite containing 9 wt % GO-NH₂ demonstrated a mixum capacitance of about 562.2 F·g-1 with a capacity retention of 67% of its initial capacitance after 1000 charge-discharge cycles at a current density of 0.3 A·g-1.According to the results presented,the nanocomposites are also of great potential as electrode materials for supercapacitors.