Preparation And Electrochemical Performance Of Conductive Polymer Based Supercapacitor Electrode Materials

Supercapacitors have become one of the hot spots in the research of new energy sources and new materials worldwide.The electrode materials are the key to restrict the improvement of electrochemical performance in supercapacitors.In this thesis,graphene/polypyrrole composites,graphene oxide/polypyrrole composites and Ti3C2Tx/polyaniline composites were prepared by in-situ chemical polymerization method.And their structure characterization and electrochemical performance tests were performed.In this essay,firstly,a simple and facile method for graphene/polypyrrole nanocomposite(GPy)was developed using sodium anthraquinone-2-sulfonate monohydrate(AQS)and anthraquinone-2,6-disulfonic acid disodium salt(AQDS)as both"theoxidizing active agents' as well as "redox modifier".The AQS and AQDS(AQ(D)S)modified graphene oxide(GO)played the role of"active oxidant' to in situ polymerize pyrrole and convert itself to AQ(D)S modified graphene synchronously at 70?.Specifically,sodium anthraquinone sulfonate-graphene/polypyrrole(AQ(D)S-GPy)provided both higher specific capacitances(237 and 300 F g"')and better cycle stability.Moreover,working potential windows were enlarged to 1.5 V and 1.7 V due to the redox activity of the AQ(D)S.The symmetric supercapacitor based on AQDS-GP y exhibited high energy density(31.2 Wh Kg-1 at a power density of 1.12 kW kg-1)and good cycling stability(86%capacitance retention after 2000 cycles).Secondly,1,4-diaminoanthraquinone(DAQ)grafted graphene oxide(DGO)was prepared by the ring opening reaction of epoxy group on GO surface with-NH2 in DAQ.DGO/PPy composites(DGPs)have been prepared by a facile chemical oxidative polymerization method with different DGO weight loadings(3 wt%,5 wt%,9 wt%and 15 wt%).The introduction of redox active DGO thus endows DGPs with improved electrochemical performances.Among the DGPs,due to the delaminated DGO sheets as well as interconnect composite microstructure,the specific capacitance of DGP5(5 wt%DGO weight loadings)can reach 389 F g-1,which is more than two times as much as that of pristine PPy.The high specific capacitance,enlarged window(as much as 1.4 V)as well as the good cycle stability,which are ascribed to the synergistic effect as well as the redox activity of DGO could be benefit for DGP5 as potential supercapacitor electrodes.Finally,Ti3C2Tx/DL-TA/Polyaniline nanocomposites(TDPs)with different Ti3C2Tx weight loadings(10 wt%,20 wt%,30 wt%and 40 wt%)were prepared by a simple chemical oxidation method using DL-tartaric acid(DL-TA)as "dopant" and "soft template".The introduction of DL-TA can increase the electrochemical activity of PANI and induce the oriented growth of PANI.Among all TDPs,TDP2(20 wt%Ti3C2Tx weight loadings)exhibits a lamellar and short rod-like overlap microstructure,which facilitates ion diffusion and charge transport.The specific capacitance of TDP2 can reach as high as 452 F g-1,with a wide potential window of 2.1V and good cycle stability.