Structural Control Of Graphene/Polyaniline Composite Films And Properties Of Supercapacitors

As a clean and safe electrochemical energy storage method,supercapacitorss have gained wide attention due to their characteristics like high power density,long cycle life,fast charging and discharging time,and so on.Conductive polymers and carbon materials are the main candidate materials for supercapacitors electrodes,especially for graphene/polyaniline composites.Due to the synergistic effect of the composites,the composite active electrode materials not only have the characteristics of graphene double-layer electrode,but have the high pseudo-capacitance of polyaniline.As a low-cost and easily synthesized conductive polymer,under different synthesis conditions and methods,polyaniline monomer can be polymerized into polyaniline nanostructures with different morphologies and structural characteristics.However,the structure of two-dimensional polyaniline nanosheet is rarely reported.The design and preparation of graphene/polyaniline composite thin film electrode structure is of great significance for greatly improving the volume specific capacity of supercapacitorss.Considering that polyaniline itself will undergo drastic volume changes during the cycling process,the cycling stability is also a key problem to be solved.For this reason,this paper designed and preparated the graphene quantum dots-polyaniline composite nanometer film,using two-dimensional graphene quantum dots formed by the induced compound nanometer film,as well as using the unique structure of two-dimensional quantum dots to stabilize the polyaniline chain,and will get a graphene quantum dots-polyaniline composite nanoparticles and graphene sheets form close packing thin film electrode structure,so as to realize the high volume of supercapacitors specific capacity and long cycle stability.Specific study contents are as follows:1.Graphene quantum dots were used to induce aniline polymerization in an innovative way.By controlling the reaction temperature and the amount of graphene quantum dots,graphene quantum dot-polyaniline composite nanosheet structure with uniform morphology was induced to obtain.The nanosheet has a uniform lamellar thickness of about 4.2 nm.2.The graphene/graphene quantum dot/polyaniline composite lamellar structure electrode was prepared by innovative design.By adjusting the mass ratio of graphene/polyaniline composites,flexible self-supporting films with different proportions were obtained,and the optimal mass ratio of composites was determined by analyzing the morphology characteristics,composition and electrochemical properties.Further studies were made to improve the properties of electrode materials,and to change the thickness of composite materials to study their effects on the electrochemical properties of electrode materials.Finally,the electrode materials were assembled into supercapacitorss to study their electrochemical properties.Through this design,the electrode volume specific capacity of the layer upon layer compact stacking structure is as high as 527 F cm^-3(0.2 A g^-1).3.The structure of rGO/polyaniline was further studied with different reducing agents,and the electrochemical properties of different rgo composite films were investigated.The results showed that the electrochemical properties of the films were better than those of vitamin c and cysteine reduced graphene oxide films.