Preparation Of Graphene And Its Application In Supercapacitors

ABSTRACT:As a new two dimensional nanomaterial, graphene with a number of novel physical properties has attracted lots of Research interests. Different from other carbon materials, both physical properties and method of massive production and application in device of graphene need to be investigated more. In this paper, basing on fabrication of graphene, taking advantages of high production ratio and great properties of it, and combing researching of graphene, supercapacitors with graphene electrodes and different electrolyte systems were investigated, main works include:1. Based on the graphite oxide chemical exfoliated method, the fabrication process and reduction methods for single layer graphene oxide with large size were studied. The influence of oxidation process and exfoliated parameters on the structure and morphology of material was discussed. By improving washing process and reduction methods, flake and spongy graphene with single or few-layer was fabricated. The sample was characterized by XRD, Raman spectroscopic, and electron microscopy to get a series of optimal parameters for small production of graphene at laboratory conditions.2. The supercapacitors with graphene electrodes in water system were manufactured using buckle structure. The fabrication technology of supercapacitors was studied. The impact of the electrodes molding pressure, the diaphragm materials and the content of adhesive materials on the performance of supercapacitors were discussed. Based on these facts, the parameters of the production process of graphene supercapacitors were determined and practical supercapacitors were successfully manufactured.3. The organic system graphene supercapacitors were assembled in the same way and the influence of the types of diaphragm and electrode materials on the performance of capacitors were investigated. The concentration was focused on the important role which diaphragm materials played in the performance of capacitors. The comprehensive explanation for high resistance of organic system supercapacitors was proposed and the reduction methods were studied.4. Based on the research of ionic system graphene supercapacitors, it was found that ionic liquid used as electrolyte played a very important role in the performance of supercapacitors. The importance of novel electrolyte liquid with high conductivity and wide electrochemical window to the basic electrical properties such as power density and specific energy of double layer capacitors was investigated.5. The reduction method assisted with microwave for graphene oxide was studied. The activation treatment of graphene with molten caustic soda was attempted to fabricate ionic supercapacitors. The reduction process in high speed for graphene was studied and developed to become more appropriate for industrial production. In order to suit the fast motion of ion in large size, the morphology of graphene surface was optimized. Based on this fact, the important significance of graphene with new surface structure which was used as electrode materials to develop the performance of capacitors was researched.