Synthesis Of Micro/Mesoporous Carbons And Their Capacitance Performance For Capacitors

Templated nanoscale porous carbons are well-suited to many applicationsinvolving catalyst supports, gas separation, water purification and electrodes forelectrochemical double layer capacitors. Following the lithium-ion battery, there hasbeen another huge potential value of electrical storage devices, electrochemicaldouble layer capacitors (EDLCs), and play an important role in the future life. A seriescarbons composite microporous and mesoporous synthesized by hard template thatcan be used as the supercapacitor electrode materials. From the previous disorderedporous structure, we make these carbons with ordered structural and adjustable poresize. Through the electrochemical workstation, we test their cyclic voltammetrycurves and capacitances, they not only have the both advantages of microporous andmesoporous materials but also will greatly increase energy storage and transferproperties. In future, we will increase the value of the carbon materials and improvethe performance, make more efficient to establish a super capacitor applicationprospects.Our study focus on the porous carbon as the main object, with two kinds ofpreparations, the one is hard template method, the other is using hard and soft templates as the synthetic method, researching the full effects of various carbonmaterials of different microporous and mesoporous rates, such as cyclic voltammetrycurves, discussing pore structure for electrochemical capacitors. The main results areas follows:1. On the previous synthesis of porous carbon basis, first we optimize thesynthesis of a series of hexagonal framework structures with a high texturalporosity which are assembled from Y seeds as silicon source,tetraethylorthodisilicate (TEOS) as another kind of silicon source,cetyltrimethylammonium bromide (CTAB) is used as a structure-directingagent and sulfuric acid or sodium hydroxide is used as adjuster. Then use themas templates and liquid furfuryl alcohol (FA) as carbon precursor for preparingporous carbon materials. In order to reduce the production cost to make thismethod to be more suitable for industrial production, we only use the liquidimmersion method, and then nitrogen protection during high temperaturecarbonized process. After perfusion carbon source, carbonization, and removethe template, we get a series of porous carbons have a high specific surfacearea and a suitable pore size distribution.2. In order to study the differences in the electrochemical performance of theporous carbons, we test cyclic voltammetry of the materials. The results showthat the larger surface area of the carbon material is, the greater theelectrochemical capacitor is; addition to the effect of the specific surface area,the contents of the micropores and mesopores are also important factors toaffect the electrochemical capacitor. Because a large number of microporescan increase the storage of electricity, then increase the specific capacitance,and mesoporous can conductive ion transportation and make themfast-moving. We explore suitable templates to synthesis carbon electrodematerials for electric double layer capacitor and hope to provide a theoreticalnd experimental basis about high performance porous carbon electrodematerial for further study of EDLC.3. We also try to expand the synthesis method from only hard template method to another that including soft template and hard template to prepare themulti-stage porous carbons. This new way reduces the step of preparationprocess, and reduces the portion of the synthetic cost. We get two microporous/mesoporous carbon materials have similar structure of core-shell, the core isthe regular arrangement of mesoporous structure and the shell is a largenumber of microporous. But may be due to this part of the microporous is sosmall, about only5, the researches of these two carbons are still going on.