Dissertation
Dissertation > Industrial Technology > General industrial technology > Materials science and engineering > Non-metallic materials > Non-organic materials

Preparation and EDLC Applications of Mesoporous Carbons with High Specific Surface

Author HouChaoHui
Tutor LiXinHai
School Central South University
Course Physical Chemistry of Metallurgy
Keywords Electric double layer capacitor Mesoporous carbon Charring Template Pore ??structure Oxygen functional groups
CLC TB321
Type PhD thesis
Year 2004
Downloads 1025
Quotes 24
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Electric double layer capacitor electrode carbon material for the purpose to produce high-power applications in electrochemical capacitor electrode materials, electrolytes in progress on the basis of detailed review, preparation of high surface area mesoporous carbon materials and its electric double the layer capacitance performance of a series of studies. First using the novel polymer the chemical mixing carbonization method of organic monomers in the synthetic carbon precursor polymer - resorcinol (R) - formaldehyde (F) was mixed with a solution of the thermal instability of poly the Ethanol (PEG), the preparation hole PEG-RF carbon xerogel study of PEG-RF carbon xerogel pore-forming mechanism and preparation conditions of carbon xerogel pore structure. The results showed that the PEG relative thermal stability and uniformity of PEG-RF hybrid organic gel is formed by chemical mixing micro phase separation structure is formed in particular in the pore structure of the PEG-RF charcoal dry gel reasons: prepared by adjusting the conditions, effective adjustment of the pore structure of the carbon xerogel. Preparation conditions on the electric double layer capacitor performance of PEG-RF carbon xerogel, especially its high current charge and discharge performance, and PEG-RF carbon xerogel preparation conditions were optimized. The study results showed that the carbonization temperature of the PEG-RF charcoal dry gel for an electric double layer capacitor can not be less than 1000 ° C, a large current charge-discharge characteristics of the carbon xerogel by their pore size distribution affect. The PEG-RF carbon xerogel 30wt% H 2 SO 4 solution, its maximum specific capacity of up to 215F · g -1 The operating current is 1000 times larger than the capacity of up to 160 F · g still -1 with excellent high-current charge-discharge capacity, suitable for high-power electric double layer capacitor applications: the maximum energy density and The power density of up to 4.9Wh · kg -1 and 38 kW · kg -1 . Organic electrolyte system than the capacity of up to 118F · g -1 , the maximum energy density and power density of up to 14Wh · kg -1 and 22kW · kg -1 . The novel simultaneous synthetic template carbonization method, for the first time as a template silicon source TEOS, resorcinol - formaldehyde gel as carbon precursor preparation SSTCM carbon materials with controlled pore structure. The results show that the synthesis, the adjustable structure of the silica template, resulting SSTCM Carbons controllable pore structure formed in synchronization with the carbon precursor polymer. More SSTCM Carbons specific surface area of ??up to 1300 m 2 · g -1 , the pore structure is subject to the influence of the preparation conditions, the average pore diameter in the range of 5 ~ 10nm adjustment. System of various conditions on SSTCM pore structure of carbon, mainly through the influence of the SiO 2 relative rate of formation of the template and the RF resin to achieve. Electric double layer capacitance of SSTCM carbon materials performance research in 30wt% H 2 SO 4 maximum quality of solution and the organic electrolyte system specific capacitance can 265 and 180 F · g -1 , the maximum energy density and power density, respectively, up to 6Wh · kg -1 , 33kW · kg -1 25Wh · kg -1 21kW · kg -1 . SSTCM carbon materials with good current performance, suitable for high-power electric double layer capacitor applications. Mesoporous carbon materials purchased outside the microporous carbon materials prepared in this study for the research object, the pore structure of carbon materials of electric double layer capacitor performance. Parsing of the capacitor AC impedance spectroscopy, carbon materials pore structure of Central South University Dr. abstracts differences result in a the capacitor \For the Carbons purposes of the hole, the \larger, the power characteristics are poor, not suitable for high power capacitor applications. The first comparative study of the surface oxygen-containing functional groups on carbon materials with different pore structure of the electric double layer capacitor performance. Oxygen functional groups than the capacitance of the quality of the carbon materials significantly enhance the role, but this enhance the role of the magnitude of differences with the functional groups of the type and concentration differences. The oxygen-containing functional groups lead to increased internal resistance of the capacitor. An oxygen-containing functional group by the Faraday oxidation-reduction reaction, adsorption and promote the Carbons wettability improved characteristics to increase the specific capacitance of the carbon material, but with use of value is the characteristic of the functional groups to adsorb and to promote wettability. Oxygen functional groups have different effects on the electrochemical capacitance performance of different pore structure of carbon materials. For microporous carbon materials, the oxygen-containing functional groups to improve specific capacity, but to reduce the power performance; mesoporous carbon materials, the oxygen-containing functional groups both to increase its capacity, and no negative effect on its power characteristics. The introduction of oxygen-containing functional groups in mesoporous carbon materials more suitable for the application of high power electrochemical capacitors.

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