Synthesis and Capacitive Performance of Ordered Porous Carbon Via a Template Method
|Course||Polymer Chemistry and Physics|
|Keywords||Supercapacitor Pore structure Electrolyte|
In recent years, the supercapacitor as a new type of energy storage devices by the world's governments and the attention of scientists, carbon materials for electric double layer capacitor electrode has been widely used in the social life. Usually the porous carbon material having a high specific surface area and a high theoretical specific capacity, but since the aperture is too small, limiting the free diffusion of electrolyte ions in its pores, than the capacity and specific power performance decline. The research of the structural characteristics of the electrode material with electrolyte matching excellent electrochemical performance, in-depth research supercapacitor charging and discharging mechanism has a very important significance. Based on the above idea, using templates prepared aperture uniform pore size distribution template carbon material, which were tested in different electrolytes in electrochemical performance, matching examine the pore structure of the electrode material and electrolyte ions. First, the Na type Y zeolite as a template, the furfuryl alcohol as a carbon source, the prepared the template carbon material of structural rules. The effects of process parameters on the structure of the sample, the use of nitrogen adsorption, transmission electron microscopy testing methods such as carbon materials were characterized by determination of the specific surface area and pore structure characteristics of carbon materials. The results show that the best conditions for the use of carbon materials prepared template: Zeolite quality and furfuryl alcohol volume ratio of 1:1.5, carbonization temperature of 700 ° C. The resulting template carbon material than the largest surface area of 826m2 / g, pore size uniformity and the aperture diameter is mainly concentrated in the 1.1-1.6nm. Second, the resulting template carbon material for electrode materials, NaOH, NaCl, Na2SO4 and KOH four electrolyte charge-discharge, cyclic voltammetry and AC impedance test to study the electrochemical properties of the capacitor, specific analysis of carbon materials matching of the pore structure and the electrolyte ions. The results showed that when the current intensity of 1.0mA in the four electrolyte, electrode materials have exhibited good electrochemical performance and the specific capacitance of the capacitor NaOH electrolyte highest reached 129F / g, when the current is increasing , the capacitors in both alkaline solution was still able to maintain a higher than the capacity, with a good capacity retention performance; in the high-potential scan rate of 10mV / s under the conditions, the capacitor in the KOH electrolyte having a larger electrochemical window and Good capacitive properties;, NaOH, KOH two alkali solution resistance than NaCl, Na2SO4 low. The studies show that the carbon material for the prepared template, Na, OH-due to the smaller radius is more conducive to the diffusion within its pores, a capacitor containing the ions in the electrolyte greater than the capacitance and the internal resistance smaller; SO42-because of having a large ion radius, the migration and diffusion in the pores of material is restricted in the kinds of ion-containing electrolyte, the capacitance of the capacitor performance is poor as a whole. Integrated charge-discharge, cyclic voltammetry and AC impedance test, capacitor KOH as electrolyte showed excellent capacitance performance, KOH electrolyte and electrode materials match the best.