Preparation And Electrochemical Properties Of Porous Carbon Materials Prepared By Potassium Citrate As Carbon Precursor

The supercapacitor is a new energy storage device. It has a wide application market and a hot research field in the new energy field. The three dimensional porous carbon material with high specific surface area and good conductivity is widely used in the electrode material of the supercapacitor. In this paper,potassium citrate is used as carbon precursor,by introducing the template Magnesium Oxide and bacterial cellulose as carbon precursor. Three dimensional porous carbon materials with different structures were prepared by one step carbonization activation method. The effects of preparation conditions, morphology and electrochemical properties were studied in detail. The microstructure and surface properties of the prepared porous carbon materials were investigated by SEM, TEM, XRD, BET and Raman tests,electrochemical properties of materials were evaluated by cyclic voltammetry, galvanostatic charge/discharge method and AC impedance method. The specific research contents are as follows:First, with potassium citrate (CK) as the carbon precursor, magnesium oxide as template,cage like lamellar porous carbon material were prepared. It is show that this has a unique three-dimensional structure to make the material with a high specific surface area(1589 m2·g-1 ),open three dimensional channel and excellent electrical conductivity,so it has excellent electrochemical properties, When the scanning speed is 2 mv·s-1, the specific capacity of the carbon material MgO/CK-CZ-0.1 is 307 F·g-1, when the scanning speed is 500 mv·s-1, the specific capacity is 240 F·g-1, the capacity retention rate is 78.2%.Secondly, with potassium citrate (CK) and biomass bacterial cellulose (BC) as the mixed carbon precursor, Three dimensional layered porous carbon materials with fiber network and multi layer porous sheets CK-BC-C were prepared. This three dimensional laminated structure is conducive to the rapid transmission of electrolyte ions and electrons, thus significantly improve the carbon material of the electrochemical capacity and rate characteristics, When the scanning speed is 2 mv-s'1, the specific capacity can reach 261 F·g-1,the capacity retention rate is 76.6%. After 10000 cycles of cyclic voltammetry, the capacitance retention rate is as high as 97.6%.Finally, symmetrical supercapacitor assembly based on 3D layered porous carbon material CK-BC-C, higher energy density and power density were obtained, When the power density is 81.8 W·kg-1, the energy density reaches 20.4 Wh·kg-1.