Influence Of Ultra Pure Coals Solvent Extraction Process On Performances Of Activated Carbon

The electric double layer capacitor has a simple structure,high power density,and wide utilization prospect.There are many kinds of electrode materials,and activated carbon is widely used with low price and stable nature.Coal is used as a precursor of activated carbon due to its high carbon content and large reserves.The ash in the coal has many adverse effects when preparing the electrode,so the coal is extracted to remove the ash.The project selected Hyper-coal preparation process,changed the extraction temperature,coal type and solvent,and defined the prepared coal sample as ultra-pure coal.The effects of extraction process and coal type changes on the properties of ultra-pure coal and activated carbon were investigated.Four coals with different temperatures and coal ranks and three solvents were selected for extraction experiments.The ultra-pure coal prepared by the extraction is activated to prepare activated carbon.The effects of extraction conditions on ultra-pure coal structure and surface functional groups and the pore structure and surface functional groups of activated carbon were analyzed.The results show that changing the extraction conditions can control the structure of the activation site in ultra-pure coal.Low temperature extraction can significantly enrich the active sites.High rank coal can be used for extraction to prepare ultra-pure coal with abundant active sites.Adding aliphatic extractant can significantly increase the active sites on the aromatic nucleus.The more active sites are the more intense the reaction is,the more fully the corresponding pore structure of the activated carbon developed.The control of the pore structure of the activated carbon is achieved by controlling the extraction process.The ultra-pure coal based activated carbon prepared by extracting lignite using a pure solvent of N-methylpyrrolidone at 330°C has the most excellent performance.The specific surface area is as high as 1252 m~2/g,and the pores which are most favorable for the adsorption of the electric double layer account for 36%of the total pore volume,and the specific capacitance is as high as 322 F/g.Figure 32,Table 15,Reference 96.