The Preparation Of Energy Storage Carbon Materials From Coal Tar Pitch And Petroleum Coke

Coal tar pitch and petroleum coke are important non-renewable carbon sources in the chemical industry's production process.They not only have low utilization efficiency,but also cause serious pollution to the environment.Through its deep processing and lightweighting,the unique energy storage carbon material with unique performance is designed to improve resource utilization,thereby increasing the added value of its products.The carbon content of petroleum coke accounts for more than80%,and coal tar pitch is a very complex and changeable chemical composition.Its basic constituent units are polycyclic,polycyclic aromatic hydrocarbons and their derivatives,which carbon content is as more as 90%.so they are carbon materials prepared from carbon sources,which have high yield,good conductivity,and excellent electrochemical performance.This paper aims at the perparation of electrochemical energy storage carbon materials from coal tar pitch and petroleum coke.The main research contents were as follows:?1?Using petroleum coke as carbon precursor and K₂CO₃ as activator,a series of petroleum coke-based porous carbons were prepared by carbonization-activation one-step method.The effect of pore structure of the activation time,and the heating rate pre-oxidized process were explored.The specific surface area of the porous carbon with wt20%H₂O₂ was maximum which is 1886 m² g^-1 and the total pore volume of 1.477 cm³ g^-1;The electrochemical performance was best which the specific capacitance is 227 F g^-1 at the activation ratio is 2:1,the activation temperature of 800?,the activation time of 2 h and the heating rate of 5?min^-1at 0.5 A g^-1,when the current density reaches 50 A g^-1 capacity is 168 F g^-1 and the retention rate is up to 74.0%.?2?The porous carbon with high specific surface area was prepared by using potassium carbonate chemical activation technology,When the single coal tar pitch was used as the carbon precursor,the specific surface area of the porous carbon prepared at the activation ratio of 2 and the activation temperature of 800?for 2 h was the maximum,which is 1886 m² g^-1 and the electrochemical performance was the best,which has the specific capacitance of 248 F g^-1of the three-electrode system at0.5 A g^-1 in 6 M KOH.Using coal tar pitch and phenolic resin as carbon precursor,the influence of the proportion of coal tar pitch on the structure and electrochemical performance of porous carbon was investigated under the optimal activation conditions.The specific surface area is 2163 m² g^-1 at 75%of coal tar pitch,and the electrochemical performance is best which has the specific capacitance of 244 F g^-11 of the three-electrode system at 0.5 A g^-1.?3?In order to improve the problem of graphite stripping of the Li-ion battery,combined with the advantages of carbon materials,the core-shell graphite@coal tar pitch material was designed and synthesized using the liquid-phase coating method.When the carbonization temperature was 900?and the coating amount was 5%,The carbon layer is approximately 7 nm.Electrochemical test results show that graphite@coal tar pitch has good cycling performance,the reversible capacity reaches 387.5 mA h g^-1 after 100 cycles,and its capacity retention rate is 96.5%.