Research On Preparation Of Supercapacitor Electrode Materials Based On Tongting Coal Heavy Component

Tongting coal heavy component was served as the basic carbon precursor.Pretreatment heavy component,addition dense medium component,and addition rice bran are used to prepare porous carbon materials with different morphologies and pore structure.As supercapacitor electrode materials,the optimal process conditions,the preparation mechanism of pretreatment method and the self-template method were investigated,and the results show that:Heavy Component are treated with HCl-HNO₃ and acetone,the mixed acid solution caused the macromolecular skeleton structure in heavy component be broken,and the aliphatic chains be shortened;the addition of acetone increased the surface quinone group under the catalysis of acid.A unique 3D tremella-like layer structure with high-oxygen-content porous carbon was synthesized after KOH activation.The optimal porous carbon is obtained when the activation temperature is 750 ^oC and the KOH ratio is 1:4.The obtained porous carbon possess a large specific surface area(3422 m² g^-1)and a total pore volume(1.9 cm³ g^-1).As electrode of supercapacitor,the specific capacitance is 483 F g^-1 at 0.1 A g^-1,and still maintains 290 F g^-1 at 2 A g^-1.The major mineral matters in the heavy component is kaolinite[Al₂?Si₂O₅??OH?₄].During the activation process,the mineral matters and its produce react with KOH to form natrolite(K₂Al₂Si₃O₁₀·2H₂O),which be effectively used as template to prepare hierarchical pores carbons.By the addition dense medium component,the self-template makes a supreme employ.The synergistic effect of KOH and mineral matters produce a hierarchical pores system with excellent pore structure and obtain excellent electrochemical performance.The optimal sample be synthesized at the 750 ^oC and the dense medium component ratio is 1:0.4,displaying a high surface area(up to 3851 m²g^-1),a highest V_t is 2.47 cm³ g^-1,and the most abundant V_meso is 0.70 cm³ g^-1.As electrode materials of supercapacitors,it shows a high capacitor of 336 F g^-1 at 0.5 A g^-1 in 6 M KOH electrolyte,an eminent capacitance retention ratio with remain 212 F g^-1 at 10 A g^-1.The co-activation was carried out with rice bran and heavy component,and the narrow and tortuous pore of heavy-component porous carbon be improved.The small pores?<1 nm?was grafted to the surface of porous carbon,and electrolyte ions easily enter the inside of pore,which increases the pore utilization rate.The mesopores are served as ion buffering,and bringing out a high capacitance performance at high current density.The prepared porous carbon displayed the best grafting effect.Micropores are evenly distributed on the surface of porous carbon,and the superior electrochemical performance is obtained,when the rice bran is 1 g,the KOH is 6 g,and the activation temperature is 750 ^oC.The specific capacitance is 479 F g^-1 at 0.1 A g^-1,and still maintain 253 F g^-1 at 10 A g^-1.