Coal Engineering ›› 2022, Vol. 54 ›› Issue (11): 177-181.doi: 10.11799/ce202211031

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Study on Preparation of Spherical Activated Carbon for Supercapacitor by High Temperature Spray

  

  • Received:2022-11-15 Revised:2022-11-16 Online:2022-11-15 Published:2023-03-09

Abstract: In view of the characteristics of Shenhua coal liquefied asphalt (CLA), such as high softening point, high aromaticity, high carbon content and easy polymerization or cross-linking, spherical activated carbon with specific surface area over 2,000 m2/g was prepared by 700℃ high temperature spray method and KOH activation method using CLA as carbon source. CLA, spherical carbon (SC) and spherical activated carbon (SAC) were characterized by scanning electron microscopy (SEM), low temperature nitrogen adsorption (BET), infrared spectroscopy (IR), X-ray diffraction (XRD) and Raman spectroscopy. It was found that the process of atomization, spheronization, non-melting oxidation and carbonization can be completed in one step by high temperature spray, avoiding the problems of low spheronization temperature, easy adhesion, deformation and crushing of microspheres when the temperature rises that occur in a conventional preparation process, thereby obtaining an activated precursor with spherical morphology and relatively uniform structure and size. Under condition that KOH is in a mass ratio of 1: 2 and activated for 90 mins at 700℃, SC can produce spherical activated carbon (SAC) with specific surface area of 2,340 m2/g. When the current density increased from 0.5A/g to 20A/g, the specific capacitance decreased from 243.36F/g to 226.08F/g in a two-electrode electrochemical performance test. The capacity remained unchanged after 10000 cycles at a current density of 5A/g.

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