Paper Title:
Preparation of Activated Carbons from Lignite for Electrochemical Capacitors by Microwave and Electrical Furnace Heating
  Abstract

Activated carbons (ACs) were prepared from lignite by microwave (MW) and electrical furnace (EF) heating with KOH as activation agent. In order to compare pore structures and electrochemical performances of ACs prepared by both heating methods, the ACs were characterized by N2 adsorption at 77K, X-ray diffraction (XRD) and scanning electron microscope (SEM). The electrochemical performances of Electrochemical capacitors (ECs) with ACs as electrodes in 3mol/L KOH electrolyte were evaluated by constant current charge-discharge, cyclic voltammetry and electrochemical impedance spectroscopy. The results show that the pore structures of ACs prepared by MW and EF heating significantly enhance when the weight ratio of KOH to coal increases from 2 to 4. The BET specific surface area, total pore volume, the ratio of mesopore and average pore diameter of ACs prepared by MW heating (denoted as AC-MW4) reaches 2094m2/g, 1.193cm3/g, 53.6%, 2.28nm when the weight ratio of KOH to coal is 4, and ACs prepared by EF heating (denoted as AC-EF4) reaches 2580m2/g, 1.683cm3/g, 67.3%, 2.61nm. The ECs with AC-MW4 and AC-EF4 as electrodes present a high specific capacitance of 348F/g and 377F/g at a current density of 50mA/g, and still remain 325F/g and 350F/g after 500 cycles, respectively. Although the specific surface area, total pore volume and specific capacitance of ACs prepared by MW heating are slightly lower than EF heating, taking into account the heating time in the activation process, ACs prepared by EF heating needs approximate 140min, while MW heating only needs 10min, which have demonstrated that microwave heating technology is a promising and efficient technique to prepare ACs.

  Info
Periodical
Advanced Materials Research (Volumes 194-196)
Edited by
Jianmin Zeng, Taosen Li, Shaojian Ma, Zhengyi Jiang and Daoguo Yang
Pages
2472-2479
DOI
10.4028/www.scientific.net/AMR.194-196.2472
Citation
B. L. Xing, C. X. Zhang, L. J. Chen, G. X. Huang, "Preparation of Activated Carbons from Lignite for Electrochemical Capacitors by Microwave and Electrical Furnace Heating", Advanced Materials Research, Vols. 194-196, pp. 2472-2479, 2011
Online since
February 2011
Export
Price
$32.00
Share

In order to see related information, you need to Login.

In order to see related information, you need to Login.

Authors: Xiao Jun He, Ting Wang, Ru Chun Li, Ming Dong Zheng, Xiao Yong Zhang
Abstract:Activated carbons (ACs) were prepared by microwave−assisted heating of bituminous coal with KOH as activation agent in different gas media...
1230
Authors: Xiao Jun He, Ru Chun Li, Ming Dong Zheng, Ting Wang, Xiao Yong Zhang
Abstract:Activated carbons (ACs) from petroleum coke by microwave heating KOH activation are treated by microwave to investigate the effect of...
2151
Authors: Rui Zhang, Xiao Jia Duan, Quan Gui Guo, Bei Zhou, Xi Miao Liu, Ming Lin Jin, Li Cheng Ling
New Energy Materials
Abstract:High surface area activated carbon (AC) obtained by KOH activation of petroleum coke was leached by HCl aqueous solution and the effects of...
1469
Authors: Bao Lin Xing, Lun Jian Chen, Chuan Xiang Zhang, Hui Guo
Abstract:Activated carbons (ACs) were prepared from lignite by microwave heating with KOH as activation agent, the effects of the weight ratio of KOH...
1061
Authors: Cui Zhang, Cheng Yang Wang, Ming Ming Chen, Jia Ming Zheng, Jiu Zhou Wang
Chapter 1: Chemical Engineering
Abstract:Activated carbons to be used as electrode in electrochemical double-layer capacitors were fabricated using amphiphilic carbonaceous material...
96