摘要
以褐煤萃取物为炭前驱体,MgO为阻隔剂,KOH为活化剂,在800℃惰性气氛下制备出类石墨状多孔炭材料。对该多孔炭材料进行了红外(FTIR)、X射线衍射(XRD)、透射电镜(TEM)和拉曼(Raman)表征。以活化前和活化后多孔炭为电极材料,利用循环伏安、恒电流充放电、交流阻抗对其进行了电化学电容性能评价和比较。结果表明:活化后炭材料呈现多孔的薄膜状,比表面积高达1396 m^2/g,而活化前炭材料比表面积仅为138.4 m^2/g。当电流密度为1 A/g和4 A/g时,活化后炭材料比电容分别为533 F/g和390 F/g;而活化前炭材料对应的比电容为366 F/g和198 F/g。在电流密度为5 A/g下循环8000圈后,活化前后炭材料的电容保持率分别为72.5%和89.6%。可见,经过KOH活化后的炭材料比电容和电化学稳定性有了显著提高。该研究证明阻隔剂和活化剂的使用,能够获得高度柔性的高电容性能的类石墨状多孔炭。
By using extracts of lignites as carbon precursors, MgO as isolation agent, and KOH as activator, porous graphene-like carbon materials were prepared at 800℃ under an inert atmosphere. Porous carbon materials were char- acterized by FTIR, XRD, TEM and Raman. Further, electrochemical capacitive properties of porous carbons before and after activation as the electrodes were evaluated by cyclic voltammetry, galvanostatic charge-discharge and im- pedance spectroscopic techniques. Results indicate that carbon materials after activation exhibit porous film-like shape The specific surface areas of carbon materials before and after activation are 138.4 m2/g and 1396 m2/g, respectively. Specific capacitances of carbon materials after activation reach 533 F/g and 390 F/g at 1 A/g and 4 A/g, respectively, while those of carbon materials before activation at same conditions are 366 F/g and 198 F/g. After 8000 cycles at a current density of 5 A/g, the capacitance retentions of carbon materials before and after activation are 72.5% and89.6%, respectively. Accordingly, after KOH activation, the specific capacitance and electrochemical stability of car- bon materials are significantly improved. This study verifies that the use of the isolation agent and the activator can obtain highly flexible graphene-like porous carbon with high capacitance performance.
出处
《无机材料学报》
SCIE
EI
CAS
CSCD
北大核心
2016年第1期39-46,共8页
Journal of Inorganic Materials
基金
新疆维吾尔自治区科技厅国际科技合作计划项目(20136007)~~
关键词
煤萃取物
多孔炭
电极材料
电容性能
coal extracts
porous carbon
electrode material
capacitive performance
