硝酸铜改性超级电容器用煤基活性炭电极材料的电化学性能  

Electrochemical performance of coal-based activated carbon electrodes modified by copper nitrate for supercapacitor

作　　者：马亚芬[1,2] 谌伦建[1] 邢宝林[1] 徐冰[1] 黄光许[1] 张传祥[1] 

机构地区：[1]河南理工大学材料科学与工程学院,河南焦作454003 [2]河南安彩高科股份有限公司,河南安阳455000

出　　处：《煤炭学报》2012年第A02期472-477,共6页Journal of China Coal Society

基　　金：河南省重点科技攻关资助项目(082102340028);河南省教育厅自然科学研究计划资助项目(2011A480003)

摘　　要：以印尼褐煤为原料、KOH活化法制备的煤基活性炭,采用硝酸铜溶液浸渍-高温热解法对其进行改性处理,低温N2吸附法对改性前后活性炭的孔结构进行表征,SEM和XRD对改性前后活性炭的表面形态和微晶结构进行表征,并测定KOH对活性炭的润湿性及活性炭电极的恒流充放电、循环伏安、交流阻抗等电化学性能。结果表明:硝酸铜改性可能使部分孔隙(尤其是微孔堵塞)的比表面积和孔容积降低,但中孔率有所提高;硝酸铜改性可以提高KOH溶液对活性炭的润湿性,在活性炭表面负载氧化铜,提高活性炭对电解液的吸附能力,并产生赝电容效应,提高活性炭的电化学性能。在试验条件下改性硝酸铜溶液的最佳浓度为2%,其电容器的质量比电容可达322 F/g,并使交流阻抗等电化学性能得到改善。Coal-based activated carbon（AC）was prepared from Indonesia lignite by KOH as activator.In order to improve electrochemical properties of AC,the AC was modified by means of soaking in copper nitrate solution and subsequent pyrolysis.The specific surface area and pore distribution of activated carbons before and after modification were studied by nitrogen adsorption at 77 K,the crystallite structure and surface morphology of activated carbons were characterized by SEM and XRD.Moreover,the wettability and electrochemical performance of activated carbon electrodes were researched by contact angle and constant current charge-discharge,cyclic voltammograms,alternating current impedance,respectively.The results indicate that the portion pores of modified AC,especially the micropores,are blocked by the oxides produced from the Cu（NO3）2 decomposition,the specific surface and total pore volume decrease,the rate of mesopores increases.Meanwhile,the oxides loaded on AC by copper nitrate modification not only improves the wettability of AC to electrolyte,but also produces an obvious pseudo-capacitance effect,the specific capacitance of modified AC can be enhanced.Based on this study,the optimum concentration of Cu（NO3）2 solution was 2%,the specific capacitance of modified AC electrode can be reached up to 322 F/g,and the electrochemical performance can be improved.

关 键 词：硝酸铜 改性 超级电容器 煤基活性炭 电化学性能 

分 类 号：TQ424.1[化学工程] TQ536