预活化时间对稻壳基活性炭结构和电化学性能的影响  

Effect of Pre-activation Time on Structure and Electrochemical Performance for Rice Husk-based Activated Carbon

作　　者：宋晓岚[1,2] 刘汉俊[1,2] 王海波[1,2] 段海龙[1,2] 张颖[1,2] 刘时超[1,2] 周永鑫[1,2] 周志海 

机构地区：[1]中南大学资源加工与生物工程学院,长沙410083 [2]中南大学矿物材料及其应用湖南省重点实验室,长沙410083

出　　处：《材料导报》2017年第20期25-29,共5页Materials Reports

基　　金：湖南省国土资源厅科技计划项目(2013-14);国家大学生创新创业项目

摘　　要：以农业废料稻壳为碳源,氢氧化钠为活化剂,采用干法两步活化法制备活性炭。X射线衍射分析表明该法能有效去除稻壳中的灰分,提高活性炭的孔隙率。扫描电镜结果表明,活性炭具有发达的孔隙结构。以活性炭制备超级电容器的电极,并组装成扣式电容器。采用恒流充放电、循环伏安、交流阻抗等测定超级电容器的电化学性能,并着重探究了预活化时间对活性炭的结构及电化学性能的影响。结果表明,预活化时间为120 min的活性炭的比电容最大,在0.25 A/g电流密度下,可达219F/g,经过1 000次循环后,其电容保持率仍达85.4%。这表明活性炭电极具有较理想的电容特性,且循环性能稳定。In this paper,agricultural waste rice husk as carbon source,sodium hydroxide as activator,dry two-step activation was used to prepare activated carbon.The results of X-ray diffraction(XRD)showed that this activation method could effectively remove ash from rice husk and improve the porosity of activated carbon.Scanning electron microscopy(SEM)revealed that the activated carbon has a developed pore structure.And then the electrode of supercapacitor was prepared with activated carbon and assembled into a button capacitor.The electrochemical performance of supercapacitor was measured by constant current charging-discharging,cyclic voltammetry(CV)and alternating current(AC)impedance.In addition,the effect of pre-activation time on structure and electrochemical properties of activated carbon was investigated.The results showed that the activated carbon with the pre-activation time of 120 min possessed the largest specific capacitance of 219 F/g at 0.25 A/g for current density.And the capacitance retention rate was as high as 85.4% after 1 000 cycles,indicating that the activated carbon electrode had ideal capacitance characteristics and stable cycling performance.

关 键 词：稻壳 活性炭 预活化时间 超级电容器 比电容 

分 类 号：TB34[一般工业技术—材料科学与工程] O646[理学—物理化学]