KOH添加方式对煤基电极材料结构及性能的影响  

Effects of KOH Addition Methods on Structure and Properties of Coal-based Electrode Material

作　　者：苏婷 兰新哲 宋永辉 高雯雯 景兴鹏 SU Ting;LAN Xinzhe;SONG Yonghui;GAO Wenwen;JING Xingpeng(School of Chemistry and Chemical Engineering,Shaanxi Key Laboratory of Low Metamorphic Coal Clean Utilization,Yulin University,719000 Yulin,China;School of Metallurgical Engineering,Xi’an University of Architecture and Technology,Key Laboratory of Gold and Resources of Shaanxi Province,710055 Xi’an,China;Xi’an Research Institute Compand Limited China Coal Technology and Engineering Group Corporation,710054 Xi’an,China)

机构地区：[1]榆林学院化学与化工学院,陕西省低变质煤洁净利用重点实验室,陕西榆林719000 [2]西安建筑科技大学冶金工程学院,陕西省黄金与资源重点实验室,西安710055 [3]中煤科工集团西安研究院有限公司,西安710054

出　　处：《煤炭转化》2020年第3期73-80,共8页Coal Conversion

基　　金：国家自然科学基金资助项目(51774227);陕西省自然科学基金资助项目(2019JM-542,2019JLM-44);2019榆林市产学研合作项目(2019-83-4)。

摘　　要：采用低变质粉煤的成型热解KOH-HNO3联合活化技术制备煤基电极材料(CEM),考察活化剂粉末直接添加方式和溶液浸渍添加方式对煤基电极材料结构及性能的影响,将两种添加方式所对应的两组实验分别记为P组和S组。采用扫描电子显微镜(SEM)、傅立叶红外光谱(FTIR)和N2吸附法对煤基电极材料的微观形貌特征、表面官能团组成及孔隙结构、孔径分布进行分析表征,并对其电化学性能进行测试。结果表明:添加方式对材料收率及微孔率的影响表现在两个方面,在KOH添加量为5%~15%(质量分数)时,热解产物收率变化很小,P组实验生成CEM的微孔发育程度相对较好,在KOH添加量为20%时,P组实验生成CEM的酸化收率整体偏低,S组实验生成CEM的抗压强度和碘吸附值整体偏高,溶液浸渍方式更有利于微孔结构的发展;在P15试样和S15试样的电化学性能对比测试中,S15试样具有较大的比电容,内阻为2.05Ω,电荷转移电阻较低;KOH在浸渍阶段可先行与煤中含酸性官能团有机物发生降解反应,K+优先进入煤料的大分子结构中,从煤料内部基质产生初级微孔结构,在后续热解过程中增强了活化效果,孔径分布和孔道布局更加合理,实现较高离子迁移效果;S20试样的抗压强度为3.96 MPa,碘吸附值为987 mg/g,微孔率可达87.62%,比表面积为487.21 m2/g、总孔容为0.173 cm3/g,微孔孔容为0.152 cm3/g,平均孔径1.931 nm。A pyrolysis and KOH-HNO3 combined activation technology of low-rank pulverized coal was adopted to prepare the coal-based electrode material(CEM).The structure and property of coal-based electrode material was investigated by two kinds of KOH adding methods(the direct addition of powder marked as group powder experiment and addition of soak way marked as group soak experiment).Scanning electron microscope(SEM),Fourier infrared spectroscopy(FTIR)and N2 adsorption methods were used to analyze and characterize the micro-morphological features,surface functional group composition,pore structure,and pore size distribution of CEM,as well as the electrochemical performance was test by electrochemical station.The effects of the addition method on the products yield and microporosity can be shown in two aspects.When the KOH addition is between 5%-15%,the yield of pyrolysis products nearly unchanges,and the micropore structure shows good development in group powder experiment.When the addition amount is 20%,the acidification yield of the group powder experiment is significantly lower,the compressive strength and the iodine adsorption value of the group soak experiment are higher as a whole,and the soak method is more conducive to the development of the microporous structure the direct addition of powder method.In the electrochemical performance comparison test between P15 sample and S15 sample,S15 sample has a large specific capacitance,with an internal resistance of 2.05Ωand a low charge transfer resistance.KOH can react with acid-containing organic compounds in the coal during the soak stage first,and K+preferentially enters the macromolecular structure of the coal material,generating a primary microporous structure from the internal matrix of the coal,which enhances the activation effect during subsequent pyrolysis and activation.The pore size distribution and the channel layout are more reasonable,achieving a higher ion migration effect.The compressive strength of the S20 sample is 3.96 MPa,the iodine adsorption value

关 键 词：KOH活化 煤基电极材料(CEM) 浸渍法 降解反应 微孔结构 

分 类 号：TQ536.1[化学工程—煤化学工程]