玉米芯基多孔碳的制备及其在锂硫电池中的应用  

Preparation of corncob-derived porous carbon materials and the application in lithium-sulfur batteries

作　　者：燕映霖[1] 魏一奇 李巧乐 陈世煜 蔺佳明 杨蓉 许云华[1] YAN Yinglin;WEI Yiqi;LI Qiaole;CHEN Shiyu;LIN Jiaming;YANG Rong;XU Yunhua(School of Materials Science and Engineering, Xi’an University of Technology, Xi’an710048, China)

机构地区：[1]西安理工大学材料科学与工程学院,陕西西安710048

出　　处：《西安理工大学学报》2019年第1期40-46,共7页Journal of Xi'an University of Technology

基　　金：国家国际科技合作专项资助项目(2015DFR50350);国家自然科学基金资助项目(51702256);陕西省科技计划资助项目(2017GY-160);陕西省自然科学基础研究计划资助项目(2017JQ5055)

摘　　要：锂硫电池理论比容量高、成本低、环境友好,但硫正极仍面临导电性差、容量衰减快、体积膨胀等问题。采用生物质废弃物玉米芯作为碳源,KOH为活化剂,通过不同工艺制备了三种多孔碳材料。利用XRD、SEM、BET等对多孔碳产品的物相形貌等进行表征后发现,采用一次活化工艺所制备的多孔碳材料具有大量相互贯通的孔道结构,故具有高的比表面积(1 578.64 m^2/g)与较大的孔容(0.93 cm^3/g)。覆硫后用于锂硫电池正极,可作为三维导电骨架显著提高硫正极的导电率,并对单质硫表现出较高的吸附性能。电化学测试表明改性正极材料首次放电比容量为1 050.7 mAh/g,50周循环后容量保持率为50.4%。综合对比表明,一次活化工艺为利用此类生物质废弃物制备多孔碳材料提供了优化方案。Lithium-Sulfur(Li-S)battery has received an increasing attention due to high theoretical capacity,low cost and environmental friendliness,but it still faces a lot of drawbacks,including the poor conductivity of S,capability fading and volume expansion.In this paper,three different processes were managed to fabricate biomass derived porous carbon materials with corncob as the carbon source,and KOH as the activating agent.The synthesized carbon materials were characterized by XRD,SEM,BET,etc.Among them,the product fabricated by the one-step activation method delivered a three-dimensional interconnected microstructure with abundant micro/mesopores,and thus it possessed the largest specific surface area(1 578.64 m^2/g)and the largest total pore volume(0.93 cm^3/g).After being combined with S,the C/S composite as cathode materials,the electronic conductivity was significantly improved and the carbon material exhibited a strong adsorption to S.The electrochemical testing results demonstrated that the obtained C/S composite cathode exhibited a high initial specific capacity(1 050.7 mAh/g)and good capacity retention(50.4%)after 50 cycles.A promising commercial synthesis method is suggested for biomass wastes derived porous carbon materials.

关 键 词：锂硫电池 正极 玉米芯 生物质 多孔碳 高比表面积 

分 类 号：TM912.9[电气工程—电力电子与电力传动]