多壁碳纳米管涂层修饰苘麻基生物碳/硫复合正极材料的制备及对锂硫电池性能的影响  

Preparation of MWCNTs Coating Modified Carbon/Sulfur CompositeCathode Materials on Lithium-sulfur Battery Performance

作　　者：雷紫杰 柴英杰 李博文 王利江 宋士涛 李巍 李叶 曹甲旭 王艳慧 张佳丽 林风雅 LEI Zijie;CHAI Yingjie;LI Bowen;WANG Lijiang;SONG Shitao;LI Wei;LI Ye;CAO Jiaxu;WANG Yanhui;ZHANG Jiali;LIN Fengya(College of Chemical Engineering,Hebei Normal University of Science&Technology,Qinhuangdao Hebei,066600,China)

机构地区：[1]河北科技师范学院化学工程学院,河北秦皇岛066600

出　　处：《河北科技师范学院学报》2023年第1期1-9,共9页Journal of Hebei Normal University of Science & Technology

基　　金：国家自然科学基金项目(项目编号:21501043);河北省高等学校科学技术研究项目(项目编号:ZD2016086);2022年度大中学生科技创新能力培育专项项目(项目编号:202151001010544);河北科技师范学院研究生创新项目(项目编号:CXZZ202107,CXZZSS2022092);2020年省级研究生示范课程(项目编号:KCJSX2020085);2022年省级研究生课程思政示范课程(项目编号:YKCSZ2022117);河北省重点研发计划项目(项目编号:21327310D)。

摘　　要：锂硫(Li-S)电池因高理论能量密度在众多新型电池中受到广泛关注,但存在硫正极导电性差、多硫化物的穿梭等问题,制约其商业应用。针对上述问题,本次试验制备苘麻基生物碳(AC),通过熔融扩散法与升华硫(S)复合形成碳/硫复合材料(AC@S),并使用碳涂层法在正极材料表面涂覆多壁碳纳米管(MWCNTS)作为Li-S电池正极片与隔膜之间的夹层,进一步抑制多硫化物的溶解和扩散,阻止穿梭效应,减小活性物质的损失,提高Li-S电池的容量和循环性能。AC@S+MWCNTs电池首次放电容量为1242.8 mAh·g^(-1),循环150次后仍保持982.4 mAh·g^(-1),相同条件下比AC@S高出275.0 mAh·g^(-1)。将MWCNTS涂层与正极材料结合设计工艺简单,成本低,且可提高材料导电性、抑制多硫化物的穿梭效应,表现出良好的循环性能和库伦效率,是一种解决Li-S电池穿梭效应的有效途径。Lithium-sulfur batteries(Li-S)have received widespread attention among many new batteries due to their high theoretical energy density,but existing problems such as poor conductivity of the sulfur cathode and shuttle of polysulfides hinder the commercial application.Abutilon base biocarbon(AC)is prepared with the melt diffusion method and compounded with sulfur(S)to form a carbon/sulfur composite(AC@S),and multi-wall carbon nanotubes(MWCNTs)are coated on the surface of the cathode material with the carbon coating method as an interlayer between the cathode sheet and the diaphragm of the Li-S battery,further inhibiting the dissolution and diffusion of polysulfides,preventing the shuttle effect,reducing the loss of active material and improving the capacity and cycling performance of the Li-S batteries.The first discharge capacity of AC@S+MWCNTs is 1242.8 mAh·g^(-1) and maintains 982.4 mAh·g^(-1) after 150 cycles,which is 275.0 mAh·g^(-1) higher than that of AC@S under the same conditions.The combination of MWCNTS coating and cathode material is a simple and low-cost design,which can improve the electrical conductivity of the material and suppress the shuttle effect of polysulfides with good cycling performance and Coulomb efficiency,proving to be an effective way to solve the shuttle effect of Li-S batteries.

关 键 词：锂硫电池 碳/硫复合正极材料 多壁碳纳米管涂层 

分 类 号：TM912[电气工程—电力电子与电力传动] TB332[一般工业技术—材料科学与工程]