石墨烯/碳纳米管复合导电剂制备  

Preparation of graphene/carbon nanotube composite conductive agent

作　　者：苏国士 梁阚 李虓 罗超贵 赵胜贤 全金 靳龙[2] 莫有堂[2] 王明月 尤胜利 陈鑫[2] 刘林聪 李亮川 周铭 Su Guo-shi;Liang Kan;Li Xiao;Luo Chao-gui;Zhao Sheng-xian;Quan Jin;Jin Long;Mo You-tang;Wang Ming-yue;You Sheng-li;Chen Xin;Liu Lin-cong;Li Liang-chuan;Zhou Ming(Guangxi Tsinglube New Material Technologies Co.,Ltd.,Guangxi Liuzhou 545600,China;School of Mechanical and Traffic Engineering,Guangxi University of Science and Technology,Guangxi Liuzhou 545616,China;Chengdu Carbon Co.,Ltd.,Sichuan Chengdu 610199,China)

机构地区：[1]广西清鹿新材料科技有限责任公司,广西柳州545600 [2]广西科技大学机械与汽车工程学院,广西柳州545616 [3]成都炭素有限责任公司,四川成都610199

出　　处：《炭素技术》2022年第1期23-27,40,共6页Carbon Techniques

基　　金：国家自然科学基金项目(12062002);广西自然科学基金项目(2018GXNSFAA138174);国家级大学生创新创业训练计划项目(201810594017);广西科学研究与技术开发项目计划(桂科AC19245071);柳州市科技计划项目(2020NACC0801)。

摘　　要：石墨烯(GN)与碳纳米管(CNTs)都具有良好的导电和导热特性。通过有效结合,利用二者的优点,制备出了一种新型高导电的石墨烯/碳纳米管复合导电添加剂,并对导电浆料进行SEM表征,分析其导电机理。在自组装的半电池的方式下,通过制备和对比三元镍钴锰(NCM)正极体系,3种不同比例下,不同种类导电剂(2种碳纳米管CNTs、1种石墨烯GN和不同比例混合的GN+CNTs)对电化学性能的影响。结果表明,在NCM∶PVDF∶导电剂质量比为8∶1∶1下对比不同导电剂的电阻率和方阻,再结合SEM表征,发现在复合GN∶CNTs为1∶3时石墨烯与碳纳米管分散情况较好,可以形成有效的导电网络,具有最优导电性;在0.1C倍率下,首次充放电比容量为117 mAh/g和104 mAh/g,首次库伦效率为88.9%,循环5周后容量保持率达到91.8%,首次放电比容量比单独使用GN高20 mAh/g,比纯CNTs高13 mAh/g。GN/CNTs复合导电剂以CNTs网络为力学骨架和导电桥梁,可以有效解决GN无法自支撑的问题,能形成分散均匀的导电网络,提高电容量和循环稳定性。有效结合与利用石墨烯与碳纳米管的优点,制备混合导电剂与三元正极材料复合来改善电化学性能,为动力电池应用于新能源领域提供了新的探索思路。Graphene(GN)and carbon nanotubes(CNTs)have good electrical and thermal conductivity.A new type of high conductivity graphene/carbon nanotube composite conductive additive is prepared by combining the advantages of graphene and carbon nanotube.The conductive paste is characterized by SEM and its conductive mechanism is analyzed.By assembling half cells,the effects of three kinds of conductive agents(two kinds of carbon nanotube(CNTs),one kind of graphene(GN)and different proportion of GN+CNTs)on the electrochemical performance of ternary NCM cathode system are studied.The resistivity and square resistance of different conductive agents are compared when the mass ratio of NCM∶PVDF∶conductive agent is 8∶1∶1,and the SEM characterization shows that the dispersion of graphene and carbon nanotubes is better when the raito of GN to CNTs is 1∶3,which can form an effective conductive network and have the optimal conductivity.At 0.1C rate,the first charge discharge specific capacity is 117 mAh/g and 104 mAh/g,respectively,the first coulombic efficiency is 88.9%,and the capacity retention rate reaches 91.8%after 5 cycles.The first discharge capacity is 20 mAh/g higher than that of GN alone and 13 mAh/g higher than that of pure CNTs addition.GN/CNTs composite conductive agent takes CNTs network as mechanical framework and conductive bridge,which can effectively solve the problem that GN can not support itself,form dispersed and uniform conductive network,and improve the capacitance and cycle stability.Combining and utilizing the advantages of graphene and carbon nanotubes effectively,the composite of mixed conductive agent and ternary cathode material is prepared to improve the electrochemical performance,which provides a new exploration for the application of power battery in the field of new energy.

关 键 词：锂离子电池 导电添加剂 石墨烯 碳纳米管 三元正极材料 

分 类 号：TB332[一般工业技术—材料科学与工程] O613.71[理学—无机化学]