利用微量碳纳米管与石墨烯协同包覆提高LiCoO_(2)正极材料的性能  

Improving Performance of LiCoO_(2) Positive Material by Coating Micro Carbon Nanotubes in Collaboration with Graphene

作　　者：谭洁慧 邓凌峰[1,2,3] 张淑娴 李金磊 王壮 覃榕荣 TAN Jiehui;DENG Lingfeng;ZHANG Shuxian;LI Jinlei;WANG Zhuang;QIN Rongrong(School of Materials Science and Engineering,Central South University of Forestry and Technology,Changsha 410004,China;Hunan Province Key Laboratory of Materials Surface and Interface Science and Technology,Central South University of Forestry and Technology,Changsha 410004,China;Hunan Xineng New Material Co.,Ltd.,Changsha 410205,China)

机构地区：[1]中南林业科技大学材料科学与工程学院,长沙410004 [2]中南林业科技大学材料表界面科学与技术湖南省重点实验室,长沙410004 [3]湖南烯能新材料有限公司,长沙410205

出　　处：《材料导报》2022年第2期18-23,共6页Materials Reports

基　　金：国家自然科学基金重点资助项目(31530009)。

摘　　要：采用高温固相法制备钴酸锂(LiCoO_(2))正极材料,将碳纳米管(CNTs)、氧化石墨烯(GO)与LiCoO_(2)超声分散,经喷雾干燥和高温还原后,氧化石墨烯被还原成石墨烯(GR),最终得到均匀分散的碳纳米管/石墨烯/钴酸锂(CNTs/GR/LiCoO_(2))复合正极材料。实验采用X射线衍射(XRD)、红外光谱(FTIR)、扫描电镜(SEM)、透射电镜(TEM)以及电化学测试等方法,对材料的结构、形貌和电化学性能进行表征。实验结果表明,碳纳米管与石墨烯交替分散在LiCoO_(2)颗粒表面,形成三维分层纳米级导电网络,能有效防止复合材料的团聚,与纯LiCoO_(2)、GR/LiCoO_(2)、CNTs/LiCoO_(2)相比,CNTs/GR/LiCoO_(2)复合材料表现出更优异的电化学性能,在0.5C时放电比容量为171.28 mAh/g,循环100次后放电比容量为154.50 mAh/g,容量保持率为90.24%,5C大倍率下放电比容量达到143.60 mAh/g。LiCoO_(2) positive material was prepared by high temperature solid phase method.Carbon nanotubes(CNTs),graphene oxide(GO)and LiCoO_(2) were dispersed by ultrasonic.Graphene(GR)were reduced by graphene oxide and CNTs/GR/LiCoO_(2) composite positive material was uniformly dispersed by spray drying and high temperature reduction.The structure,morphology and electrochemistry performance of the materials were characterized by XRD,FTIR,SEM,TEM and electrochemical measurement.The experimental results show that carbon nanotubes and graphene were alternately dispersed on the surface of LiCoO_(2) particles,to form a three-dimensional layered nanoscale conductive network,effectively preventing the reunion of composite material.Compared with pure LiCoO_(2),GR/LiCoO_(2) and CNTs/LiCoO_(2),the CNTs/GR/LiCoO_(2) composite shows better electrochemical properties,whose discharge specific capacity is 171.28 mAh/g at 0.5 C,and 154.50 mAh/g after 100 cycles,the capacity retention rate is 90.24%,and the capacity reaches 143.60 mAh/g at 5 C.

关 键 词：碳纳米管 石墨烯 钴酸锂 协同包覆 复合材料 电化学性能 

分 类 号：TM912[电气工程—电力电子与电力传动]