摘要
为改善金属有机框架(MOF)材料作为锂离子电池负极材料的电化学性能,采用静电吸附及化学液相沉积法,以还原氧化石墨烯(RGO)为基体、氯化钴和氯化镍为前驱体、对苯二甲酸为有机配体,制备了CoNi-MOF/RGO复合物纳米片。RGO的引入不仅诱导CoNi-MOF由交联的片层结构向二维纳米片状转变,而且提高了复合材料的导电性。将获得的CoNi-MOF/RGO复合材料作为工作电极,组装成扣式锂离子电池。电化学测试结果表明:在0.2 A/g的电流密度下充放电循环100圈后,电池的放电比容量可达747 mA·h/g;在5.0 A/g的大电流密度下,电池的放电比容量仍维持在289 mA·h/g,均高于CoNi-MOF的放电比容量,展现了良好的电化学性能。
Over the past few decades,lithium-ion batteries(LIBs)have attracted extensive interests in energy storage devices due to their high energy density,long cycle life and environmental friendliness.However,the low specific capacity of conventional anode materials restricts the commercial applications of LIBs.Therefore,it is crucial to develop advanced electrodes for next-generation LIBs to meet the increasing energy requirements.Metal-organic frameworks(MOFs)are potential candidates for anode materials due to their high surface area,controlled pore size and structural diversity,but their poor conductivity and easy aggregation often result in the decline of electrochemical performances of LIBs.To further improve the overall performances of MOF as anode materials for lithium ion batteries,an approach involved electrostatic attraction and chemical liquid deposition was developed to fabricate CoNi-MOF/RGO composite nanoflakes using reduced graphene oxide(RGO)as substrate,cobalt chloride and nickel chloride as precursors,and benzenedicarboxylic acid as organic ligands.The addition of RGO not only induced the structural transformation of CoNi-MOF from cross-linked lamellae to two-dimensional nanoflakes,but also enhanced the conductivity of CoNi-MOF/RGO composite.Subsequently,the coin type lithium ion battery was assembled by using CoNi-MOF/RGO as anode materials.The electrochemical tests indicated that the obtained CoNi-MOF/RGO electrode possessed a high charge specific capacity of 747 mA·h/g at a current density of 0.2 A/g after 100 cycles.Even at a high current density of 5.0 A/g,a high capacity of 289 mA·h/g was still achieved,which is much higher than that of CoNi-MOF,demonstrating its excellent electrochemical performances.
作者
徐田
刘艺军
何颖
程起林
XU Tian;LIU Yijun;HE Ying;CHENG Qilin(Key Laboratory for Ultrafine Materials of Ministry of Education,School of Materials Science and Engineering,East China University of Science and Technology,Shanghai 200237,China)
出处
《华东理工大学学报(自然科学版)》
CAS
CSCD
北大核心
2020年第4期502-509,共8页
Journal of East China University of Science and Technology
基金
国家重点研发计划(2016YFE0131200)
国家自然科学基金(51702098)。
关键词
还原氧化石墨烯
金属有机框架
负极材料
锂离子电池
reduced graphene oxide
metal-organic framework
anode materials
lithium ion batteries