中空多层级FeS_(2)@FeS_(2)@N,S-C纳米立方体的制备及锂存储性能  

Hierarchical FeS_(2)@FeS_(2)@N,S-C hollow nanocubes for lithium storage

作　　者：曹新荣 陈平[1] 闵卫星 刘东璇 Xinrong Cao;Ping Chen;Weixing Min;Dongxuan Liu(State Key Laboratory of Fine Chemicals,School of Chemical Engineering,Dalian University of Technology,Dalian 116024,China)

机构地区：[1]大连理工大学化工学院精细化工国家重点实验室,大连116024

出　　处：《科学通报》2022年第35期4281-4288,共8页Chinese Science Bulletin

基　　金：辽宁省兴辽英才计划(XLYC1802085);国家自然科学基金(51873109);中央高校基本科研业务费(DUT20TD207);大连市科技创新基金(2019J11CY007)资助。

摘　　要：通过一系列溶剂热、聚多巴胺原位聚合和高温硫化过程成功构筑了中空多层级FeS_(2)@FeS_(2)@N,S-C纳米立方体.采用X射线衍射仪和X射线光电子能谱表征了样品的组成成分及元素价态;采用扫描电子显微镜、透射电子显微镜以及N2吸/脱附测试表征了样品的形貌和微观结构.在锂离子电池中该材料不仅能有效保持结构稳定,还具有不断提高的电极反应动力学.研究结果表明, FeS_(2)@FeS_(2)@N,S-C在0.2、0.5和2 A/g时的放电容量分别为505.6、472.2和360 mAh/g,在1 A/g下循环500次后仍保持492.1 mAh/g的可逆容量.该材料优异的电化学性能可归因于其杂原子掺杂碳层包覆的中空纳米花形结构及多组分的协同作用.With the increasingly prominent problems of energy shortage and environmental pollution, the requirement for highefficiency energy storage devices is becoming more urgent. Lithium-ion batteries(LIBs) are commonly used in portable electronic devices, such as laptops, mobile phones. However, their limited performances cannot meet the demands of ultrahigh energy density and safety in the fields of new energy vehicles and energy storage systems. The development and application of novel anode materials can increase the capacity of LIBs. Transition metal sulfides(TMSs) with ultrahigh theoretical capacity and chemical stability present bright application prospects. Among them, iron sulfide(FeSx) is regarded as one of the most promising anode materials due to its abundant reserves and environmental friendliness.However, the shortcomings of large volume expansion during cycling severely hinder the application of Fe Sxand other TMSs. Designing TMS anode materials with special structures and combining them with carbon-based materials can effectively improve their electrochemical performance.Constructing nanosized TMSs with a hierarchical hollow structural property is a common strategy to increase their cycling stability. The abundant free volume inside the hollow structure can serve as a buffer space for TMSs with severe volume expansion, greatly reducing the structural fracture phenomenon. The internal free volume is also conducive to the electrolytic penetration into the composites. In addition, the dense nanosheets on the surface enable the active materials to fully contact the electrolyte, and subsequently, more reaction sites are generated for the electrochemical reactions.Combining amorphous carbon with TMSs can increase the dispersity of composites and reduce the presence of agglomerated structures. The amorphous carbon layer can serve as a stable interface for electrochemical reactions, which is beneficial for maintaining high coulombic efficiency and structure retention during cycling. The disordered structures and

关 键 词：过渡金属硫化物 锂离子电池 中空多层级结构 负极材料 

分 类 号：TB383.1[一般工业技术—材料科学与工程] TM912[电气工程—电力电子与电力传动]