Co-Mn金属有机骨架衍生的双金属硫化物及其在锂离子电池负极材料中的应用

介绍了一种通过简单的室温搅拌合成具有多孔结构的 Co-Mn 金属有机框架(metal-organic-framework, MOF)材料的方法, 并对制备的双金属 MOF 进行气相硫化, 得到多孔 CoS介绍了一种通过简单的室温搅拌合成具有多孔结构的Co-Mn金属有机框架(metalorganic-framework,MOF)材料的方法,并对制备的双金属MOF进行气相硫化,得到多孔CoS_2/MnS双金属复合材料.与相同方法制备的单金属MnS与CoS2材料对比发现,CoS_2/MnS双金属复合材料表现出了类似花瓣状的多孔片状结构以及更小的粒径,在作为锂离子电池电极材料使用时表现出了最好的储锂性能.这主要归因于类花瓣状的多孔结构:一方面为锂离子提供了更短的传输路径以及更多的接触位点;另一方面也缓解了材料锂化/去锂化过程的体积变化.此外,两种金属硫化物的有机结合也抑制了材料在循环过程中由于体积变化而导致的容量快速衰减.最后,MOF有机配体衍生的碳骨架也为增强材料的导电性起到了积极的作用.

Design and application of Co-Mn metal-organic-frameworks derived bimetallic sulfides as anode for lithium-ion batteries

The facile synthesis of a Co-Mn metal-organic-framework (MOF) with a porous structure is reported. The prepared bimetallic MOF was then vulcanized to obtain a porous CoS$_{2}$/MnS bimetallic composite. By comparing single metal MnS and CoS$_{2}$ materials prepared by the same method, it was observed that the CoS$_{2}$/MnS bimetal composite exhibited a petal-like porous sheet structure and a smaller particle size than that of single metal composites. When used as an electrode material in lithium-ion batteries, the CoS$_{2}$/MnS composite exhibited the best lithium storage performance among contemporary composites. It was believed that the porous petal-like structure provided a short transport pathway for lithium-ions. The synergistic combination of the two metal sulfides also effectively inhibited the rapid capacity decay caused by volume changes during cycling. In addition, the carbon skeleton derived from the MOF organic ligands further played a positive role in the enhancement of the electronic conductivity of the material.