School of Materials Science and Engineering and Guangdong Provincial Key Laboratory of Advanced Energy Storage Materials, South China University of Technology , Guangzhou 510641, P. R. China.
Key Laboratory of Low Dimensional Materials & Application Technology, Ministry of Education, School of Materials Science and Engineering, Xiangtan University , Xiangtan 411105, P. R. China.
ACS Appl Mater Interfaces. 2017 Jan 25;9(3):2516-2525. doi: 10.1021/acsami.6b14233. Epub 2017 Jan 10.
The MOFs (metal-organic frameworks) have been extensively used for electrode materials due to their high surface area, permanent porosity, and hollow structure, but the role of antimony on the MOFs is unclear. In this work, we design the hollow spheres Ni-MOFs with SbCl to synthesize NiSb⊂CHSs (NiSb-embedded carbon hollow spheres) via simple annealing and galvanic replacement reactions. The NiSb⊂CHSs inherited the advantages of Ni-MOFs with hollow structure, high surface area, and permanent porosity, and the NiSb nanoparticles are coated by the formed carbon particles which could effectively solve the problem of vigorous volume changes during the Li insertion/extraction process. The porous and network structure could well provide an extremely reduced pathway for fast Li diffusion and electron transport and provide extra free space for alleviating the structural strain. The NiSb⊂CHSs with these features were used as Li-ion batteries for the first time and exhibited excellent cycling performance, high specific capacity, and great rate capability. When coupled with a nanostructure LiMnO cathode, the NiSb⊂CHSs//LiMnO full cell also characterized a high voltage operation of ≈3.5 V, high rate capability (210 mA h g at a current density of 2000 mA g), and high Coulombic efficiency of approximate 99%, meeting the requirement for the increasing demand for improved energy devices.
金属-有机骨架（MOFs）由于其高比表面积、永久孔隙率和中空结构而被广泛用于电极材料，但锑在 MOFs 中的作用尚不清楚。在这项工作中，我们设计了具有 SbCl 的空心球体 Ni-MOFs，通过简单的退火和电置换反应合成了 NiSb⊂CHSs（嵌入碳空心球的 NiSb）。NiSb⊂CHSs 继承了 Ni-MOFs 的中空结构、高比表面积和永久孔隙率的优点，并且 NiSb 纳米颗粒被形成的碳颗粒所包覆，这可以有效地解决在 Li 插入/提取过程中剧烈的体积变化问题。多孔和网络结构可以为快速 Li 扩散和电子传输提供极好的还原途径，并为缓解结构应变提供额外的自由空间。首次将具有这些特点的 NiSb⊂CHSs 用作锂离子电池，表现出优异的循环性能、高比容量和出色的倍率性能。当与纳米结构 LiMnO 阴极结合时，NiSb⊂CHSs//LiMnO 全电池还表现出 ≈3.5 V 的高压操作、高倍率性能（在 2000 mA g 的电流密度下为 210 mA h g）和接近 99%的高库仑效率，满足了对改进能量器件的需求不断增加的要求。
