Ningbo Institute of Materials Technology & Engineering, Chinese Academy of Sciences, Ningbo 315201, P. R. China.
Department of Materials Science and Engineering, Zhejiang University, Hangzhou 310027, P. R. China.
Nanoscale. 2015 Dec 28;7(48):20426-34. doi: 10.1039/c5nr04416b.
Hollow silica-copper-carbon (H-SCC) nanocomposites are first synthesized using copper metal-organic frameworks as skeletons to form Cu-MOF@SiO(2) and then subjected to heat treatment. In the composites, the hollow structure and the void space from the collapse of the MOF skeleton can accommodate the huge volume change, buffer the mechanical stress caused by lithium ion insertion/extraction and maintain the structural integrity of the electrode and a long cycling stability. The ultrafine copper with a uniform size of around 5 nm and carbon with homogeneous distribution from the decomposition of the MOF skeleton can not only enhance the electrical conductivity of the composite and preserve the structural and interfacial stabilization, but also suppress the aggregation of silica nanoparticles and cushion the volume change. In consequence, the resulting material as an anode for lithium-ion batteries (LIBs) delivers a reversible capacity of 495 mA h g(-1) after 400 cycles at a current density of 500 mA g(-1). The synthetic method presented in this paper provides a facile and low-cost strategy for the large-scale production of hollow silica/copper/carbon nanocomposites as an anode in LIBs.
中空硅铜碳(H-SCC)纳米复合材料是首先利用金属有机骨架作为骨架合成铜 MOF@SiO2,然后进行热处理。在复合材料中,中空结构和 MOF 骨架塌陷产生的空隙空间可以容纳巨大的体积变化,缓冲锂离子插入/提取引起的机械应力,并保持电极的结构完整性和长循环稳定性。来自 MOF 骨架分解的尺寸均匀的约 5nm 的超细铜和均匀分布的碳不仅可以提高复合材料的电导率并保持结构和界面稳定性,而且可以抑制纳米硅颗粒的聚集并缓冲体积变化。因此,作为锂离子电池(LIB)的阳极材料,该材料在 500 mA g-1 的电流密度下循环 400 次后,可逆容量为 495 mA h g-1。本文提出的合成方法为大规模制备中空硅/铜/碳纳米复合材料作为 LIB 阳极提供了一种简便、低成本的策略。