钴-铁双金属有机骨架衍生的硅/碳复合材料的制备及其电化学性能

Preparation and Electrochemical Performance of Silicon/Carbon Composite Derived from Cobalt-Iron Bimetallic Organic Framework

硅拥有理论比容量高、锂化电压低和资源丰富的突出优势,是最具潜力的负极材料之一。然而,其巨大的体积变化导致的性能快速衰减和高成本的复杂合成工艺,仍是阻碍其工业化应用的关键。因此,我们通过将纳米硅嵌入到钴-铁双金属有机骨架(MOFs)中,制备得到多孔硅基复合材料(Si@CoFe/NC)。该结构兼具MOFs衍生材料的高导电性和独特的多孔特性,能有效的减缓充放电过程中电极的体积效应,因而展现出优异的电化学性能。所制备材料具有高达832 mAhg-(11Ag-)1的初始可逆比容量,且经过100次循环后,比容量依然维持在598mAhg-1。这项研究工作提出了一种简单的方法来制备具有优异电化学性能的硅基复合材料,在锂离子电池负极中具有较大的应用潜力。

Silicon has been deemed to be one of the most prospective anode material for lithium-ion batteries becauseof its high theoretical capacity,low lithiation potential,and bountiful resources.However,the rapid decay of electrochemical performance caused by its huge volume expansion during charge and discharge is still the key to hindering the industrial application of silicon-based anodes.Therefore,by embedding nano-silicon into cobaltiron bimetallic organic frameworks(MOFs),we finally prepared porous silicon-based composites(Si@CoFe/NC).This structure combines the high conductivity and unique porous characteristics of MOFs-derived material,which can effectively suppress the volume expansion of Si during charge and discharge,thus exhibiting excellent electrochemical performance.The initial reversible specific capacity is as high as 832 mAh g-1(1Ag-1),and it still remainat 598 mAhg-1 after 100 cycles.This work proposes a simple method to prepare silicon-based composite with good electrochemical performance,which has great application potential in the anodes of lithium ion batteries.