用于锂离子电池的Fe_3O_4/C纳米结构的可控制备(英文)

Morphology-controlled synthesis of Fe_3O_4/carbon nanostructures for lithium ion batteries

采用溶剂热反应并经在氮气中煅烧的方法制备出不同形貌的Fe3O4/C纳米复合物。无需表面活性剂或模板剂,仅通过调控反应物的浓度,合成出花状、纳米片状、空心球形结构3种纳米结构,并对不同形貌的形成机理进行探讨。此外,三种不同形貌样品的电化学结果表明,花状样品的电化学综合性能显著优于另外两种形貌,在5 C的充放电电流下,其可逆比容量能达到227mAh/g,而空心球形、纳米片状结构样品的容量则分别为45、10mAh/g。

Morphology-controlled Fe3 O4 / carbon nanocomposites were synthesized by a solvothermal reaction followed by calcina-tion under a nitrogen atmosphere. Flower-like structures, dispersed nanoflakes and hollow microspheres could be readily obtained by adjusting the concentrations of the reactants. Based on the time-dependent structure evolution, a possible mechanism for the forma-tion of the different morphologies under various conditions was discussed. The lithium storage properties of the different Fe bon composites were compared. The flower-like sample shows the best electrochemical performance with the highest specific capaci-ty of 227 mAh/ g at a current rate of 5 C while hollow microspheres and dispersed nanoflakes have specific capacities of only 45 and 10 mAh/ g, respectively.