石墨烯负载团簇结构CoFe_2O_4及其电化学储锂性能

Graphene Loaded with Cluster Structural CoFe_2O_4 Particles and Its Li-Storage Performance

以氧化石墨为碳前驱体,利用含氧官能团与金属离子的价键结合,一步水热工艺同时实现石墨烯的制备及均匀负载团簇结构CoFe_2O_4。微观形貌显示CoFe_2O_4为一次颗粒组成的团簇结构。复合材料独特的结构有助于充分发挥石墨烯高导电性、大比表面积的优势,相比单纯的CoFe_2O_4,该复合材料具有优异的倍率特性和循环稳定性。石墨烯的高导电性提升了复合材料的整体导电和导锂特性。同时,独特的团簇结构及石墨烯的限制作用抑制了活性纳米颗粒在充放电过程中的体积变化,提高了活性材料的稳定性。

Oxidized graphite was used as carbon precursor, the preparations of graphene and cluster structural CoFe2O4 particles which homogeneously loaded on the grasphene were realized on the same time by one-step hydrothermal process combined with the bonding of oxygen-containing functional groups and metal ions. The microstructure observation shows that CoFe2O4 particles are composed of many primary particles. The unique structure of the composites helps graphene to develop its advantages of high conductivity and large specific surface area. Compared with pure CoFe2O4, the composites have excellent cycle stability and high rate performance. High-rate characteristics arise from high conductivity of graphene which enhances the overall conductivity and the diffusion of lithium in the composites. At the same time, the unique cluster structure and the confine of graphene inhibit the volume change of active nanoparticles in the charging and discharging process, and ensure the stability of active materials.