Three-dimensional graphene-hollow carbon sphere nanocomposite and preparation method thereof

Abstract

The invention discloses a three-dimensional graphene-hollow carbon sphere nano composite and a preparation method thereof. The three-dimensional graphene-hollow carbon sphere nano composite is prepared from hollow carbon spheres and graphene, wherein the hollow carbon spheres are distributed in a three-dimensional net structure formed by the graphene. The preparation method comprises the following steps: (1) preparing silicon dioxide microspheres coated with phenolic resin; (2) preparing three-dimensionalgraphene-microsphere hydrogel; (3) preparing a three-dimensional graphene-carbon sphere nano composite; and (4) preparing the three-dimensional graphene-hollow carbon sphere nano composite. The three-dimensional graphene-hollow carbon sphere nano composite is good in conductivity, is rich in graded hole structure, can be applied to a positive electrode material of a lithium-sulphur battery so as to supply rapid electron conduction, restrain dissolution and shuttle of polysulfide sulphur and alleviate the volume change of a sulphur positive electrode in a circulating process. The preparation method is simple and convenient and has a good effect.

Description

technical field [0001] The invention relates to the field of nano-carbon materials and preparation thereof, in particular to a three-dimensional graphene-hollow carbon sphere nanocomposite and a preparation method thereof. Background technique [0002] Secondary batteries with high energy density and low cost have promising applications in portable electronic devices, electric vehicles, and smart grids. Lithium-sulfur batteries have high theoretical specific capacity (1672mAh / g) and energy density (2600Wh / kg), which are several times that of ordinary lithium-ion batteries. In addition, sulfur elemental resources are abundant, cheap, and environmentally friendly. These remarkable advantages make lithium-sulfur batteries regarded as one of the most promising power sources for next-generation electric vehicles. [0003] At present, the main problems that restrict the practical application of lithium-sulfur batteries are as follows: (1) The conductivity of sulfur element is po...

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