Composite graphene electrode material and solid-phase catalysis preparation method thereof

Abstract

The invention discloses a composite graphene electrode material. The material comprises an electrode material body and is characterized in that a graphene coating structure grows on the surface of the electrode material body in situ. The graphene coating structure is composed of a graphene close coating layer which is located on an electrode active material surface and a peripheral graphene conductive network and can improve the electrical conductivity of particles of the electrode material and the conductive connection among the particles. The invention also discloses a solid-phase catalysis preparation method for the composite graphene electrode material. The method comprises the steps of 1) mixing electrode materials, organic carbon source and catalyst precursors fully and uniformly as per the ratio of 200:(1-5):(5-30); 2) performing heat treatment on the mixture obtained through Step 1) in reducing atmosphere at 400-1000DEG C for 1-24 hours; 3) naturally cooling the mixture to the room temperature, performing porphyrizing and sieving, and finally obtaining the composite graphene electrode material. The method has the advantages of being low in cost and easy to implement and popularize.

Description

technical field [0001] The invention relates to a graphene composite electrode material and a solid-phase catalytic preparation method thereof. Background technique [0002] Due to the advantages of high energy density, lithium-ion batteries have been developed rapidly in the past 20 years, and are widely used as power sources for portable electronic products such as mobile phones, cameras, and notebook computers. In recent years, the development of hybrid electric vehicles, plug-in hybrid electric vehicles and large-scale energy storage equipment has put forward higher requirements for the next-generation lithium-ion batteries in terms of energy density, rate performance and cycle life. Although the performance of a large number of new materials as electrode materials for lithium-ion batteries has been exhaustively studied, only a few materials have been commercialized so far. [0003] Under the existing conditions, there are two main ways to improve the energy density, ra...

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Problems solved by technology

However, this simple mechanical mixing method makes it difficult to completely coat the material with graphene, and serious agglomeration of graphene itself will occur during the mixing process.

Application No. 201110079630.9 discloses a nanometer metal oxide / graphene doped LiFePO 4 The preparation method of electrode material is to modify graphene by nanometer metal oxide to solve the problem of graphene in contact with LiFePO 4 In order to solve the problem of easy agglomeration in the composite process, this method still adopts the method of mechanical ball milling and mixing. Compared with the traditional mechanical mixing method, although the dispersion of graphene is improved to a certain extent, the combination between electrode materials and graphene still remains not ideal

The Chinese patent with application number 201110083171.1 discloses a method for preparing LiFePO4 / graphene composite electrode material by chemical vapor deposition (CVD) on LiFePO4 precursor. Due to the existing shadow effect, it is still impossible to achieve a complete and uniform coating of LiFePO4, and it is not conducive to large-scale industrial production

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