Graphene material and preparation method, and saggar used for graphene preparation

Abstract

The invention relates to a saggar used for graphene preparation. A material of the saggar is high-density graphite, the saggar comprises a saggar main body and a saggar cover, the top of the saggar main body is opened, the top of the saggar main body is covered by the saggar cover, wherein, the saggar main body comprises an external saggar wall body and an external cavity formed by the external saggar wall body, a gap is arranged on the external saggar wall body, so that the external cavity is communicated with the outside part; an internal saggar is arranged in the saggar main body, the internal comprises an internal saggar wall body and an internal cavity formed by the internal saggar wall body, and the external cavity is communicated with the internal cavity. The invention also provides a method for preparing a graphene material by using the saggar and the graphene material.

Description

technical field [0001] The invention relates to a graphene material, in particular to a sagger for preparing graphene, a graphene material and a preparation method thereof. Background technique [0002] Due to the development of new energy technology, especially electric vehicle technology, there is a huge demand for high-performance power batteries with high capacity and high power density. As a two-dimensional nanomaterial with high conductivity, graphene is considered to be one of the key materials for high-performance conductive agents for power batteries. [0003] Existing methods for preparing graphene include chemical oxidation-reduction methods, mechanical exfoliation methods, CVD vapor deposition methods, and the like. However, the graphene produced by these methods has defects. For example, using the chemical redox method, although the thickness of graphene is small and the single-layer rate is high, it will cause great damage to graphene during the oxidation pro...

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Problems solved by technology

However, graphene produced by these methods has defects

For example, using the chemical redox method, although the thickness of graphene is small and the single-layer rate is high, it will cause great damage to graphene during the oxidation process, resulting in voids and the introduction of other functional groups, a large amount of sulfur, and iron-cobalt. Metal impurities such as nickel and manganese greatly affect the conductivity of graphene, resulting in damage to the performance of the battery when it is subsequently applied to the battery

Using the mechanical exfoliation method, although the electrical conductivity of graphene is high, there are disadvantages of thicker graphene and more layers, and the biggest problem of this method is that the raw materials used are flake graphite, expandable graphite or expanded worms. Graphite, when physically and mechanically stripped by liquid or gas methods, the raw material contains a large amount of sulfur and residual impurities such as iron, cobalt, nickel, manganese, potassium and calcium. The content of impurities greatly exceeds the standard, which will damage the battery. performance

Using CVD vapor deposition method, although the obtained graphene has the characteristics of thin single layer or double layer thickness and high electrical conductivity, but due to the need to use a substrate with a large amount of metallic nickel, the substrate needs to be dissolved and stripped. As a result, the output of graphene is extremely low and cannot be used for large-scale ton-level applications

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