Preparation method of composite modified graphite cathode material, composite modified graphite cathode material and application

Abstract

The invention provides a preparation method of a composite modified graphite cathode material, the composite modified graphite cathode material and an application and relates to the technical field of graphite cathode materials. According to the method, a graphite intercalation compound is subjected to coating modification through a phenolic resin mixed solution, wherein the phenolic resin mixed solution is mainly prepared from phenolic resin, a phosphorus compound and water. Different from graphite, the graphite intercalation compound can enlarge the interplanar spacing of graphite and increase the Lithium storage capacity, so that the reversible capacity is increased; besides, a phosphorus-doped carbon coating layer can increase the compactness of the composite modified graphite cathode material and further improve the rate capability of the material; besides, the phosphorus-doped carbon coating layer can uniformly and completely coat the surface of the graphite intercalation compound, the irreversible capacity is reduced, and accordingly, the circulation efficiency is improved. The invention also provides the composite modified graphite cathode material prepared with the preparation method of the composite modified graphite cathode material.

Description

technical field [0001] The invention relates to the technical field of graphite negative electrode materials, in particular to a preparation method of a composite modified graphite negative electrode material, a composite modified graphite negative electrode material and applications. Background technique [0002] Lithium-ion batteries prepared with carbon materials as negative electrode materials have shown certain safety and stability performance, so the research on carbon materials has attracted the attention of researchers from various countries. Carbon materials mainly include graphite carbon materials, non-graphite carbon materials, doped carbon materials, and coated carbon materials. Among the many carbon anode materials, graphite has rapidly attracted widespread attention due to its rich resources, low price, high reversible capacity, low charge and discharge voltage platform, no voltage hysteresis, and excellent conductivity. There are not a few researches and appli...

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Problems solved by technology

[0006] The first object of the present invention is to provide a kind of preparation method of composite modified graphite negative electrode material, and this preparation method is to adopt phenolic resin mixed solution to modify graphite intercalation compound, wherein, phenolic resin mixed solution is mainly composed of phenolic resin, Composed of phosphorus compounds and water, this preparation method can improve the traditional preparation method of modifying graphite by using phenolic resin aqueous solution to reduce the irreversible capacity of graphite negative electrode materials, improve the rate performance and cycle efficiency of graphite negative electrode materials.

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