Preparation method of natural graphite composite N-doped carbon nanofibers webs cathode material

Abstract

Belonging to the technical field of lithium ion battery electrode material preparation, the invention particularly discloses a preparation method of a natural graphite composite N-doped carbon nanofibers webs cathode material. The method includes: firstly subjecting natural flake graphite to spheroidizing treatment, and activating natural graphite under a small argon flow, then mixing the activated natural graphite with a mixed solution of emulsified asphalt / water-soluble polymer uniformly in certain proportion, conducting spray drying, then performing high temperature heat treatment in an argon atmosphere, mixing the obtained product with N-doped carbon nanofibers webs, an inorganic lithium salt and a composite conductive agent according to certain mass ratio, and then carrying out spheroidizing fusion treatment, sieving, and vacuum heat treatment, thus obtaining the natural graphite composite N-doped carbon nanofibers webs cathode material. The method provided by the invention can effectively improve the conductivity and structural stability of the material, greatly increases the compaction density of natural graphite, enhances the specific capacity, the reversible capacity and the coulombic efficiency, and effectively improves the cycle stability of the lithium ion battery cathode material.

Description

technical field [0001] The invention relates to the technical field of preparation of lithium-ion battery electrode materials, in particular to a preparation method of a natural graphite composite nitrogen-containing carbon fiber net negative electrode material. Background technique [0002] Lithium-ion secondary battery has the characteristics of high voltage, large specific capacity, and environmental protection. It has become a new type of energy storage material to solve the "energy crisis" and "environmental crisis", and is of great significance to the sustainable development of energy. With the rapid development of electric vehicles and other electronic devices, the demand for lithium-ion batteries with high specific energy, high cycle stability, and long service life has increased exponentially. In lithium-ion batteries, the anode material is crucial to the performance of the battery. Most of the current commercial lithium-ion battery anode materials use various lith...

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Problems solved by technology

[0005] The purpose of the present invention is to overcome the common defects of low compaction density, poor structural stability, high preparation temperature and low synergy in graphite negative electrode materials prepared by existing methods, and provide a new lithium ion battery negative electrode material. The preparation method, the obtained negative electrode material has high compaction density, low specific surface area, high charge and discharge efficiency, good reversibility of charge and discharge reaction, large diffusion coefficient of lithium ions, stable structure, excellent cycle performance, stable high current charge and discharge performance, lithium intercalation Good dimensional and mechanical stability during the process, high product cost performance, simple preparation process conditions, stable in the air, no toxic and side effects, etc.

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