Graphite negative electrode material of lithium-ion battery and preparation method of graphite negative electrode material

Abstract

The invention discloses a preparation method of a graphite negative electrode material of a lithium-ion battery. The method comprises the following steps of firstly mixing natural graphite with asphalt and carrying out surface modification treatment of natural graphite; carrying out vacuum carbonization treatment on the mixture of which the surface is modified; and finally carrying out screening treatment on the materials obtained by vacuum carbonization treatment to obtain a finished product, wherein the mass ratio of the natural graphite to the asphalt is (85:15) to (98:2) and the carbonization treatment temperature is 1,000-1800 DEG C. The graphite negative electrode material of the lithium-ion battery has high tap density, small specific surface area, high discharge capacity, high initial charge-discharge efficiency and long cycle life; the initial discharge capacity is over 360mAh/g; the initial charge-discharge efficiency is over 93%; and the cycle performance is over 90% after 500 cycles. According to the preparation method of the graphite negative electrode material of the lithium-ion battery, the process is simple and feasible, the raw material source is wide and the cost is low.

Description

technical field [0001] The invention relates to the field of lithium ion battery production, in particular to a lithium ion battery graphite negative electrode material and a preparation method thereof. Background technique [0002] Lithium-ion battery is a secondary battery, that is, a rechargeable battery. It mainly relies on lithium ions to move between the positive and negative electrodes to work. During the charging and discharging process, Li + Intercalation and deintercalation back and forth between two electrodes: when charged, Li + It is deintercalated from the positive electrode and embedded in the negative electrode through the electrolyte, and the negative electrode is in a lithium-rich state; the opposite is true during discharge, and its negative electrode material is generally graphite negative electrode material, which is a representative of modern high-performance batteries; lithium-ion batteries are characterized by their high energy density and long cycle ...

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Problems solved by technology

[0003] The purpose of the present invention is to provide a preparation method of lithium-ion battery graphite negative electrode material and the lithium-ion battery graphite negative electrode material prepared therefrom, to overcome the partial surface area of ​​the modified material in the existing modified natural graphite preparation method Large, the produced battery has a large irreversible capacity for the first charge and discharge, low initial efficiency, poor cycle and other defects

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