Quick-charging graphite negative electrode material and preparation method thereof

Abstract

The invention discloses a preparation method of a quick-charging graphite negative electrode material. The method comprises the following steps: (1) composite granulation: adding a graphite precursor,a binder and tackifying resin into a mechanical fusion machine according to a certain ratio, and performing treating for 5-20 minutes to obtain a quick-charging graphite precursor; and (2) putting the quick-charging graphite precursor prepared in the step (1) into a graphitization furnace, and carrying out high-temperature graphitization treatment for 20-50 hours to obtain the quick-charging graphite negative electrode material. According to the method, the asphalt coats the surface of the graphite with a layer of uniform amorphous carbon, the secondary particles formed by strong adhesion under high-speed stirring are different from the secondary particles prepared by common low-temperature low-speed stirring heat treatment, and the graphite particles are smooth and flat in surface, freeof burrs, more stable in structure, higher in isotropy and better in rate capability and cycle performance. The method is simple in technological process, high in operability, low in cost and suitablefor large-batch preparation.

Description

technical field [0001] The invention relates to the technology in the field of negative electrode materials, in particular to a fast-charging graphite negative electrode material and a preparation method thereof. Background technique [0002] Carbon materials have the advantages of low chemical potential, good cycle performance, low price, and environmental friendliness, and are currently the most ideal and commonly used anode materials for lithium-ion batteries. Among carbon materials, compared with soft carbon and hard carbon, graphite materials have obvious advantages in terms of specific capacity, discharge platform and cost. However, as the fields of consumer electronics and power batteries put forward higher and higher requirements for fast charging, it is mainly reflected in the need for good fast charging capabilities at room temperature and low temperature conditions. At present, graphite anode materials are usually specially designed and processed to meet the requ...

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Problems solved by technology

[0003] Patent document 201410787061.7 discloses a fast-charging graphite lithium-ion battery negative electrode material and its preparation method. After mixing petroleum coke / pitch coke and pitch - kneading - high-temperature graphitization treatment, an artificial graphite material with a secondary particle structure is obtained. Due to the kneading process Complex and difficult to control, short heating and kneading time will lead to agglomeration of materials, uneven mixing, long heating and kneading time will cause volatilization loss of adhesive asphalt, affect the bonding effect, and lead to poor product consistency

[0004] Patent document 201710186423.0 discloses a preparation method of high-rate fast-charging graphite, which involves crushing and shaping graphite flakes, mixing binders, high-temperature graphitization treatment, mixing binders, low-temperature heat treatment, carbonization heat treatment, mixing and screening, etc. , many process steps, high cost

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