阅读说明：本技术 一种高性能天然石墨锂离子电池负极材料的制备工艺 (Preparation process of high-performance natural graphite lithium ion battery negative electrode material ) 是由 陈新江 赵亮 于 2021-07-27 设计创作，主要内容包括：本发明公开了一种高性能天然石墨锂离子电池负极材料的制备工艺,涉及锂电池石墨负极材料制备技术领域,其制备过程包括以下步骤：对天然石墨进行整形处理；对整形处理过的天然石墨进行纯化处理；对纯化处理过的天然石墨进行硬碳包覆处理；包覆处理后进行碳化处理；碳化处理后进行1-4次浸渍处理；浸渍处理后进行破碎；破碎后进行高温处理得到高容量高功率高倍率天然石墨负极材料,本发明天然石墨整形和纯化处理提高容量,硬碳包覆处理提高倍率,浸渍和高温处理提高循环性能。(The invention discloses a preparation process of a high-performance natural graphite lithium ion battery negative electrode material, which relates to the technical field of preparation of lithium battery graphite negative electrode materials, and the preparation process comprises the following steps: shaping natural graphite; purifying the natural graphite after the shaping treatment; carrying out hard carbon coating treatment on the purified natural graphite; carrying out carbonization treatment after coating treatment; carrying out 1-4 times of dipping treatment after carbonization treatment; crushing after dipping treatment; the high-capacity high-power high-multiplying-power natural graphite cathode material is obtained by high-temperature treatment after crushing, the capacity is improved by natural graphite shaping and purifying treatment, the multiplying power is improved by hard carbon coating treatment, and the cycle performance is improved by impregnation and high-temperature treatment.)

1. A preparation process of a high-performance natural graphite lithium ion battery cathode material is characterized by comprising the following steps:

s1, shaping the natural graphite;

s2, purifying the natural graphite subjected to shaping treatment: adding the shaped natural graphite into a reaction tank, adding water, stirring, adding sulfuric acid which accounts for 2-4% of the mass of the natural graphite into the reaction tank, uniformly stirring, purifying for 15-20 h, washing and washing to be neutral to obtain purified natural graphite;

s3, carrying out hard carbon coating treatment on the purified natural graphite: melting and coating a hard carbon source on purified natural graphite to obtain a first precursor, and carrying out curing reaction on the first precursor and an additive to obtain a second precursor, wherein the curing temperature is 100-150 ℃;

s4, carbonizing after coating treatment: placing the second precursor in a kiln, and heating to 800-950 ℃ in an argon atmosphere for carbonization;

s5, performing 1-4 times of dipping treatment after carbonization treatment;

s6, carrying out immersion treatment and then crushing, wherein the crushing granularity is 8-20 mu m;

and S7, crushing, and then carrying out high-temperature treatment to obtain the high-capacity, high-power and high-magnification natural graphite cathode material.

2. The preparation process of the high-performance natural graphite lithium ion battery negative electrode material according to claim 1, wherein in the step S2, the material is stirred once every 3 hours within the purification time, and the stirring time is 5-8 min.

3. The preparation process of the high-performance natural graphite lithium ion battery negative electrode material according to claim 1, wherein the ratio of the hard carbon source to the purified natural graphite in step S3 is (10-25): 100.

4. the preparation process of the high-performance natural graphite lithium ion battery negative electrode material according to claim 1, wherein the additive in step S3 comprises a dispersant and a cross-linking agent.

5. The process for preparing the high-performance natural graphite lithium ion battery anode material according to claim 1, wherein the kiln in the step S4 is any one of a box furnace, a rotary furnace and a pushed slab kiln.

6. The preparation process of the high-performance natural graphite lithium ion battery negative electrode material according to claim 1, wherein the carbonization time in step S4 is 4-8 h.

7. The preparation process of the high-performance natural graphite lithium ion battery negative electrode material according to claim 1, wherein the step S5 comprises the following steps: and placing the carbonized second precursor into a pitch solvent for dipping treatment, wherein the dipping pressure is 1-3 MPa.

8. The preparation process of the high-performance natural graphite lithium ion battery negative electrode material according to claim 1, wherein the temperature of the high-temperature treatment in the step S7 is 2000-3200 ℃.

Technical Field

The invention relates to the technical field of graphite cathode material preparation, in particular to a preparation process of a high-performance natural graphite lithium ion battery cathode material.

Background

The graphite is crystalline carbon and a hexagonal system, is iron black to dark gray, has the density of 2.25 g/cm & lt 3 & gt, the hardness of 1.5, the melting point of 3652 ℃, the boiling point of 4827 ℃, is soft, has a greasy feeling, can conduct electricity, is inactive in chemical property, resists corrosion, and is not easy to react with acid, alkali and the like.

Because graphite has good conductivity, graphite is often used in a preparation process of a lithium battery cathode material, and has the advantages of high crystallization degree, high specific capacity, good processing performance and the like, and along with the progress and development of science and technology, the demand of the lithium battery cathode material is increased.

Chinese patent CN108832124A discloses a preparation method of a graphite cathode material, which mainly comprises the following steps: mineral processing, crushing, purifying, drying, organic coating, mesoporous treatment and high-temperature crystal transformation;

the preparation of the lithium battery cathode material is completed through coating and high-temperature treatment, however, with the increasingly high requirements on the performance of the cathode material in the fields of consumer electronics and power batteries, the common cathode material cannot meet the daily requirements of people, and therefore a production method of the high-performance lithium battery graphite cathode material is urgently needed to be provided.

Disclosure of Invention

The invention aims to provide a preparation process of a high-performance natural graphite lithium ion battery negative electrode material, and mainly aims to solve the problems that the performance of the lithium battery graphite negative electrode material prepared by the existing process is poor and the use requirement cannot be met.

The technical scheme of the invention is that the preparation process of the high-performance natural graphite lithium ion battery cathode material comprises the following steps:

s1, shaping the natural graphite;

s2, purifying the natural graphite subjected to shaping treatment: adding the shaped natural graphite into a reaction tank, adding water, stirring, adding sulfuric acid which accounts for 2-4% of the mass of the natural graphite into the reaction tank, uniformly stirring, purifying for 15-20 h, washing and washing to be neutral to obtain purified natural graphite;

s3, carrying out hard carbon coating treatment on the purified natural graphite: melting and coating a hard carbon source on purified natural graphite to obtain a first precursor, and carrying out curing reaction on the first precursor and an additive to obtain a second precursor, wherein the curing temperature is 100-150 ℃;

s4, carbonizing after coating treatment: placing the second precursor in a kiln, and heating to 800-950 ℃ in an argon atmosphere for carbonization;

s5, performing 1-4 times of dipping treatment after carbonization treatment;

s6, carrying out immersion treatment and then crushing, wherein the crushing granularity is 8-20 mu m;

and S7, crushing, and then carrying out high-temperature treatment to obtain the high-capacity, high-power and high-magnification natural graphite cathode material.

Preferably, in step S2, the mixture is stirred once every 3 hours for 5-8 min during the purification time.

Preferably, the ratio of the hard carbon source to the purified natural graphite in the step S3 is (10-25): 100.

preferably, the additives in step S3 include a dispersant and a crosslinking agent.

Preferably, the kiln in step S4 is any one of a box furnace, a rotary furnace, and a pusher kiln.

Preferably, the carbonization time in step S4 is 4-8 h.

Preferably, the step S5 includes the following steps: and placing the carbonized second precursor into a pitch solvent for dipping treatment, wherein the dipping pressure is 1-3 MPa.

Preferably, the temperature of the high-temperature treatment in step S7 is 2000 to 3200 ℃.

The invention has the beneficial effects that: the method has reasonable process, adopts the steps of shaping, purification, carbon coating, carbonization, impregnation, high-temperature treatment and the like, can effectively improve the capacity of the graphite cathode material through shaping and purification treatment, can effectively improve the multiplying power of the graphite cathode material through hard carbon coating and carbonization treatment, and can effectively improve the cycle performance of the graphite cathode material through impregnation and high-temperature treatment, thereby obtaining the graphite cathode material meeting the requirements of people.

Detailed Description

The present invention will be further described with reference to the following examples.

Example 1: a preparation process of a high-performance natural graphite lithium ion battery negative electrode material comprises the following steps:

s1, shaping the natural graphite;

s2, purifying the natural graphite subjected to shaping treatment: adding the shaped natural graphite into a reaction tank, adding water, stirring, adding sulfuric acid which accounts for 2% of the mass of the natural graphite into the reaction tank, uniformly stirring, purifying for 15 hours, stirring once every 3 hours within the purification time, stirring for 5min, washing, and washing to be neutral to obtain purified natural graphite;

s3, carrying out hard carbon coating treatment on the purified natural graphite: coating a hard carbon source on purified natural graphite in a melting manner to obtain a first precursor, and carrying out a curing reaction on the first precursor and an additive to obtain a second precursor, wherein the curing temperature is 100 ℃; the additive comprises a dispersant and a cross-linking agent; the ratio of the hard carbon source to the purified natural graphite is 10: 100, respectively;

s4, carbonizing after coating treatment: placing the second precursor in a kiln, heating to 800 ℃ in an argon atmosphere for carbonization for 4 h; the kiln is a box-type furnace;

s5, performing 1-time dipping treatment after carbonization treatment; the impregnation comprises the following specific steps: placing the carbonized second precursor into a pitch solvent for impregnation treatment, wherein the impregnation pressure is 1 MPa;

s6, crushing after dipping treatment, wherein the crushing granularity is 8 mu m;

s7, crushing, and then performing high-temperature treatment to obtain the high-capacity, high-power and high-magnification natural graphite cathode material, wherein the temperature of the high-temperature treatment is 2000 ℃.

Example 2: a preparation process of a high-performance natural graphite lithium ion battery negative electrode material comprises the following steps:

s1, shaping the natural graphite;

s2, purifying the natural graphite subjected to shaping treatment: adding the shaped natural graphite into a reaction tank, adding water, stirring, adding sulfuric acid which accounts for 3% of the mass of the natural graphite into the reaction tank, uniformly stirring, purifying for 17 hours, stirring once every 3 hours within the purification time, wherein the stirring time is 7min, and then washing and flushing to be neutral to obtain purified natural graphite;

s3, carrying out hard carbon coating treatment on the purified natural graphite: coating a hard carbon source on purified natural graphite in a melting manner to obtain a first precursor, and carrying out a curing reaction on the first precursor and an additive to obtain a second precursor, wherein the curing temperature is 120 ℃; the additive comprises a dispersant and a cross-linking agent; the ratio of the hard carbon source to the purified natural graphite is 18: 100, respectively;

s4, carbonizing after coating treatment: placing the second precursor in a kiln, heating to 870 ℃ in an argon atmosphere for carbonization for 6 hours; the kiln is a rotary furnace;

s5, performing 3 times of dipping treatment after carbonization treatment; the impregnation comprises the following specific steps: placing the carbonized second precursor into an asphalt solvent for impregnation treatment, wherein the impregnation pressure is 2 MPa;

s6, crushing after dipping treatment, wherein the crushing granularity is 14 mu m;

s7, crushing, and then performing high-temperature treatment to obtain the high-capacity, high-power and high-magnification natural graphite cathode material, wherein the temperature of the high-temperature treatment is 2600 ℃.

Example 3: a preparation process of a high-performance natural graphite lithium ion battery negative electrode material comprises the following steps:

s1, shaping the natural graphite;

s2, purifying the natural graphite subjected to shaping treatment: adding the shaped natural graphite into a reaction tank, adding water, stirring, adding sulfuric acid into the reaction tank according to 4% of the mass of the natural graphite, uniformly stirring, purifying for 20 hours, stirring once every 3 hours within the purification time, wherein the stirring time is 8min, and then washing and flushing to be neutral to obtain purified natural graphite;

s3, carrying out hard carbon coating treatment on the purified natural graphite: coating a hard carbon source on purified natural graphite in a melting manner to obtain a first precursor, and carrying out a curing reaction on the first precursor and an additive to obtain a second precursor, wherein the curing temperature is 150 ℃; the additive comprises a dispersant and a cross-linking agent; the ratio of hard carbon source to the purified natural graphite is 25: 100, respectively;

s4, carbonizing after coating treatment: placing the second precursor in a kiln, heating to 950 ℃ in an argon atmosphere for carbonization, wherein the carbonization time is 8 h; the kiln is a pushed slab kiln;

s5, performing 4 times of dipping treatment after carbonization treatment; the impregnation comprises the following specific steps: placing the carbonized second precursor into an asphalt solvent for impregnation treatment, wherein the impregnation pressure is 3 MPa;

s6, crushing after dipping treatment, wherein the crushing granularity is 20 mu m;

s7, crushing, and then performing high-temperature treatment to obtain the high-capacity, high-power and high-magnification natural graphite cathode material, wherein the temperature of the high-temperature treatment is 3200 ℃.

The above embodiments are merely illustrative of the technical ideas and features of the present invention, and the purpose thereof is to enable those skilled in the art to understand the contents of the present invention and implement the present invention, and not to limit the protection scope of the present invention. All equivalent changes and modifications made according to the spirit of the present invention should be covered within the protection scope of the present invention.