阅读说明：本技术 一种高压实倍率型锂离子电池负极材料及制备方法 (High compaction rate type lithium ion battery cathode material and preparation method thereof ) 是由 王庆成 宋爽 韩团辉 于 2021-11-04 设计创作，主要内容包括：本发明属于锂离子电池负极材料领域,一种高压实倍率型锂离子电池负极材料及制备方法,通过对人造石墨原料制粉、混合、球化、改性和二次球化后进行石墨化,得到锂离子电池负极材料。对设备要求低,极易大规模生产,经测定,制备的锂离子电池负极材料具有粒度分布宽,压实密度高、倍率性能好。(The invention belongs to the field of lithium ion battery cathode materials, and relates to a high compaction rate type lithium ion battery cathode material and a preparation method thereof. The lithium ion battery cathode material has low requirement on equipment, is easy to produce on a large scale, and has the advantages of wide particle size distribution, high compaction density and good rate capability after being determined.)

1. A preparation method of a high compaction rate type lithium ion battery cathode material is characterized by comprising the following steps:

2) preparing artificial graphite raw materials into graphite raw material powder;

3) uniformly mixing the graphite raw material powder obtained in the step 1) with a binder to obtain a mixture;

4) under the protection of inert gas, carrying out surface chemical modification treatment on the mixture obtained in the step 2) to obtain secondary particles;

5) spheroidizing the secondary particles obtained in the step 3) to obtain a spheroidized material;

6) graphitizing the spheroidized material in the step 4) to obtain the lithium ion battery cathode material.

2. The preparation method of the high compaction rate type lithium ion battery negative electrode material according to claim 1, characterized by comprising the following steps: the artificial graphite raw material in the step 1) is one or a combination of more than one of petroleum coke, needle coke or pitch coke.

3. The preparation method of the high compaction rate type lithium ion battery negative electrode material according to claim 1, characterized by comprising the following steps: the graphite raw material powder in the step 1) is dried, coarsely crushed and finely crushed to obtain powder with the D50 particle size value of 5-10 mu m.

4. The preparation method of the high compaction rate type lithium ion battery negative electrode material according to claim 1, characterized by comprising the following steps: the ratio of the graphite raw material powder in the step 2) to the binder is 90:10-99:1, and the binder is petroleum asphalt or coal asphalt.

5. The preparation method of the high compaction rate type lithium ion battery negative electrode material according to claim 1, characterized by comprising the following steps: and 3) carrying out chemical modification treatment on the mixture in the step 3) through a roller furnace to obtain secondary particles, wherein the treatment temperature of the roller furnace is 300-680 ℃, the treatment time is 7-15h, and the particle size D50 of the obtained secondary particles is 10-20 μm.

6. The preparation method of the high compaction rate type lithium ion battery negative electrode material according to claim 1, characterized by comprising the following steps: and 4) spheroidizing the secondary particles by using a spheroidizing machine in the step 4), wherein the rotating speed of the spheroidizing machine is 200-800r/min, the spheroidizing time is 1-20min, the particle size D50 of the spheroidized material is 6-12 mu m, and the D90/D10 is 4-8.

7. The preparation method of the high compaction rate type lithium ion battery negative electrode material according to claim 1, characterized by comprising the following steps: the graphitization treatment temperature in the step 5) is 2600-3000 ℃, and the treatment time is 36-48 h.

8. A high compaction rate type lithium ion battery negative electrode material: the preparation method is characterized by being prepared by adopting the method.

Technical Field

The invention relates to a high compaction rate type lithium ion battery cathode material and a preparation method thereof, belonging to the field of preparation of lithium ion battery cathode materials.

Background

The lithium ion battery mainly uses graphite as a negative electrode material, and the traditional graphite negative electrode material has the problems of low compaction density, poor multiplying power performance and the like, so that the lithium ion battery has low energy density, poor power performance and low heavy-current charge and discharge performance, and the application of the lithium ion battery in electric tools, digital and new energy automobiles is limited.

Disclosure of Invention

The invention aims to solve the technical problem of providing a high-compaction-rate lithium ion battery cathode material and a preparation method thereof, the process is simple, the requirement on equipment is low, the large-scale production is easy, and the prepared lithium ion battery cathode material has the advantages of wide particle size distribution, high compaction density and good rate performance through determination.

In order to solve the above problems, the specific technical scheme of the invention is as follows: a preparation method of a high compaction rate type lithium ion battery cathode material comprises the following steps:

1) preparing artificial graphite raw materials into graphite raw material powder;

2) uniformly mixing the graphite raw material powder obtained in the step 1) with a binder to obtain a mixture;

3) under the protection of inert gas, carrying out surface chemical modification treatment on the mixture obtained in the step 2) to obtain secondary particles;

4) spheroidizing the secondary particles obtained in the step 3) to obtain a spheroidized material;

5) graphitizing the spheroidized material in the step 4) to obtain the lithium ion battery cathode material.

The artificial graphite raw material in the step 1) is one or a combination of more than one of petroleum coke, needle coke or pitch coke.

The graphite raw material powder in the step 1) is dried, coarsely crushed and finely crushed to obtain powder with the D50 particle size value of 5-10 mu m.

The ratio of the graphite raw material powder in the step 2) to the binder is 90:10-99:1, and the binder is petroleum asphalt or coal asphalt.

And 3) carrying out chemical modification treatment on the mixture in the step 3) through a roller furnace to obtain secondary particles, wherein the treatment temperature of the roller furnace is 300-680 ℃, the treatment time is 7-15h, and the particle size D50 of the obtained secondary particles is 10-20 μm.

And 4) spheroidizing the secondary particles by using a spheroidizing machine in the step 4), wherein the rotating speed of the spheroidizing machine is 200-800r/min, the spheroidizing time is 1-20min, the particle size D50 of the spheroidized material is 6-12 mu m, and the D90/D10 is 4-8.

The graphitization treatment temperature in the step 5) is 2600-3000 ℃, and the treatment time is 36-48 h.

The high compaction rate type lithium ion battery cathode material is prepared by adopting the method.

The invention has the following beneficial effects: 1. compared with the prior art, the invention has the advantages of simple process, low cost and easy quality control, and the compacted density of the pole piece is higher than that of the prior art;

2. the particle surface is modified through shaping after crushing the raw materials and spheroidizing shaping after modification, so that the orientation of graphite is reduced, the rate capability is improved, meanwhile, the spheroidizing machine spheroidizing controls the ratio of the particle size D90/D10, the particle size distribution is widened, the filling density among material particles is improved, the consumption of glue can be effectively reduced, the energy density is improved, and the processing performance is improved;

3. the graphite cathode material prepared by the invention has higher compacted density and excellent rate capability, and has higher application value in power type lithium ion batteries.

Detailed Description

Example 1:

the embodiment provides a method for producing a high compaction rate type lithium ion battery cathode material, which comprises the following steps:

1) firstly, carrying out coarse crushing and fine crushing on petroleum coke, and shaping to obtain fine powder with the particle size of D50 being 5 mu m;

2) mixing the fine powder obtained in the step 1) with asphalt according to a ratio of 97:3 to obtain mixed powder;

3) carrying out surface modification treatment on the mixed powder obtained in the step 2) in a roller furnace at 650 ℃ for 8h under the protection of nitrogen atmosphere to obtain secondary particles with D50 of 13 mu m;

4) spheroidizing the secondary particles obtained in the step 3) in a spheroidizing machine with the rotating speed of 400r/min for 2min to obtain a spheroidized material with the D50 particle size value of 9 mu m and the D90/D10 value of 4.3;

5) graphitizing the spheroidized material obtained in the step 4) at 2600 ℃ for 20h to obtain the lithium ion battery cathode material.

Example 2:

the embodiment provides a method for producing a high compaction rate type lithium ion battery cathode material, which comprises the following steps:

1) firstly, drying, coarsely crushing and finely crushing the pitch coke, and shaping to obtain fine powder with the particle size of D50 being 10 mu m;

2) mixing the fine powder obtained in the step 1) with asphalt according to a ratio of 95:5 to obtain mixed powder;

3) carrying out surface modification treatment on the mixed powder obtained in the step 2) in a roller furnace at 600 ℃ for 10h under the protection of nitrogen atmosphere to obtain secondary particles with the D50 particle size value of 15 mu m;

4) spheroidizing the secondary particles obtained in the step 3) in a spheroidizing machine with the rotating speed of 600r/min for 4min to obtain D50 with the particle size value of 12 mu m, wherein D90/D10 is 6.1;

5) and (4) graphitizing the spheroidized material obtained in the step (4) at the high temperature of 3000 ℃ for 28h to obtain the lithium ion battery cathode material.

Example 3:

the embodiment provides a method for producing a high compaction rate type lithium ion battery cathode material, which comprises the following steps:

1) drying, coarse crushing and fine crushing needle coke, and shaping to obtain fine powder with the particle size of D50 being 8 mu m;

2) mixing the fine powder obtained in the step 1) with asphalt according to a ratio of 90:10 to obtain mixed powder;

3) carrying out surface modification treatment on the mixed powder obtained in the step 2) at 680 ℃ for 10h under the protection of nitrogen atmosphere to obtain secondary particles with the D50 particle size value of 14 mu m;

4) spheroidizing the secondary particles obtained in the step 3) in a spheroidizing machine with the rotating speed of 800r/min for 5min to obtain D50 with the particle size of 10 mu m, wherein D90/D10 is 5.1;

5) graphitizing the spheroidized material obtained in the step 4) at the high temperature of 3000 ℃ for 24 hours to obtain the lithium ion battery cathode material.

Example 4:

the embodiment provides a method for producing a high compaction rate type lithium ion battery cathode material, which comprises the following steps:

1) firstly, mixing petroleum coke, asphalt coke and needle coke according to the ratio of 1:1:1 to obtain mixed coarse powder;

2) drying, coarsely crushing and finely crushing the mixed coarse powder obtained in the step 1), and shaping to obtain fine powder with the particle size of D50 being 10 microns;

3) mixing the fine powder obtained in the step 2) with asphalt according to a ratio of 95:5 to obtain mixed powder;

4) carrying out surface modification treatment on the mixed powder obtained in the step 3) in a roller furnace at 600 ℃ for 10h under the protection of nitrogen atmosphere to obtain secondary particles with the D50 particle size value of 14 mu m;

5) fusing the secondary particles obtained in the step 4) in a spheroidizing machine with the rotating speed of 600r/min for 4min to obtain the secondary particles with the D50 particle size value of 12 mu m and the D90/D10 value of 5.8;

6) graphitizing the spheroidized material obtained in the step 5) at the high temperature of 3000 ℃ for 28h to obtain the lithium ion battery cathode material.

Example 5:

the embodiment provides a method for producing a high compaction rate type lithium ion battery cathode material, which comprises the following steps:

1) drying needle coke, coarse pulverizing, fine pulverizing, and shaping to obtain fine powder with D50 particle size of 6 μm

2) Mixing the fine powder obtained in the step 1) with asphalt according to the ratio of 92:8 to obtain mixed powder

3) Carrying out surface modification treatment on the mixed powder obtained in the step 2) at 680 ℃ for 8h under the protection of nitrogen atmosphere to obtain secondary particles with the particle size value of D50 being 12 microns;

4) spheroidizing the secondary particles obtained in the step 3) in a spheroidizing machine with the rotating speed of 500r/min for 5min to obtain D50 with the particle size of 8 mu m, wherein D90/D10 is 5.5;

5) graphitizing the spheroidized material obtained in the step 4) at the high temperature of 3000 ℃ for 28h to obtain the lithium ion battery cathode material.

In order to verify the performances of the lithium ion battery cathode material obtained by the invention and the commercially available cathode material, the lithium ion battery cathode material is tested for conventional indexes and electrochemical performances, and the results are shown in the following table:

results and conclusions:

the results of the examples 1 to 5 show that the example 5 has the best effect in the item tests of tap density, discharge capacity, primary efficiency, discharge capacity retention rate and pole piece compaction density; and examples 1 to 5

The performance of the obtained graphite cathode material is generally superior to that of the graphite cathode material sold in the market, which shows that the graphite cathode material obtained by the invention has high performance

The compaction rate type lithium ion battery cathode material has good performance.

The above description is only an embodiment of the present invention, but the protection scope of the present invention is not limited to the following,

those skilled in the art can easily conceive of alterations and substitutions within the technical scope of the present disclosure,

are intended to be covered by the scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the appended claims.

What has been described above is merely a preferred embodiment of the invention. It should be noted that variations and modifications can be made by those skilled in the art without departing from the principle of the present invention, and they should also be considered as falling within the scope of the present invention.