CN114074939A - Preparation method of solid asphalt liquid phase coating modified negative electrode material - Google Patents

Preparation method of solid asphalt liquid phase coating modified negative electrode material Download PDF

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CN114074939A
CN114074939A CN202010809449.8A CN202010809449A CN114074939A CN 114074939 A CN114074939 A CN 114074939A CN 202010809449 A CN202010809449 A CN 202010809449A CN 114074939 A CN114074939 A CN 114074939A
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negative electrode
electrode material
asphalt
temperature
liquid phase
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边浩苹
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Wuxi Taixian Powder Technology Co ltd
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Abstract

The preparation method of the solid asphalt liquid phase coated modified negative electrode material comprises the following steps of preparing 800-1200 parts of negative electrode material fine powder and 10-50 parts of liquid asphalt. Fluidizing the negative electrode material fine powder at a high speed in a high-speed mixer, controlling the temperature within the range of 50-200 ℃, melting solid asphalt at the temperature of 80-300 ℃, coating the solid asphalt on the surface of the negative electrode material fine powder to obtain a precursor, carrying out high-temperature heat treatment under the protection of inert gas in a tube furnace, preserving the heat, and cooling to room temperature to obtain the liquid-phase coated modified negative electrode material. The modified negative electrode material has excellent electrochemical performance, the first charge-discharge efficiency is up to more than 90%, the rate capability is good, the capacity is high, and the modified negative electrode material can be applied to high-rate power batteries of electric vehicles, model airplanes, electric tools and the like.

Description

Preparation method of solid asphalt liquid phase coating modified negative electrode material
Technical Field
The invention relates to the field of materials and electrochemistry, in particular to a solid asphalt liquid phase coating modified negative electrode material and a preparation method thereof.
Background
With the development of science and technology, people put higher demands on the performance of chemical power sources (batteries). For example, the development of integrated circuit technology makes electronic instruments increasingly miniaturized and portable, and accordingly, batteries are required to have the characteristics of small volume, light weight and high specific energy; the continuous development of space exploration technology and national defense and military equipment technology requires batteries with high specific energy and long storage life; the increasing awareness of environmental protection is attracting increasing attention to the development of electric vehicles, and such batteries should have large specific energy and specific power. Among many battery systems, lithium batteries are distinguished by their advantages of high operating voltage, high energy density, and light weight, and are regarded as important in various countries around the world.
The development of portable electronic devices has advanced dramatically in recent years. In addition, lithium ion secondary batteries are also being gradually pushed into the traffic field. Thus, the demand for lithium ion secondary batteries is continuously increasing, and due to this higher demand, the limitation of graphite negative electrode materials in terms of capacity and power characteristics is becoming more and more significant. In this context, the research on modification of graphite anode materials has been focused on by researchers. The existing preparation method adopts a solvent to dissolve the wrapping agent which is solid in a normal state into liquid, and the solvent is unnecessary impurities and is used as an auxiliary coating agent to bring certain influence on the purity of the material.
Disclosure of Invention
The invention aims to provide a preparation method of a solid asphalt liquid phase coated modified negative electrode material, and the prepared material has excellent electrochemical performance, the first charge-discharge efficiency is as high as more than 94%, the rate capability is good, and the capacity is high.
The purpose of the invention can be realized by the following steps:
s1, obtaining high-temperature liquid phase asphalt by the solid asphalt with high softening point at the temperature of 80-300 ℃; filtering the high-temperature liquid-phase asphalt, wherein the mesh number of a filter screen is 100-200 meshes;
s2, mixing 800-1200 parts of negative electrode material fine powder and 10-50 parts of liquid asphalt in parts by weight; firstly, feeding the fine powder of the negative electrode material into a high-speed mixer to be fluidized at a high speed according to the proportion, keeping the temperature of the high-speed mixer at 50-300 ℃, and then adding high-temperature liquid phase asphalt into the high-speed mixer to be coated on the fine powder of the negative electrode material;
s3, feeding the coated material into a coating machine, shaping the coated material, and enabling the asphalt to be more uniform on the surface of the fine powder of the negative electrode material and complete in coating;
and S4, carrying out high-temperature heat treatment on the shaped coating material under the protection of inert gas in a tube furnace at the heating rate of 2-8 ℃/min, preserving the heat for 3-10 h, and cooling to room temperature to obtain the liquid-phase coating modified negative electrode material.
Furthermore, the negative electrode material is graphite or silicon monoxide, and the particle size is 12.2-20.2 um.
Further, the fine powder of the negative electrode material is fluidized at high speed in a high-speed mixer, the stirring linear speed is 10-42 m/s, and the stirring time is 5-20 minutes; and (3) when the high-temperature liquid phase asphalt is added, stirring while adding, wherein the stirring linear speed is 10-42 m/s, and the stirring time is 3-20 minutes.
Further, the stirring linear speed of the coating machine is 10-42 m/s, and the time is 3-20 minutes.
Further, the temperature of the wrapping machine is 100-300 ℃.
Further, the high temperature heat treatment in step S4 is a carbonization treatment at 1000 to 2000 ℃ or a graphitization treatment at 2000 to 3200 ℃.
Further, the inert gas in step S4 is nitrogen gas having a purity of 99% or more.
Further, the graphite fine powder is one or more of spherical natural graphite, spheroidal natural graphite, crystalline flake graphite, artificial graphite, petroleum coke, pitch coke and mesocarbon microbeads.
The invention adopts a heating melting mode, has no solvent, does not increase extra impurities and ensures the purity of the material. The modified cathode material produced by the method has excellent electrochemical performance, the first charge-discharge efficiency is up to more than 94%, the rate capability is good, the capacity is high, and the modified cathode material can be applied to high-rate power batteries of electric automobiles, model airplanes, electric tools and the like.
Drawings
FIG. 1 is a graph of rate discharge curves for a preferred embodiment of the present invention;
FIG. 2 is an SEM image of a preferred embodiment of the invention.
Detailed Description
The present invention will be further described with reference to the following examples.
A preparation method of a solid asphalt liquid phase coating modified negative electrode material comprises the following steps:
s1, obtaining high-temperature liquid phase asphalt by the solid asphalt with high softening point at the temperature of 80-300 ℃; and filtering the high-temperature liquid-phase asphalt, wherein the mesh number of the filter screen is 100-200 meshes.
The cost of high softening point asphalt is lower than that of low softening point asphalt, and the coking value of high softening point asphalt is large. One of the purposes of the coating is to form a layer of amorphous carbon on the surface of the graphite particles, so that the larger the coking value, the better.
The solid asphalt is solvent-free, so that the influence of other impurities on a final product can be reduced.
S2, mixing 800-1200 parts of negative electrode material fine powder and 10-50 parts of liquid asphalt in parts by weight; firstly, feeding the fine powder of the negative electrode material into a high-speed mixer to be fluidized at a high speed according to the proportion, keeping the temperature of the high-speed mixer at 50-300 ℃, and then adding high-temperature liquid phase asphalt into the high-speed mixer to be coated on the fine powder of the negative electrode material.
Fluidizing the fine powder of the negative electrode material at high speed in a high-speed mixer, wherein the stirring linear speed is 10-42 m/s, and the stirring time is 5-20 minutes; and (3) when the high-temperature liquid phase asphalt is added, stirring while adding, wherein the stirring linear speed is 10-42 m/s, and the stirring time is 3-20 minutes.
The temperature of the high-speed mixer is 50-300 ℃, and the temperature is correspondingly adjusted along with the softening point temperature of the solid asphalt with high softening point.
The cathode material is graphite or silicon monoxide, and the particle size is 12.2-20.2 um.
The graphite fine powder is one or more of spherical natural graphite, spheroidal natural graphite, crystalline flake graphite, artificial graphite, petroleum coke, pitch coke and mesocarbon microbeads. In the embodiment, the fine graphite powder is spherical natural graphite, which is a material commercially available for producing a graphite negative electrode of a lithium battery; the main components are as follows: carbon and hydrogen, the content is more than 99.97 percent, the carbon-hydrogen ratio is 25:1, the trace elements e is less than 20ppm, Na is less than 5ppm, Cr is less than 5ppm, Cu is less than 5ppm, Ni is less than 5ppm, Al is less than 5ppm, and Mo is less than 5 ppm. The other graphite fine powder is a material which is sold in the market for producing the graphite negative electrode of the lithium battery and is a single component or a combination.
S3, feeding the coated material into a coating machine, shaping the coated material, and enabling the asphalt to be more uniform on the surface of the fine powder of the negative electrode material and complete in coating; the stirring linear speed of the coating machine is 10-42 m/s, and the time is 3-20 minutes; the temperature of the wrapping machine is 100-300 ℃, and is adjusted correspondingly according to the softening point temperature of the used asphalt, which is slightly higher than the softening point temperature of the used asphalt.
And S4, carrying out high-temperature heat treatment on the shaped coating material under the protection of inert gas in a tube furnace at the heating rate of 2-8 ℃/min, preserving the heat for 3-10 h, and cooling to room temperature to obtain the liquid-phase coating modified negative electrode material.
The high-temperature heat treatment in the step is carbonization treatment at 1000-2000 ℃ or graphitization treatment at 2000-3200 ℃. The inert gas in the step is nitrogen with the purity of more than 99 percent.
The primary effect of the coated negative electrode material is checked through the loose packing density, the powder flowability, the particle size change and the tap density change, and the coating condition of the surface is checked by using a mirror, as shown in fig. 2; and then, directly manufacturing a finished product to verify the actual effect.
The high-speed mixer, the wrapping machine and the tube furnace are all commercially available equipment.
Preparing a liquid-phase coating modified negative electrode material:
example 1
(1) And (3) obtaining high-temperature liquid asphalt by the solid asphalt at the high temperature of 80 ℃, and filtering the high-temperature liquid asphalt, wherein the mesh number of a filter screen is 100 meshes.
(2) 10 parts of high-temperature liquid asphalt is dripped or flows into a high-speed mixer to be coated on 1000 parts of graphite fine powder with the particle size of 12.2um, and the graphite fine powder is subjected to heat preservation and high-speed mixing in the high-speed mixer, wherein the stirring linear speed of the high-speed mixer is about 42m/s, the temperature of the high-speed mixer is about 50 ℃, and the temperature of the asphalt is about 80 ℃.
The graphite fine powder was added and stirred for 5 minutes. After the graphite fine powder is fluidized at a high speed, adding high-temperature liquid phase asphalt, stirring while adding, wherein the stirring linear speed is 42m/s, and the stirring time is 20 minutes.
(3) And (4) feeding the coated material into a coating machine, and shaping the coated material to ensure that the asphalt is more uniform on the graphite surface and completely coated. The stirring linear speed of the coating machine is 10m/s, and the time is 10 minutes. The temperature of the wrapping machine was 100 ℃.
(4) And heating the shaped coating material to 2000 ℃ at the speed of 2 ℃/min under the protection of nitrogen in a tubular furnace, preserving the heat for 3h for graphitization treatment, and cooling to room temperature to obtain the liquid-phase coating modified graphite cathode material.
Example 2
(1) And (3) obtaining high-temperature liquid asphalt by the solid asphalt at the high temperature of 200 ℃, and filtering the high-temperature liquid asphalt, wherein the mesh number of a filter screen is 110 meshes.
(2) 20 parts of high-temperature liquid asphalt is dripped or flows into a high-speed mixer to be coated on 800 parts of graphite fine powder with the particle size of 16.8um, and the graphite fine powder is subjected to heat preservation and high-speed mixing in the high-speed mixer, wherein the stirring linear speed of the high-speed mixer is 41m/s, the temperature of the high-speed mixer is about 180 ℃, and the temperature of the asphalt is about 200 ℃.
The graphite fine powder is added and then stirred for 8 minutes. After the graphite fine powder is fluidized at a high speed, adding high-temperature liquid phase asphalt, stirring while adding, wherein the stirring linear speed is 41m/s, and the stirring time is 12 minutes.
(3) The coated material enters a coating machine to shape the coated material, so that the asphalt is more uniform on the graphite surface and is completely coated; the stirring linear speed of the coating machine was 41m/s and the time was 3 minutes. The temperature of the wrapping machine was 185 ℃.
(4) And heating the shaped coating material to 2200 ℃ at the speed of 3 ℃/min under the protection of nitrogen in a tubular furnace, preserving the heat for 4h for graphitization treatment, and cooling to room temperature to obtain the liquid-phase coating modified graphite cathode material.
Example 3
(1) And (3) obtaining high-temperature liquid asphalt by the solid asphalt at the high temperature of 300 ℃, and filtering the high-temperature liquid asphalt, wherein the mesh number of a filter screen is 200 meshes.
(2) 30 parts of high-temperature liquid asphalt is dripped or flows into a high-speed mixer to be coated on 1100 parts of graphite fine powder with the particle size of 17.5um, and the graphite fine powder is subjected to heat preservation and high-speed mixing in the high-speed mixer, wherein the stirring linear speed of the high-speed mixer is 10m/s, the temperature of the high-speed mixer is about 300 ℃, and the temperature of the asphalt is about 300 ℃. The graphite fine powder was added and stirred for 20 minutes. After the graphite fine powder is fluidized at a high speed, adding high-temperature liquid phase asphalt, stirring while adding, wherein the stirring linear speed is 10m/s, and the stirring time is 20 minutes.
(3) The coated material enters a coating machine to shape the coated material, so that the asphalt is more uniform on the graphite surface and is completely coated; the stirring linear speed of the coating machine is 10m/s, and the time is 20 minutes. The temperature of the wrapping machine was 300 ℃.
(4) And heating the shaped coating material to 2400 ℃ at a speed of 4 ℃/min under the protection of nitrogen in a tubular furnace, preserving the heat for 5h for graphitization treatment, and cooling to room temperature to obtain the liquid-phase coating modified graphite cathode material.
Example 4
(1) The solid asphalt is processed at the high temperature of 280 ℃ to obtain high-temperature liquid asphalt, and the liquid asphalt is filtered, wherein the mesh number of a filter screen is 180 meshes.
(2) Dripping or flowing 40 parts of high-temperature liquid asphalt into a high-speed mixer to coat 1150 parts of graphite fine powder with the particle size of 20.2um, and carrying out heat preservation, heating and high-speed mixing in the high-speed mixer, wherein the stirring linear speed of the high-speed mixer is 15m/s, the temperature of the high-speed mixer is about 250 ℃, and the temperature of the asphalt is about 280 ℃; the graphite fine powder was added and stirred for 15 minutes. After the graphite fine powder is fluidized at a high speed, adding high-temperature liquid phase asphalt, stirring while adding, wherein the stirring linear speed is 15m/s, and the stirring time is 15 minutes.
(3) The coated material enters a coating machine to shape the coated material, so that the asphalt is more uniform on the graphite surface and is completely coated; the stirring linear speed of the coating machine is 16m/s, and the time is 15 minutes. The temperature of the wrapping machine was 270 ℃.
(4) And heating the shaped coating material to 2600 ℃ at the speed of 5 ℃/min under the protection of nitrogen in a tubular furnace, preserving the heat for 6h for graphitization treatment, and cooling to room temperature to obtain the liquid-phase coating modified graphite cathode material.
Example 5
(1) And (3) obtaining high-temperature liquid asphalt by the solid asphalt at the high temperature of 250 ℃, and filtering the high-temperature liquid asphalt, wherein the mesh number of the filter screen is 170 meshes.
(2) 50 parts of high-temperature liquid asphalt is dripped or flows into a high-speed mixer to be coated on 1200 parts of graphite fine powder with the particle size of 17.1um, and the graphite fine powder is subjected to heat preservation and high-speed mixing in the high-speed mixer, wherein the stirring linear speed of the high-speed mixer is 20m/s, the temperature of the high-speed mixer is about 220 ℃, and the temperature of the asphalt is about 250 ℃.
The graphite fine powder was added and stirred for 16 minutes. After the graphite fine powder is fluidized at a high speed, adding high-temperature liquid phase asphalt, stirring while adding, wherein the stirring linear speed is 20m/s, and the stirring time is 19 minutes.
(3) The coated material enters a coating machine to shape the coated material, so that the asphalt is more uniform on the graphite surface and is completely coated; the stirring linear speed of the coating machine is 21m/s, and the time is 18 minutes. The temperature of the wrapping machine was 230 ℃.
(4) And heating the shaped coating material to 2800 ℃ at the speed of 6 ℃/min under the protection of nitrogen in a tubular furnace, preserving the heat for 7h for graphitization treatment, and cooling to room temperature to obtain the liquid-phase coating modified graphite cathode material.
Example 6
(1) And (3) obtaining high-temperature liquid asphalt by the solid asphalt at the high temperature of 240 ℃, and filtering the high-temperature liquid asphalt, wherein the mesh number of the filter screen is 160 meshes.
(2) 30 parts of high-temperature liquid asphalt is dripped or flows into 950 parts of silicon fine powder with the grain diameter of 17.8um to be coated, and the mixture is heated and mixed at high speed in a high-speed mixer, the stirring linear speed of the high-speed mixer is 30m/s, the temperature of the high-speed mixer is about 200 ℃, and the temperature of the asphalt is about 240 ℃.
The silicon fine powder was fluidized at a high speed in a high-speed mixer at a stirring line speed of 30m/s for 7 minutes. Adding high-temperature liquid phase asphalt after the silicon fine powder is fluidized at a high speed, stirring while adding, wherein the stirring linear speed is 30m/s, and the stirring time is 16 minutes.
(3) The coated materials enter a coating machine to shape the coated materials, so that the asphalt is more uniform on the surface of the silicon and is completely coated; the stirring linear speed of the coating machine is 28m/s, and the time is 18 minutes. The temperature of the wrapping machine was 220 ℃.
(4) And heating the shaped wrapping material to 1000 ℃ at the speed of 7 ℃/min under the protection of nitrogen in a tubular furnace, preserving the heat for 6h for carbonization, and cooling to room temperature to obtain the liquid-phase coated modified silicon negative electrode material.
Example 7
(1) And (3) obtaining high-temperature liquid asphalt by the solid asphalt at the high temperature of 230 ℃, and filtering the high-temperature liquid asphalt, wherein the mesh number of a filter screen is 140 meshes.
(2) 30 parts of high-temperature liquid asphalt is dripped or flows into a high-speed mixer to be coated on 1000 parts of silicon fine powder with the particle size of 15.8um, the mixture is heated and mixed at high speed in a high-speed mixer, the stirring linear speed of the high-speed mixer is 25m/s, the temperature of the high-speed mixer is about 200 ℃, and the temperature of the asphalt is about 230 ℃.
The silicon fine powder is fluidized at high speed in a high-speed mixer, the stirring linear speed is 25m/s, and the stirring time is 8 minutes. Adding high-temperature liquid phase asphalt after the silicon fine powder is fluidized at a high speed, stirring while adding, wherein the stirring linear speed is 25m/s, and the stirring time is 14 minutes.
(3) The coated materials enter a coating machine to shape the coated materials, so that the asphalt is more uniform on the surface of the silicon and is completely coated; the stirring linear speed of the coating machine is 28m/s, and the time is 15 minutes. The temperature of the wrapping machine was 210 ℃.
(4) And heating the shaped wrapping material to 2000 ℃ at the speed of 8 ℃/min under the protection of nitrogen in a tubular furnace, preserving the heat for 7h for carbonization, and cooling to room temperature to obtain the liquid-phase coated modified silicon negative electrode material.
Example 8
(1) And (3) obtaining high-temperature liquid asphalt by the solid asphalt at the high temperature of 220 ℃, and filtering the high-temperature liquid asphalt, wherein the mesh number of the filter screen is 150 meshes.
(2) And (2) spraying and atomizing 30 parts of high-temperature liquid asphalt, then coating 1050 parts of silica fine powder with the particle size of 13.6um, and carrying out heat preservation, heating and high-speed mixing in a high-speed mixer, wherein the stirring linear speed of the high-speed mixer is 30m/s, the temperature of the high-speed mixer is about 160 ℃, and the temperature of the asphalt is about 220 ℃.
The addition of the fine silica powder was followed by stirring for 7 minutes. After the fine silicon oxide powder is fluidized at a high speed, adding high-temperature liquid phase asphalt, stirring while adding, wherein the stirring linear speed is 30m/s, and the stirring time is 15 minutes.
(3) The coated material enters a coating machine to shape the coated material, so that the asphalt is more uniform on the surface of the silicon oxide and is completely coated; the stirring linear speed of the coating machine is 30m/s, and the time is 14 minutes. The temperature of the wrapping machine was 160 ℃.
(4) And heating the shaped wrapping material to 2800 ℃ at the speed of 5 ℃/min under the protection of nitrogen in a tubular furnace, preserving the heat for 8h for graphitization treatment, and cooling to room temperature to obtain the liquid-phase coated modified silicon monoxide negative electrode material.
Example 9
(1) And (3) obtaining high-temperature liquid asphalt by the solid asphalt at a high temperature of 150 ℃, and filtering the high-temperature liquid asphalt, wherein the mesh number of the filter screen is 140 meshes.
(2) Spraying and atomizing 30 parts of high-temperature liquid asphalt, coating 950 parts of silica fine powder with the particle size of 13.1um, and carrying out heat preservation, heating and high-speed mixing in a high-speed mixer, wherein the stirring linear speed of the high-speed mixer is 20m/s, the temperature of the high-speed mixer is about 100 ℃, and the temperature of the asphalt is about 150 ℃.
The addition of the fine silica powder was followed by stirring for 7 minutes. After the fine silicon oxide powder is fluidized at a high speed, adding high-temperature liquid phase asphalt, stirring while adding, wherein the stirring linear speed is 20m/s, and the stirring time is 12 minutes.
(3) The coated material enters a coating machine to shape the coated material, so that the asphalt is more uniform on the surface of the silicon oxide and is completely coated; the stirring linear speed of the coating machine is 25m/s, and the time is 13 minutes. The temperature of the wrapping machine was 110 ℃.
(4) And heating the shaped wrapping material to 3000 ℃ at the speed of 5 ℃/min under the protection of nitrogen in a tubular furnace, preserving heat for 9h for graphitization treatment, and cooling to room temperature to obtain the liquid-phase coated modified silicon monoxide negative electrode material.
Example 10
(1) And (3) obtaining high-temperature liquid asphalt by the solid asphalt at the high temperature of 100 ℃, and filtering the high-temperature liquid asphalt, wherein the mesh number of a filter screen is 110 meshes.
(2) Spraying and atomizing 30 parts of high-temperature liquid asphalt, coating 980 parts of graphite fine powder with the particle size of 12.2um, and carrying out heat preservation, heating and high-speed mixing in a high-speed mixer, wherein the stirring linear speed of the high-speed mixer is 33m/s, the temperature of the high-speed mixer is about 80 ℃, and the temperature of the asphalt is about 100 ℃.
The graphite fine powder is added and then stirred for 8 minutes. After the graphite fine powder is fluidized at a high speed, adding high-temperature liquid phase asphalt, stirring while adding, wherein the stirring linear speed is 33m/s, and the stirring time is 13 minutes.
(3) The coated materials enter a coating machine, and the coated materials are shaped, so that the asphalt is more uniform on the graphite surface and is completely coated; the stirring linear speed of the coating machine is 28m/s, and the time is 14 minutes. The temperature of the wrapping machine was 100 ℃.
(4) And heating the shaped wrapping material to 3200 ℃ at the speed of 5 ℃/min under the protection of nitrogen in a tubular furnace, preserving the heat for 10h for graphitization treatment, and cooling to room temperature to obtain the liquid-phase coated modified graphite cathode material.
The testing method of the half-cell comprises the steps of uniformly mixing a modified negative electrode material sample, N-methyl pyrrolidone containing 6-7% of polyvinylidene fluoride and 2% of conductive carbon black, coating the mixture on a copper foil, and putting the coated pole piece into a vacuum drying oven at the temperature of 110 ℃ for vacuum drying for 4 hours for later use. The simulated cell assembly was carried out in a nitrogen-filled german braun glove box, with an electrolyte of 1MLiPF6+ EC: DEC: DMC ═ l: 1: 1 (volume ratio), the metal lithium sheet is a counter electrode, the electrochemical performance test is carried out on a battery tester of ArbinBT2000 type U.S. the charging and discharging voltage range is 0.005-1.0V, and the charging and discharging rate is 0.1C. The data are listed in table 1.
Figure BDA0002630393540000091
The test method of the full cell used by the invention comprises the following steps of taking the graphite as a negative electrode and taking lithium cobalt oxide as a positive electrode, wherein lM-LiPF6EC is DMC: EMC 1: 1: a full cell was assembled with 1 (volume ratio) solution as the electrolyte and the rate curves of example 10 at different discharge rates were tested as shown in fig. 1.
The modified cathode material produced by the method has excellent electrochemical performance, the first charge-discharge efficiency is up to more than 93%, the rate performance is good, the capacity is high, and the modified cathode material can be applied to high-rate power batteries of electric automobiles, model airplanes, electric tools and the like.

Claims (8)

1. A preparation method of a solid asphalt liquid phase coated modified negative electrode material is characterized by comprising the following steps:
s1, obtaining high-temperature liquid phase asphalt by the solid asphalt with high softening point at the temperature of 80-300 ℃; filtering the high-temperature liquid-phase asphalt, wherein the mesh number of a filter screen is 100-200 meshes;
s2, mixing 800-1200 parts of negative electrode material fine powder and 10-50 parts of liquid asphalt in parts by weight; firstly, feeding the fine powder of the negative electrode material into a high-speed mixer to be fluidized at a high speed according to the proportion, keeping the temperature of the high-speed mixer at 50-300 ℃, and then adding high-temperature liquid phase asphalt into the high-speed mixer to be coated on the fine powder of the negative electrode material;
s3, feeding the coated material into a coating machine, shaping the coated material, and enabling the asphalt to be more uniform on the surface of the fine powder of the negative electrode material and complete in coating;
and S4, carrying out high-temperature heat treatment on the shaped coating material under the protection of inert gas in a tube furnace at the heating rate of 2-8 ℃/min, preserving the heat for 3-10 h, and cooling to room temperature to obtain the liquid-phase coating modified negative electrode material.
2. The preparation method of the solid asphalt liquid phase coating modified negative electrode material according to claim 1, characterized in that: the cathode material is graphite or silicon monoxide, and the particle size is 12.2-20.2 um.
3. The preparation method of the solid asphalt liquid phase coating modified negative electrode material according to claim 1, characterized in that: fluidizing the fine powder of the negative electrode material at high speed in a high-speed mixer, wherein the stirring linear speed is 10-42 m/s, and the stirring time is 5-20 minutes; and (3) when the high-temperature liquid phase asphalt is added, stirring while adding, wherein the stirring linear speed is 10-42 m/s, and the stirring time is 3-20 minutes.
4. The preparation method of the solid asphalt liquid phase coating modified negative electrode material according to claim 1, characterized in that: the stirring linear speed of the coating machine is 10-42 m/s, and the time is 3-20 minutes.
5. The preparation method of the solid asphalt liquid phase coating modified negative electrode material according to claim 1, characterized in that: the temperature of the wrapping machine is 100-300 ℃.
6. The preparation method of the solid asphalt liquid phase coating modified negative electrode material according to claim 1, characterized in that: the high temperature heat treatment in step S4 is carbonization treatment at 1000 to 2000 ℃ or graphitization treatment at 2000 to 3200 ℃.
7. The preparation method of the solid asphalt liquid phase coating modified negative electrode material according to claim 1, characterized in that: the inert gas in step S4 is nitrogen gas having a purity of 99% or more.
8. The preparation method of the solid asphalt liquid phase coating modified negative electrode material according to claim 2, characterized in that: the graphite fine powder is one or more of spherical natural graphite, spheroidal natural graphite, crystalline flake graphite, artificial graphite, petroleum coke, pitch coke and mesocarbon microbeads.
CN202010809449.8A 2020-08-12 2020-08-12 Preparation method of solid asphalt liquid phase coating modified negative electrode material Pending CN114074939A (en)

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Citations (1)

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CN108832091A (en) * 2018-06-11 2018-11-16 深圳市贝特瑞新能源材料股份有限公司 A kind of long circulating modified graphite based composites, preparation method and the lithium ion battery comprising the material

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN108832091A (en) * 2018-06-11 2018-11-16 深圳市贝特瑞新能源材料股份有限公司 A kind of long circulating modified graphite based composites, preparation method and the lithium ion battery comprising the material

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