CN116053424A

CN116053424A - Granulated asphalt, preparation method and application thereof, and preparation method of lithium ion battery anode material

Info

Publication number: CN116053424A
Application number: CN202111261793.9A
Authority: CN
Inventors: 王永邦; 黄友生; 罗望群; 姚思涵; 罗勤高; 张勤松
Original assignee: China Petroleum and Chemical Corp; Sinopec Asphalt Sales Branch Co
Current assignee: China Petroleum and Chemical Corp; Sinopec Asphalt Sales Branch Co
Priority date: 2021-10-28
Filing date: 2021-10-28
Publication date: 2023-05-02

Abstract

The invention relates to the field of lithium ion battery cathode materials, in particular to granulated asphalt, a preparation method and application thereof, and a preparation method of a lithium ion battery cathode material. The method comprises the following steps: (1) Extracting light components in raw material ethylene tar to obtain heavy distillate; (2) And (3) under the oxygen-containing atmosphere, carrying out pressurized thermal polycondensation on the heavy distillate oil to obtain the granulated asphalt. The invention extracts light components in ethylene tar, can obviously improve the subsequent thermal shrinkage polymerization efficiency, and can obtain the pelleting asphalt with proper softening point and high carbon residue rate by matching with the subsequent pressurized thermal polycondensation.

Description

Granulated asphalt, preparation method and application thereof, and preparation method of lithium ion battery anode material

Technical Field

The invention relates to the field of lithium ion battery cathode materials, in particular to granulated asphalt, a preparation method and application thereof, and a preparation method of a lithium ion battery cathode material.

Background

By the end of 2020, the total ethylene productivity of China exceeds 3120 ten thousand tons, the yield of ethylene tar accounts for about 10-15% of the ethylene yield, the ethylene tar resource amount is rich, and the efficient comprehensive utilization of ethylene tar is a long-standing problem in the chemical industry. At present, ethylene tar is mainly used as fuel, carbon black raw materials and the like, and has low utilization value. Ethylene tar is a high-temperature condensation product of ethylene raw materials, mainly aromatic compounds, has high hydrocarbon ratio, low sulfur content and ash content, and is a high-quality carbonaceous precursor. Ethylene tar is developed as a raw material for producing the cathode material, so that the development requirement of new energy industry is met, and the utilization value of chemical byproducts is improved, and the cathode material has important significance.

In the preparation process of the lithium ion battery cathode material, a granulating process is generally used. The general method of granulation is that the anode material precursor and asphalt are uniformly mixed and stirred at a certain temperature, so that small-particle-size coke powder single particles are bonded by asphalt to form secondary particles with target particle size. The anode material formed by the granulating process can improve the multiplying power performance and the capacitance of the battery and comprehensively improve the electrochemical performance of the anode material.

CN109233305a discloses a method for preparing coated asphalt of carbon negative electrode material by using coal tar soft asphalt, wherein the coated asphalt with softening point more than 100 ℃ is obtained by adding coumarone resin. However, coal-based asphalt generally has a high QI (quinoline insoluble) content and releases much asphalt smoke at high temperatures.

Disclosure of Invention

The invention aims to solve the problems of high QI content and complex preparation method of the pelleting asphalt in the prior art, and provides the pelleting asphalt, the preparation method and application thereof and the preparation method of the lithium ion battery anode material.

In order to achieve the above object, a first aspect of the present invention provides a method for producing a granulated asphalt, the method comprising:

(1) Extracting light components in raw material ethylene tar to obtain heavy distillate;

(2) And (3) under the oxygen-containing atmosphere, carrying out pressurized thermal polycondensation on the heavy distillate oil to obtain the granulated asphalt.

The second aspect of the invention provides the granulated asphalt prepared by the method.

The third aspect of the invention provides an application of the granulated asphalt prepared by the method in preparing lithium ion battery anode materials.

The fourth aspect of the invention provides a preparation method of a lithium ion battery anode material, which comprises the steps of mixing a crushed carbonaceous raw material with granulated asphalt prepared by the method, performing high-temperature treatment, graphitizing and cooling to obtain the anode material; preferably, the method comprises the steps of,

the conditions of the high temperature treatment include:

under the protection of inert gas, the temperature is 700-1100 ℃; and/or

The graphitization conditions include: 2200-3000 ℃; and/or

The D50 of the crushed carbonaceous raw material is 5-20 mu m;

more preferably, the inert gas is nitrogen;

the carbonaceous raw material is selected from one or more of needle coke, petroleum coke and natural graphite;

the dosage mass ratio of the carbonaceous raw material to the granulated asphalt is 0.8:9.2-1.2:8.8.

Through the technical scheme, the invention has the following advantages:

according to the invention, the ethylene tar is extracted, for example, the light component is extracted by adopting reduced pressure distillation, so that the subsequent thermal polycondensation efficiency can be remarkably improved, and the subsequent pressurized thermal polycondensation is matched, so that the granulated asphalt with proper softening point and high carbon residue rate can be obtained.

Detailed Description

The following describes specific embodiments of the present invention in detail. It should be understood that the detailed description and specific examples, while indicating and illustrating the invention, are not intended to limit the invention.

The invention provides a preparation method of granulated asphalt, which comprises the following steps:

The invention extracts light components in ethylene tar, can obviously improve the subsequent thermal shrinkage polymerization efficiency, and can obtain the pelleting asphalt with proper softening point and high carbon residue rate by matching with the subsequent pressurized thermal polycondensation.

In the present invention, the starting ethylene tar may be a conventional choice in the art, and according to a preferred embodiment of the present invention, the ethylene tar has a C/H mass ratio of > 1.05, the content of N element and/or S element, based on the total mass of the ethylene tar<0.1 percent, ash content less than or equal to 0.1 percent, density of 1.01 to 1.10g/cm ³ Viscosity of 45-100mm ² The flash point is more than 70 ℃.

In the present invention, as long as the object of the present invention can be attained, the means for extracting the light component from the raw ethylene tar may be a conventional choice in the art, and according to a preferred embodiment of the present invention, the means for extracting the light component from the raw ethylene tar includes a reduced pressure distillation treatment under conditions including: the light component is distilled at 190-230 deg.C, preferably 200-220 deg.C.

According to a preferred embodiment of the present invention, the conditions of the reduced pressure distillation treatment include: the vacuum degree is 80-110kPa, preferably 90-100kPa.

By adopting the preferable scheme, the light components in the raw material ethylene tar can be further reduced, and the subsequent thermal polycondensation efficiency is improved.

In the present invention, the manner of the pressure thermal polycondensation is not particularly required, and according to a preferred embodiment of the present invention, the pressure thermal polycondensation includes:

firstly, performing thermal polycondensation under the conditions of a first temperature and a first pressure, and then performing thermal polycondensation under the conditions of a second temperature and a second pressure; preferably, the method comprises the steps of,

the second pressure is 0.03-0.10MPa higher than the first pressure; the second temperature is the same as the first temperature.

By adopting the preferable scheme, the polymerization of the heavy distillate oil can be promoted, the reaction intensity can be controlled, and the generation of QI components can be avoided.

In the present invention, the conditions of the pressure thermal polycondensation are not particularly required as long as the object of the present invention can be attained, and according to a preferred embodiment of the present invention, the conditions of the pressure thermal polycondensation include:

the first temperature is 250-350 ℃, and the first pressure is 0.08-0.12MPa, and the thermal polycondensation is carried out for 3-15h, preferably 6-10 h.

The second temperature is 250-350 ℃, and the second pressure is 0.15-0.3MPa, and the thermal polycondensation is carried out for 1-5h, preferably 2-4 h.

According to a preferred embodiment of the invention, the first temperature is 310-340 ℃, the second temperature is 310-340 ℃, and the second pressure is 0.15-0.2MPa.

By adopting the preferable scheme, the reaction depth can be increased, the reaction time can be shortened, the reaction yield can be improved, and the comprehensive performance of the granulated asphalt can be improved.

In the present invention, the concentration of the oxygen-containing gas in the oxygen-containing atmosphere is not particularly limited as long as the object of the present invention can be achieved, and according to a preferred embodiment of the present invention, the concentration of the oxygen-containing gas in the oxygen-containing atmosphere is not less than 15% by volume.

According to the invention, the oxygen-containing gas is at least one of air, oxygen-enriched or pure oxygen.

In the present invention, the gas velocity of the oxygen-containing gas depends on the oxygen content of the oxygen-containing gas, and according to a preferred embodiment of the present invention, the gas velocity of the oxygen-containing gas is 0.2 to 1.0L/min, preferably 0.5 to 0.8L/min. By employing the foregoing preferred embodiment, the reaction rate can be controlled to further enhance the production of toluene-insoluble quinoline-soluble (TI-QS) components of the pelletized asphalt.

The invention provides the granulated asphalt prepared by the method.

The carbon residue rate of the granulated asphalt at 850 ℃ is more than 30%, the softening point is 130-200 ℃, and the content of quinoline insoluble matters in the granulated asphalt is less than 0.50% and the content of toluene insoluble matters in the granulated asphalt is more than 25% based on the total mass of the granulated asphalt, so that the electrochemical performance of the anode material can be improved, the granulated asphalt is particularly suitable for low-temperature granulation of the anode material, and the utilization value of ethylene tar can be remarkably improved.

The invention provides an application of the granulated asphalt prepared by the method in preparing lithium ion battery anode materials.

The pelleting asphalt is applied to preparing the anode material of the lithium ion battery, can improve the electrochemical performance of the anode material, is beneficial to improving the comprehensive performance of the lithium ion battery, and improves the utilization value of ethylene tar.

The invention provides a preparation method of a lithium ion battery anode material, which comprises the steps of crushing a carbonaceous raw material, mixing the crushed carbonaceous raw material with granulated asphalt prepared by the method, carrying out high-temperature treatment, graphitizing and cooling to obtain the anode material.

According to a preferred embodiment of the present invention, the conditions of the high temperature treatment include: under the protection of inert gas, the temperature is 800-1100 ℃.

According to a preferred embodiment of the present invention, the graphitization conditions include: 2500-3000 deg.c.

According to a preferred embodiment of the invention, the D50 of the crushed carbonaceous feedstock is between 5 and 20. Mu.m.

According to a preferred embodiment of the invention, the inert gas is nitrogen.

According to a preferred embodiment of the present invention, the carbonaceous feedstock is selected from one or more of needle coke, petroleum coke and natural graphite.

According to a preferred embodiment of the invention, the ratio of the carbonaceous feedstock to the granulated asphalt is in the range of 0.8:9.2 to 1.2:8.8 by mass.

The lithium ion battery cathode material prepared by the method has obviously improved comprehensive performance.

The technical scheme of the invention is further described by examples, but the protection scope of the invention is not limited by the examples. In the invention, the related data calculation method is as follows:

the softening point test is carried out by adopting a DMA Q800 type dynamic mechanical thermal analyzer in the United states;

analyzing the raw material composition by adopting a Soxhlet extraction method, putting an asphalt sample into a glass fiber filter paper tube, and sequentially extracting according to the order of toluene and quinoline, wherein the obtained components are marked as toluene-soluble (TS), toluene-insoluble quinoline-soluble (TI-QS) and quinoline-insoluble (QI);

yield = coated bitumen weight/ethylene tar weight x 100%;

first charge and discharge efficiency= (first charge capacity/first discharge capacity) ×100%.

Example 1

Ethylene tar from a refinery was used as a feedstock, the specific properties of which are shown in Table 1. The ethylene tar is distilled under reduced pressure to extract light components, the distillation temperature is controlled to be 210 ℃, the vacuum degree is controlled to be 90kPa, the residual heavy distillate oil enters a reactor, the temperature of the reactor is controlled to be 330 ℃, the pressure is controlled to be 0.1MPa, air is introduced, the air speed is controlled to be 0.7L/min, the temperature is unchanged after the constant-temperature reaction is carried out for 8 hours, and the pressure in the reactor is controlled to be 0.2MPa by adopting variable pressure, so that the duration is 3 hours. The properties of the finally obtained granulated asphalt are shown in Table 2.

TABLE 1 basic Properties of ethylene Tar

Project	Properties of (C)
		Density (20 ℃ C.)/g.cm ^-3	1.045
Viscosity (40 ℃ C.)/mm ² ·s ^-1	49
		Flash point (open)/DEGC	89
Ash/%	0.01
		S/％	0.10
N/％	0.07

Example 2

By adopting the same device and raw materials as in the example 1, extracting light components from ethylene tar through reduced pressure distillation, controlling the distillation temperature to 230 ℃, controlling the vacuum degree to 110kPa, feeding the residual heavy distillate into a reactor, controlling the temperature of the reactor to 350 ℃, controlling the pressure to 0.1MPa, introducing air, controlling the air speed to 1.0L/min, and after reacting at constant temperature for 8 hours, controlling the pressure in the reactor to 0.2MPa for 3 hours by adopting variable pressure control. The properties of the finally obtained granulated asphalt are shown in Table 2.

Example 3

By adopting the same device and raw materials as in the example 1, extracting light components from ethylene tar through reduced pressure distillation, controlling the distillation temperature to 190 ℃, controlling the vacuum degree to 80kPa, feeding the residual heavy distillate into a reactor, controlling the temperature of the reactor to 250 ℃, controlling the pressure to 0.1MPa, introducing air, controlling the air speed to 0.5L/min, and after reacting at constant temperature for 8 hours, controlling the temperature unchanged, wherein the pressure in the reactor is controlled to be 0.2MPa by adopting variable pressure, and the duration is 3 hours. The properties of the finally obtained granulated asphalt are shown in Table 2.

Example 4

By adopting the same device and raw materials as in the example 1, extracting light components from ethylene tar through reduced pressure distillation, controlling the distillation temperature to 210 ℃, controlling the vacuum degree to 90kPa, feeding the residual heavy distillate into a reactor, controlling the temperature of the reactor to 250 ℃, controlling the pressure to 0.1MPa, introducing air, controlling the air speed to 0.5L/min, and after the constant temperature reaction for 8 hours, controlling the temperature unchanged, wherein the pressure in the reactor is controlled to be 0.15MPa by adopting variable pressure, and the duration is 3 hours. The properties of the finally obtained granulated asphalt are shown in Table 2.

Example 5

By adopting the same device and raw materials as in the example 1, extracting light components from ethylene tar through reduced pressure distillation, controlling the distillation temperature to 220 ℃, controlling the vacuum degree to 100kPa, feeding the residual heavy distillate into a reactor, controlling the temperature of the reactor to 300 ℃, controlling the pressure to 0.1MPa, introducing air, controlling the air speed to 0.5L/min, and after the constant temperature reaction for 12 hours, controlling the temperature unchanged, wherein the pressure in the reactor is controlled to be 0.2MPa by adopting variable pressure, and the duration is 3 hours. The properties of the finally obtained granulated asphalt are shown in Table 2.

Example 6

By adopting the same device and raw materials as in the example 1, extracting light components from ethylene tar through reduced pressure distillation, controlling the distillation temperature to 250 ℃, controlling the vacuum degree to 150kPa, feeding the residual heavy distillate into a reactor, controlling the temperature of the reactor to 360 ℃, controlling the pressure to 0.1MPa, introducing air, controlling the air speed to 1.0L/min, and after the constant temperature reaction for 8 hours, controlling the temperature unchanged, wherein the pressure in the reactor is controlled to be 0.2MPa by adopting variable pressure, and the duration is 3 hours. The properties of the finally obtained granulated asphalt are shown in Table 2.

Example 7

By adopting the same device and raw materials as in the example 1, extracting light components from ethylene tar through reduced pressure distillation, controlling the distillation temperature to 210 ℃, controlling the vacuum degree to 90kPa, feeding the residual heavy distillate into a reactor, controlling the temperature of the reactor to 330 ℃, controlling the pressure to 0.1MPa, introducing air, controlling the air speed to 0.7L/min, and after reacting at constant temperature for 8 hours, controlling the temperature unchanged, wherein the pressure in the reactor is controlled to be 0.3MPa by adopting variable pressure, and the duration is 3 hours. The properties of the finally obtained granulated asphalt are shown in Table 2.

Comparative example 1

The same device and raw materials as in example 1 are adopted, the ethylene tar is not distilled under reduced pressure to extract light components, the whole fraction enters a reactor, the temperature of the reactor is controlled to be 330 ℃, the pressure is controlled to be 0.1MPa, air is introduced, the air speed is controlled to be 0.7L/min, the temperature is unchanged after the constant-temperature reaction is carried out for 8 hours, and the pressure in the reactor is controlled to be 0.2MPa for 3 hours by adopting variable pressure control. The properties of the finally obtained granulated asphalt are shown in Table 2.

Comparative example 2

By adopting the same device and raw materials as in the example 1, the ethylene tar is distilled under reduced pressure to extract light components, the distillation temperature is controlled to be 210 ℃, the vacuum degree is controlled to be 90kPa, the residual heavy distillate oil enters a reactor, the temperature of the reactor is controlled to be 330 ℃, the pressure is controlled to be 0.1MPa, air is introduced, the air speed is controlled to be 0.7L/min, and the constant temperature reaction is carried out for 11 hours. The properties of the finally obtained granulated asphalt are shown in Table 2.

Table 2 basic properties of asphalt

Sequence number	Softening point/. Degree.C	TI/％	QI/％	Residual carbon/%	Yield/%
						Example 1	175	32	0.29	46	50.3
Example 2	196	35	0.31	49	42.4
						Example 3	136	26	0.05	33	60.5
Example 4	146	28	0.08	36	58.7
						Example 5	182	34	0.28	46	48.1
Example 6	198	43	0.46	56	34.1
						Example 7	180	34	0.50	47	47.6
Comparative example 1	121	22	0.05	23	63.9
						Comparative example 2	126	23	0.06	24	63.4

As can be seen from the comparison of the data in Table 2, the granulated asphalt obtained in the examples has a softening point of 130-200 ℃ and a high carbon residue, and the granulated asphalt has a high TI content and a low QI content, and is particularly suitable for low-temperature granulation of cathode materials.

Preparation of a negative electrode material:

asphalt prepared in examples 1-7 and comparative examples 1-2 is crushed and ground, and then is uniformly mixed with the same carbonaceous raw material (needle coke with D50 of 10 microns obtained by crushing) according to the mass ratio of 1:9, and is subjected to high-temperature treatment under the protection of nitrogen at the temperature of 800-1100 ℃. After cooling, scattering the materials, transferring the materials into a graphitizing furnace for graphitizing, cooling the materials at 2500-3000 ℃ to obtain the cathode material. Carrying out buckling performance test on a negative electrode material, uniformly dispersing the obtained negative electrode material, a binder PVDF and conductive carbon black Super C in N-methyl pyrrolidone according to the mass ratio of 92:5:3, fully stirring to form homogenate, uniformly coating the homogenate on a carbon-coated copper foil by adopting an automatic coating machine, drying, stamping into an electrode plate with the diameter of 12mm, finally transferring to a vacuum oven with the temperature of 50 ℃ for drying for 12 hours for standby, wherein the surface loading of the electrode plate is about 2mg/cm ² . The pole piece is assembled into a button half battery of CR2016, the counter electrode is a metal lithium piece, the diaphragm is Celgard 2400, and the electrolyte is 1mol/L LiPF ₆ (EC: DMC: emc=1:1:1, v/v). Constant current charge and discharge experiments were performed at a current density of 0.2C (1c=372 mAh/g), with a test voltage range of 0.001 to 2.0V. The test results are shown in Table 3.

Blank control group:

the same carbonaceous material was prepared as described above for the negative electrode material, but without addition of granulated pitch, as a blank. The test results are shown in Table 3.

TABLE 3 electrochemical Performance test results

As can be seen from the comparison of the data in Table 3, the pelleting asphalt obtained according to the scheme of the invention can be used for preparing the anode material of the lithium ion battery, so that the utilization value of ethylene tar is greatly improved, and further, the pelleting asphalt obtained according to the embodiment of the preferred scheme of the invention can be used for remarkably improving the electrochemical performance of the anode material, and is beneficial to improving the comprehensive performance of the lithium ion battery.

The preferred embodiments of the present invention have been described in detail above, but the present invention is not limited thereto. The technical solution of the invention can be subjected to a plurality of simple variants within the scope of the technical idea of the invention. Including the various specific features being combined in any suitable manner. The various possible combinations of the invention are not described in detail in order to avoid unnecessary repetition. Such simple variations and combinations are likewise to be regarded as being within the scope of the present disclosure.

Claims

1. A method for preparing a granulated asphalt, the method comprising:

2. The method of claim 1, wherein the means for withdrawing light components from the raw ethylene tar comprises reduced pressure distillation, the conditions of the reduced pressure distillation comprising:

the light component distillation temperature is 190-230 ℃, preferably 200-220 ℃; and/or

The vacuum degree is 80-110kPa, preferably 90-100kPa.

3. The process of claim 1 or 2, wherein the pressurized thermal polycondensation comprises:

4. A process according to any one of claims 1-3, wherein the conditions of the pressurized thermal polycondensation comprise:

heat-shrinking at the first temperature of 250-350 ℃ and the first pressure of 0.08-0.12MPa for 3-15h, preferably 6-10 h; and/or

Thermal polycondensation is carried out for 1 to 5 hours, preferably 2 to 4 hours, at a second temperature of 250 to 350 ℃ and a second pressure of 0.15 to 0.3 MPa; preferably, the method comprises the steps of,

the first temperature is 310-340 ℃, the second temperature is 310-340 ℃, and the second pressure is 0.15-0.2MPa.

5. The method of any one of claims 1-4, wherein the concentration of oxygen-containing gas within the oxygen-containing atmosphere is greater than or equal to 15 volume percent.

6. The method according to claim 5, wherein the oxygen-containing gas has a gas velocity of 0.2 to 1.0L/min, preferably 0.5 to 0.8L/min.

7. A granulated asphalt produced by the method of any of claims 1-6.

8. The granulated asphalt according to claim 7, wherein the granulated asphalt has a char yield of > 30% at 850 ℃, a softening point of 130 to 200 ℃, and the granulated asphalt has a quinoline insoluble content of less than 0.50% and a toluene insoluble content of > 25% based on the total mass of the granulated asphalt.

9. Use of the granulated asphalt prepared by the method of any of claims 1-6 in the preparation of a lithium ion battery negative electrode material.

10. A method for preparing a negative electrode material of a lithium ion battery, which is characterized in that the method comprises the steps of crushing a carbonaceous raw material, mixing the crushed carbonaceous raw material with the granulated asphalt prepared by the method of any one of claims 1 to 6, carrying out high-temperature treatment, graphitizing and cooling to obtain the negative electrode material; preferably, the method comprises the steps of,

the conditions of the high temperature treatment include: under the protection of inert gas, the temperature is 700-1100 ℃; and/or

The graphitization conditions include: 2200-3000 ℃; and/or

The D50 of the crushed carbonaceous raw material is 5-20 mu m;

more preferably, the inert gas is nitrogen;