CN113816370A - Coal-based graphite composite material, preparation method thereof and battery using same - Google Patents
Coal-based graphite composite material, preparation method thereof and battery using same Download PDFInfo
- Publication number
- CN113816370A CN113816370A CN202111393938.0A CN202111393938A CN113816370A CN 113816370 A CN113816370 A CN 113816370A CN 202111393938 A CN202111393938 A CN 202111393938A CN 113816370 A CN113816370 A CN 113816370A
- Authority
- CN
- China
- Prior art keywords
- coal
- composite material
- coke powder
- graphite composite
- graphitization
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Images
Classifications
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B32/00—Carbon; Compounds thereof
- C01B32/20—Graphite
- C01B32/205—Preparation
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B32/00—Carbon; Compounds thereof
- C01B32/05—Preparation or purification of carbon not covered by groups C01B32/15, C01B32/20, C01B32/25, C01B32/30
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B32/00—Carbon; Compounds thereof
- C01B32/20—Graphite
- C01B32/21—After-treatment
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M10/00—Secondary cells; Manufacture thereof
- H01M10/05—Accumulators with non-aqueous electrolyte
- H01M10/052—Li-accumulators
- H01M10/0525—Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M4/36—Selection of substances as active materials, active masses, active liquids
- H01M4/58—Selection of substances as active materials, active masses, active liquids of inorganic compounds other than oxides or hydroxides, e.g. sulfides, selenides, tellurides, halogenides or LiCoFy; of polyanionic structures, e.g. phosphates, silicates or borates
- H01M4/583—Carbonaceous material, e.g. graphite-intercalation compounds or CFx
- H01M4/587—Carbonaceous material, e.g. graphite-intercalation compounds or CFx for inserting or intercalating light metals
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M2004/021—Physical characteristics, e.g. porosity, surface area
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M2004/026—Electrodes composed of, or comprising, active material characterised by the polarity
- H01M2004/027—Negative electrodes
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
- Y02E60/10—Energy storage using batteries
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Inorganic Chemistry (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Geology (AREA)
- General Life Sciences & Earth Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Electrochemistry (AREA)
- General Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Manufacturing & Machinery (AREA)
- Carbon And Carbon Compounds (AREA)
Abstract
The invention relates to a negative electrode material of a lithium ion battery, in particular to a coal-based graphite composite material, a preparation method and a battery using the material, wherein the preparation method of the coal-based graphite composite material comprises the following steps: directly carrying out graphitization treatment on the coal-based coke powder which is not purified, and adding coal pitch to carry out carbonization treatment before and/or after the graphitization treatment; the ash content of the coal-based coke powder is 5-15wt%, and the ash content contains Si, Al, Fe, Ca, K, Na, Mg and Ti. The method is mainly improved aiming at the graphitization process of the inferior coal-based coke powder with the ash content of more than 5wt%, the purification process is omitted, meanwhile, no additional catalyst is needed to be added, the ash content of the coal-based coke powder is used as the catalyst, the preparation process of the coal-based graphite composite material is simplified, and the coal-based graphite composite material is used for the lithium ion battery, so that the first discharge specific capacity and the first coulombic efficiency of the battery can be improved.
Description
Technical Field
The invention relates to a negative electrode material of a lithium ion battery, in particular to a coal-based graphite composite material, a preparation method and a battery using the material.
Background
The rate capability of the negative electrode material produced by using the oil coke as a precursor is not good as that of the coal coke precursor, and along with the wide application of the lithium ion battery, the lithium ion battery with various functional attributes is produced by the way, and the lithium ion battery comprises a high energy density type, a power type, a rate type and the like.
At present, in the production process for producing coal-based graphite by using coal-based precursors such as coal and coal coke (metallurgical coke and foundry coke) with ash content of more than 5wt%, the excessive ash in the precursors needs to be removed by adopting purification procedures such as a hydrofluoric acid method and an alkaline method, and the ash content of the materials is ensured to be less than 1wt% before the materials are graphitized into a furnace. The process for producing the coal-based graphite refers to the process for producing the artificial graphite by using petroleum coke/needle coke and other precursors, and at present, the process for producing the artificial graphite comprises the following steps: sequentially grinding, granulating, graphitizing and screening petroleum coke/needle coke, and then demagnetizing and packaging; the production process of the coal-based graphite comprises the following steps: the coal/coke is sequentially subjected to grinding, purification, granulation, graphitization and screening, and then demagnetized and packaged. By comparing the two process flows, the coal-based graphite produced by using coal/coal coke has more purification processes than the artificial graphite produced by using petroleum coke/needle coke, and the purification processes prolong the production flow of the whole coal-based graphite and improve the production cost.
In order to further simplify the purification process, in the prior art, a catalytic graphitization process is adopted to improve the graphitization degree and further reduce ash content in coal and coke, for example, boron is used as a catalyst, but the specific surface area of the prepared product is increased, and the subsequent preparation of a negative electrode material is not facilitated. In addition, chlorine is introduced in the process of graphitizing the precursor to achieve the purposes of purification and graphitization, but the chlorine has great potential safety hazard in the use process, has great damage to equipment and is not beneficial to large-scale industrial production.
Disclosure of Invention
The invention aims to solve the problems that the purification process is complex in the coal-based precursor graphitization production process with the ash content of more than 5wt% in the prior art, and the existing purification process cannot simultaneously consider the graphitization effect and the production cost, and provides a coal-based graphite composite material, a preparation method and a battery using the material.
In order to achieve the above object, the present invention provides a method for preparing a coal-based graphite composite material, wherein unrefined coal-based coke powder is graphitized, and coal pitch is added before and/or after the graphitization for carbonization;
the ash content of the unrefined coal-based coke powder is 5-15wt%, and SiO is calculated by the oxide of each element by taking the total ash content as the reference235-55wt% of Al2O312-35wt% of Fe2O33-45wt% of CaO, 1-5wt% of CaO, K2O content of 0.1-5wt%, Na20.1-3wt% of O, 0.1-5wt% of MgO, and TiO2The content is 0.4-5 wt%.
The invention also provides the coal-based graphite composite material prepared by the preparation method.
The invention also provides a battery cathode which comprises the coal-based graphite composite material.
The invention also provides a lithium ion battery which comprises the battery cathode.
The invention creatively provides a method for improving the graphitization degree of a coal-based graphite composite material by using the ash content of coal-based coke powder as a catalyst while simplifying the process aiming at the poor-quality coal-based coke powder graphitization production process with the ash content of more than 5wt% without a purification process and additionally adding the catalyst, and the coal-based graphite composite material is used as a lithium ion battery cathode, wherein the compaction density of the battery cathode is more than or equal to 1.42g/cm3Preferably ≥ 1.45g/cm3. The negative electrode of the battery is assembled to form the lithium ion battery, the first discharge specific capacity of the battery is more than or equal to 335mAh/g, and the first coulombic efficiency is more than or equal to 90.2%, preferably more than or equal to 91.2%.
Additional features and advantages of the invention will be set forth in the detailed description which follows.
Drawings
FIG. 1 is an SEM topography of the coal-based graphite composite material A2 prepared in example 2.
Detailed Description
The endpoints of the ranges and any values disclosed herein are not limited to the precise range or value, and such ranges or values should be understood to encompass values close to those ranges or values. For ranges of values, between the endpoints of each of the ranges and the individual points, and between the individual points may be combined with each other to give one or more new ranges of values, and these ranges of values should be considered as specifically disclosed herein.
The invention provides a preparation method of a coal-based graphite composite material, wherein unpurified coal-based coke powder is subjected to graphitization treatment, and coal pitch is added before and/or after the graphitization treatment for carbonization treatment;
the ash content of the unrefined coal-based coke powder is 5-15wt%, and SiO is calculated by the oxide of each element by taking the total ash content as the reference235-55wt% of Al2O312-35wt% of Fe2O33-45wt% of CaO, 1-5wt% of CaO, K2O content of 0.1-5wt%, Na20.1-3wt% of O, 0.1-5wt% of MgO, and TiO2The content is 0.4-5 wt%.
At present, the process of carrying out direct graphitization treatment on coal-based coke powder is only suitable for coal-based coke powder with ash content of less than 1wt%, and poor quality coal-based coke powder with ash content of more than 5wt% can only be subjected to graphitization treatment after purification treatment to ensure that the ash content is less than 1 wt%. The method is characterized in that unrefined coal-based coke powder with ash content of 5-15wt% is used as a raw material to be directly graphitized, and the inventor creatively discovers that ash content in the unrefined coal-based coke powder reacts with surrounding amorphous carbon in the graphitizing process to form carbide, the carbide is decomposed along with the rise of temperature, ash elements are gasified, the left carbon elements are recombined in the graphitizing process to form covalent bonds, and finally a 'perfect graphite' structure is formed. The inventor of the application finds that when the ash content of the coal-based coke powder is within the content range, the specific surface area of the coal-based graphite composite material obtained by subsequent treatment is proper, and the coal-based graphite composite material is prepared into a battery cathode, so that the compaction density of the battery cathode can be improved; in addition, the process also comprises a coal pitch carbonization treatment step, wherein the coal pitch carbonization treatment step is combined with a direct graphitization treatment step of coal-based coke powder, so that the specific surface area of the coal-based graphite composite material is effectively reduced, and an amorphous carbon layer is formed on the surface of graphite particles.
According to the present invention, the unrefined coal-based coke powder means that the coal-based coke powder is not subjected to any ash removal step before the graphitization treatment, and the ash removal purification methods conventionally used in the prior art include hydrofluoric acid purification, alkaline purification, purification with addition of a catalyst (e.g., boron), and the like.
According to the present invention, in order to further improve the first coulombic efficiency of the prepared coal-based graphite composite material for a lithium ion battery, it is preferable to add coal pitch to perform carbonization treatment after the graphitization treatment.
According to the invention, the unrefined coal-based coke powder used is low grade coke, preferably at least one of metallurgical coke, foundry coke and carbonized main coke coal, more preferably metallurgical coke and/or foundry coke.
Preferably, the ash content of the unrefined coal-based coke powder is 10.5 to 15wt%, for example the ash content of the unrefined coal-based coke powder is 10.7 to 13.9 wt%.
Further preferably, as ashSiO in total amount of oxides of the respective elements245-55wt% of Al2O328-35 wt.% of Fe2O33-10wt% of CaO, 2-5wt% of CaO, K2O content of 0.5-5wt%, Na20.5-3wt% of O, 0.5-5wt% of MgO, and TiO2The content is 1-5 wt%; more preferably, SiO is calculated by the oxide of each element based on the total ash content246-50wt% of Al2O328-32wt% of Fe2O34-7wt%, CaO 2-4.5wt%, K2O content of 0.5-4wt%, Na20.5-2wt% of O, 0.5-3wt% of MgO, and TiO2The content is 1-3 wt%.
According to the invention, through research on unpurified coal-based coke powder, the inventors of the present application found that when ash content of the coal-based coke powder is in the above range, the graphitization degree of the coal-based coke powder is higher, and a battery cathode prepared from the coal-based coke powder has higher compaction density, and when the coal-based coke powder is used for a lithium ion battery, the first discharge specific capacity and the first coulombic efficiency of the battery can be effectively improved.
Preferably, the particle size distribution of the unrefined coal-based coke powder is: d10=1-5 μm, D50=8-18 μm, D90=20-50 μm, preferably, the particle size distribution of the unrefined coal-based coke powder is: d10=2-5 μm, D50=12-18 μm, D90=20-30 μm, for example, the particle size distribution of the unrefined coal-based coke powder is: d10=2-4.718 μm, D50=12.4-15 μm, D90=22.64-30 μm. According to the present invention, the coal-based coke powder used may be optionally subjected to crushing and shaping treatment as long as it can achieve a particle size distribution of the raw material used within the above range. Preferably, the coal-based coke powder is crushed and then subjected to shaping treatment. Through crushing and shaping, the particle roundness of the coal-based coke powder is good, the tap density is improved, and the processability of the material during battery pulping in the later stage is ensured.
Preferably, the sulphur content of the ash is in the range of from 4 to 10wt%, more preferably 4 to 8wt%, for example 4 to 6.19wt%, calculated as elemental sulphur, based on the total amount of the ash.
Preferably, the coal tar pitch is added in an amount of 1 to 10wt%, preferably 2 to 8wt%, more preferably 4 to 7wt% based on the total amount of the treated material;
preferably, the softening point of the coal tar pitch is 95-180 ℃;
more preferably, the coal tar pitch particle size is < 10 μm.
According to the invention, if coal tar pitch is added for carbonization treatment before graphitization treatment, mainly coal-based coke powder and coal tar pitch are mixed, and the mixture of the coal-based coke powder and the coal tar pitch is a treatment material; if coal pitch is added for carbonization after graphitization, the coal-based coke powder is mixed with the coal pitch, and the mixture of the coal-based coke powder subjected to graphitization and the coal pitch is used as a treatment material. The mixing step is not particularly limited, and any mixing device known in the art may be used as long as sufficient mixing of the two components can be achieved, and it is preferable to use a VC mixer for a mixing time of 5 to 30 min. Through the mixing, the holes on the surface of the coal-based coke powder can be filled by utilizing the wettability and the rheological property of the asphalt, the specific surface area of the material is reduced, and the processability of the coal-based graphite composite material is improved.
Preferably, the carbonization conditions include: inert atmosphere, preferably N2The atmosphere is 400-1300 ℃, preferably 1150-1300 ℃ and the time is 20-45h, preferably 28-43 h; the temperature of the carbonization treatment in the invention refers to the temperature of heat preservation treatment required in the carbonization process, and the time is the time of the whole carbonization step. More preferably, the temperature raising process of the carbonization treatment adopts a stage temperature raising method, which comprises the following steps: heating from room temperature to 150-200 ℃ at a rate of 0.5-0.8 ℃/min, heating to 650-800 ℃ at a rate of 1-1.5 ℃/min, heating to 1150-1300 ℃ at a rate of 1.72-2 ℃/min, and carrying out heat preservation treatment for 600min, and then reducing to room temperature within the time of 600-700 min. Preferably, the volatile matter of the carbonized material is 0.01 to 2.5 wt%. According to the present invention, the carbonization step after the addition of coal pitch is performed under the above conditions, and the effective coating of coal pitch can be achieved.
Preferably, the conditions of the graphitization treatment include: the temperature is 2800-3200 ℃, preferably 2950-3100 ℃, and the time is 30-55h, preferably 42-50 h.
According to the invention, the catalytic action of ash in the coal-based coke powder can be fully exerted according to the graphitization treatment conditions, so that the graphitization conversion of the coal-based coke powder is realized.
Preferably, the graphitization degree of the coal-based graphite composite material is more than or equal to 91.5 percent; preferably, the particle size distribution of the coal-based graphite composite material is: d50=8-20 μm; more preferred are D10=2-7.5 μm, D50=8-20 μm, D90=15-40 μm, e.g. D10=3.25-7.02 μm, D50=8.36-18.58 μm, D90=18.26-36.14 μm.
According to the invention, after the non-purified coal-based coke powder is subjected to graphitization treatment, the particle size of the obtained coal-based graphite composite material is improved compared with that of the coal-based coke powder, which is mainly the effect brought by secondary particle agglomeration in the direct graphitization process of the non-purified coal-based coke powder.
According to the present invention, the coal-based graphite composite material subjected to graphitization and carbonization or carbonization and graphitization treatment further preferably comprises demagnetization, sieving and mixing treatment. The demagnetizing is mainly used for removing magnetic separation materials in products, and the screening is mainly used for removing caking in the materials, so that the products are all powder. The consistency of the final graphitization degree of the material is ensured by mixing.
The invention also provides the coal-based graphite composite material prepared by the preparation method.
The invention also provides a battery cathode which comprises the coal-based graphite composite material.
The invention also provides a lithium ion battery which comprises the battery cathode.
According to the invention, the graphitization degree of the coal-based graphite composite material prepared by the preparation method is more than or equal to 91.5 percent, and the specific surface area is less than or equal to 2.75m2A/g, preferably 2.45m or less2(g), tap density is more than or equal to 0.8g/cm3Preferably not less than 0.87g/cm3. The coal-based graphite composite material is used as a lithium ion battery cathode, and the compaction density of the battery cathode is more than or equal to 1.42g/cm3Preferably ≥ 1.45g/cm3. The negative electrode of the battery is assembled to form the lithium ion battery, the first discharge specific capacity of the battery is more than or equal to 335mAh/g, and the first coulombic efficiency is more than or equal to 90.2%, preferably more than or equal to 91.2%.
The present invention will be described in detail below by way of examples.
The starting materials used in the following examples and comparative examples are commercially available unless otherwise specified.
The ash measurement method for the coke powder raw material in the following examples and comparative examples is: weighing 100g of a sample to be detected, placing the sample in a muffle furnace, heating to 815 ℃, heating at a speed of 10 ℃/min, continuously introducing air in the heating process, wherein the flow rate is 0.6L/min, burning until the mass is constant, and calculating the ash content mass percentage of the coal sample according to the mass of the residue, namely the mass percentage of the residue and the coal sample to be detected.
Example 1
This example is intended to illustrate the coal-based graphite composite material and the method for producing the same according to the present invention.
(1) Crushing and shaping unpurified coal-based coke powder (purchased from special coke preparation division of Shanxi Qin New energy group, Ltd.) with ash content of 12.5wt%, wherein the particle size distribution of the shaped coal-based coke powder is as follows: d10=4.718 μm, D50=12.4 μm, D90=22.64 μm; tap density of 1.2 g/cm3。
(2) And (2) mixing the material obtained in the step (1) with coal tar pitch (the softening point is 150 ℃, and the particle size is D50=3.5 μm) according to the weight ratio of 95:5 for 20 min.
(3) Putting the material obtained in the step (2) in N2Carbonizing treatment is carried out under the atmosphere, and the carbonizing treatment conditions comprise: the temperature is raised from room temperature to 200 ℃ at the rate of 0.8 ℃/min, raised to 650 ℃ at the rate of 1.5 ℃/min, raised to 1150 ℃ at the rate of 1.72 ℃/min, kept at 1150 ℃ for 300min, and then lowered to room temperature over 600 min.
(4) Performing graphitization treatment on the material obtained in the step (3), wherein the graphitization treatment conditions comprise: the temperature was 2950 ℃ and the time was 42 h.
(5) And (5) demagnetizing, screening and mixing the product obtained in the step (4) to obtain the coal-based graphite composite material A1.
The ash content distribution of the coal-based coke powder used in this example is shown in table 1.
TABLE 1
Example 2
This example is intended to illustrate the coal-based graphite composite material and the method for producing the same according to the present invention.
(1) The unrefined coal-based coke powder (same as the coal-based coke powder in example 1) with ash content of 12.5wt% is crushed and shaped, and the particle size distribution of the shaped coal-based coke powder is as follows: d10=4.718 μm, D50=12.4 μm, D90=22.64 μm; tap density of 1.2 g/cm3。
(2) Carrying out graphitization treatment on the material obtained in the step (1), wherein the graphitization treatment conditions comprise: the temperature was 2950 ℃ and the time was 42 h.
(3) And (3) mixing the material obtained in the step (2) with coal tar pitch (the softening point is 150 ℃, and the particle size is D50=3.5 μm) according to the weight ratio of 95:5 for 20 min.
(4) The mixture obtained in the step (3) is added in N2Carbonizing treatment is carried out under the atmosphere, and the carbonizing treatment conditions comprise: the temperature is raised from room temperature to 200 ℃ at the rate of 0.8 ℃/min, raised to 650 ℃ at the rate of 1.5 ℃/min, raised to 1150 ℃ at the rate of 1.72 ℃/min, kept at 1150 ℃ for 300min, and then lowered to room temperature over 600 min.
(5) And (5) demagnetizing, screening and mixing the product obtained in the step (4) to obtain the coal-based graphite composite material A2, wherein the SEM topography is shown in figure 1.
Example 3
This example is intended to illustrate the coal-based graphite composite material and the method for producing the same according to the present invention.
This example differs from example 2 in the way of example 2 in that: the raw material used in step (1) was an unrefined coal-based coke powder having an ash content of 10.7wt%, and then subjected to the same treatment steps (2) to (5) as in example 2, thereby obtaining a coal-based graphite composite material a 3.
Example 4
This example is intended to illustrate the coal-based graphite composite material and the method for producing the same according to the present invention.
This example differs from example 2 in the way of example 2 in that: the raw material used in step (1) was an unrefined coal-based coke powder having an ash content of 13.9wt%, and then subjected to the same treatment steps (2) to (5) as in example 2, thereby obtaining a coal-based graphite composite material a 4.
Example 5
This example is intended to illustrate the coal-based graphite composite material and the method for producing the same according to the present invention.
This example differs from example 2 in the way of example 2 in that: in the step (3), the material obtained in the step (2) was mixed with coal pitch (softening point 150 ℃, particle size D50=3.5 μm) at a weight ratio of 85:15 for 20min, and then subjected to the same treatment steps (4) - (5) as in example 2, thereby obtaining a coal-based graphite composite material a 5.
Example 6
This example is intended to illustrate the coal-based graphite composite material and the method for producing the same according to the present invention.
This example differs from example 2 in the way of example 2 in that: in the step (1), unpurified coal-based coke powder (same as the coal-based coke powder in example 1) with ash content of 12.5wt% is crushed and shaped, and the particle size distribution of the shaped coal-based coke powder is as follows: d10=3.25 μm, D50=8.36 μm, D90=18.26 μm; the tap density is 1.08 g/cm3Thereafter, the same treatment steps (2) to (5) as in example 2 were performed, thereby obtaining a coal-based graphite composite material a 6.
Comparative example 1
This comparative example differs from example 3 in that: adding Al between the steps (1) and (2)2O3Mixed treatment (1-1). The method comprises the following specific steps:
mixing the material obtained in the step (1) with Al2O3Mixing the powder in a 4-cubic VC mixer, and taking the material obtained in the step (1) as a reference, wherein Al is used as a raw material2O3The amount of powder added was 5.35 wt%. The resultant mixture was subjected to the same treatment steps (2) to (5) as in example 3 to obtain a coal-based graphite composite materialD1。
Comparative example 2
This comparative example differs from example 3 in that: and (1-1) adding NaCl mixing treatment process between the steps (1) and (2). The method comprises the following specific steps:
and (3) mixing the material obtained in the step (1) and NaCl powder in a 4-cubic VC mixer, wherein the addition amount of the NaCl powder is 0.54 percent by weight based on the material obtained in the step (1). The resultant mixture was subjected to the same treatment steps (2) to (5) as in example 3, to thereby obtain a coal-based graphite composite material D2.
Comparative example 3
The comparative example shows that hydrofluoric acid is conventionally required to purify coal-based coke powder in the prior art.
This comparative example 3 is different from example 2 in that an acid treatment process (1-1) is added between steps (1) and (2). The method specifically comprises the following steps:
HF and HCl in a molar ratio of 1:3.5 are mixed to form a pickling solution, the coal-based coke powder obtained in the step (1) and the pickling solution are stirred and mixed in a volume ratio of 1:1.5, then pure water washing is carried out, solid-liquid separation treatment is carried out to obtain solid dried coke powder for later use, the ash content of the purified dried coke powder is 1.53wt%, and the purified dried coke powder is subjected to the same treatment steps (2) - (5) as in the example 2, so that the coal-based graphite composite material D3 is obtained.
Comparative example 4
Comparative example 4 differs from example 2 in that: the raw material used in step (1) is unrefined tertiary metallurgical coke (purchased from black longjiang gecko coke) with ash content of 17.3wt%, the metallurgical coke is crushed and shaped, and the particle size distribution of the shaped metallurgical coke is D10=4.24 μm, D50=12.62 μm, and D90=21.95 μm; tap density of 1.15 g/cm3Thereafter, the same treatment steps (2) to (5) as in example 2 were performed, thereby obtaining a coal-based graphite composite material D4.
Test example
The particle size distribution measuring method comprises the following steps: and testing the granularity of the active material by using a laser diffraction method, wherein the testing instrument is a Malvern Master Size 3000 Malvern granularity tester, dispersing a sample to be tested in a dispersing agent (ethanol), carrying out ultrasonic treatment for 30min, adding the sample into the Malvern granularity tester, and starting testing.
The specific surface area measurement method comprises the following steps: passing through N by using a V-sorb 2800P specific surface area and aperture analyzer2And (4) absorbing and desorbing to test the BET specific surface area of the sample to be tested.
The graphitization degree measuring method comprises the following steps: testing the interplanar spacing d (002) according to JJS K0131-1996 'general rule of X-ray diffraction analysis method', testing the XRD crystal surface structure of a sample to be tested by an X-ray diffractometer, and analyzing d (002), Lc, graphitization degree and different peak intensity ratios, the type of the X-ray diffractometer: da vinci, manufacturer: bruker AXS ltd, germany, specification 3kw, scan range 10 to 90 degrees, scan speed 12 degrees per minute, test conditions: 40kV/40 mA. Wherein d (002) is calculated according to formula λ/(2sin θ); the graphitization degree was calculated as (0.344-d (002))/(0.344-0.3354) × 100%.
Tap density is measured by a tap density tester.
The coal-based graphite composite materials of A1-A6 and D1-D4 are respectively prepared into battery cathodes of lithium ion batteries, and the battery cathodes are prepared into button type lithium ion batteries which are respectively recorded as CA1-CA6 and CD1-CD 4. The method comprises the following specific steps:
dispersing the coal-based graphite composite material, the conductive carbon black, the thickening agent CMC and the binder SBR in solvent deionized water according to the weight ratio of 96:1:1:2, and uniformly mixing to obtain negative electrode slurry; uniformly coating the negative electrode slurry on a copper foil of a negative electrode current collector; and drying, cold pressing, slitting and cutting into pieces to obtain the battery cathode. Design compaction gradient from 1.20g/cm3To 1.50g/cm3And performing gradient rolling on the battery cathode until the head and the tail of the battery cathode are bright seriously, wherein the final compaction density of the battery cathode is the compaction density corresponding to the uniform color of the battery cathode.
And assembling the negative electrode of the battery to form the button lithium ion battery, and testing the first discharge specific capacity and the first coulombic efficiency of the button lithium ion battery.
The assembling method of the button type lithium ion battery comprises the following steps: the battery cathode prepared in the above steps is used as the cathode of the button lithium ion battery, and is punched into a wafer for standby. The lithium metal is also punched into a round piece to be used as a positive electrode, the positive electrode and the negative electrode are separated by a polyethylene diaphragm, and the electrolyte is a 1mol/L lithium hexafluorophosphate ethylene carbonate/methyl ethyl carbonate (the volume ratio of the ethylene carbonate to the methyl ethyl carbonate is 1:1) solution.
And testing the first discharge specific capacity and the first coulombic efficiency of the button type lithium ion battery by adopting LAND CT 2001. The charge and discharge voltage range is 0.005-1.0V, and the charge and discharge rate is 0.1C.
The data measured in the above examples and comparative examples are shown in tables 2 and 3.
TABLE 2
TABLE 3
The test results show that the method can effectively carry out simplified process treatment on the inferior coal-based coke powder with higher ash content, the graphitization degree of the coal-based graphite composite material prepared by the method is higher, the battery cathode prepared by the method has higher compaction density, and the battery cathode is assembled to form the button lithium ion battery, so that the button lithium ion battery can give consideration to the first discharge specific capacity and the first coulombic efficiency, wherein the first discharge specific capacity is more than or equal to 335mAh/g, and the first coulombic efficiency is more than or equal to 90.2%.
The preferred embodiments of the present invention have been described above in detail, but the present invention is not limited thereto. Within the scope of the technical idea of the invention, many simple modifications can be made to the technical solution of the invention, including combinations of various technical features in any other suitable way, and these simple modifications and combinations should also be regarded as the disclosure of the invention, and all fall within the scope of the invention.
Claims (11)
1. A preparation method of a coal-based graphite composite material is characterized in that unpurified coal-based coke powder is subjected to graphitization treatment, and coal pitch is added before and/or after the graphitization treatment for carbonization treatment;
the ash content of the unrefined coal-based coke powder is 5-15wt%, and SiO is calculated by the oxide of each element by taking the total ash content as the reference235-55wt% of Al2O312-35wt% of Fe2O33-45wt% of CaO, 1-5wt% of CaO, K2O content of 0.1-5wt%, Na20.1-3wt% of O, 0.1-5wt% of MgO, and TiO2The content is 0.4-5 wt%.
2. The production method according to claim 1, wherein a carbonization treatment is performed by adding coal pitch after the graphitization treatment; and/or the ash content of the unpurified coal-based coke powder is 10.5-15 wt%; and/or SiO, calculated as the oxide of each element, based on the total ash content245-55wt% of Al2O328-35 wt.% of Fe2O33-10wt% of CaO, 2-5wt% of CaO, K2O content of 0.5-5wt%, Na20.5-3wt% of O, 0.5-5wt% of MgO, and TiO2The content is 1-5 wt%.
3. The production method according to claim 1 or 2, wherein the particle size distribution of the unrefined coal-based coke powder is: d10=1-5 μm, D50=8-18 μm, D90=20-50 μm.
4. The method of claim 3, wherein the unrefined coal-based coke powder has a particle size distribution of: d10=2-5 μm, D50=12-18 μm, D90=20-30 μm.
5. The production method as claimed in claim 1, 2 or 4, wherein the sulfur content of the ash is 4 to 10wt% in terms of elemental sulfur based on the total amount of the ash.
6. The production method according to claim 1, 2 or 4, wherein the coal pitch is added in an amount of 1 to 10wt% based on the total amount of the treated materials; and/or the softening point of the coal tar pitch is 95-180 ℃; and/or the particle size of the coal tar pitch is less than 10 mu m.
7. The method according to claim 6, wherein the coal pitch is added in an amount of 2 to 8wt% based on the total amount of the processed materials.
8. The production method according to claim 1 or 2 or 4 or 7, wherein the carbonization treatment conditions include: the temperature is 400-1300 ℃, and the time is 20-45 h; and/or, the graphitization treatment conditions include: the temperature is 2800-; and/or the graphitization degree of the coal-based graphite composite material is more than or equal to 91.5 percent; and/or the particle size distribution of the coal-based graphite composite material is D10=2-7.5 μm, D50=8-20 μm, and D90=15-40 μm.
9. A coal-based graphite composite material produced by the production method according to any one of claims 1 to 8.
10. A battery negative electrode comprising the coal-based graphite composite material according to claim 9.
11. A lithium ion battery comprising the battery negative electrode of claim 10.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111393938.0A CN113816370B (en) | 2021-11-23 | 2021-11-23 | Coal-based graphite composite material, preparation method thereof and battery using same |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111393938.0A CN113816370B (en) | 2021-11-23 | 2021-11-23 | Coal-based graphite composite material, preparation method thereof and battery using same |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN113816370A true CN113816370A (en) | 2021-12-21 |
| CN113816370B CN113816370B (en) | 2022-02-08 |
Family
ID=78919737
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202111393938.0A Active CN113816370B (en) | 2021-11-23 | 2021-11-23 | Coal-based graphite composite material, preparation method thereof and battery using same |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN113816370B (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114394590A (en) * | 2022-01-21 | 2022-04-26 | 山西沁新能源集团股份有限公司 | Graphitized negative electrode material prepared from graphitized waste and preparation method thereof |
| CN114914433A (en) * | 2022-06-28 | 2022-08-16 | 山西沁新能源集团股份有限公司 | Coal-based graphite composite material and preparation method and application thereof |
| CN114927685A (en) * | 2022-06-28 | 2022-08-19 | 山西沁新能源集团股份有限公司 | Catalytic graphitization coal-based negative electrode material and preparation method thereof |
| CN114920243A (en) * | 2022-06-28 | 2022-08-19 | 山西沁新能源集团股份有限公司 | Coal-based graphite composite material and preparation method and application thereof |
Citations (21)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0269356A (en) * | 1988-09-02 | 1990-03-08 | Nippon Steel Corp | Production of isotropic graphite material having high purity |
| US5607770A (en) * | 1985-10-22 | 1997-03-04 | Ucar Carbon Technology Corporation | Carbon-carbon composites containing poorly graphitizing pitch as a binder and/or impregnant having a reduced coefficient of thermal expansion and improved flexural strength |
| CN102148355A (en) * | 2011-03-03 | 2011-08-10 | 江西正拓新能源科技有限公司 | Cathode material for lithium-ion power battery and preparation method thereof |
| CN103066243A (en) * | 2012-12-06 | 2013-04-24 | 中南大学 | Coke powder-based cathode material of lithium ion power battery and preparation method thereof |
| CN104401974A (en) * | 2014-10-24 | 2015-03-11 | 中国海洋石油总公司 | Preparation method of high capacity carbon cathode material for lithium ion batteries |
| CN104681786A (en) * | 2015-03-04 | 2015-06-03 | 深圳市贝特瑞新能源材料股份有限公司 | Coal-based anode material, preparation method and lithium-ion battery |
| CN105236395A (en) * | 2015-09-01 | 2016-01-13 | 大连宏光锂业股份有限公司 | Production method of composite artificial graphite anode material |
| CN106058304A (en) * | 2016-08-10 | 2016-10-26 | 广东东岛新能源股份有限公司 | Artificial graphite negative electrode material used for lithium ion power batteries, and preparation method thereof |
| CN106532053A (en) * | 2016-12-22 | 2017-03-22 | 上海杉杉科技有限公司 | Graphite anode material for lithium ion batteries and preparation method thereof |
| WO2017050260A1 (en) * | 2015-09-25 | 2017-03-30 | 深圳市贝特瑞新能源材料股份有限公司 | Method for preparing composite graphite, composite graphite and lithium ion battery |
| CN107265450A (en) * | 2017-06-20 | 2017-10-20 | 中国科学院山西煤炭化学研究所 | A kind of preparation method of fine structure graphite |
| CN107369823A (en) * | 2017-07-25 | 2017-11-21 | 广东海洋大学 | A kind of lithium ion battery artificial composite cathode material of silicon/carbon/graphite and preparation method thereof |
| JP2018006270A (en) * | 2016-07-07 | 2018-01-11 | 新日鉄住金化学株式会社 | Graphite carbon material for lithium ion secondary battery negative electrode, method for manufacturing the same, and negative electrode or battery arranged by use thereof |
| US20180155201A1 (en) * | 2015-05-19 | 2018-06-07 | Key Team Enterprises Limited | Method for preparing graphene using coal as raw material |
| CN109585803A (en) * | 2018-10-16 | 2019-04-05 | 湖南宸宇富基新能源科技有限公司 | A kind of artificial plumbago negative pole material and its preparation and application with gradient-structure |
| CN111244453A (en) * | 2018-11-28 | 2020-06-05 | 上海杉杉科技有限公司 | Artificial composite graphite negative electrode material, lithium ion battery, preparation method and application |
| CN111732096A (en) * | 2019-03-25 | 2020-10-02 | 中信国安盟固利动力科技有限公司 | Negative electrode material of high-power lithium ion battery and preparation method thereof |
| CN111777414A (en) * | 2020-06-24 | 2020-10-16 | 山西沁新能源集团股份有限公司 | Carbon negative electrode material precursor, preparation method and application thereof, carbon negative electrode material, preparation method and application thereof |
| CN113023725A (en) * | 2020-11-26 | 2021-06-25 | 宁波杉杉新材料科技有限公司 | Coated modified artificial graphite negative electrode material, preparation method thereof and lithium ion battery |
| KR20210090562A (en) * | 2020-01-10 | 2021-07-20 | 주식회사 엘지에너지솔루션 | Artificial graphite, Method for preparing the same, Anode Comprising the same, and Lithium Secondary Battery Comprising the same |
| CN113548662A (en) * | 2021-07-12 | 2021-10-26 | 孙仲振 | Preparation method of coal-based artificial graphite negative electrode material |
-
2021
- 2021-11-23 CN CN202111393938.0A patent/CN113816370B/en active Active
Patent Citations (21)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5607770A (en) * | 1985-10-22 | 1997-03-04 | Ucar Carbon Technology Corporation | Carbon-carbon composites containing poorly graphitizing pitch as a binder and/or impregnant having a reduced coefficient of thermal expansion and improved flexural strength |
| JPH0269356A (en) * | 1988-09-02 | 1990-03-08 | Nippon Steel Corp | Production of isotropic graphite material having high purity |
| CN102148355A (en) * | 2011-03-03 | 2011-08-10 | 江西正拓新能源科技有限公司 | Cathode material for lithium-ion power battery and preparation method thereof |
| CN103066243A (en) * | 2012-12-06 | 2013-04-24 | 中南大学 | Coke powder-based cathode material of lithium ion power battery and preparation method thereof |
| CN104401974A (en) * | 2014-10-24 | 2015-03-11 | 中国海洋石油总公司 | Preparation method of high capacity carbon cathode material for lithium ion batteries |
| CN104681786A (en) * | 2015-03-04 | 2015-06-03 | 深圳市贝特瑞新能源材料股份有限公司 | Coal-based anode material, preparation method and lithium-ion battery |
| US20180155201A1 (en) * | 2015-05-19 | 2018-06-07 | Key Team Enterprises Limited | Method for preparing graphene using coal as raw material |
| CN105236395A (en) * | 2015-09-01 | 2016-01-13 | 大连宏光锂业股份有限公司 | Production method of composite artificial graphite anode material |
| WO2017050260A1 (en) * | 2015-09-25 | 2017-03-30 | 深圳市贝特瑞新能源材料股份有限公司 | Method for preparing composite graphite, composite graphite and lithium ion battery |
| JP2018006270A (en) * | 2016-07-07 | 2018-01-11 | 新日鉄住金化学株式会社 | Graphite carbon material for lithium ion secondary battery negative electrode, method for manufacturing the same, and negative electrode or battery arranged by use thereof |
| CN106058304A (en) * | 2016-08-10 | 2016-10-26 | 广东东岛新能源股份有限公司 | Artificial graphite negative electrode material used for lithium ion power batteries, and preparation method thereof |
| CN106532053A (en) * | 2016-12-22 | 2017-03-22 | 上海杉杉科技有限公司 | Graphite anode material for lithium ion batteries and preparation method thereof |
| CN107265450A (en) * | 2017-06-20 | 2017-10-20 | 中国科学院山西煤炭化学研究所 | A kind of preparation method of fine structure graphite |
| CN107369823A (en) * | 2017-07-25 | 2017-11-21 | 广东海洋大学 | A kind of lithium ion battery artificial composite cathode material of silicon/carbon/graphite and preparation method thereof |
| CN109585803A (en) * | 2018-10-16 | 2019-04-05 | 湖南宸宇富基新能源科技有限公司 | A kind of artificial plumbago negative pole material and its preparation and application with gradient-structure |
| CN111244453A (en) * | 2018-11-28 | 2020-06-05 | 上海杉杉科技有限公司 | Artificial composite graphite negative electrode material, lithium ion battery, preparation method and application |
| CN111732096A (en) * | 2019-03-25 | 2020-10-02 | 中信国安盟固利动力科技有限公司 | Negative electrode material of high-power lithium ion battery and preparation method thereof |
| KR20210090562A (en) * | 2020-01-10 | 2021-07-20 | 주식회사 엘지에너지솔루션 | Artificial graphite, Method for preparing the same, Anode Comprising the same, and Lithium Secondary Battery Comprising the same |
| CN111777414A (en) * | 2020-06-24 | 2020-10-16 | 山西沁新能源集团股份有限公司 | Carbon negative electrode material precursor, preparation method and application thereof, carbon negative electrode material, preparation method and application thereof |
| CN113023725A (en) * | 2020-11-26 | 2021-06-25 | 宁波杉杉新材料科技有限公司 | Coated modified artificial graphite negative electrode material, preparation method thereof and lithium ion battery |
| CN113548662A (en) * | 2021-07-12 | 2021-10-26 | 孙仲振 | Preparation method of coal-based artificial graphite negative electrode material |
Non-Patent Citations (7)
| Title |
|---|
| GUEL,O: "Characterization of cokes from delayed Co-coking of decant oil,coal,resid,and cracking catalyst", 《ENERGY & FUELS》 * |
| KUMAR,M: "Demineralization study of Indian Assam coking coal by sodium hydroxide leaching", 《ENERGY SOURCES》 * |
| XIAO,JIN: "Effect of high-temperature pyrolysis on the structure and properties of coal and petroleum coke", 《JOURNAL OF ANALYTICAL AND APPLIED PYROLYSIS》 * |
| 杨鹏: "焦粉活性炭及其复合物电极材料的制备与性能研究", 《中国优秀硕士学位论文全文数据库》 * |
| 王丽琼等: "煤系焦用于锂电池负极材料的性能研究", 《通信电源技术》 * |
| 董亚威: "改性石油沥青和煤沥青共炭化对焦形成的影响", 《新型炭材料》 * |
| 马路路: "以煤基焦粉为原料制备锂离子电池负极材料的研究", 《中国优秀硕士学位论文全文数据库 工程科技II辑》 * |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114394590A (en) * | 2022-01-21 | 2022-04-26 | 山西沁新能源集团股份有限公司 | Graphitized negative electrode material prepared from graphitized waste and preparation method thereof |
| CN114914433A (en) * | 2022-06-28 | 2022-08-16 | 山西沁新能源集团股份有限公司 | Coal-based graphite composite material and preparation method and application thereof |
| CN114927685A (en) * | 2022-06-28 | 2022-08-19 | 山西沁新能源集团股份有限公司 | Catalytic graphitization coal-based negative electrode material and preparation method thereof |
| CN114920243A (en) * | 2022-06-28 | 2022-08-19 | 山西沁新能源集团股份有限公司 | Coal-based graphite composite material and preparation method and application thereof |
Also Published As
| Publication number | Publication date |
|---|---|
| CN113816370B (en) | 2022-02-08 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN113816370B (en) | Coal-based graphite composite material, preparation method thereof and battery using same | |
| CN110615423B (en) | Preparation method of silicon-based composite negative electrode material of lithium battery | |
| KR101204192B1 (en) | Silicon Composite and Method for Preparing the Same, and Negative Electrode Material for Non-aqueous Electrolyte Secondary Battery | |
| CN112661148B (en) | Composite graphite negative electrode material, preparation method and application thereof, and lithium ion battery | |
| CN113036253B (en) | Method for selective oxidation-reduction regeneration of waste lithium iron phosphate, regenerated lithium iron phosphate and lithium ion battery | |
| CN112645300B (en) | Hard carbon negative electrode material, lithium ion battery, and preparation method and application of hard carbon negative electrode material | |
| CN111244400B (en) | Silicon-oxygen-carbon composite material, lithium ion battery, and preparation method and application of silicon-oxygen-carbon composite material | |
| CN114956037B (en) | Carbon material for negative electrode of sodium ion battery, preparation method of carbon material, negative electrode piece of sodium ion battery and sodium ion battery | |
| CN109553080B (en) | Lithium ion battery negative electrode active material, lithium ion battery negative electrode, lithium ion battery, battery pack and battery power vehicle | |
| WO2007066673A1 (en) | Graphite material, carbon material for battery electrode and battery | |
| CN109553085B (en) | Lithium ion battery negative electrode active material, lithium ion battery negative electrode, lithium ion battery, battery pack and battery power vehicle | |
| JP2022537926A (en) | Negative electrode material, preparation method thereof and lithium ion battery | |
| CN116119643B (en) | Preparation method of high-rate long-cycle pyrolytic carbon negative electrode material for sodium storage | |
| CN112803001B (en) | Coating agent, quick-charge graphite, preparation method and application of coating agent and quick-charge graphite, and battery | |
| KR102620786B1 (en) | Lithium-ion battery cathode material, lithium-ion battery cathode, lithium-ion battery, battery pack and battery power vehicle | |
| CN112713271B (en) | Modified graphite material, preparation method thereof, lithium ion battery and application | |
| CN112479197A (en) | Preparation method of high-capacity quick-charging graphite negative electrode material | |
| CN112018386A (en) | Artificial graphite material, composite material, preparation method of composite material and lithium ion secondary battery | |
| CN111799098A (en) | Porous carbon/metal oxide composite material and preparation method and application thereof | |
| CN111864206B (en) | Hard carbon negative electrode material, preparation method thereof, pole piece containing hard carbon negative electrode material and lithium ion battery | |
| CN114394590A (en) | Graphitized negative electrode material prepared from graphitized waste and preparation method thereof | |
| CN115432699B (en) | Waste negative electrode-based regenerated graphite material and preparation and application thereof | |
| CN115548322A (en) | Preparation method and application of modified microcrystalline graphite secondary particle negative electrode material | |
| JP2024523842A (en) | Graphite anode material, its preparation method and use thereof | |
| CN113086979A (en) | Preparation method of graphite material, graphite material and application thereof, and lithium ion battery negative electrode material |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |