CN113764644A - Quick-filling composite graphite material and preparation method thereof - Google Patents
Quick-filling composite graphite material and preparation method thereof Download PDFInfo
- Publication number
- CN113764644A CN113764644A CN202111079750.9A CN202111079750A CN113764644A CN 113764644 A CN113764644 A CN 113764644A CN 202111079750 A CN202111079750 A CN 202111079750A CN 113764644 A CN113764644 A CN 113764644A
- Authority
- CN
- China
- Prior art keywords
- graphite
- composite
- graphite material
- metal oxide
- oxide
- 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
-
- 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
- H01M4/362—Composites
-
- 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
-
- 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
Abstract
The invention relates to the technical field of lithium ion battery materials, and provides a quick-charging composite graphite material and a preparation method thereof. The composite material utilizes the reaction of hydroxyl and carboxyl on the surface of the porous graphite and the groups of the components in the shell to improve the structural stability of the material, and simultaneously, the metal oxide has high electronic conductivity, and the phosphoric acid is carbonized to generate a channel and specific capacity of the porous structure improved material, so that the prepared graphite composite material has the characteristics of good rate capability, high specific capacity, good cycle performance and the like.
Description
Technical Field
The invention relates to the technical field of lithium ion battery materials, in particular to a quick-charging composite graphite material and a preparation method thereof.
Background
The current marketed fast-charging negative electrode material mainly takes a graphite material as a main material, the impedance is reduced mainly by reducing the particle size of a material aggregate and the surface coating of the material, the inner core of the material is graphite, the shell coating material is soft carbon or hard carbon, the larger the coating capacity is, the lower the specific capacity is, the lower the first efficiency of the material is caused while the fast-charging performance of the battery material is improved, meanwhile, the inner core graphite is of a laminated structure, the large-rate lithium-embedding path is longer, and the rate is influenced. The metal oxide material can be used as a lithium ion battery cathode material due to the characteristics of high specific capacity, high conductivity and the like, but the metal oxide material has large polarization and poor cycle performance, so that the metal oxide material is limited to be directly used as the cathode material. For example, patent CN201911123121.4 discloses a method for assembling a high-performance transition metal oxide negative electrode material and a battery, which mainly comprises the following steps: pretreatment of the carbon material: the three processes of preparing the transition metal oxide/carbon material composite can be seen from the charge-discharge curve of the material, the voltage platform of the material is higher, the polarization is larger, the material is not suitable as a negative electrode material, the impedance of the material needs to be reduced, and the polarization needs to be reduced, so that the voltage platform of the material is reduced, and the specific capacity of the material is improved.
Disclosure of Invention
The invention provides a quick-filling composite graphite material and a preparation method thereof, which improve the conductivity and specific capacity of the material, reduce the impedance and improve the multiplying power.
The technical scheme of the invention is as follows:
a quick-filling composite graphite material is of a core-shell structure, wherein an inner core is porous graphite, and a shell comprises metal oxide, carbon nano tubes and amorphous carbon thereof.
Further, the specific surface area of the porous graphite is 2-10m2Per g, particle diameter of 5-15 μm, tap density of 0.9g/cm or less3The surface hydroxyl/carboxyl content is 0.5-5%.
Further, the preparation method of the porous graphite comprises the following steps: dissolving urea and inorganic carbonate in water, heating, adding graphite, performing ball milling dispersion, drying, sintering, crushing, dissolving carbonate in dilute hydrochloric acid, washing, and drying to obtain the porous graphite.
Furthermore, in the preparation method of the porous graphite, the mass ratio of the urea to the inorganic carbonate to the graphite is (0.5-2): (1-5): 100.
further, in the preparation method of the porous graphite, the temperature is heated to 40-90 ℃.
Furthermore, in the preparation method of the porous graphite, sintering is carried out for 1-6h at the temperature of 300-500 ℃ under inert atmosphere.
Further, the shell accounts for 1-10% of the composite graphite material by mass.
Furthermore, the total weight of the metal oxide, the carbon nano tube and the amorphous carbon in the shell accounts for 90-99% of the mass of the shell, and the balance is nitrogen-containing substances and impurities.
Further, the mass ratio of the metal oxide, the carbon nano tube, the nitrogen-containing substance and the amorphous carbon is as follows: (40-60): (1-10): (1-3): (30-60).
Further, the metal oxide is selected from one or more of tin oxide, manganese oxide, iron oxide, cobalt oxide, nickel oxide and zirconium oxide.
Further, the nitrogen-containing substance is formed after the nitrogen source is carbonized at high temperature.
Still further, the nitrogen source is selected from one or more of ammonia, urea, aniline, pyrrole and thiophene.
Further, the amorphous carbon is formed by carbonizing a binder.
Still further, the binder is selected from one or more of low-temperature asphalt, phenolic resin, furfural resin and epoxy resin, wherein the softening point of the low-temperature asphalt is 50-150 ℃.
The invention further provides a preparation method of the quick-filling composite graphite material, which comprises the following steps:
(1) soaking the porous graphite in a catalyst solution, filtering and drying to obtain modified porous graphite;
(2) dissolving metal oxide, carbon nano tubes, a nitrogen source and a binder in an organic solvent, and performing ball milling, dispersion and drying to obtain a binder composite material;
(3) uniformly mixing the binder composite material, phosphoric acid and modified porous graphite, carbonizing, cooling and crushing to obtain the graphite composite material with the outer layer coated with the metal oxide composite material.
Further, the catalyst in the step (1) is selected from one or more of nickel chloride, ferric chloride and cobalt chloride.
Further, the concentration of the catalyst solution in the step (1) is 1 to 5 wt%.
Further, the organic solvent in the step (2) is selected from one or more of N-methyl pyrrolidone, carbon tetrachloride, N-dimethylformamide, cyclohexane and xylene.
Further, in the step (3), the mass ratio of the binder composite material to the phosphoric acid to the modified porous graphite is 5-20: 1-5: 100.
further, the carbonization temperature in the step (3) is 700-1100 ℃, and the carbonization time is 1-6 h.
Further, the temperature reduction in the step (3) is specifically to be room temperature.
The invention has the beneficial effects that:
(1) according to the invention, the porous graphite is prepared, on one hand, the lithium active sites embedded in the graphite can be increased, and the dynamic performance of the material is improved, and on the other hand, the surface of the porous graphite contains hydroxyl and carboxyl groups, and the hydroxyl and carboxyl groups can be matched with-NH-basic groups in a nitrogen source in a shell and CH in a binder2COONa chemically reacts to form a structurally stable material.
(2) The metal oxide and the carbon nano tube in the shell have a synergistic effect, wherein the metal oxide has high electronic conductivity and high specific capacity, the specific capacity of the material can be obviously improved, and the impedance of the material is reduced; the carbon nano tube forms a net structure in the shell, so that the electronic conductivity of the material is further improved under the synergistic action of the metal oxide, the impedance is reduced, and the multiplying power is improved.
(3) According to the invention, the inner core and the outer shell of the material are both doped with nitrogen-containing substances, and because the electronegativity of nitrogen is stronger than that of carbon, a pair of electrons can be provided for adjacent carbon atoms through N doping, so that the electronic conductivity of the material is improved, the impedance of the material is reduced, and the multiplying power is improved.
Drawings
Fig. 1 is an SEM image of the graphite composite material prepared in example 1.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any inventive step, are intended to be within the scope of the present invention.
Example 1
The rapid-filling composite graphite material of the embodiment is of a core-shell structure, wherein the inner core is porous graphite, and the shell comprises manganese oxide, carbon nanotubes and amorphous carbon thereof.
The preparation method of the porous graphite comprises the following steps: 1g of urea and 3g of calcium carbonate are dissolved in 500ml of deionized water, heated and stirred at 60 ℃, then 100g of artificial graphite is added and ball-milled and dispersed for 24 hours in a high-energy ball mill, vacuum drying is carried out for 48 hours at 60 ℃, then the mixture is transferred to a carbonization furnace, and sintering is carried out for 3 hours at 400 ℃ under the inert atmosphere of argon, then crushing is carried out, calcium carbonate is dissolved in 1000ml of 0.1mol/L dilute hydrochloric acid, deionized water is used for washing for 3 times, and drying is carried out for 48 hours at 80 ℃ to obtain the porous graphite.
The specific surface area of the prepared porous graphite is 5m2Per g, particle diameter of 5-15 μm, tap density of 0.82g/cm3The hydroxyl/carboxyl content of the surface was 2.5%.
Wherein the shell accounts for 5.8% of the composite graphite material by mass.
Wherein, the total weight of manganese oxide, carbon nano tube and amorphous carbon in the shell accounts for 95.4 percent of the mass of the shell, and the balance is nitrogen-containing substances and impurities.
Wherein the mass ratio of the manganese oxide to the carbon nano tube to the nitrogen-containing substance to the amorphous carbon is as follows: 50:3:2: 45.
furthermore, the amorphous carbon is obtained by sintering low-temperature asphalt, and the softening point of the low-temperature asphalt is 100 DEG C
The preparation method of the quick-filling composite graphite material comprises the following steps:
(1) adding 100g of porous graphite into 500ml of 2 wt% nickel chloride catalyst solution, soaking for 24h, filtering, and drying at 60 ℃ for 48h to obtain modified porous graphite;
(2) dissolving 50g of manganese oxide, 3g of carbon nano tube, 2g of aniline and 45g of low-temperature asphalt in 500ml of N-methyl pyrrolidone, ultrasonically dispersing uniformly, transferring the mixture into a ball mill for ball milling and dispersion for 48 hours, and spray drying to obtain the binder composite material
(3) Uniformly mixing 10g of binder composite material, 3g of phosphoric acid and 100g of modified porous graphite by a vertical mixer, heating to 800 ℃ in an argon inert atmosphere, carbonizing for 3h, cooling to room temperature, crushing and grading to obtain the graphite composite material with the outer layer coated with the manganese oxide composite material.
Example 2
The rapid-filling composite graphite material of the embodiment is of a core-shell structure, wherein the inner core is porous graphite, and the shell comprises tin oxide, carbon nanotubes and amorphous carbon thereof.
The preparation method of the porous graphite comprises the following steps: dissolving 0.5g of urea and 1g of magnesium carbonate in 500ml of deionized water, heating to 40 ℃, stirring, adding 100g of artificial graphite, performing ball milling dispersion in a high-energy ball mill for 48 hours, performing vacuum drying at 60 ℃ for 48 hours, transferring to a carbonization furnace, sintering at 300 ℃ for 6 hours under the inert atmosphere of helium, crushing, dissolving the magnesium carbonate in 1000ml of 0.1mol/L dilute hydrochloric acid, washing with deionized water for 1 time, and drying at 80 ℃ for 48 hours to obtain the porous graphite.
The specific surface area of the prepared porous graphite is 2m2Per g, particle diameter of 5-15 μm, tap density of 0.64g/cm3The hydroxyl/carboxyl content of the surface was 0.5%.
Wherein the shell accounts for 1.1 percent of the composite graphite material by mass.
Wherein, the total weight of the tin oxide, the carbon nano tube and the amorphous carbon in the shell accounts for 90.4 percent of the mass of the shell, and the balance is nitrogen-containing substances and impurities.
Wherein the mass ratio of the tin oxide to the carbon nano tube to the nitrogen-containing substance to the amorphous carbon is as follows: 40:1:1: 58.
further, the amorphous carbon is obtained by sintering a phenolic resin.
The preparation method of the quick-filling composite graphite material comprises the following steps:
(1) adding 100g of porous graphite into 100ml of 1 wt% ferric chloride catalyst solution, soaking for 48 hours, filtering, and vacuum drying at 80 ℃ for 48 hours to obtain modified porous graphite;
(2) dissolving 40g of tin oxide, 1g of carbon nano tube, 1g of thiophene and 58g of phenolic resin in N, N-dimethylformamide, ultrasonically dispersing uniformly, transferring to a ball mill for ball milling and dispersing for 48 hours, and performing spray drying to obtain a binder composite material;
(3) uniformly mixing 5g of binder composite material, 1g of phosphoric acid and 100g of modified porous graphite by a vertical mixer, heating to 700 ℃ in helium inert atmosphere, carbonizing for 6h, cooling to room temperature, crushing and grading to obtain the graphite composite material with the outer layer coated with the tin oxide composite material.
Example 3
The rapid-filling composite graphite material of the embodiment is of a core-shell structure, wherein the inner core is porous graphite, and the shell comprises iron oxide, carbon nanotubes and amorphous carbon thereof.
The preparation method of the porous graphite comprises the following steps: dissolving 2g of urea and 5g of potassium carbonate in 500ml of deionized water, heating to 90 ℃, stirring, adding 100g of graphite, performing ball milling dispersion in a high-energy ball mill for 48 hours, performing vacuum drying at 80 ℃ for 48 hours, transferring to a carbonization furnace, sintering at 500 ℃ for 1 hour under a neon inert atmosphere, crushing, dissolving potassium carbonate in 1000ml of 1 wt% diluted hydrochloric acid, washing with deionized water for 5 times, and drying at 80 ℃ for 48 hours to obtain porous graphite.
The specific surface area of the prepared porous graphite is 10m2Per g, particle diameter of 5-15 μm, tap density of 0.73g/cm3The hydroxyl/carboxyl content of the surface was 5%.
Wherein the shell accounts for 9.8 percent of the composite graphite material by mass.
Wherein the total weight of the ferric oxide, the carbon nano tube and the amorphous carbon in the shell accounts for 98.7 percent of the mass of the shell, and the balance is a nitrogen-containing substance pyrrole and impurities.
Wherein the mass ratio of the ferric oxide to the carbon nano tube to the pyrrole to the amorphous carbon is as follows: 60:2:3: 35.
further, the amorphous carbon is a substance obtained by sintering furfural resin.
The preparation method of the quick-filling composite graphite material comprises the following steps:
(1) adding 100g of porous graphite into 20ml of 5 wt% cobalt chloride solution, soaking for 48h, filtering, and vacuum drying at 80 ℃ for 48h to obtain modified porous graphite;
(2) dissolving 60g of ferric oxide, 2g of carbon nano tube, 3g of pyrrole and 35g of furfural resin in 500ml of carbon tetrachloride organic solvent, transferring the mixture into a ball mill for ball milling dispersion after uniform ultrasonic dispersion, and performing spray drying to obtain a binder composite material;
(3) uniformly mixing 20g of the binder composite material, 5g of phosphoric acid and 100g of modified porous graphite by a vertical mixer, heating to 1100 ℃ in neon inert atmosphere, carbonizing for 1h, cooling to room temperature, crushing and grading to obtain the graphite composite material with the outer layer coated with the iron oxide composite material.
Comparative example 1
100g of artificial graphite and 20g of asphalt are uniformly mixed by a ball mill, then are mixed by a vertical mixer, are heated to 800 ℃ under the inert atmosphere of argon gas for carbonization for 3 hours, are cooled to room temperature, and are crushed and graded to obtain the graphite composite material.
Comparative example 2
The same as in example 1 except that graphite without pores is used as the core, the details are as follows:
comparative example 3
The preparation method of the core material is the same as that of example 1 except that unmodified porous graphite is used as the core:
(1) dissolving 50g of manganese oxide, 3g of carbon nano tube, 2g of aniline and 45g of low-temperature asphalt in 500ml of N-methyl pyrrolidone, ultrasonically dispersing uniformly, transferring the mixture into a ball mill for ball milling and dispersion for 48 hours, and spray drying to obtain the binder composite material
(2) Uniformly mixing 10g of binder composite material, 3g of phosphoric acid and 100g of porous graphite by a vertical mixer, heating to 800 ℃ in an argon inert atmosphere, carbonizing for 3h, cooling to room temperature, crushing and grading to obtain the graphite composite material with the outer layer coated with the manganese oxide composite material.
Comparative example 4
The shell was prepared without adding a nitrogen source, as in example 1, and the specific preparation method was as follows:
(1) adding 100g of porous graphite into 500ml of 2 wt% nickel chloride catalyst solution, soaking for 24h, filtering, and drying at 60 ℃ for 48h to obtain modified porous graphite;
(2) dissolving 50g of manganese oxide, 3g of carbon nano tube and 45g of low-temperature asphalt in 500ml of N-methyl pyrrolidone, ultrasonically dispersing uniformly, transferring the mixture into a ball mill for ball milling and dispersing for 48 hours, and spray drying to obtain the binder composite material
(3) Uniformly mixing 10g of binder composite material, 3g of phosphoric acid and 100g of modified porous graphite by a vertical mixer, heating to 800 ℃ in an argon inert atmosphere, carbonizing for 3h, cooling to room temperature, crushing and grading to obtain the graphite composite material with the outer layer coated with the manganese oxide composite material.
Comparative example 5
In the preparation of the shell, the mass ratio of the metal oxide, the carbon nano tube, the nitrogen-containing substance and the amorphous carbon is as follows: 65: 3: 2: 45, the rest of the process was the same as in example 1.
Comparative example 6
In the preparation of the shell, the mass ratio of the metal oxide, the carbon nano tube, the nitrogen-containing substance and the amorphous carbon is as follows: 50: 12: 2: 45, the rest of the process was the same as in example 1.
Comparative example 7
In the preparation of the shell, the mass ratio of the metal oxide, the carbon nano tube, the nitrogen-containing substance and the amorphous carbon is as follows: 50:3: 5: 45, the rest of the process was the same as in example 1.
Comparative example 8
In the preparation of the shell, the mass ratio of the metal oxide, the carbon nano tube, the nitrogen-containing substance and the amorphous carbon is as follows: 50:3: 2: 65, the rest of the process was the same as in example 1.
Experimental example 1 test of physical and chemical Properties of composite graphite materials
1.1SEM test
The artificial graphite composite material prepared in example 1 was subjected to SEM test, and the test results are shown in fig. 1.
As can be seen from FIG. 1, the artificial graphite composite material prepared in example 1 is spheroidal and has a uniform size distribution and a particle size of (8-15) μm.
1.2 powder conductivity test:
pressing the powder into a blocky structure, and then testing the conductivity of the powder by adopting a four-probe tester. The test results are shown in table 1.
1.3 powder compaction Density test
The graphite composite materials prepared in examples 1 to 3 and comparative examples 1 to 8 were subjected to a powder compaction density test. During testing, powder with a certain mass is weighed and placed in a mold, 2T pressure pressing is adopted (1 g of powder is placed in a fixed kettle and then pressed by 2T pressure by adopting a powder compaction density instrument, the powder is static for 10S, the volume under pressing is calculated, and the compaction density is calculated), and the powder compaction density is calculated. The test results are shown in table 1.
TABLE 1 comparison of the physico-chemical properties of the graphite materials in the examples and comparative examples
As can be seen from Table 1, the powder resistivity of the graphite composite materials prepared in examples 1 to 3 was significantly smaller than that of each comparative example. The composite material is prepared by adopting common graphite to wrap the asphalt in the comparative example 1, and the resistivity of the composite material is obviously improved; comparative examples 2 and 3 adopt graphite which is not subjected to pore forming and modification as a core to prepare the composite graphite material, and due to lack of combination of proper hydroxyl and carboxyl groups and basic groups in a shell, the structural stability of the composite material is reduced, so that the resistivity of the material cannot be further reduced by metal oxides and nitrogen-containing substances. Comparative example 4 no nitrogen source was added and the resistivity of the material increased, indicating that the nitrogen-containing species had a large effect on improving the resistivity of the material. Comparative examples 5 to 8 respectively prepare shells of metal oxide, carbon nano tube, nitrogen-containing substance and amorphous carbon with different proportions, and the resistivity of the composite graphite material is increased, which shows that the metal oxide, carbon nano tube, nitrogen-containing substance and amorphous carbon need to be in proper proportions to realize the effect of reducing the resistivity, and the more any one component is, the better the resistivity is. Compared with the comparative example, the powder compaction density of the composite graphite material prepared in the example is not greatly different, but the whole comparative example is higher, so that the composite graphite material prepared in the example has higher compaction density, higher active substance mass per unit volume and better capacity improvement of the battery.
Experimental example 2 button cell test
The artificial graphite composite materials in examples 1-3 and comparative examples 1-8 were assembled into button cells A1, A2, A3, B1-8, respectively. The assembling method comprises the following steps: and adding a binder, a conductive agent and a solvent into the negative electrode material, stirring and pulping, coating the mixture on copper foil, and drying and rolling to obtain the negative electrode plate. The binder used was LA132 binder, the conductive agent was SP, the negative electrode material was the artificial graphite composite material in examples 1 to 3 and comparative example, respectively, and the solvent was secondary distilled water. The proportion of each component is as follows: and (3) anode material: SP: LA 132: 95g of secondary distilled water: 1 g: 4 g: 220 mL; the electrolyte is LiPF6/EC+DEC(LiPF6The concentration of the lithium ion battery is 1.2mol/L, the volume ratio of EC to DEC is 1:1), the metal lithium sheet is used as a counter electrode, and the diaphragm is a Polyethylene (PE), polypropylene (PP) or polyethylene propylene (PEP) composite membrane. The button cell is assembled in a hydrogen-filled glove box, the electrochemical performance test is carried out on a Wuhan blue electricity CT2001A type battery tester, the charging and discharging voltage range is 0.005V-2.0V, and the charging and discharging multiplying power is 0.1C. The test results are shown in table 2.
Meanwhile, the above negative electrode plate was taken out, and the liquid absorption and retention ability of the plate was tested, and the results are shown in table 2.
Table 2 button cell of examples and comparative examples and their pole piece imbibition performance comparison
As can be seen from Table 2, the lithium ion batteries using the graphite composite negative electrode materials obtained in examples 1 to 3 had significantly higher first discharge capacity, first charge-discharge efficiency, and liquid absorption capacity than the comparative examples. The first discharge capacity, the first efficiency and the liquid absorption capacity of the comparative examples 1 and 2 are all remarkably reduced, and the liquid absorption capacity is remarkably reduced because the core graphite has no porous structure; on the other hand, the combination of the hydroxyl group and the carboxyl group which are not suitable and the basic group in the shell is adopted, so that the first discharge capacity of the composite material is obviously reduced. The graphite of comparative example 3, which is not modified, also lacks suitable combination of hydroxyl and carboxyl groups with basic groups in the shell, so that the specific capacity of the material cannot be further improved by metal oxides and nitrogen-containing substances, and the liquid absorption capacity of the composite material is also influenced to a certain extent. The composite materials of comparative examples 1-3 also had a reduced first discharge capacity due to the lack of phosphoric acid added during the preparation process, which also increased the specific capacity of the material and further increased the first efficiency. Comparative example 4 no nitrogen source was added and the first discharge capacity of the material was reduced, indicating that the nitrogen-containing species can increase the specific volume ratio of the material. The shells with different proportions are respectively prepared in comparative examples 5 to 8, the first discharge capacity of the composite graphite material is reduced, and the effect of improving the specific volume ratio of the material can be realized only by the metal oxide, the carbon nano tube, the nitrogen-containing substance and the amorphous carbon in proper proportions.
Experimental example 3 pouch cell test
The artificial graphite composite materials in examples 1 to 3 and comparative examples 1 to 8 were used as negative electrode materials to prepare negative electrode sheets. With ternary materials (LiNi)1/3Co1/3Mn1/3O2) As the positive electrode, LiPF6Solution (solvent EC + DEC, volume ratio 1:1, LiPF)6Concentration of 1.3mol/L) is used as electrolyte, celegard2400 is used as a diaphragm, and 2Ah soft package batteries A10, A20, A30 and B10 are prepared. And testing the cycle performance and the rate performance of the soft package battery.
Multiplying power performance test conditions: charging rate: 1C/2C/3C/5C, discharge multiplying power of 1C; voltage range: 2.8-4.2V.
The test results are shown in Table 3.
Table 3 comparative table of rate charging performance of examples and comparative examples
As can be seen from table 3, the graphite composite materials prepared in examples 1 to 3 of the present invention have better constant current ratio for the pouch cells. The constant current ratios of the comparative examples 1 and 2 are remarkably reduced because the core graphite has no porous structure, so that the liquid absorption capacity is poor, the binding force with the alkaline group in the shell is poor, the doped metal oxide, the carbon nano tube, the nitrogen-containing substance and the like are not tightly bound, the resistivity of the material is improved, and the constant current ratio of the material is further influenced. The graphite of comparative example 3 is not modified, and similarly lacks suitable combination of hydroxyl and carboxyl groups and basic groups in the shell, so that the combination of doped metal oxide, carbon nano tube, nitrogen-containing substance and the like is not tight, the resistivity of the material is improved, and the constant current ratio of the material is influenced. The composite materials of comparative examples 1 to 3 also have a reason for the reduction of the first discharge capacity due to the lack of addition of phosphoric acid during the preparation process, and the presence of phosphoric acid causes pores to be formed on the surface of the material after the material is sintered, so that the internal resistance of the material can be reduced, and the constant current ratio can be improved. The comparative example 4 does not add nitrogen source, and the nitrogen-containing substance can directly influence the internal resistance and specific capacity of the material, thereby influencing the constant current ratio of the material. Compared with the cases with different proportions prepared in the comparative examples 5-8, the constant current ratio of the composite graphite material is reduced, which shows that the metal oxide, the carbon nano tube, the nitrogen-containing substance and the amorphous carbon can improve the constant current ratio of the material only under the appropriate proportion.
The present invention is not limited to the above preferred embodiments, and any modifications, equivalent substitutions, improvements, etc. within the spirit and principle of the present invention should be included in the protection scope of the present invention.
Claims (10)
1. A quick-filling composite graphite material is characterized in that the graphite material is of a core-shell structure, wherein an inner core is porous graphite, and a shell comprises metal oxide, carbon nano tubes and amorphous carbon thereof; the shell accounts for 1-10% of the composite graphite material by mass.
2. The rapid-fill composite graphite material according to claim 1, wherein the porous graphite has a specific surface area of 2 to 10m2Per g, particle diameter of 5-15 μm, tap density of 0.9g/cm or less3The surface hydroxyl/carboxyl content is 0.5-5%.
3. The rapid-fill composite graphite material of claim 1, wherein the porous graphite is prepared by: dissolving urea and inorganic carbonate in water, heating, adding graphite, performing ball milling dispersion, drying, sintering, crushing, dissolving carbonate in dilute hydrochloric acid, washing, and drying to obtain the porous graphite.
4. The rapid-filling composite graphite material according to claim 1, wherein the total weight of the metal oxide, the carbon nanotubes and the amorphous carbon thereof in the shell accounts for 90-99% of the mass of the shell, and the balance is nitrogen-containing substances and impurities.
5. The rapid-filling composite graphite material according to claim 4, wherein the mass ratio of the metal oxide to the carbon nanotubes to the nitrogen-containing substance to the amorphous carbon is as follows: (40-60): (1-10): (1-3): (30-60).
6. The rapid-fill composite graphite material of claim 5, wherein the metal oxide is selected from one or more of tin oxide, manganese oxide, iron oxide, cobalt oxide, nickel oxide, and zirconium oxide.
7. The rapid-charging composite graphite material according to claim 5, wherein the nitrogen-containing substance is a substance formed by carbonizing a nitrogen source at a high temperature;
the nitrogen source is selected from one or more of ammonia, urea, aniline, pyrrole and thiophene.
8. The rapid-filling composite graphite material according to claim 5, wherein the amorphous carbon is a substance formed by carbonizing a binder;
the binder is selected from one or more of low-temperature asphalt, phenolic resin, furfural resin and epoxy resin, wherein the softening point of the low-temperature asphalt is 50-150 ℃.
9. A method for preparing a rapid-charging composite graphite material according to any one of claims 1 to 8, comprising the steps of:
(1) soaking the porous graphite in a catalyst solution, filtering and drying to obtain modified porous graphite;
(2) dissolving metal oxide, carbon nano tubes, a nitrogen source and a binder in an organic solvent, and performing ball milling, dispersion and drying to obtain a binder composite material;
(3) uniformly mixing the binder composite material, phosphoric acid and modified porous graphite, carbonizing, cooling and crushing to obtain the graphite composite material with the outer layer coated with the metal oxide composite material.
10. The method for preparing the quick-filling composite graphite material according to claim 9, wherein the catalyst in the step (1) is selected from one or more of nickel chloride, ferric chloride and cobalt chloride;
the organic solvent in the step (2) is one or more selected from N-methylpyrrolidone, carbon tetrachloride, N-dimethylformamide, cyclohexane and xylene.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111079750.9A CN113764644B (en) | 2021-09-15 | 2021-09-15 | Quick-filling composite graphite material and preparation method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111079750.9A CN113764644B (en) | 2021-09-15 | 2021-09-15 | Quick-filling composite graphite material and preparation method thereof |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN113764644A true CN113764644A (en) | 2021-12-07 |
| CN113764644B CN113764644B (en) | 2022-07-22 |
Family
ID=78795784
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202111079750.9A Active CN113764644B (en) | 2021-09-15 | 2021-09-15 | Quick-filling composite graphite material and preparation method thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN113764644B (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114551836A (en) * | 2022-02-25 | 2022-05-27 | 蜂巢能源科技股份有限公司 | Negative electrode material, preparation method thereof, negative electrode sheet and battery |
| CN114883537A (en) * | 2022-03-31 | 2022-08-09 | 格龙新材料科技(常州)有限公司 | High-capacity fast-charging negative electrode composite material and preparation method thereof |
| CN115172710A (en) * | 2022-07-26 | 2022-10-11 | 晖阳(贵州)新能源材料有限公司 | Iron oxide graphite composite material for lithium ion battery and preparation method thereof |
| WO2023124025A1 (en) * | 2021-12-28 | 2023-07-06 | 蜂巢能源科技股份有限公司 | Graphite composite negative electrode material, preparation method therefor and application thereof |
Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2008288153A (en) * | 2007-05-21 | 2008-11-27 | Sumitomo Metal Ind Ltd | Carbon material powder and method of manufacturing the same |
| CN102623684A (en) * | 2012-04-18 | 2012-08-01 | 长沙理工大学 | Graphite-base carbonaceous anode composite material with special shell structure and preparation method for graphite-base carbonaceous anode composite material |
| CN106784710A (en) * | 2016-12-28 | 2017-05-31 | 广东工业大学 | A kind of carbon@metal oxide@metals/three-dimensional porous graphene composite material of core shell structure and its preparation method and application |
| CN108134044A (en) * | 2016-12-01 | 2018-06-08 | 内蒙古欣源石墨烯科技有限公司 | A kind of high-safety lithium ion battery cathode material and preparation method thereof |
| CN108172794A (en) * | 2017-12-27 | 2018-06-15 | 中科廊坊过程工程研究院 | A kind of composite positive pole and its preparation method and application |
| CN109449428A (en) * | 2018-12-05 | 2019-03-08 | 中南大学 | A kind of nitrogen-doped carbon cladding admixed graphite composite material and preparation method and the application in lithium ion battery |
| CN112786887A (en) * | 2021-01-14 | 2021-05-11 | 广东凯金新能源科技股份有限公司 | Graphite negative electrode material for high temperature and preparation method thereof |
| JP2021101421A (en) * | 2019-11-11 | 2021-07-08 | 昭和電工株式会社 | Composite material, manufacturing method thereof, negative electrode material for lithium ion secondary battery, negative electrode, and secondary battery |
| CN113104845A (en) * | 2020-01-13 | 2021-07-13 | 上海昱瓴新能源科技有限公司 | Method for preparing porous artificial graphite cathode material by using electrode joint powder as raw material |
-
2021
- 2021-09-15 CN CN202111079750.9A patent/CN113764644B/en active Active
Patent Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2008288153A (en) * | 2007-05-21 | 2008-11-27 | Sumitomo Metal Ind Ltd | Carbon material powder and method of manufacturing the same |
| CN102623684A (en) * | 2012-04-18 | 2012-08-01 | 长沙理工大学 | Graphite-base carbonaceous anode composite material with special shell structure and preparation method for graphite-base carbonaceous anode composite material |
| CN108134044A (en) * | 2016-12-01 | 2018-06-08 | 内蒙古欣源石墨烯科技有限公司 | A kind of high-safety lithium ion battery cathode material and preparation method thereof |
| CN106784710A (en) * | 2016-12-28 | 2017-05-31 | 广东工业大学 | A kind of carbon@metal oxide@metals/three-dimensional porous graphene composite material of core shell structure and its preparation method and application |
| CN108172794A (en) * | 2017-12-27 | 2018-06-15 | 中科廊坊过程工程研究院 | A kind of composite positive pole and its preparation method and application |
| CN109449428A (en) * | 2018-12-05 | 2019-03-08 | 中南大学 | A kind of nitrogen-doped carbon cladding admixed graphite composite material and preparation method and the application in lithium ion battery |
| JP2021101421A (en) * | 2019-11-11 | 2021-07-08 | 昭和電工株式会社 | Composite material, manufacturing method thereof, negative electrode material for lithium ion secondary battery, negative electrode, and secondary battery |
| CN113104845A (en) * | 2020-01-13 | 2021-07-13 | 上海昱瓴新能源科技有限公司 | Method for preparing porous artificial graphite cathode material by using electrode joint powder as raw material |
| CN112786887A (en) * | 2021-01-14 | 2021-05-11 | 广东凯金新能源科技股份有限公司 | Graphite negative electrode material for high temperature and preparation method thereof |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2023124025A1 (en) * | 2021-12-28 | 2023-07-06 | 蜂巢能源科技股份有限公司 | Graphite composite negative electrode material, preparation method therefor and application thereof |
| CN114551836A (en) * | 2022-02-25 | 2022-05-27 | 蜂巢能源科技股份有限公司 | Negative electrode material, preparation method thereof, negative electrode sheet and battery |
| WO2023159863A1 (en) * | 2022-02-25 | 2023-08-31 | 蜂巢能源科技股份有限公司 | Negative electrode material and preparation method therefor, negative electrode plate and battery |
| CN114883537A (en) * | 2022-03-31 | 2022-08-09 | 格龙新材料科技(常州)有限公司 | High-capacity fast-charging negative electrode composite material and preparation method thereof |
| CN115172710A (en) * | 2022-07-26 | 2022-10-11 | 晖阳(贵州)新能源材料有限公司 | Iron oxide graphite composite material for lithium ion battery and preparation method thereof |
Also Published As
| Publication number | Publication date |
|---|---|
| CN113764644B (en) | 2022-07-22 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN113764644B (en) | Quick-filling composite graphite material and preparation method thereof | |
| CN107492645B (en) | Silicon oxide-graphene composite material and preparation method thereof | |
| CN114447305B (en) | Multi-carbon-based quick-charge anode composite material and preparation method thereof | |
| WO2022166059A1 (en) | Boron-doped resin-coated artificial graphite material | |
| CN114122372B (en) | Low-expansion silicon-carbon negative electrode material for lithium ion battery and preparation method thereof | |
| CN114613974B (en) | Long-life quick-charging type lithium ion battery cathode material and preparation method thereof | |
| CN114122391B (en) | High-power graphite composite material and preparation method thereof | |
| CN110190284B (en) | Water-based binder for lithium-sulfur battery positive electrode and preparation method and application thereof | |
| CN113745489B (en) | Low-expansion silicon-carbon composite negative electrode material and preparation method thereof | |
| CN113594459B (en) | Composite negative electrode material with multilayer structure and preparation method and application thereof | |
| CN114400312A (en) | Low-expansion silicon-carbon composite negative electrode material and preparation method thereof | |
| CN115566170B (en) | Preparation method of high-energy-density quick-charging lithium ion battery anode material | |
| CN114678505B (en) | Sulfur-phosphorus co-doped hard carbon composite material and preparation method thereof | |
| CN114655951B (en) | Preparation method of lithium ion battery cathode material | |
| CN113594461B (en) | Carbon-silicon composite material and preparation method and application thereof | |
| CN113764645B (en) | Preparation method of hard carbon composite material with three-dimensional structure | |
| CN115172710A (en) | Iron oxide graphite composite material for lithium ion battery and preparation method thereof | |
| CN112467138B (en) | Preparation method of aluminum-doped porous silicon-carbon composite material and lithium ion battery | |
| CN114975918A (en) | Graphite composite material coated with fast ion conductor and preparation method thereof | |
| CN114843483A (en) | Hard carbon composite material and preparation method and application thereof | |
| CN208674263U (en) | Compound cathode and lithium secondary battery | |
| CN114162814A (en) | Modification method of graphite | |
| CN110649213A (en) | Coating diaphragm material for lithium-sulfur secondary battery and application thereof | |
| CN115954465B (en) | High-power hard carbon composite material and preparation method thereof | |
| CN114899384B (en) | Three-dimensional porous silica anode composite material and preparation method thereof |
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 | ||
| CB02 | Change of applicant information |
Address after: 051130 No. 8, kuntian Avenue, Suyang Township, Yuanshi County, Shijiazhuang City, Hebei Province Applicant after: Hebei kuntian new energy Co.,Ltd. Address before: 051130 south of Su Yang Xiang Nan Bai Lou Cun, Yuanshi County, Shijiazhuang City, Hebei Province Applicant before: HEBEI KUNTIAN NEW ENERGY TECHNOLOGY Co.,Ltd. |
|
| CB02 | Change of applicant information | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |