Graphite negative electrode material and preparation and application thereof

Abstract

The application discloses a battery graphite negative electrode material, and the interlayer spacing of the material is greater than or equal to 0.36 nm. The application also discloses a preparation method and application of the graphite negative electrode material. The graphite negative electrode material provided by the application uses catalytic oil slurry as raw material, greatly improves the added value of the catalytic oil slurry on one hand, and on the other hand, by adding lignin sulfonate and metal catalyst in the preparation process, the cross-linking degree of cross-linked calcined coke prepared from the catalytic oil slurry can be significantly improved based on the oxygen-containing functional groups in the lignin sulfonate, so that the cross-linked calcined coke forms a three-dimensional cross-linked structure, the three-dimensional cross-linked structure can further improve the interlayer spacing of the product after graphitization, the stacking of carbon layers in the prepared graphite negative electrode material is more disordered, so that the lithium intercalation / sodium intercalation resistance of the graphite negative electrode material is smaller, and then the fast charging and discharging process of the graphite negative electrode material is facilitated, and the specific capacity and cycle stability are improved.

Description

TECHNICAL FIELD

[0001] The present application relates to a battery graphite negative material and its preparation and application BACKGROUND

[0002] As a by-product of heavy oil catalytic cracking reaction, the annual production of catalytic oil slurry in China is about 8 million tons, so it is very important to recycle and reuse catalytic oil slurry. At present, the recycling and reuse of catalytic oil slurry is mainly used as fuel or asphalt raw material, but due to the fact that catalytic oil slurry usually contains a large amount of saturated hydrocarbons and aromatic hydrocarbons, the carbon content is high, therefore, the existing recycling and reuse method of catalytic oil slurry is not conducive to the full utilization of abundant carbon source, thereby causing resource waste.

[0003] Therefore, how to fully utilize the carbon source in catalytic oil slurry is a problem to be solved at present. Lithium ion battery and sodium ion battery are the two most commercialized secondary batteries, with a market of trillions of yuan in the fields of electric vehicles, energy storage and 3C digital. The negative electrode of both batteries is carbon material, with a market demand of more than 1.5 million tons in 2022, and a market demand of 3 million tons in 2030. SUMMARY

[0004] In order to improve the utilization efficiency of catalytic oil slurry, the present application uses catalytic oil slurry to prepare battery graphite negative material, which can be used in lithium battery and sodium battery.

[0005] As an aspect of the present application, a battery graphite negative material is involved, the material has an interlayer spacing of ≥0.36 nm, a lithium battery negative electrode capacity of ≥320 mAh / g, a first efficiency of ≥90%, and a capacity retention rate of 80% or more after 1000 cycles; a sodium battery negative electrode capacity of ≥220 mAh / g, a first efficiency of ≥80%, and a capacity retention rate of 80% or more after 1000 cycles.

[0006] As another aspect of the present application, a method for preparing the above-mentioned battery graphite negative material is involved, comprising:

[0007] S1: mixing catalytic oil slurry, lignin sulfonate and metal catalyst mixture in a pressure reaction kettle at 350-450℃ under inert gas atmosphere to obtain a solid product;

[0008] S2: removing metal salt from the solid product to obtain a catalytic oil slurry crosslinked product;

[0009] S3: subjecting the catalytic oil slurry crosslinked product to polycondensation treatment at 500-600℃, and then subjecting the obtained product to high-temperature calcination at 800-1500℃ to obtain a crosslinked calcined coke;

[0010] S4: subjecting the crosslinked calcined coke to graphitization treatment to obtain the graphite negative material.

[0011] Optionally, the inert gas is nitrogen or argon.

[0012] Optionally, the lignin sulfonate is selected from at least one of sodium lignin sulfonate, calcium lignin sulfonate.

[0013] Optionally, the metal catalyst is selected from at least one of aluminum trichloride, ferric trichloride, ferrocene, sodium nitrate, potassium nitrate.

[0014] Optionally, the mass ratio of the catalytic oil slurry, the lignin sulfonate and the metal catalyst ranges from (100-300):(50-200):(1-10).

[0015] Optionally, the reaction time in the pressure reactor in step S1 ranges from 3-12h.

[0016] Optionally, the calcination time in step S3 ranges from 1-3h.

[0017] As a further aspect of the present application, the use of the above-mentioned battery graphite negative electrode material in the preparation of a lithium ion battery or a sodium ion battery is disclosed.

[0018] As a further aspect of the present application, a lithium ion battery or a sodium ion battery using the above-mentioned battery graphite negative electrode material is disclosed.

[0019] The graphite negative electrode material provided by the present application uses catalytic oil slurry as raw material, which greatly improves the added value of the catalytic oil slurry, realizes the full utilization of the carbon source in the catalytic oil slurry and avoids resource waste; on the other hand, by adding lignin sulfonate and metal catalyst in the preparation process, based on the oxygen-containing functional groups in the lignin sulfonate, the cross-linking degree of the cross-linked calcined coke prepared from the catalytic oil slurry can be significantly improved, so that the cross-linked calcined coke forms a three-dimensional cross-linked structure, and the three-dimensional cross-linked structure can further improve the interlayer spacing of the graphitized product, so that the stacking of the carbon layers in the prepared graphite negative electrode material is more disordered, thereby the lithium / sodium intercalation resistance of the graphite negative electrode material is smaller, which is conducive to the rapid charging and discharging process of the graphite negative electrode material and helps to improve the specific capacity and cycle stability.

[0020] Since the radius of sodium ion is larger than that of lithium ion, the artificial graphite prepared from traditional needle coke and petroleum coke has small interlayer spacing and does not have microporous structure, so it does not have sodium storage capacity. Therefore, the present application adds lignin with cross-linked structure into the catalytic oil slurry, and the lignin is a typical hard carbon precursor. The catalytic oil slurry and lignin are uniformly mixed, and the graphite product obtained by polycondensation, carbonization and graphitization has a hard carbon structure formed by cross-linking and stacking of carbon microcrystals, and can store lithium and sodium at the same time, which can be applied in the field of sodium ion battery and greatly expands the application field of catalytic oil slurry. DETAILED DESCRIPTION

[0021] The application will now be further described. The examples described below are illustrative and are not intended to limit the present application, and all other examples that can be derived by those skilled in the art without creative work based on the examples of the present application, fall within the scope of protection of the present application.

[0022] The inventors conducted experiments referring to the invention patent CN114243010A, using catalytic oil slurry as carbon source, obtaining clear oil slurry by chemical sedimentation method, and reacting with metal complex prepared by SbCl3 in thioacetamide conditions, and then calcining to obtain a composite material; it was found that the interlayer spacing of the composite material was small, the lithium ion insertion would have significant volume expansion, and the sodium ion could not be inserted, and could not be used for sodium battery.

[0023] The inventors conducted experiments referring to the invention patent CN112551504A, pretreated the catalytic oil slurry to obtain clear oil; heated and stirred the clear oil, added nano silicon powder and mixed; heated to 800-1200℃, and kept constant temperature for 30-180min to obtain a carbon-silicon composite material; it was found that the crosslinking degree of the composite material was insufficient, it did not have a hard carbon structure, the lithium insertion resistance was large, it could not insert sodium, and could not be used for sodium battery.

[0024] The inventors conducted experiments referring to the invention patent CN114381295A, prepared refined tar from tar as raw material, mixed the refined tar with catalytic oil slurry, and then performed shallow thermal polycondensation and deep thermal polycondensation transformation to prepare carbon material; it was found that without adding lignin precursor with crosslinking structure, three-dimensional crosslinking structure could not be formed, lithium / sodium ion insertion resistance could not be reduced, and it could not be used for sodium ion battery.

[0025] The inventors conducted experiments referring to the invention patent CN:114477126A, added catalytic oil slurry into a reactor, performed first heat treatment to obtain a first stream; continued to heat and pressurize the reactor to perform second heat treatment to obtain a second stream; mixed the second stream with the first stream, treated and then cooled and settled to obtain a third stream and a fourth stream; mixed the third stream with an organic solvent for treatment, and then performed solid-liquid separation to obtain mesocarbon microbeads; it was found that without adding lignin sulfonate and metal catalyst, the crosslinking degree could not be significantly improved to form three-dimensional crosslinking structure, which was not conducive to improving specific capacity and cycle stability, the product had small interlayer spacing, and could not be used for sodium ion battery.

[0026] In summary, the preparation method of the graphite negative electrode material of the present application comprises the following steps:

[0027] S1: uniformly mix catalytic oil slurry, lignin sulfonate and metal catalyst under inert gas atmosphere, and react in a 350-450℃ pressure reactor to obtain a solid product;

[0028] S2: After crushing the solid product, the solid product is sequentially washed with hydrochloric acid and deionized water to remove metal salts, and a catalytic oil slurry crosslinking product is obtained;

[0029] S3: The catalytic oil slurry crosslinking product is subjected to polycondensation treatment at 500-600 DEG C, and the obtained product is subjected to high-temperature calcination at 800-1500 DEG C, and a crosslinked calcined coke is obtained;

[0030] S4: The product of S3 is crushed and granulated by a ball mill, an air flow crusher or a mechanical impact mill, and the material is crushed to a desired particle size;

[0031] S5: The product obtained in S4 is subjected to graphitization treatment by a graphitization furnace at 2600-3000 DEG C, and the graphite negative electrode material is obtained.

[0032] The preparation method of the graphite negative electrode material provided by the application greatly improves the added value of the catalytic oil slurry, realizes the full utilization of the carbon source in the catalytic oil slurry, avoids resource waste, and reduces carbon emissions.

[0033] In the preparation process, by adding lignin sulfonate and a metal catalyst, based on the oxygen-containing functional groups in the lignin sulfonate, the crosslinking degree of the crosslinked calcined coke prepared from the catalytic oil slurry can be significantly improved, so that the crosslinked calcined coke forms a three-dimensional crosslinked structure, and the three-dimensional crosslinked structure can further improve the interlayer spacing of the product after graphitization, so that the stacking of the carbon layers in the prepared graphite negative electrode material is more disordered, thereby the lithium / sodium intercalation resistance of the graphite negative electrode material is smaller, and the fast charging and discharging process of the graphite negative electrode material is facilitated, and the specific capacity and cycle stability are improved.

[0034] In the preparation process, by adding lignin sulfonate and a metal catalyst, based on the oxygen-containing functional groups in the lignin sulfonate, the crosslinking degree of the crosslinked calcined coke prepared from the catalytic oil slurry can be significantly improved, so that the crosslinked calcined coke forms a three-dimensional crosslinked structure, and the three-dimensional crosslinked structure can further improve the interlayer spacing of the product after graphitization, so that the stacking of the carbon layers in the prepared graphite negative electrode material is more disordered, thereby the lithium / sodium intercalation resistance of the graphite negative electrode material is smaller, and the fast charging and discharging process of the graphite negative electrode material is facilitated, and the specific capacity and cycle stability are improved.

[0035] The metal catalyst is preferably at least one selected from aluminum trichloride, iron trichloride, ferrocene, sodium nitrate, potassium nitrate and calcium oxide.

[0036] In order to balance the performance, economy and preparation efficiency of the graphite negative electrode material, the mass ratio of the catalytic oil slurry, the lignin sulfonate and the metal catalyst is preferably (100-300):(50-200):(1-10); the reaction time in the pressure reaction kettle in step S1 is preferably 3-12 h; and the calcination time in step S3 is preferably 1-3 h.

[0037] In order to make the above objectives, features and advantages of the present application more apparent, a specific embodiment of the present application is described in detail below.

[0038] Example 1

[0039] The present embodiment provides a preparation method of a graphite negative electrode material, which comprises the following steps:

[0040] S1: 200 g of catalytic oil slurry was added to a 1000 mL pressure reactor under a nitrogen atmosphere, 130 g of calcium lignosulfonate and 5 g of aluminum trichloride were added, and the mixture was reacted at 400°C for 12 h to obtain a solid product;

[0041] S2: The solid product was crushed to 300 mesh, washed with hydrochloric acid for 2 times, and then washed with deionized water until neutral to obtain a catalytic oil slurry crosslinked product;

[0042] S3: The catalytic oil slurry crosslinked product was subjected to polycondensation treatment at 600°C, and the obtained product was subjected to high-temperature calcination at 1500°C to obtain a crosslinked calcined coke;

[0043] S4: The product of S3 was crushed and granulated by mechanical impact grinding, and the material was crushed to a desired particle size: d50 = 10-20 μm;

[0044] S5: The product obtained in S4 was subjected to graphitization treatment at 2800°C by a graphitization furnace to obtain the graphite negative electrode material.

[0045] Example 2

[0046] The present embodiment provides a preparation method of a graphite negative electrode material, which comprises the following steps:

[0047] S1: 100 g of catalytic oil slurry was added to a 1000 mL pressure reactor under a nitrogen atmosphere, 50 g of sodium lignosulfonate and 1 g of ferric trichloride were added, and the mixture was reacted at 450°C for 8 h to obtain a solid product;

[0048] S2: The solid product was crushed to 200 mesh, washed with hydrochloric acid for 1 time, and then washed with deionized water until neutral to obtain a catalytic oil slurry crosslinked product;

[0049] S3: The catalytic oil slurry crosslinked product was subjected to polycondensation treatment at 550°C, and the obtained product was subjected to high-temperature calcination at 1000°C to obtain a crosslinked calcined coke;

[0050] S4: The product of S3 was crushed and granulated by a ball mill, and the material was crushed to a desired particle size: d50 = 10-20 μm;

[0051] S5: subjecting the product obtained in S4 to graphitization treatment in a graphitization furnace at 2600°C to obtain the graphite negative electrode material.

[0052] Example 3

[0053] The embodiment provides a preparation method of a graphite negative electrode material, and the preparation method comprises the following steps:

[0054] S1: under an argon atmosphere, 300 g of catalytic oil slurry is added into a 1000 mL pressure reaction kettle, 200 g of calcium lignosulfonate and 10 g of ferrocene are added, and stirring reflux reaction is carried out at 380°C for 10 h to obtain a solid product;

[0055] S2: the solid product is crushed to 400 meshes, washed with hydrochloric acid for 3 times, and then washed with deionized water until neutral to obtain a catalytic oil slurry crosslinked product;

[0056] S3: the catalytic oil slurry crosslinked product is subjected to polycondensation treatment at 550°C, and the obtained product is subjected to high-temperature calcination at 1000°C to obtain a crosslinked calcined coke;

[0057] S4: the product in S3 is subjected to crushing and granulation by using an airflow crusher, and the material is crushed to a required particle size: d50=10-20 μm;

[0058] S5: the product obtained in S4 is subjected to graphitization treatment in a graphitization furnace at 2600°C to obtain the graphite negative electrode material.

[0059] Example 4

[0060] The embodiment provides a preparation method of a graphite negative electrode material, and the preparation method comprises the following steps:

[0061] S1: under an argon atmosphere, 300 g of catalytic oil slurry is added into a 1000 mL pressure reaction kettle, 200 g of calcium lignosulfonate and 10 g of ferrocene are added, and stirring reflux reaction is carried out at 380°C for 10 h to obtain a solid product;

[0062] S2: the solid product is crushed to 400 meshes, washed with hydrochloric acid for 3 times, and then washed with deionized water until neutral to obtain a catalytic oil slurry crosslinked product;

[0063] S3: the catalytic oil slurry crosslinked product is subjected to polycondensation treatment at 550°C, and the obtained product is subjected to high-temperature calcination at 1000°C to obtain a crosslinked calcined coke;

[0064] S4: the product in S3 is subjected to crushing and granulation by using an airflow crusher, and the material is crushed to a required particle size: d50=10-20 μm;

[0065] S5: subjecting the product obtained in S4 to graphitization treatment in a graphitization furnace at 2600°C to obtain the graphite negative electrode material.

[0066] Example 5

[0067] The present embodiment provides a preparation method of a graphite negative electrode material, which comprises the following steps:

[0068] S1: under an argon atmosphere, 150 g of catalytic oil slurry is added to a 1000 mL pressure reactor, 150 g of calcium lignosulfonate and 5 g of potassium nitrate are added, and stirred reflux reaction is carried out at 435°C for 10 h to obtain a solid product;

[0069] S2: the solid product is crushed to 400 mesh, washed with hydrochloric acid for 3 times, and then washed with deionized water until neutral to obtain a catalytic oil slurry crosslinked product;

[0070] S3: the catalytic oil slurry crosslinked product is subjected to polycondensation treatment at 550°C, and the obtained product is subjected to high-temperature calcination at 1000°C to obtain a crosslinked calcined coke;

[0071] S4: the product of S3 is crushed and granulated by an air flow crusher, and the material is crushed to a desired particle size: d50 = 10-20 μm;

[0072] S5: the product obtained in S4 is subjected to graphitization treatment in a graphitization furnace at 2600°C to obtain the graphite negative electrode material.

[0073] Comparative Example 1

[0074] The present comparative example provides a preparation method of a graphite negative electrode material, which comprises the following steps:

[0075] S1: under a nitrogen atmosphere, 300 g of catalytic oil slurry and 5 g of aluminum trichloride are added to a 1000 mL pressure reactor, and reaction is carried out at 400°C for 12 h to obtain a solid product A;

[0076] S2: the solid product A is crushed to 300 mesh, washed with hydrochloric acid for 2 times, and then washed with deionized water until neutral to obtain a catalytic oil slurry crosslinked product B;

[0077] S3: the catalytic oil slurry crosslinked product B is subjected to polycondensation treatment at 600°C, and the obtained product is subjected to high-temperature calcination at 1500°C to obtain a crosslinked calcined coke C;

[0078] S4: the product of S3 is crushed and granulated by mechanical impact grinding, and the material is crushed to a desired particle size: d50 = 10-20 μm;

[0079] S5: the product obtained in S4 is subjected to graphitization treatment in a graphitization furnace at 2800°C to obtain the graphite negative electrode material.

[0080] The graphite negative electrode material prepared in each of the above embodiments and the comparative example was subjected to performance detection, and under the condition that the preparation parameters were the same, the carbon layer of the graphite negative electrode material prepared after the lignosulfonate and the metal catalyst were added in the embodiments of the application was more disordered in stacking; through xrd testing and formula calculation, the interlayer spacing of the graphite negative electrode material prepared in the embodiments 1-5 of the application was 0.363-0.378 nm, while the interlayer spacing of the graphite negative electrode material prepared in the comparative example 1 was about 0.335 nm, thereby proving that the interlayer spacing of the graphite negative electrode material prepared by the method of taking the catalytic oil slurry as the raw material, preparing petroleum coke or needle coke through a traditional process, and then preparing artificial graphite negative electrode through graphitization is small, and the sodium ion is difficult to be embedded into the graphite negative electrode material, so the graphite negative electrode material prepared by the traditional method is difficult to be used in a sodium ion battery; and when the graphite negative electrode material is used in a lithium ion battery, the embedding of lithium ions will cause significant volume expansion, which also limits its application in the lithium ion battery; and the preparation method of the graphite negative electrode material provided by the application has a larger interlayer spacing of the graphite negative electrode material, so that the sodium ion and the lithium ion can be embedded, and the embedding of the sodium ion and the lithium ion will not cause significant volume expansion.

[0081] The lithium battery 5C cycle data of the graphite negative electrode material prepared in the embodiments of the application is shown in Table 1.

[0082] Table 1

[0083]

[0084] The sodium battery 2C cycle data of the graphite negative electrode material prepared in the embodiments of the application is shown in Table 2.

[0085] Table 2

[0086]

[0087]

[0088] The graphite negative electrode material prepared in each of the embodiments 1-5 and the comparative example 1 was used as a negative electrode to prepare a lithium ion secondary battery, and the prepared lithium ion secondary battery was tested, and the test data is shown in Table 3:

[0089] Table 3

[0090]

[0091] The graphite negative electrode material prepared in each of the embodiments 1-5 and the comparative example 1 was used as a negative electrode to prepare a sodium ion secondary battery, and the prepared sodium ion secondary battery was tested, and the test data is shown in Table 4:

[0092] Table 4

[0093]

[0094] As can be seen from the above data, the graphite negative electrode material prepared by the preparation method provided by the application has good specific capacity and cycle stability, and can be applied to lithium ion secondary batteries and sodium ion secondary batteries, thereby realizing full utilization of carbon sources in catalytic oil slurry and obtaining super-fast charging lithium battery / sodium battery graphite negative electrode material. The graphite negative electrode material prepared by the traditional process in Comparative Example 1 is only suitable for lithium ion batteries, and has poor specific capacity and cycle stability when used in lithium ion batteries.

[0095] Based on the above ideal embodiments according to the application, through the above description, relevant personnel can make various changes and modifications without deviating from the technical idea of the application. The technical scope of the application is not limited to the content of the specification, and the technical scope must be determined according to the scope of the claims.

Claims

1. A method for preparing graphite anode materials for batteries, characterized in that, include: S1: Under an inert gas atmosphere, a mixture of catalytic oil slurry, lignin sulfonate, and metal catalyst is reacted in a pressure reactor at 350-450℃ to obtain a solid product; S2: Remove the metal salt from the solid product to obtain the catalytic oil slurry crosslinking product; S3: The cross-linked product of the catalytic oil slurry is subjected to polycondensation treatment at 500-600℃, and the resulting product is calcined at high temperature at 800-1500℃ to obtain cross-linked calcined coke; S4: The cross-linked calcined coke is graphitized to obtain the graphite anode material; The interlayer spacing of the graphite anode material is ≥0.36nm.

2. The method according to claim 1, characterized in that, The inert gas is nitrogen or argon.

3. The method according to claim 1, characterized in that, The lignin sulfonate is selected from at least one of sodium lignin sulfonate and calcium lignin sulfonate.

4. The method according to claim 1, characterized in that, The metal catalyst is selected from at least one of aluminum trichloride, ferric chloride, ferrocene, sodium nitrate, and potassium nitrate.

5. The method according to claim 1, characterized in that, The mass ratio of the catalytic slurry, the lignosulfonate, and the metal catalyst is in the range of (100-300):(50-200):(1-10).

6. The method according to claim 1, characterized in that, The reaction time in the pressure reactor in step S1 is 3-12 hours.

7. The method according to claim 1, characterized in that, The calcination time in step S3 is 1-3 hours.

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