Method for recycling and co-producing regenerated graphite active material from waste battery graphite carbon residue

Abstract

The present application relates to the field of electrode material recycling, in particular to a recycling method of graphite carbon residue from waste batteries, wherein the graphite carbon residue separated from waste batteries is put into a water-soluble carbonate solution for transformation treatment to obtain transformed graphite material; the transformed graphite material is put into acid solution for treatment, followed by solid-liquid separation to obtain acid-treated graphite material; the acid-treated graphite material is heat-treated at a temperature of 300-600 DEG C in an oxygen-containing atmosphere to obtain regenerated graphite; the graphite carbon residue contains graphite and at least one of calcium sulfate and silicon as impurities in the recycling process. The present application also provides the regenerated carbon residue obtained by the method and its application. The method can recycle regenerated graphite material with excellent performance.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of battery electrode material recycling, and particularly relates to the field of recycling of graphite carbon residue of waste batteries. BACKGROUND

[0002] With the rapid development of the new energy automobile industry, the consumption of lithium ion batteries is increasing year by year, which also brings the problems of increasing scrap amount of lithium ion batteries and reasonable disposal of waste lithium ion batteries. The waste lithium ion batteries contain lithium, nickel, cobalt, manganese, aluminum, copper, iron and other metals. Comprehensive recovery of the waste lithium ion batteries can not only solve the problem of environmental pollution, but also realize the recycling of resources, which has important environmental protection and economic value.

[0003] At present, sulfuric acid is mostly used as a leaching agent to dissolve and recover valuable metals in the recycling of waste lithium ion batteries. The leaching waste liquid is generally neutralized by lime and then returned to the system for repeated use. Therefore, in addition to a large amount of natural graphite, artificial graphite and other negative active materials, the carbon residue generated in the recycling of waste lithium ion batteries also inevitably contains calcium sulfate, nickel-cobalt metal oxides, carbon conductive agents, and complex components such as separator carbonization, and even contains silicon dioxide dust, which makes it difficult to reuse the carbon residue generated in the recycling of waste lithium ion batteries. In the face of the rapid increase in the number of waste lithium ion batteries, how to effectively treat the carbon residue generated in the recycling of waste lithium ion batteries which accounts for a high proportion and realize its reuse is a problem to be solved. SUMMARY

[0004] In view of the deficiencies of the prior art, the present application aims to provide a recycling method for graphite carbon residue of waste batteries, which aims to recycle graphite materials in waste batteries and improve the carbon yield and electrochemical performance.

[0005] The second object of the present application is to provide a method for recycling carbon residue of waste batteries and co-producing regenerated graphite active material, which aims to co-produce active materials with high electrochemical performance based on carbon materials of waste batteries.

[0006] The third object of the present application is to provide a graphite active material prepared by the co-production method and its application in alkali metal secondary batteries.

[0007] The fourth object of the present application is to provide an alkali metal secondary battery containing the regenerated graphite active material and an electrode thereof.

[0008] The carbon residue of waste battery recycling contains a large amount of waste graphite, which has a high recycling value. However, such graphite material has a large recycling difficulty. For example, it contains a large amount of fine particle conductive agent, and there are a large number of structural damages and impurities caused by long-term circulation. Furthermore, it also contains process impurities such as calcium sulfate and silicon dioxide introduced by the recycling process. However, the existing carbon residue regeneration utilization means mainly investigates the defects and impurity problems caused by circulation, and does not pay attention to the problem of process impurities on graphite regeneration and its regeneration performance. In view of the blank in the industry, the present application provides the following solutions:

[0009] A recycling method of waste battery graphite carbon residue, graphite carbon residue separated from waste batteries is placed in a water-soluble carbonate solution for transformation treatment, and a transformed graphite material is obtained;

[0010] The transformed graphite material is treated in an acid solution, and then solid-liquid separation is performed to obtain an acid-treated graphite material;

[0011] The acid-treated graphite material is heat-treated at a temperature of 300-600 DEG C in an oxygen-containing atmosphere to obtain regenerated graphite.

[0012] On the basis of solving the problem of difficult regeneration caused by long-term circulation, the present application also first considers the influence of process impurities on regeneration. For the problem of process impurities, the present inventors found early that the process impurities such as calcium sulfate in the carbon residue are difficult to remove based on acid leaching. Furthermore, the particles are fine and often embedded in the interlayer structure of graphite, which further increases the difficulty of removal. For this problem, the present application found that the graphite carbon residue is innovatively transformed in a water-soluble carbonate solution, and further combined with acid treatment and heat treatment in an oxygen-containing atmosphere, which can realize synergy, effectively solve the structural defects and cycle impurities in waste graphite, effectively transform process impurities, remove harmful components, improve the microstructure and active groups of regenerated graphite, and further improve the primary effect and performance stability of the regenerated material. Furthermore, it can realize the carbon rate consideration effect which is difficult to realize in the industry.

[0013] In the present application, the graphite carbon residue is a graphite-containing carbon residue recovered from waste batteries;

[0014] Preferably, the graphite carbon residue comprises waste negative electrode material, and optionally comprises carbon residue after recycling of waste positive electrode metal;

[0015] Preferably, the waste battery is a waste lithium secondary battery;

[0016] Preferably, the negative electrode material of the waste battery is an electrode material stripped from the negative electrode of the waste battery;

[0017] Preferably, the positive electrode recycled carbon residue is the carbon residue after recycling metal elements in the positive electrode.

[0018] Preferably, the waste battery recycled carbon residue contains graphite, and further contains at least one of a conductive agent, a binder, and a metal impurity.

[0019] Preferably, the graphite carbon residue further contains calcium sulfate and silicon (mainly silicon dioxide) recycling process impurities. The process of the present application can be applied to any battery carbon residue, but for the carbon residue containing the recycling process impurities, the process of the present application can exhibit a more optimal regeneration effect compared to the existing process.

[0020] In the present application, the transformation of water-soluble carbonate, acid treatment and roasting treatment in oxygen-containing atmosphere are the key to solve the problems of conductive agent fine powder, cycle structure defect, cycle impurity and process impurity faced by waste graphite carbon residue. Further control of the transformation process, acid treatment process and heat treatment process is helpful to further improve the carbon yield and performance of the regenerated graphite.

[0021] In the present application, the water-soluble carbonate is at least one of ammonium carbonate, sodium carbonate and potassium carbonate.

[0022] Preferably, the concentration of water-soluble carbonate in the water-soluble carbonate solution is 1-5M.

[0023] Preferably, the volume weight ratio of the water-soluble carbonate solution to the graphite carbon residue is 1-20ml / g.

[0024] In the present application, the transformation process is carried out under microwave assistance. The present application researches find that under the preferred microwave assistance, it is helpful to improve the transformation effect and further improve the performance of the regenerated graphite.

[0025] Preferably, the temperature of the transformation process is 40-100℃, and further preferably 80-100℃.

[0026] Preferably, the treatment time of the transformation process is 0.5-5h, and further can be 1-2h.

[0027] In the present application, after the transformation process, solid-liquid separation is carried out to obtain a transformed material, the transformed material is dispersed in an acid solution for acid treatment, and then solid-liquid separation is carried out to obtain an acid-treated material.

[0028] In the present application, the acid solution includes at least one of hydrochloric acid, nitric acid and HF.

[0029] Preferably, the acid solution comprises hydrochloric acid, nitric acid and HF; further preferably, in the acid solution, chloride ions are 0.1-1 mol / L, nitrate ions are 0.1-1 mol / L, and fluoride ions are 0.1-1 mol / L. The present application has found that the mixed acid can be combined with the transformation and subsequent heat treatment process to further improve the carbon yield and electrochemical performance.

[0030] Preferably, the liquid-solid volume weight ratio in the acid treatment process is 1-10 ml / g.

[0031] In the present application, the temperature of acid treatment is not particularly required, for example, it can be 20-50 DEG C.

[0032] Preferably, the acid treatment time can be 1-3 h.

[0033] In the present application, after acid treatment, the product can be directly subjected to subsequent treatment, or subjected to washing and drying treatment before subsequent treatment.

[0034] In the present application, the acid-treated material is subjected to heat treatment in an oxygen-containing atmosphere, which helps to realize selective purification of graphite, and also helps to construct defect vacancies and improve the regenerated electrochemical performance.

[0035] In the present application, the oxygen partial pressure of the oxygen-containing atmosphere is 20-35 V %.

[0036] Preferably, the oxygen-containing atmosphere further comprises steam of at least one of HNO3 and HF. The present application has also found that the heat treatment in the combined system of oxygen and auxiliary steam helps to further unexpectedly and synergistically combine with the transformation and acid treatment process, which helps to improve the performance of the regenerated graphite, and also can take into account the excellent carbon yield.

[0037] Preferably, the temperature of the heat treatment process is 500-600 DEG C. The heat treatment time is 0.5-4 h.

[0038] Preferably, the heat treatment process comprises two-stage heat treatment, wherein the temperature of the first-stage heat treatment is 300-400 DEG C, and the temperature of the second-stage heat treatment is 500-600 DEG C. In the present application, the combination of the combined atmosphere and the two-stage treatment and the joint control of the temperature helps to further obtain a synergistic effect, so as to take into account the excellent carbon yield and performance.

[0039] Preferably, the first-stage heat treatment time is 0.5-3 h, and the second-stage heat treatment time is 0.5-2 h.

[0040] The application further provides a method for recycling waste battery graphite carbon residue and producing regenerated graphite active material in parallel, wherein the regenerated graphite is obtained by using the recycling method, the regenerated graphite is compounded with soft carbon source, first-stage roasting is performed at 600-700 DEG C in advance, and second-stage roasting treatment is performed at a temperature of 1500-2400 DEG C, so as to prepare the regenerated graphite active material.

[0041] In the application, the two-stage compounding of the soft carbon source under the innovative graphite regeneration process helps to obtain high-performance negative active material.

[0042] In the application, the soft carbon source can be a conventional material in the industry, and preferably, the soft carbon source is pitch.

[0043] Preferably, the soft carbon source accounts for 3-10% of the weight of the regenerated graphite.

[0044] Preferably, the atmosphere of the first-stage roasting is a reducing atmosphere, and further preferably, the atmosphere of the first-stage roasting contains hydrogen; more preferably, the hydrogen content of the atmosphere of the first-stage roasting is 5-15 v%. It is found that the performance of the regenerated graphite active material can be further improved under the reducing atmosphere.

[0045] Preferably, the time of the first-stage roasting is 2-4 h.

[0046] Preferably, the atmosphere of the second-stage roasting is a protective atmosphere.

[0047] Preferably, the time of the second-stage roasting is 3-6 h.

[0048] The application further provides the regenerated graphite active material prepared by the method.

[0049] In the application, the product can be endowed with special physical and structural characteristics based on the process, and in addition, the product with the distinguished characteristics can unexpectedly exhibit excellent electrochemical performance.

[0050] The application further provides the application of the regenerated graphite active material to the preparation of a battery electrode. In the application, the regenerated graphite active material can be used to prepare the required battery electrode based on the existing means.

[0051] The application further provides an alkali metal secondary battery electrode comprising the regenerated graphite active material prepared by the preparation method. Preferably, the electrode is a negative electrode.

[0052] Preferably, the alkali metal secondary battery is a sodium and / or lithium secondary battery, and further can be a lithium ion battery.

[0053] The application further provides an alkali metal secondary battery comprising the electrode comprising the regenerated graphite active material of the application.

[0054] The battery and electrode thereof described in the present application can be conventional in other components and structures except that the regenerated graphite active material described in the present application is included.

[0055] Advantages

[0056] The present application solves the problems of fine powder of conductive agent, cycle defects, cycle impurities and process impurities in the recycling process of graphite carbon residue of waste batteries through the combined process of carbonate transformation, acid treatment and heat treatment in oxygen-containing atmosphere. The present application process can realize the balance of carbon residue recycling performance and carbon yield.

[0057] In the present application, the transformation, acid treatment and heat treatment processes are controlled, which helps to further improve the graphite regeneration performance. In addition, the obtained regenerated graphite and soft carbon source are subjected to two-stage heat treatment, which further cooperates with the control of the first-stage reducing atmosphere heat treatment, and helps to further improve the performance of the prepared graphite active material. BRIEF DESCRIPTION OF DRAWINGS

[0058] 【 Figure 1 Scanning electron microscope image (SEM) of the regenerated graphite prepared in Example 1 DETAILED DESCRIPTION

[0059] The present application will be further described in conjunction with specific examples, but the present application is not limited in any way by the examples.

[0060] In the examples and comparative examples of the present application, the recycled carbon residue is a carbonaceous powder with graphite as the main component obtained after crushing, disassembling, sorting and leaching to recover metals from waste lithium ion batteries; the carbon content is 85wt%, the recovery rate of the regenerated graphite negative electrode is calculated based on the carbon content, and the recycled process impurities containing calcium sulfate and silicon dioxide are contained in an amount of 0.2-1wt.%.

[0061] Electrochemical performance test: CR2025 button cell was assembled in an argon-filled dry glove box with the graphite electrode (weight ratio of graphite active material, acetylene black and PVDF was 95:2:3) as the working electrode, lithium metal as the negative electrode, 1mol / L LiPF6 in EC / EMC (volume ratio 1:1) as the electrolyte, and PE-PP composite membrane as the separator, and the battery was charged and discharged at room temperature (25℃) in the voltage range of 0.001-1.5V at a current density of 100mA / g.

[0062] In the following cases, the heating rate is 5℃ / min unless otherwise stated.

[0063] Example 1

[0064] Step (1):

[0065] The carbon residue is added to 1 mol / L sodium carbonate solution (liquid-solid ratio of 5 ml / g) and stirred at 80°C for 1 hour. After the reaction, the transformed carbon residue is obtained by filtration;

[0066] Step (2):

[0067] The transformed carbon residue is added to a mixed acid composed of hydrochloric acid, nitric acid and hydrofluoric acid (liquid-solid ratio of 5 ml / g) and stirred at 20-35°C for 2 hours. In the mixed acid, the chloride ion is 0.5 mol / L, the nitrate ion is 0.5 mol / L, and the fluoride ion is 0.5 mol / L. After treatment, the filter residue is washed with deionized water until the pH value of the supernatant is 7. After drying, the regenerated carbon residue is obtained;

[0068] Step (3):

[0069] The regenerated carbon residue obtained in the first step is heated to 500°C and an oxygen-containing atmosphere (oxygen-N2 mixed gas, wherein the oxygen content is 30 v%) is introduced. The reaction time is 2 hours. After cooling, the heat-treated material is obtained;

[0070] Step (4):

[0071] The heat-treated material obtained in step (3) is mixed with 5 wt% high-temperature pitch, and then subjected to first-stage heat treatment at 650°C in a reaction kettle under a reducing protective atmosphere (hydrogen-argon mixed gas with a hydrogen content of 5 vol%). The reaction time is 3 hours. A first-stage carbon material is obtained. Subsequently, it is heated to 2000°C under an argon atmosphere and kept for 4 hours. After cooling, it is dispersed, demagnetized and sieved to obtain a regenerated graphite active material.

[0072] The recovery rate of the regenerated graphite active material is 92%. The electrochemical performance test of the prepared artificial graphite material product shows that the first reversible capacity is 348 mAh / g at a current density of 100 mA / g, and the first coulombic efficiency is 94%.

[0073] Example 2

[0074] Compared with Example 1, the only difference is that the operation of step (1) is changed, specifically:

[0075] Group A: the treatment temperature is 100°C, and the other operations and parameters are the same as in Example 1;

[0076] Group B: compared with Group A, the only difference is that in step (1), the treatment is assisted by microwaves, and the power of the microwaves is 100 W:

[0077] The effect is determined according to the method of Example 1, and the results are as follows:

[0078] A: The recovery rate of the regenerated graphite active material is 93.2%, and the electrochemical performance test of the prepared artificial graphite material product shows that the first reversible capacity is 352 mAh / g at a current density of 100 mA / g, and the first coulombic efficiency is 94%.

[0079] B: The recovery rate of the regenerated graphite active material is 94.1%, and the electrochemical performance test of the prepared artificial graphite material product shows that the first reversible capacity is 361 mAh / g at a current density of 100 mA / g, and the first coulombic efficiency is 95%.

[0080] Example 3

[0081] Compared with Example 1, the only difference is that the acid treatment process of step 2 is changed, specifically:

[0082] A: The acid is pure HNO3, and the total H ion concentration is the same as the mixed acid of Example 1.

[0083] B: In the mixed acid, the chloride ion is 0.3 mol / L, the nitrate ion is 0.3 mol / L, and the fluoride ion is 0.3 mol / L,

[0084] The effect is determined according to the method of Example 1, and the results are:

[0085] A: The recovery rate of the regenerated graphite active material is 91%, and the electrochemical performance test of the prepared artificial graphite material product shows that the first reversible capacity is 336 mAh / g at a current density of 100 mA / g, and the first coulombic efficiency is 94%.

[0086] B: The recovery rate of the regenerated graphite active material is 92.8%, and the electrochemical performance test of the prepared artificial graphite material product shows that the first reversible capacity is 350 mAh / g at a current density of 100 mA / g, and the first coulombic efficiency is 94%.

[0087] Example 4

[0088] Compared with Example 1, the only difference is that the process of step (3) is changed, and the experimental groups are:

[0089] A: The temperature of the heat treatment is 550℃, and the oxygen content of the oxygen-containing atmosphere is 35v%.

[0090] B: On the basis of A, 3v% nitric acid vapor is also added to the oxygen-containing atmosphere, and other operations and parameters are the same as Example 1.

[0091] C: On the basis of B, two-stage heat treatment is carried out, wherein the temperature is first raised to 350℃, the first stage of heat preservation treatment is carried out for 1h, then the temperature is raised to 550℃, the second stage of heat treatment is carried out for 1h, and other operations and parameters are the same as Example 1.

[0092] D: Compared with Example 1, the difference is that after the heat treatment of step 3, the heat-treated material is immersed in a 0.5M nitric acid solution, and then washed to neutral before the subsequent step 4 treatment.

[0093] The effect is determined according to the method of Example 1, and the results are:

[0094] A: The recovery rate of the regenerated graphite active material is 92.2%, and the electrochemical performance test is performed on the prepared artificial graphite material product, and the first reversible capacity is 349mAh / g at a current density of 100mA / g, and the first coulombic efficiency is 94%.

[0095] B: The recovery rate of the regenerated graphite active material is 95.4%, and the electrochemical performance test is performed on the prepared artificial graphite material product, and the first reversible capacity is 369mAh / g at a current density of 100mA / g, and the first coulombic efficiency is 95%.

[0096] C: The recovery rate of the regenerated graphite active material is 96.3%, and the electrochemical performance test is performed on the prepared artificial graphite material product, and the first reversible capacity is 376mAh / g at a current density of 100mA / g, and the first coulombic efficiency is 95%.

[0097] D: The recovery rate of the regenerated graphite active material is 93.6%, and the electrochemical performance test is performed on the prepared artificial graphite material product, and the first reversible capacity is 357mAh / g at a current density of 100mA / g, and the first coulombic efficiency is 94%.

[0098] Example 5

[0099] Compared with Example 1, the only difference is that the process of step (4) is changed, and the experimental groups are:

[0100] A: The addition amount of pitch is 10wt.%, the temperature of the first heat treatment is 600°C, the hydrogen content is 10%, and the temperature of the second heat treatment is 2200°C;

[0101] B: The atmosphere of the first heat treatment is nitrogen without hydrogen.

[0102] The effect is determined according to the method of Example 1, and the results are:

[0103] A: The recovery rate of the regenerated graphite active material is 92.3%, and the electrochemical performance test is performed on the prepared artificial graphite material product, and the first reversible capacity is 349mAh / g at a current density of 100mA / g, and the first coulombic efficiency is 94%.

[0104] B: The recovery rate of the regenerated graphite active material is 91.6%, and the prepared artificial graphite material product is subjected to electrochemical performance test, and the first reversible capacity thereof is 341 mAh / g at a current density of 100 mA / g, and the first coulombic efficiency thereof is 94%.

[0105] Comparative Example 1:

[0106] Compared with Example 1, the only difference is that in step (1), the sodium carbonate solution is replaced by equimolar amount of nitric acid, and other operations and parameters are the same as those in Example 1.

[0107] It is found that the recovery rate of the regenerated graphite active material is 90.7%, and the prepared artificial graphite material product is subjected to electrochemical performance test, and the first reversible capacity thereof is 328 mAh / g at a current density of 100 mA / g, and the first coulombic efficiency thereof is 92%.

[0108] Comparative Example 2:

[0109] Compared with Example 1, the only difference is that in step (1), the sodium carbonate solution is replaced by equimolar amount of sodium hydroxide, and other operations and parameters are the same as those in Example 1.

[0110] It is found that the recovery rate of the regenerated graphite active material is 91.5%, and the prepared artificial graphite material product is subjected to electrochemical performance test, and the first reversible capacity thereof is 338 mAh / g at a current density of 100 mA / g, and the first coulombic efficiency thereof is 93%.

[0111] Comparative Example 3:

[0112] Compared with Example 1, the only difference is that in step (3), the atmosphere for heat treatment does not contain oxygen, and other operations and parameters are the same as those in Example 1. The recovery rate of the regenerated graphite active material is 90.3%, and the prepared artificial graphite material product is subjected to electrochemical performance test, and the first reversible capacity thereof is 320 mAh / g at a current density of 100 mA / g, and the first coulombic efficiency thereof is 92%.

Claims

1. A method for recycling waste battery graphite carbon residue, characterized in that, The graphite carbon residue separated from the waste battery is placed in a water-soluble carbonate solution for transformation treatment, to obtain a transformed graphite material; The transformed graphite material is placed in an acid solution for treatment, followed by solid-liquid separation, to obtain an acid-treated graphite material; The acid-treated graphite material is heat-treated at a temperature of 300-600 DEG C in an oxygen-containing atmosphere, to obtain regenerated graphite; The graphite carbon residue also contains calcium sulfate and silicon recovery process impurities; The water-soluble carbonate is at least one of ammonium carbonate, sodium carbonate and potassium carbonate; The concentration of the water-soluble carbonate in the water-soluble carbonate solution is 1-5 M; The volume weight ratio of the water-soluble carbonate solution to the graphite carbon residue is 1-20 ml / g; The temperature of the transformation treatment is 40-100 DEG C; The treatment time of the transformation treatment is 0.5-5 h.

2. The recycling method of claim 1, wherein, The graphite carbon residue contains waste negative electrode material and optionally contains carbon residue after recovery of metal from the waste positive electrode.

3. The recycling method of claim 2, wherein, The waste battery is a waste lithium secondary battery.

4. The recycling method of claim 2, wherein, The negative electrode material of the waste battery is electrode material stripped from the negative electrode of the waste battery.

5. The recycling method of claim 2, wherein, The positive electrode recovery carbon residue is carbon residue after recovery of metal elements from the positive electrode.

6. The recycling method of claim 2, wherein, The waste battery recovery carbon residue contains graphite and at least one of conductive agent, binder and metal impurities.

7. The recycling method of claim 1, wherein, The transformation treatment is performed under microwave assistance.

8. The recycling method of claim 1, wherein, The acid solution contains at least one of hydrochloric acid, nitric acid and HF.

9. The recycling method of claim 8, wherein, The acid solution contains hydrochloric acid, nitric acid and HF.

10. The recycling method of claim 9, wherein, In the acid solution, the concentration of chloride ions is 0.1-1 mol / L, the concentration of nitrate ions is 0.1-1 mol / L and the concentration of fluoride ions is 0.1-1 mol / L.

11. The recycling method of claim 1, wherein, The liquid-solid volume weight ratio during the acid solution treatment is 1-10 ml / g.

12. The recycling method of claim 1, wherein, The oxygen partial pressure of the oxygen-containing atmosphere is 20-35 V%.

13. The recycling method of claim 1, wherein, The oxygen-containing atmosphere also contains steam of at least one of HNO3 and HF.

14. The recycling method of claim 1, wherein, The temperature of the heat treatment is 500-600 DEG C.

15. The recycling method of claim 1, wherein, The heat treatment includes two-stage heat treatment, wherein the temperature of the first-stage heat treatment is 300-400 DEG C and the temperature of the second-stage heat treatment is 500-600 DEG C.

16. The recycling method of claim 15, wherein, The heat treatment time is 0.5-4 h.

17. The recycling method of claim 15, wherein, The first-stage heat treatment time is 0.5-3 h and the second-stage heat treatment time is 0.5-2 h.

18. A method for recovering and co-producing a regenerated graphite active material from waste battery graphite carbon residue, characterized by, The regenerated graphite is obtained by the recovery method of any one of claims 1-17, the regenerated graphite is compounded with a soft carbon source, pre-heat treated at 600-700 DEG C for first-stage baking, followed by second-stage baking at a temperature of 1500-2400 DEG C, to obtain a regenerated graphite active material.

19. The method for recycling and producing regenerated graphite active material from spent battery graphite carbon residue according to claim 18, characterized in that, The soft carbon source is pitch.

20. The method for recycling and producing regenerated graphite active material from spent battery graphite carbon residue according to claim 18, wherein The soft carbon source is 3-10% by weight of the regenerated graphite.

21. The method for recycling and producing regenerated graphite active material from spent battery graphite carbon residue according to claim 18, characterized in that, The first-stage baking is performed in a reducing atmosphere.

22. The method for recycling and producing regenerated graphite active material from spent battery graphite carbon residue according to claim 21, wherein The first-stage baking is performed in a hydrogen-containing atmosphere.

23. The method for recycling and producing regenerated graphite active material from spent battery graphite carbon residue according to claim 22, characterized in that, The hydrogen content of the first-stage baking atmosphere is 5-15 v%.

24. The method for recycling and producing regenerated graphite active material from spent battery graphite carbon residue according to claim 18, wherein, The first-stage baking time is 2-4 h. ​ 25. The method for recycling and producing regenerated graphite active material from spent battery graphite carbon residue according to claim 18, wherein, The second-stage baking is performed in a protective atmosphere. ​ 26. The method for recycling and producing regenerated graphite active material from spent battery graphite carbon residue according to claim 18, wherein The second-stage baking time is 3-6 h.

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