Dry-method electrode waste recovery method and dry-method electrode raw material manufacturing method

Abstract

The invention belongs to the technical field of batteries, and discloses a dry-method electrode waste recovery method and a dry-method electrode raw material manufacturing method. The dry method electrode waste recovery method comprises the steps that under the first temperature condition, waste to be recovered is placed in a recovery cavity provided with a dispersion disc; starting the dispersion disc to rotate at a first rotating speed so as to disperse the to-be-recycled waste; raising the temperature in the recovery cavity to a second temperature, and adjusting the rotating speed of the dispersion disc to a second rotating speed; adjusting the temperature of the recovery cavity to a third temperature, and adjusting the rotating speed of the dispersion disc to a third rotating speed; wherein; the first rotating speed is smaller than the second rotating speed, the second rotating speed is smaller than the third rotating speed, and the first temperature and the third temperature are both smaller than the second temperature. The recovery method is suitable for large-batch waste recovery, and the recovery cost is relatively low.

Description

Technical Field

[0001] This invention relates to the field of battery technology, and in particular to a method for recycling dry electrode waste and a method for manufacturing dry electrode raw materials. Background Technology

[0002] Dry electrode technology, as a next-generation battery manufacturing process (especially solid-state batteries), has attracted much attention due to its advantages such as solvent-free operation, low energy consumption, and strong material compatibility. However, if the scraps generated during the production process (such as electrode (graphite) cutting waste, unevenly coated waste, etc.) are directly discarded, it will not only increase costs but also cause resource waste and environmental pollution. In order to recycle waste from dry electrode processes, an electrostatic sorting technology has been developed in the existing technology. This is a physical recycling method in which graphite is precipitated and binders are removed. However, this method is only suitable for small-batch waste recycling, and the recycling cost is relatively high. Summary of the Invention

[0003] The purpose of this invention is to provide a dry electrode waste recycling method, which is suitable for large-scale waste recycling and has relatively low recycling costs.

[0004] To achieve this objective, the present invention adopts the following technical solution:

[0005] A method for recycling dry electrode waste: Under a first temperature condition, the waste to be recycled is placed in a recycling chamber equipped with a dispersing disc; the dispersing disc is started to rotate at a first speed to disperse the waste to be recycled; the temperature in the recycling chamber is raised to a second temperature, and the speed of the dispersing disc is adjusted to a second speed; the temperature in the recycling chamber is adjusted to a third temperature, and the speed of the dispersing disc is adjusted to a third speed; wherein the first speed is less than the second speed, the second speed is less than the third speed, and both the first temperature and the third temperature are less than the second temperature.

[0006] The dry electrode waste recycling method of the present invention has the following advantages: It employs a dispersion disc to disperse the waste to be recycled. At a relatively low first temperature and a first rotational speed, the dispersion disc disperses the waste, which can quickly break down the large volume of dry electrode waste into smaller strip-shaped and sheet-like structures. At a relatively high second temperature and a medium second rotational speed, the dry electrode waste is further stirred, which softens the binder in the waste and further disperses it. Finally, the waste is stirred at a rapid third rotational speed to disperse it into granules, achieving recycling. Compared to the existing method of precipitating graphite, this method is low-cost and suitable for large-scale dry electrode waste recycling.

[0007] The present invention also aims to provide a dry electrode raw material manufacturing method, which has relatively low cost and can make full use of the waste generated during the dry electrode manufacturing process.

[0008] To achieve this objective, the present invention adopts the following technical solution:

[0009] A method for manufacturing dry electrode raw materials includes mixing graphite, a conductive agent, and a binder with recycled materials manufactured using the aforementioned dry electrode waste recycling method at a specified mixing ratio, followed by stirring, to serve as raw materials for manufacturing the dry electrode. The mixing ratio is a percentage of the recycled materials in the total amount of materials, and the specified mixing ratio is 10%-65%.

[0010] The beneficial effects of the dry electrode raw material manufacturing method of the present invention are as follows: by mixing graphite, conductive agent and binder with recycled materials manufactured by the dry electrode waste recycling method described above, and then stirring the mixture, the raw materials for manufacturing dry electrodes can be fully utilized, thereby reducing the manufacturing cost of dry electrodes.

[0011] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0012] Figure 1 This is a schematic flowchart of the dry electrode waste recycling method according to an embodiment of the present invention;

[0013] Figure 2 This is a schematic flowchart of the dry electrode raw material manufacturing method according to an embodiment of the present invention;

[0014] Figure 3 yes Figure 2 Detailed flowchart of step Q1;

[0015] Figure 4 yes Figure 2 Detailed flowchart of step Q2;

[0016] Figure 5 yes Figure 2 Detailed flowchart of step Q3. Detailed Implementation

[0017] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only the parts relevant to the present invention, and not all of the structures.

[0018] In the description of this invention, unless otherwise explicitly specified and limited, the terms "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0019] In the description of this embodiment, the terms "upper," "lower," "left," "right," "front," and "rear," etc., refer to the orientation or positional relationship shown in the accompanying drawings. They are used only for ease of description and simplification of operation, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the present invention. Furthermore, the terms "first" and "second" are used only for distinction in description and have no special meaning.

[0020] like Figure 1 As shown, the present invention provides a method for recycling dry electrode waste (hereinafter referred to as the recycling method for succinct description), comprising the following steps:

[0021] S1: Under the first temperature condition, the waste to be recycled is placed in the recycling chamber equipped with a dispersion plate;

[0022] S2: Start the dispersion disc to rotate at the first speed to disperse the waste to be recycled;

[0023] S3: Raise the temperature in the recovery chamber to the second temperature and adjust the rotation speed of the dispersion disc to the second rotation speed;

[0024] S4: Adjust the temperature of the recovery chamber to the third temperature, and adjust the rotation speed of the dispersion disc to the third rotation speed; wherein;

[0025] The first rotational speed is less than the second rotational speed, the second rotational speed is less than the third rotational speed, and both the first and third temperatures are less than the second temperature.

[0026] Understandably, the recycling method in this embodiment uses a dispersing disc to disperse the waste to be recycled. At a lower first temperature and a first rotation speed, the dispersing disc disperses the waste, quickly breaking down the larger dry electrode waste into smaller strip and sheet-like structures. At a higher second temperature and a medium second rotation speed, the dry electrode waste is further stirred, softening the binder and further dispersing the waste. Finally, a rapid third rotation speed disperses the waste into granules, achieving recycling. Compared to the existing method of precipitating graphite, this method is less expensive and suitable for large-scale recycling of dry electrode waste.

[0027] Optionally, the duration of the dispersing disc at the first rotational speed is the first duration, the duration at the second rotational speed is the second duration, and the duration at the third rotational speed is the third duration, with both the first and second durations being shorter than the third duration. It is understandable that the first and second rotational speeds primarily perform preliminary dispersing of the dry electrode waste, and the relatively short durations of these speeds save recycling time and improve recycling efficiency while ensuring effective preliminary dispersing. However, at the third rotational speed, the dry electrode waste needs to be dispersed into granules, requiring a relatively longer time to ensure that the dry electrode waste is dispersed into granules for easier reuse.

[0028] Further optional, the first and second durations are 245 seconds, and the third duration is 600 seconds;

[0029] Further optional, the first rotational speed is 100 r / min, the second rotational speed is 300 r / min, and the third rotational speed is 1000 r / min.

[0030] Of course, it should be noted that the first duration, second duration, third duration, first speed, second speed, and third speed can all be selected according to actual needs and are not limited to the above limitations.

[0031] Optionally, after adjusting the temperature of the recovery chamber to the third temperature and the rotation speed of the dispersing disc to the third rotation speed, the process further includes: S4: adjusting the rotation speed of the dispersing disc to the fourth rotation speed, where the fourth rotation speed is greater than the third rotation speed. It is understandable that adding an additional step after step S3 for supplementary dispersing allows the dry electrode waste to be uniformly dispersed into smaller particles, further facilitating secondary utilization.

[0032] Optionally, the duration of the dispersing disc at the third rotational speed is the third duration, and the duration of the dispersing disc at the fourth rotational speed is the fourth duration, with the third duration being longer than the fourth duration. It is understood that the fourth rotational speed allows the dry electrode waste to be uniformly dispersed into smaller particles. If the fourth duration is too long, the resulting recycled material will have excessively small particle sizes, making it inconvenient for reuse. Therefore, the fourth duration is set relatively short to ensure that the final recycled material has a particle size suitable for reuse.

[0033] An additional option is a fourth duration of 245 seconds. Of course, you can also choose according to your actual needs.

[0034] Alternatively, the dispersing disc alternates between forward and reverse rotation during the fourth rotational speed. This alternation ensures that the dry electrode waste is thoroughly dispersed into granules, facilitating secondary utilization. The forward and reverse rotation durations can be equal or unequal. In actual dispersion, the fourth duration can be divided into two periods: one period with the dispersing disc rotating forward and the other with it rotating in reverse. Of course, the fourth duration can also be divided into multiple (more than two) periods, with the dispersing disc alternating between forward and reverse rotation.

[0035] Optionally, the first temperature is 20℃-30℃. The first temperature can be 20℃, 21℃, 22℃, 23℃, 24℃, 25℃, 26℃, 27℃, 28℃, 29℃, or 30℃, or other values ​​within the 20℃-30℃ range. Since room temperature is typically within the 20℃-30℃ range, controlling the first temperature within this range facilitates the recycling method, eliminating the need for additional high or low temperature environments and reducing the manufacturing cost of the recycling method.

[0036] Optionally, the second temperature is 35℃-45℃. The second temperature can be 35℃, 36℃, 37℃, 38℃, 39℃, 40℃, 41℃, 42℃, 43℃, 44℃, or 45℃, or other values ​​within the 35℃-45℃ range. A second temperature that is too low is detrimental to the softening of the binder, while a second temperature that is too high will cause the materials to stick together during dispersion. In this embodiment, a second temperature of 35℃-45℃ facilitates the softening of the binder while preventing the materials from sticking together, ensuring that the dry electrode waste is stably dispersed and recycled.

[0037] Optionally, the third temperature is 20℃-30℃. The third temperature can be 20℃, 21℃, 22℃, 23℃, 24℃, 25℃, 26℃, 27℃, 28℃, 29℃, or 30℃, or other values ​​within the 20℃-30℃ range. Since room temperature is typically within the 20℃-30℃ range, controlling the third temperature within this range facilitates the recycling method, eliminating the need for additional high or low temperature environments and reducing the manufacturing cost of the recycling method.

[0038] Optionally, the dispersing disc alternates between forward and reverse rotation during the first rotational speed. This alternation ensures that the dry electrode waste is fully dispersed into granules, facilitating secondary utilization. The forward and reverse rotation durations can be equal or unequal. In actual dispersion, the first duration can be divided into two equal periods: one period with the dispersing disc rotating forward and the other with it rotating in reverse. Alternatively, the first duration can be divided into multiple (more than two) periods, with the forward and reverse rotations of the dispersing disc alternating.

[0039] Optionally, the dispersing disc alternates between forward and reverse rotation during the second rotational speed. This alternation ensures that the dry electrode waste is thoroughly dispersed into granules, facilitating secondary utilization. The forward and reverse rotation durations can be equal or unequal. In actual dispersion, the second duration can be divided into two equal periods: one period with the dispersing disc rotating forward and the other with it rotating in reverse. Alternatively, the second duration can be divided into multiple (more than two) periods, with the forward and reverse rotations of the dispersing disc alternating.

[0040] Optionally, the dispersing disc alternates between forward and reverse rotation during the fourth rotational speed. This alternation ensures that the dry electrode waste is thoroughly dispersed into granules, facilitating secondary utilization. The forward and reverse rotation durations can be equal or unequal. In actual dispersion, the fourth duration can be divided into two periods: one period with the dispersing disc rotating forward and the other with it rotating in reverse. Alternatively, the fourth duration can be divided into multiple (more than two) periods, with the forward and reverse rotations of the dispersing disc alternating.

[0041] Optionally, the total volume of dry electrode waste shall not exceed 70% of the recycling chamber volume. This prevents dry electrode waste from flying out of the recycling chamber during the recycling process.

[0042] The following describes a specific process of the dry electrode waste recycling method provided by the present invention.

[0043] At 25°C, the waste to be recycled is placed in a recycling chamber equipped with a dispersion disc;

[0044] Start the dispersing disc to rotate at a speed of 100 r / min to disperse the waste to be recycled. The dispersing disc rotates clockwise for 120 seconds and then counterclockwise for 120 seconds.

[0045] Raise the temperature in the recovery chamber to 45°C, adjust the rotation speed of the dispersion disc to 300 r / min, and rotate the dispersion disc clockwise for 120 seconds and then counterclockwise for 120 seconds.

[0046] Adjust the temperature of the recovery chamber to 25℃, adjust the rotation speed of the dispersion disc to 1000r / min, and rotate the dispersion disc clockwise for 300 seconds, then counterclockwise for 300 seconds.

[0047] Adjust the speed of the dispersing disc to 1500 r / min, and rotate the dispersing disc clockwise for 120 seconds, then counterclockwise for 120 seconds.

[0048] This invention discloses a method for manufacturing dry electrode raw materials (hereinafter referred to as the manufacturing method for convenience), comprising blending graphite, conductive agent, and binder with recycled materials manufactured using the aforementioned dry electrode waste recycling method at a specified blending ratio to serve as raw materials for manufacturing dry electrodes. The blending ratio is the percentage of recycled materials in the total amount of materials, i.e., the weight of recycled materials / (the total amount of graphite, conductive agent, binder, and recycled materials), and the specified blending ratio is 10%-65%.

[0049] It is understood that in the manufacturing method of the present invention, graphite, conductive agent and binder are mixed with recycled materials manufactured by the dry electrode waste recycling method described above, and after stirring, they are used as raw materials for manufacturing dry electrodes. This can make full use of the waste generated in the dry electrode manufacturing process and reduce the manufacturing cost of dry electrodes.

[0050] Optionally, the specified blending ratio can be 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, 20%, 21%, 22%, 23%, 24%, 25%, 26%, 27%, 28%, 29%, 30%, 31%, 32%, 33%, 34%, 35%, 36%, 37%, 38%, 39%, 40%, 41%, 42%, 43%, 44%, 45%, 46%, 47%, 48%, 49%, 50%, 51%, 52%, 53%, 54%, 55%, 56%, 57%, 58%, 59%, or 60%, or other values ​​within the range of 10% to 60%.

[0051] like Figure 2 As shown, the dry electrode raw material manufacturing method includes:

[0052] Q1: Add graphite and conductive agent to a mixing container and stir.

[0053] Q2: Add the adhesive to the mixing container and stir.

[0054] Q3: Increasing the temperature of the mixing container and adding the recycled material into the mixing container for mixing.

[0055] It is understandable that recycled materials contain graphite, conductive agents, and binders. During the mixing process, the graphite, conductive agents, and binders are first thoroughly mixed, and then the recycled materials are added and mixed again. This ensures that the manufactured materials can achieve a uniform mixture of graphite, conductive agents, and binders, thus ensuring the various properties of the raw materials.

[0056] Optional, such as Figure 3 As shown, the process of adding graphite and conductive agent into a stirring container and stirring includes:

[0057] Q11: Stir at a first stirring speed for a first specified duration;

[0058] Q12: Stir at a second stirring speed for a second specified duration; wherein the second stirring speed is greater than the first stirring speed, and the second specified duration is greater than the first specified duration. It is understandable that initially mixing the graphite and conductive agent at a shorter time and lower speed, followed by stirring at a longer time and higher speed, ensures thorough mixing of the graphite and conductive agent, facilitating subsequent steps.

[0059] Further optionally, the first specified duration is 120 seconds. The first stirring speed is 100 r / min, the second specified duration is 400 seconds, and the second stirring speed is 2250 r / min.

[0060] Alternatively, the temperature of the mixing container can be lowered to 17°C before adding the graphite and conductive agent to the mixing container, manually stirring, and then starting the mixing plate inside the mixing container.

[0061] Optional, such as Figure 4 As shown, adding the adhesive to the mixing container and mixing it includes:

[0062] Q21: Stir at the third stirring speed for the third specified duration;

[0063] Q22: Stir at the fourth stirring speed for the fourth specified duration;

[0064] Q23: Raise the temperature inside the mixing container to a first specified temperature, and mix at a fifth mixing speed for a fifth specified duration; wherein,

[0065] The fifth stirring speed is greater than the fourth stirring speed, and the fourth stirring speed is greater than the third stirring speed;

[0066] The fifth specified duration is greater than the fourth specified duration and the third specified duration.

[0067] Understandably, by first mixing the graphite, conductive agent, and binder at a shorter time and lower speed, and then stirring them at a longer time and higher speed, it is possible to ensure that the graphite, conductive agent, and binder are fully mixed. Finally, stirring at a higher temperature can ensure that the graphite, conductive agent, and binder are bonded together to form a fibrous structure.

[0068] Further optional, the third specified duration is 120 seconds, the third stirring speed is 100 r / min, the fourth specified duration is 120 seconds, the fourth stirring speed is 2250 r / min, and the fifth specified duration is 600 seconds, the fourth stirring speed is 4478 r / min.

[0069] Optional, such as Figure 5As shown, raising the temperature of the mixing container and adding the recycled material into the mixing container for mixing includes:

[0070] Q31: Stir at a sixth stirring speed for a sixth specified duration under a first specified temperature environment;

[0071] Q32: Stir at a seventh stirring speed for a seventh specified time at a second specified temperature; wherein the sixth stirring speed is greater than the seventh stirring speed, and the second specified temperature is less than the first specified temperature. This ensures that the completed fiber structure of graphite, conductive agent, and binder is fully mixed with the recycled material.

[0072] Further optional, the sixth specified duration is 300 seconds, the sixth stirring speed is 2250 r / min, the seventh specified duration is 300 seconds, the seventh stirring speed is 600 r / min, the first specified temperature is 65℃, and the second specified temperature is 17℃.

[0073] The following describes a specific process of the dry electrode raw material manufacturing method provided by the present invention;

[0074] Turn on the temperature control device to cool the mixing container to 17°C, add 0.814 kg of graphite and 0.006 kg of conductive agent, and stir manually.

[0075] Start the mixing tank and rotate it at 100 r / min for 120 seconds;

[0076] Adjust the stirring plate speed to 2250 r / min and rotate for 400 seconds;

[0077] Add 0.03 kg of binder and adjust the stirring plate speed to 100 r / min for 120 seconds;

[0078] Adjust the stirring plate speed to 2250 r / min and rotate for 120 seconds;

[0079] Turn on the temperature control device to heat the mixing container to 65°C, and adjust the speed of the mixing disc to 4478 r / min for 600 seconds;

[0080] Add 0.15 kg of recycled material and adjust the stirring plate speed to 2250 r / min for 300 seconds;

[0081] Adjust the stirring plate speed to 600 rpm and rotate for 300 seconds.

[0082] After manufacturing is completed, the mixed dry electrode raw materials are tested, and the areal density, compaction degree, adhesion and cohesion all meet the manufacturing requirements of dry electrodes.

[0083] In the description of this specification, references to terms such as "some embodiments," "other embodiments," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0084] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Those skilled in the art will be able to make various obvious changes, readjustments, and substitutions without departing from the scope of protection of the present invention. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A method for recycling dry electrode waste, characterized in that, Includes the following steps: Under the first temperature condition, the waste to be recycled is placed in the recycling chamber equipped with a dispersion plate; Start the dispersion disc to rotate at a first rotational speed to disperse the waste to be recycled; Raise the temperature inside the recovery chamber to a second temperature, and adjust the rotation speed of the dispersion disc to a second rotation speed; Adjust the temperature of the recovery chamber to the third temperature, and adjust the rotation speed of the dispersion disc to the third rotation speed; in; The first rotational speed is less than the second rotational speed, the second rotational speed is less than the third rotational speed, and both the first temperature and the third temperature are less than the second temperature.

2. The method for recycling dry electrode waste according to claim 1, characterized in that, The duration of the dispersing disk at the first rotational speed is the first duration, the duration of the dispersing disk at the second rotational speed is the second duration, and the duration of the dispersing disk at the third rotational speed is the third duration; wherein: Both the first duration and the second duration are less than the third duration.

3. The method for recycling dry electrode waste according to claim 1, characterized in that, After adjusting the temperature of the recovery chamber to the third temperature and adjusting the rotation speed of the dispersion disc to the third rotation speed, the process further includes: Adjust the rotation speed of the dispersing disc to a fourth rotation speed, which is greater than the third rotation speed.

4. The dry electrode waste recycling method according to claim 3, characterized in that, The duration of the dispersing disk at the third rotational speed is the third duration, and the duration of the dispersing disk at the fourth rotational speed is the fourth duration; wherein, the third duration is longer than the fourth duration.

5. The method for recycling dry electrode waste according to claim 4, characterized in that, The dispersing disk rotates alternately in both forward and reverse directions during the fourth rotational speed.

6. The method for recycling dry electrode waste according to claim 1, characterized in that, The first temperature is 20℃-30℃.

7. The method for recycling dry electrode waste according to claim 1, characterized in that, The second temperature is 35℃-45℃.

8. The method for recycling dry electrode waste according to claim 1, characterized in that, The third temperature is 20℃-30℃.

9. The method for recycling dry electrode waste according to claim 1, characterized in that, The dispersing disk rotates first clockwise and then counterclockwise during the first rotational speed; and / or, The dispersing disk rotates alternately in both forward and reverse directions during the second rotational speed; and / or, The dispersing disk rotates alternately in both forward and reverse directions during the third rotational speed.

10. The method for recycling dry electrode waste according to claim 1, characterized in that, The total volume of the waste to be recycled does not exceed 70% of the volume of the recycling chamber.

11. A method for manufacturing dry electrode raw materials, characterized in that, The method includes mixing graphite, conductive agent, and binder with recycled materials manufactured using the dry electrode waste recycling method as described in any one of claims 1-10 at a specified mixing ratio, followed by stirring, to use as raw materials for manufacturing the dry electrode. The mixing ratio is the percentage of the recycled materials in the total amount of materials, and the specified mixing ratio is 10%-65%.

12. The dry electrode raw material manufacturing method according to claim 11, characterized in that, The dry electrode raw material manufacturing method includes: The graphite and the conductive agent are added to a stirring container and stirred. The adhesive is added to the mixing container and stirred. The temperature of the mixing container is increased, and the recycled material is added to the mixing container for mixing.

13. The dry electrode raw material manufacturing method according to claim 12, characterized in that, Adding the graphite and the conductive agent to a stirring container and stirring them includes: Stir at a first stirring speed for a first specified duration; Stir at a second stirring speed for a second specified duration; wherein the second stirring speed is greater than the first stirring speed, and the second specified duration is greater than the first specified duration.

14. The dry electrode raw material manufacturing method according to claim 12, characterized in that, Adding the adhesive to the mixing container and mixing it includes: Stir at the third stirring speed for the third specified duration; Stir at the fourth stirring speed for the fourth specified duration; The temperature inside the stirring container is raised to a first specified temperature, and the mixture is stirred at a fifth stirring speed for a fifth specified duration; wherein, The fifth stirring speed is greater than the fourth stirring speed, and the fourth stirring speed is greater than the third stirring speed; The fifth specified duration is greater than the fourth specified duration and the third specified duration.

15. The dry electrode raw material manufacturing method according to claim 14, characterized in that, Increasing the temperature of the stirring container and adding the recycled material into the stirring container for stirring includes: Stirring at a sixth stirring speed for a sixth specified duration under the first specified temperature environment; Stirring at a seventh stirring speed for a seventh specified time at a second specified temperature environment; wherein the sixth stirring speed is greater than the seventh stirring speed, and the second specified temperature is less than the first specified temperature.

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