Color sorting and separating method for waste lithium ion battery pole pieces

Abstract

The invention discloses a color sorting separation method for waste lithium ion battery pole pieces, which comprises the following steps of: performing mechanical disassembly, crushing, magnetic separation and winnowing on waste lithium ion batteries to obtain a large-size positive and negative pole piece mixture; the large-size positive and negative pole piece mixture is subjected to ultrasonic water-phase stripping to increase the pole piece color difference, and after negative pole powder is filtered and separated, the positive pole piece and the copper foil are obtained through color sorting separation. The positive pole piece separated by the method provided by the invention has the advantages of no damage and high purity, can be directly applied to a regeneration process, and is simple to operate, high in efficiency and high in economic benefit.

Description

Technical Field

[0001] The invention relates to a method for color sorting and separating waste lithium-ion battery pole pieces, and in particular to a method for water-phase stripping and color sorting of a large-scale positive and negative pole piece mixture to achieve effective separation of the pole pieces, belonging to the technical field of waste battery recycling. Background Art

[0002] Lithium-ion batteries are now widely used in people's daily lives. The service life of lithium-ion batteries is limited. In the future, the efficient recycling of retired lithium-ion batteries is the key link to open up the closed loop of lithium batteries. At present, the recycling of lithium batteries mainly includes wet recycling and direct regeneration. Wet recycling is to promote the decomposition of waste battery materials through reagents such as acids and alkalis, and then obtain high-purity metal salts through extraction, purification and other processes, but the loss rate of key metal lithium resources is high, the energy consumption is high, and the pollution is large. As a new type of comprehensive recycling process, direct regeneration mainly realizes the high-quality utilization of waste materials by converting waste materials into commercial materials in a short process, with a short process and high resource utilization. However, the direct regeneration process has high requirements for the quality of raw materials. The copper content needs to be less than 100ppm, and the aluminum content needs to be less than 2000ppm. The copper content of waste battery materials crushed by traditional machinery is greater than 3000ppm, which is far lower than the quality requirements of raw materials for direct regeneration. Therefore, starting from the source, it is very important to rely on mechanical disassembly and large-scale crushing to pre-separate the positive and negative electrode sheets in advance to avoid the introduction of copper elements.

[0003] At present, some technologies have been studied on color sorting and separation of waste lithium batteries. For example, Chinese patent CN114151802A discloses a technology that depolymerizes and carbonizes PVDF by high-temperature pyrolysis of waste lithium batteries, then etches and peels off the surface of aluminum foil with dilute acid, and then separates copper foil and aluminum foil by color sorting. However, this method is to peel off the PVDF binder on the positive and negative electrodes by pyrolysis, and the color difference formed is yellow for the negative copper foil and white for the positive aluminum foil. The color difference between the positive and negative electrodes is not obvious, the degree of mixing is high, the degree of impurities is high, and the active materials on the positive electrode cannot be retained; and the dilute acid etching causes serious damage to the positive and negative electrodes.

[0004] Based on this, it is imperative to develop a color sorting and separation process for waste lithium batteries that does not damage the electrodes and increase the color difference between the positive and negative electrodes. Summary of the invention

[0005] In view of the problems in the prior art such as excessively high impurity content and severe damage to the pole pieces of recycled waste lithium-ion batteries, the purpose of the present invention is to provide a method for color sorting and separation of waste lithium-ion battery pole pieces. The method utilizes ultrasonic aqueous phase stripping to selectively strip the water-soluble binder and negative electrode powder on the negative electrode pieces without damaging the pole pieces, thereby increasing the difference between the negative electrode pieces and the positive electrode pieces, and then achieving separation by color sorting.

[0006] In order to achieve the above technical objectives, the present invention provides a method for color sorting and separation of waste lithium-ion battery pole pieces, the method is to obtain a large-size positive and negative pole piece mixture after mechanical disassembly, crushing, magnetic separation and air separation of the waste lithium-ion batteries; the large-size positive and negative pole piece mixture is subjected to ultrasonic aqueous phase stripping to increase the pole piece color difference, and the negative electrode powder is separated by filtration, and then separated by color sorting to obtain positive pole pieces and copper foil; the binder used for the negative pole pieces in the large-size positive and negative pole piece mixture is a water-soluble binder.

[0007] The key to the technical solution of the present invention is to combine the water-soluble characteristics of the binder in the negative electrode sheet, the ultrasonic aqueous phase stripping technology and the color separation, selectively remove the binder and negative electrode powder on the negative electrode sheet, increase the color difference between the positive and negative electrode sheets, and achieve a high degree of separation between the positive electrode sheet and the copper foil. Specifically, the current negative electrode sheet mainly uses a water-soluble binder to adhere the negative electrode powder and the copper foil, and the aqueous solution in the aqueous phase stripping can achieve the dissolution of the water-soluble binder without affecting the positive electrode sheet, and under the action of ultrasound, on the one hand, the dissolution of the binder can be promoted, and on the other hand, the black negative electrode powder can be separated from the yellow copper foil, which significantly increases the color difference between the black positive electrode sheet (aluminum foil + positive active material) and the yellow copper foil. The negative pressure suction cup gripper of the color sorter can be used to achieve accurate separation of the positive electrode sheet and the copper foil. More importantly, the aqueous solution in the ultrasonic aqueous phase stripping can provide a certain buffering capacity, avoiding damage to the surface of the positive electrode sheet and the copper foil in the existing recycling and separation technology.

[0008] As a preferred solution, the size of the large-sized positive and negative electrode sheet mixture is not less than 10 cm 2 . The scale of the positive and negative electrode sheet mixture in the present invention cannot be too small, otherwise the broken electrode sheets will be sucked into the suction cup during the subsequent color sorting and separation process, causing damage to the equipment, and also causing the purity of the positive electrode sheets after separation to decrease. The large-scale electrode sheet mechanical process tends to be manual disassembly technology, and the folding between the large positive electrode sheet and the large negative electrode sheet is relatively small. In addition, there are relatively few fine particles, which effectively reduces the entrainment of impurities. Therefore, as the scale increases, the purity of the obtained electrode sheet will also increase. A further preferred scale is 50 to 100 cm 2 .

[0009] As a preferred solution, the waste lithium-ion batteries mainly come from at least one of ternary lithium batteries, lithium iron phosphate batteries, lithium cobalt oxide batteries and lithium titanate batteries purchased on the market.

[0010] As a preferred solution, the conditions for ultrasonic aqueous phase stripping are: water temperature is 30-80°C, ultrasonic power is 500-2000W, and time is 30-60min. If the water temperature is low during the ultrasonic process of the present invention, it is not conducive to the dissolution of the water-soluble binder and the rapid shedding of the negative electrode material; while if the water temperature is high, although the graphite and other substances on the surface of the negative electrode copper foil can be quickly stripped, it may cause the stripping of the positive electrode material on part of the positive electrode aluminum foil and the partial dissolution of the aluminum element, resulting in a decrease in the recovery rate of the positive electrode material and a decrease in the purity of the negative electrode material. When the selected ultrasonic power is too small or the time is too short, the graphite stripping rate on the negative electrode copper foil pole piece will be slow, resulting in a significant decrease in production efficiency; if the ultrasonic power is too large or the time is too long, on the one hand, the positive electrode pole piece will break, the positive electrode powder will fall off, and will be introduced into the negative electrode material, resulting in a decrease in the positive electrode recovery rate and a significant decrease in the purity of the negative electrode.

[0011] As a preferred solution, the filtration is performed using a sieve with a hole diameter of 1 to 5 cm. The filtration is mainly used to separate the upper positive electrode sheet, copper foil and the lower negative electrode powder and binder-containing solution, so the pore size of the sieve needs to be larger than the particle size of the negative electrode powder and smaller than the size of the positive electrode sheet.

[0012] As a preferred solution, the color sorting separation uses a color sorter for color recognition, drives a negative pressure gripper to sort the materials, and each negative pressure gripper is provided with 2 to 4 suction cup grippers, each of which has an area of ​​0.5 to 1.0 cm 2 If there are too few suction cups on the negative pressure gripper or the suction cup area is too small, it will be difficult for the gripper to adsorb the positive electrode material or the negative electrode material; if there are too many suction cups on the negative pressure gripper or the suction cup area is too large, the equipment investment is too large, and other impurities will be introduced into the material suction pipe during the adsorption process.

[0013] As a preferred solution, the number of negative pressure grippers of the color sorter is 2 to 4; the vacuum degree is 0.01 to 0.5 MPa.

[0014] As a preferred solution, after filtering and separating the negative electrode powder, the material is conveyed through a conveyor belt for color sorting and separation. The total length of the conveyor belt is 8 to 10 meters, and a color sorter is set every 0.5 to 0.7 meters. Among them, a color sorter only recognizes one color, black or yellow, at a time, and the colors of two adjacent color sorters are different. The present invention alternately distributes and arranges color sorters of different colors at intervals. The alternating arrangement allows the material to be gradually screened by color sorters with different functions on the conveyor belt, which can not only separate the black and yellow materials more accurately, improving the overall color sorting and separation efficiency and accuracy, but also makes the screening process of the material on the conveyor belt more balanced, improving the stability of the entire color sorting and separation process. If it is not arranged alternately, the recognition error of the color sorter may increase.

[0015] The mechanical disassembly, crushing, magnetic separation, wind separation and other processes involved in the present invention are conventional operation processes in the prior art, and the purpose is to obtain a relatively pure mixture of positive and negative pole pieces of waste lithium-ion batteries with the iron shell removed.

[0016] Compared with the prior art, the technical solution of the present invention brings the following beneficial technical effects:

[0017] 1) The method provided by the present invention combines the water-soluble properties of the binder in the negative electrode sheet, ultrasonic aqueous phase stripping technology and color separation, selectively removes the binder and negative electrode powder on the negative electrode sheet, increases the color difference between the positive and negative electrode sheets, and achieves a high degree of separation between the positive electrode sheet and the copper foil.

[0018] 2) The positive electrode sheet separated by the method of the present invention is undamaged and has high purity (impurity content is less than 2%), and can be directly applied to the regeneration process.

[0019] 3) The color sorting separation of the present invention utilizes a negative pressure gripper to achieve accurate separation of waste lithium ion positive and negative electrode sheets to obtain pure positive and negative electrode sheets.

[0020] 4) The method of the present invention is simple to operate, high in efficiency and high in economic benefit.

[0021] 5) The present invention arranges yellow and black color sorters alternately and at intervals, so that the materials can be gradually screened by color sorters with different functions on the conveyor belt, which can not only separate the black and yellow materials more accurately, improving the overall color sorting and separation efficiency and accuracy, but also makes the screening process of the materials on the conveyor belt more balanced, improving the stability of the entire color sorting and separation process BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a process flow chart of the present invention.

[0023] Figure 2 It is the process route diagram of the present invention.

[0024] Figure 3 This is an optical comparison of the large-sized positive and negative electrode sheet mixture before and after water phase stripping in the present invention. Figure 3 It shows that after the aqueous phase stripping method of the present invention, the color difference of the electrode piece is significantly increased, and the surface of the electrode piece remains intact and undamaged. DETAILED DESCRIPTION

[0025] The following examples are only specific descriptions of the preferred embodiments of the present invention, and are not intended to limit the scope of implementation of the present invention. For ordinary technicians in the technical field, any improvements made without departing from the present invention should be deemed to be within the scope of protection of the present invention.

[0026] The waste lithium-ion batteries used in the present invention mainly come from waste lithium iron phosphate batteries purchased on the market. The waste batteries cannot be crushed by tearing, but must be shredded.

[0027] In the embodiment of the present invention, the total length of the conveyor belt is 10m, each color sorter is provided with 3 negative pressure grippers, the vacuum degree is 0.1MPa, the color recognition setting of the first color sorter is yellow, the color recognition setting of the second color sorter is black, and the color recognition setting of the third color sorter is yellow, and they are distributed alternately in this order.

[0028] Example 1 (Comparative Example)

[0029] Through the front-end mechanical disassembly, crushing, magnetic separation, wind separation and other processes, large-sized crushed materials are obtained to obtain positive and negative electrode sheet mixtures. The size of the electrode sheet is 1.0 cm 2 The positive and negative electrodes are placed in a 60°C aqueous solution, stirred for 30 minutes at an ultrasonic power of 1000W, and filtered through a sieve with a hole diameter of 3cm. The separated upper layer of material is dried and placed on a conveyor belt. Every 0.5m, a color sorter is distributed and equipped with a negative pressure gripper. Each negative pressure gripper has 3 suction cup grippers, and the area of ​​each suction cup is 0.8cm 2 , sorting and classifying the electrodes, and obtaining positive electrode sheets and copper foil respectively. However, broken electrodes are sucked into the suction cup, which affects the service life of the equipment and has low efficiency. The impurity content in the separated positive electrode sheets is as high as 29%, and the obtained electrode sheets are difficult to be used in the direct regeneration process.

[0030] Example 2 (Comparative Example)

[0031] Through the front-end mechanical disassembly, crushing, magnetic separation, wind separation and other processes, large-sized crushed materials are obtained to obtain the positive and negative electrode sheet mixture. The size of the electrode sheet is 20cm 2 , placed on the conveyor belt, with a color sorter and a negative pressure gripper distributed every 0.5m. Each negative pressure gripper has 3 suction cup grippers, and the area of ​​each suction cup is 0.8cm 2, the electrode pieces are sorted and classified. Due to the small color difference, the positive electrode pieces obtained contain a small amount of copper foil, making it difficult to obtain pure electrode pieces. The impurity content in the separated positive electrode pieces is as high as 32%, and the obtained electrode pieces are difficult to be used in the direct regeneration process.

[0032] Example 3 (Comparative Example)

[0033] Through the front-end mechanical disassembly, crushing, magnetic separation, wind separation and other processes, large-sized crushed materials are obtained to obtain the positive and negative electrode sheet mixture. The size of the electrode sheet is 20cm 2 , the positive and negative pole pieces are placed in a 60°C aqueous solution, stirred for 30 minutes at an ultrasonic power of 1000W, filtered through a screen with a hole diameter of 3cm, and the separated upper layer material is dried and placed on a conveyor belt. The pole pieces are sorted and classified using a color selection and blowing process. Due to the small density difference and partial wrinkles, the obtained positive pole piece contains a small amount of copper foil, making it difficult to obtain a pure pole piece. The impurity content in the separated positive pole piece is as high as 14%, and the obtained pole piece material is difficult to apply to the direct regeneration process.

[0034] Example 4

[0035] Through the front-end mechanical disassembly, crushing, magnetic separation, wind separation and other processes, large-sized crushed materials are obtained to obtain the positive and negative electrode sheet mixture. The size of the electrode sheet is 20cm 2 The positive and negative electrodes are placed in a 60°C aqueous solution, stirred for 30 minutes at an ultrasonic power of 1000W, and filtered through a sieve with a hole diameter of 3cm. The separated upper layer of material is dried and placed on a conveyor belt. Every 0.5m, a color sorter is distributed and equipped with a negative pressure gripper. Each negative pressure gripper has 3 suction cup grippers, and the area of ​​each suction cup is 0.8cm 2 , and the electrode pieces are sorted and classified to obtain pure positive electrode pieces and copper foil. The impurity content in the separated positive electrode pieces is 0.5%.

[0036] Example 5

[0037] Through the front-end mechanical disassembly, crushing, magnetic separation, wind separation and other processes, large-sized crushed materials are obtained to obtain the positive and negative electrode sheet mixture. The size of the electrode sheet is 50cm 2 The positive and negative electrodes are placed in a 60°C aqueous solution, stirred for 30 minutes at an ultrasonic power of 1000W, and filtered through a sieve with a hole diameter of 3cm. The separated upper layer of material is dried and placed on a conveyor belt. Every 0.5m, a color sorter is distributed and equipped with a negative pressure gripper. Each negative pressure gripper has 3 suction cup grippers, and the area of ​​each suction cup is 0.8cm 2 , and the electrode pieces are sorted and classified to obtain pure positive electrode pieces and copper foil. The impurity content in the separated positive electrode pieces is 0.2%.

[0038] Example 6

[0039] Through the front-end mechanical disassembly, crushing, magnetic separation, wind separation and other processes, large-sized crushed materials are obtained to obtain the positive and negative electrode sheet mixture. The scale of the electrode sheet is 100cm 2 The positive and negative electrodes are placed in a 60°C aqueous solution, stirred for 30 minutes at an ultrasonic power of 1000W, and filtered through a sieve with a hole diameter of 3cm. The separated upper layer of material is dried and placed on a conveyor belt. Every 0.5m, a color sorter is distributed and equipped with a negative pressure gripper. Each negative pressure gripper has 3 suction cup grippers, and the area of ​​each suction cup is 0.8cm 2 , and the pole pieces are sorted and classified to obtain pure positive pole piece materials and copper foils. The impurity content in the separated positive pole piece is 0.02%, which is suitable for direct regeneration and repair, and the product consistency is high. From the comparison of Examples 4, 5 and 6, it can be seen that as the pole piece size increases, the impurity content in the positive pole piece decreases.

[0040] Example 7

[0041] Through the front-end mechanical disassembly, crushing, magnetic separation, wind separation and other processes, large-sized crushed materials are obtained to obtain the positive and negative electrode sheet mixture. The size of the electrode sheet is 20cm 2 The positive and negative electrodes are placed in a 30°C aqueous solution, stirred for 30 minutes at an ultrasonic power of 1000W, and filtered through a sieve with a hole diameter of 3cm. The separated upper layer of material is dried and placed on a conveyor belt. Every 0.5m, a color sorter is distributed and equipped with a negative pressure gripper. Each negative pressure gripper has 3 suction cup grippers, and the area of ​​each suction cup is 0.8cm 2 , sorting and classifying the electrodes, and obtaining pure positive electrode sheets and copper foils. Due to the decrease in water temperature, some graphite particles stick to the electrodes. The impurity content in the separated positive electrode sheets is 0.7%.

[0042] Example 8

[0043] Through the front-end mechanical disassembly, crushing, magnetic separation, wind separation and other processes, large-sized crushed materials are obtained to obtain the positive and negative electrode sheet mixture. The size of the electrode sheet is 20cm 2 The positive and negative electrodes are placed in an aqueous solution at 80°C, stirred for 30 minutes at an ultrasonic power of 1000W, and filtered through a sieve with a hole diameter of 3cm. The separated upper layer of material is dried and placed on a conveyor belt. Every 0.5m, a color sorter is distributed and equipped with a negative pressure gripper. Each negative pressure gripper has 3 suction cup grippers, and the area of ​​each suction cup is 0.8cm 2 , sorting and classification of the electrode pieces, and obtaining pure positive electrode sheet materials and copper foils. When the water temperature rises, some fine copper pieces are introduced, and the impurity content in the separated positive electrode pieces is 0.4%.

[0044] Example 9

[0045] Through the front-end mechanical disassembly, crushing, magnetic separation, wind separation and other processes, large-sized crushed materials are obtained to obtain the positive and negative electrode sheet mixture. The size of the electrode sheet is 20cm 2 The positive and negative electrodes are placed in a 60°C aqueous solution, stirred for 30 minutes at an ultrasonic power of 500W, and filtered through a sieve with a hole diameter of 3cm. The separated upper layer of material is dried and placed on a conveyor belt. Every 0.5m, a color sorter is distributed and equipped with a negative pressure gripper. Each negative pressure gripper has 3 suction cup grippers, and the area of ​​each suction cup is 0.8cm 2 , the electrode sheets are sorted and classified to obtain pure positive electrode sheet materials and copper foil respectively. The impurity content in the separated positive electrode sheets is 0.2%.

[0046] Example 10

[0047] Through the front-end mechanical disassembly, crushing, magnetic separation, wind separation and other processes, large-sized crushed materials are obtained to obtain the positive and negative electrode sheet mixture. The size of the electrode sheet is 20cm 2 The positive and negative electrodes are placed in a 60°C aqueous solution, stirred for 30 minutes at an ultrasonic power of 2000W, and filtered through a sieve with a hole diameter of 1cm. The separated upper layer of material is dried and placed on a conveyor belt. Every 0.5m, a color sorter is distributed and equipped with a negative pressure gripper. Each negative pressure gripper has 3 suction cup grippers, and the area of ​​each suction cup is 0.8cm 2 , the electrode sheets were sorted and classified to obtain pure positive electrode sheet materials and copper foil respectively. The impurity content in the separated positive electrode sheets was 1.2%.

[0048] Embodiment 11

[0049] Through the front-end mechanical disassembly, crushing, magnetic separation, wind separation and other processes, large-sized crushed materials are obtained to obtain the positive and negative electrode sheet mixture. The size of the electrode sheet is 20cm 2 The positive and negative electrodes are placed in a 60°C aqueous solution, stirred for 30 minutes at an ultrasonic power of 1000W, and filtered through a sieve with a hole diameter of 5cm. The separated upper layer of material is dried and placed on a conveyor belt. Every 0.5m, a color sorter is distributed and equipped with a negative pressure gripper. Each negative pressure gripper has 2 suction cup grippers, and the area of ​​each suction cup is 0.8cm 2 , the electrode pieces are sorted and classified to obtain pure positive electrode pieces and copper foil. The mesh size is increased, and the impurity content in the separated positive electrode pieces is 0.4%.

[0050] Example 12

[0051] Through the front-end mechanical disassembly, crushing, magnetic separation, wind separation and other processes, large-sized crushed materials are obtained to obtain the positive and negative electrode sheet mixture. The size of the electrode sheet is 20cm 2 The positive and negative electrodes are placed in a 60°C aqueous solution, stirred for 30 minutes at an ultrasonic power of 1000W, and filtered through a sieve with a hole diameter of 3cm. The separated upper layer of material is dried and placed on a conveyor belt. Every 0.5m, a color sorter is distributed and equipped with a negative pressure gripper. Each negative pressure gripper has 4 suction cup grippers, and the area of ​​each suction cup is 0.8cm 2 , sorting and classifying the electrodes, respectively obtaining pure positive electrode sheets and copper foil, the impurity content in the separated positive electrode sheets is 0.7%. Increasing the number of suction cup grippers will lead to the introduction of other impurity components into the material suction tube during the adsorption process, thus increasing the impurity content.

[0052] Embodiment 13

[0053] Through the front-end mechanical disassembly, crushing, magnetic separation, wind separation and other processes, large-sized crushed materials are obtained to obtain the positive and negative electrode sheet mixture. The size of the electrode sheet is 20cm 2 The positive and negative electrodes are placed in a 60°C aqueous solution, stirred for 30 minutes at an ultrasonic power of 1000W, and filtered through a sieve with a hole diameter of 3cm. The separated upper layer of material is dried and placed on a conveyor belt. Every 0.5m, a color sorter is distributed and equipped with a negative pressure gripper. Each negative pressure gripper has 3 suction cup grippers, and the area of ​​each suction cup is 0.5cm 2 , sorting and classifying the electrode sheets, respectively obtaining pure positive electrode sheet materials and copper foil, the impurity content in the separated positive electrode sheets is 0.3%. Reducing the suction cup area reduces the impurity content in the positive electrode sheets.

[0054] Embodiment 14

[0055] Through the front-end mechanical disassembly, crushing, magnetic separation, wind separation and other processes, large-sized crushed materials are obtained to obtain the positive and negative electrode sheet mixture. The size of the electrode sheet is 20cm 2 The positive and negative electrodes are placed in a 60°C aqueous solution, stirred for 30 minutes at an ultrasonic power of 1000W, and filtered through a sieve with a hole diameter of 3cm. The separated upper layer of material is dried and placed on a conveyor belt. Every 0.5m, a color sorter is distributed and equipped with a negative pressure gripper. Each negative pressure gripper has 3 suction cup grippers, and the area of ​​each suction cup is 1.0cm 2 , sort and classify the electrodes, and obtain pure positive electrode sheets and copper foils. Some impurities will be sucked into the negative pressure gripper, which is not conducive to the long life of the equipment. The impurity content in the separated positive electrode sheets is 0.8%.

[0056] The separation conditions and separation results of Examples 1 to 14 are shown in Table 1.

[0057] Table 1

[0058]

Claims

1. A method for color sorting and separating waste lithium-ion battery pole pieces, characterized in that: The waste lithium-ion batteries are mechanically disassembled, crushed, magnetically separated and winnowed to obtain a large-sized positive and negative electrode sheet mixture; the large-sized positive and negative electrode sheet mixture is subjected to ultrasonic aqueous phase stripping to increase the electrode sheet color difference, the negative electrode powder is filtered and separated, and then separated by color sorting to obtain positive electrode sheets and copper foil; the binder used for the negative electrode sheet in the large-sized positive and negative electrode sheet mixture is a water-soluble binder.

2. The method for color sorting and separating waste lithium-ion battery pole pieces according to claim 1, characterized in that: The size of the large-sized positive and negative electrode sheet mixture is not less than 10 cm 2 .

3. The method for color sorting and separating waste lithium-ion battery pole pieces according to claim 1, characterized in that: The waste lithium-ion battery includes at least one of a ternary lithium battery, a lithium iron phosphate battery, a lithium cobalt oxide battery and a lithium titanate battery.

4. A method for color sorting and separating waste lithium-ion battery pole pieces according to any one of claims 1 to 3, characterized in that: The conditions for ultrasonic aqueous phase stripping are: water temperature is 30-80° C., ultrasonic power is 500-2000 W, and time is 30-60 min.

5. The method for color sorting and separating waste lithium-ion battery pole pieces according to claim 4, characterized in that: The filtration is performed using a sieve with a hole diameter of 1 to 5 cm.

6. The method for color sorting and separating waste lithium-ion battery pole pieces according to claim 5, characterized in that: The color separation adopts a color sorter to identify the color and drives the negative pressure gripper to sort the materials. Each negative pressure gripper is provided with 2 to 4 suction cup grippers, and the area of ​​each suction cup is 0.5 to 1.0 cm 2 .

7. The method for color sorting and separating waste lithium-ion battery pole pieces according to claim 6, characterized in that: The number of negative pressure grippers of the color sorter is 2 to 4, and the vacuum degree is 0.01 to 0.5 MPa.

8. A method for color sorting and separating waste lithium-ion battery pole pieces according to claim 6 or 7, characterized in that: After filtering and separating the negative electrode powder, the material is conveyed through a conveyor belt for color sorting and separation. The total length of the conveyor belt is 8 to 10 meters, and a color sorter is set every 0.5 to 0.7 meters. Among them, a color sorter only recognizes one color, black or yellow, at a time, and the recognition colors of two adjacent color sorters are different.

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