A method for purely physical separation of all components of waste lithium-ion batteries

Abstract

The present invention discloses a method for the purely physical separation of all components of waste lithium-ion batteries. This method involves mechanically crushing the waste lithium-ion batteries into large-sized fragments, removing the diaphragm through air separation, and removing the iron shell through magnetic separation to obtain a positive and negative electrode mixture. This mixture is then subjected to aqueous separation of the negative electrode powder, followed by a primary color separation of the copper foil to obtain positive electrode sheets. These positive electrode sheets are then subjected to roller pyrolysis, low-speed airflow milling, and a secondary color separation to obtain high-purity positive electrode powder and aluminum foil. The positive electrode powder obtained by this method is highly pure, and through step-by-step removal, all components can be recycled.

Description

Technical Field

[0001] The present invention relates to a method for purely physical separation of all components of waste lithium-ion batteries, and in particular to a method for obtaining ultra-high-purity electrode materials from mechanically crushed lithium-ion batteries through a purely physical method, belonging to the technical field of battery recycling. Background Art

[0002] Efficient disposal of used batteries is a key step in closing the loop in the new energy industry. Current comprehensive recycling of lithium-ion batteries primarily involves wet recovery and direct regeneration processes. Wet recovery primarily converts materials into elements, achieving efficient recovery of used battery materials. However, this process consumes significant amounts of acid and alkali, and produces significant amounts of waste, wastewater, and pollutants. Direct regeneration, on the other hand, directly converts waste materials into raw materials, significantly shortening the process and improving resource recycling efficiency, making it a highly effective new recycling technology. However, direct regeneration requires high raw material purity, with copper content required to be less than 200 ppm and aluminum content less than 3000 ppm. Current processes for obtaining powder from direct regeneration primarily rely on manual disassembly, which is inefficient and poses significant risks to human health. Traditional mechanical crushing and separation methods struggle to produce the raw material quality required for direct regeneration. Gravity separation effectively separates phases by exploiting density differences between different substances, offering advantages such as low cost, minimal energy consumption, and promising scalability.

[0003] Therefore, there is an urgent need to develop a method for gravity separation of all components of waste lithium-ion batteries. Summary of the Invention

[0004] In response to the problems in the prior art of waste lithium battery crushing and separation methods, such as high impurity content in the positive electrode powder material, which is difficult to repair, low recovery rate, and other components that cannot be utilized, the present invention aims to provide a method for the purely physical separation of all components of waste lithium-ion batteries. The positive electrode powder obtained by this method has high purity, and through step-by-step removal, each component can be recycled and utilized, avoiding the problems in the prior art of introducing chemical methods that damage the crystal phase structure of the material, introduce copper and aluminum impurity components, and cause the generation of waste acid and waste liquid.

[0005] In order to achieve the above technical objectives, the present invention provides a method for purely physical separation of all components of waste lithium-ion batteries. The method comprises the following steps: mechanically crushing the waste lithium-ion batteries into large-scale crushed materials, removing the diaphragm by air separation, and removing the iron shell by magnetic separation to obtain a positive and negative electrode mixture; the positive and negative electrode mixture is subjected to aqueous phase stripping of the negative electrode powder, and a first color separation of the copper foil to obtain a positive electrode sheet mixture; the positive electrode sheet mixture is sequentially subjected to roller pyrolysis, low-speed airflow milling, and a second color separation to obtain high-purity positive electrode powder and aluminum foil.

[0006] Most of the electrode mixtures processed in the current waste battery processing technology are for low-scale electrodes. The positive electrode materials on such electrodes are conducive to pyrolysis and stripping, but the recycling path is relatively rough, and the purity of the recovered positive and negative electrode raw materials is low, which has a great impact on the wet leaching and direct regeneration in the later stage, making it difficult to achieve high-quality recycling of positive and negative electrode materials. The present invention cleverly combines the aqueous phase stripping process and the roller pyrolysis process with the existing process to purely physically separate waste lithium-ion batteries and achieve the effect of recycling all components in steps. Specifically, the present invention first crushes the waste lithium-ion batteries into large-scale crushed materials, and removes the diaphragm and iron shell by air separation and magnetic separation, so as to obtain relatively pure positive and negative electrode mixtures, and crushing into large-scale electrode sheet materials is conducive to the subsequent aqueous phase stripping. In view of the characteristics of using water-soluble binders in the negative electrode sheets of waste lithium-ion batteries, the present invention uses aqueous phase stripping to not only remove the negative electrode material from the negative electrode sheet, but also obtain relatively pure yellow copper foil. Therefore, aqueous phase stripping also increases the color difference between the positive and negative electrode sheets, further facilitating the improvement of the accuracy of subsequent color sorting and separation. In addition, compared with the traditional process of long-term pyrolysis or acid washing to remove the positive electrode material, the combined process of roller hot pressing and low-speed airflow milling of the present invention can quickly degrade PVDF through the action of high temperature and pressure in a short period of time. The fluoride and carbide formed by pyrolysis are volatilized and removed, which not only ensures the purity of the material but also reduces damage to the electrode sheet. The low-speed airflow mill significantly improves the de-powdering efficiency of the positive electrode material. Finally, a simple color sorting and separation process can achieve efficient separation of the positive electrode material and aluminum foil.

[0007] As a preferred solution, the waste lithium-ion batteries are mainly derived from one of lithium iron phosphate batteries, ternary batteries, and lithium cobalt oxide batteries purchased on the market.

[0008] As a preferred solution, the size of the large-sized crushed material is 5mm to 5cm. The large size of the crushed material of the present invention can effectively avoid the entrainment of fine impurity components, the winding and folding of small pole pieces, and is conducive to the subsequent control of material purity.

[0009] As a preferred solution, the air separation speed is 4 m s -1 ~10ms -1 . In the present invention, the density of the diaphragm in the battery crushed material is relatively light, and the density difference between the diaphragm and the positive and negative electrode mixture is utilized to remove the diaphragm in the crushed material through the action of airflow. If the air separation speed is too low, the diaphragm may not be effectively taken away, and part of the diaphragm will remain in the positive and negative electrode mixture, affecting the purity of the material in the subsequent processing steps; when the air separation speed is too high, some smaller particles in the positive and negative electrode mixture will be entrained by the airflow due to the high wind speed, and mixed into the separated diaphragm light material, causing material loss and reducing the recovery rate of the positive and negative electrode mixture.

[0010] As a preferred solution, the magnetic induction intensity of the magnetic separation is 1.0 T to 3.0 T. Within the preferred magnetic separation intensity range of the present invention, the iron shell in the positive and negative electrode mixtures can be effectively removed.

[0011] As a preferred embodiment, the aqueous phase exfoliation is ultrasonic aqueous phase exfoliation or agitated aqueous phase exfoliation, and the aqueous phase exfoliation uses a mixed solution of water and ethanol as the exfoliating solution. In the present invention, due to the strong hydrophobicity of graphite, the graphite electrode sheet is difficult to highly disperse in the aqueous solution, resulting in poor contact between the graphite electrode sheet and the aqueous phase, making it difficult to effectively exfoliate the graphite powder from the negative electrode sheet. However, using a mixed solution of water and ethanol as the exfoliating solution can significantly enhance the exfoliation effect.

[0012] As a preferred embodiment, the aqueous phase stripping of the positive and negative electrode mixtures is performed by filtering the negative electrode powder through a sieve with a mesh size of 1 to 4 mm. The selection of the mesh size of the present invention comprehensively considers the size of the negative electrode powder, the positive electrode mixture, and the copper foil, thereby achieving separation of the negative electrode powder, the positive electrode mixture, and the copper foil.

[0013] As a preferred solution, the roller pyrolysis conditions are: roller heating, roller temperature is 1000-1500°C, rotation speed is 2-5min -1 The roller pyrolysis method of the present invention mainly utilizes high temperature and pressure to render the binder PVDF ineffective. During the roller pyrolysis process, if the temperature is too high or the time is too long, the crystalline structure of the positive electrode material will be damaged, which is not conducive to the subsequent repair process. At the same time, the fluorine-containing substances produced by PVDF during the pyrolysis process may react with the material, resulting in the introduction of fluorine impurity elements, causing the fluorine content to exceed the standard during the subsequent regeneration process and a serious decline in material performance. If the roller temperature is too low or the time is too short, the PVDF pyrolysis will be incomplete, and the carbide produced after the pyrolysis will not be volatilized, resulting in a decrease in the recovery rate and purity of the positive electrode sheets, and a decrease in the recovery efficiency of the positive electrode materials.

[0014] As a preferred solution, the grinding rate of the low-speed airflow mill is 3 to 8 m / s. 3 min -1 The higher the jet mill speed, the lower the efficiency of positive electrode powder removal and the lower the efficiency of positive electrode powder recovery; if the jet mill speed is too fast, it will cause the electrode aluminum impurities to be introduced into the positive electrode powder, reducing the activity of the positive electrode material.

[0015] As a preferred solution, the first color sorting and separation and the second color sorting and separation are both implemented by a color sorter, and the first color sorting and separation is set to identify the color yellow; the second color sorting and separation is set to identify the color white.

[0016] The present invention involves large-scale mechanical crushing, drying and other processes, which are conventional operating procedures in the prior art, and the purpose is to obtain a large-scale powder structure and remove excess moisture from the material.

[0017] Compared with the prior art, the technical solution of the present invention brings the following beneficial technical effects:

[0018] 1) The present invention can realize the recycling and utilization of all components of waste lithium-ion batteries, which not only improves the resource recovery efficiency but also reduces pollution to the environment. Moreover, the use of a purely physical separation method avoids the secondary pollution problem that may be caused by traditional chemical treatment methods, and also reduces the recycling cost.

[0019] 2) The present invention can significantly improve the recovery rate and purity of positive and negative electrode materials by combining the aqueous phase stripping process and the roller pyrolysis process, which is beneficial to subsequent wet leaching and direct regeneration.

[0020] 3) The combined process of roller hot pressing and low-speed airflow milling of the present invention can rapidly degrade and pyrolyze PVDF through the action of high temperature and pressure in a short period of time, and the fluorides and carbides formed by pyrolysis are volatilized and removed, which not only ensures the purity of the material but also reduces damage to the electrode sheet. In addition, the de-powdering efficiency of the positive electrode material is greatly improved by low-speed airflow milling.

[0021] 4) The method of the present invention is simple, low-cost, conducive to commercial production, and has high economic benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a flow chart of the technology for gravity separation of all components of waste lithium-ion batteries of the present invention.

[0023] Figure 2 This is a process flow chart of the technology for gravity separation of all components of waste lithium-ion batteries of the present invention. DETAILED DESCRIPTION

[0024] 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 those skilled in the art, any improvements made without departing from the present invention should be considered to be within the scope of protection of the present invention.

[0025] The waste lithium-ion batteries used in the present invention are mainly derived from any one of lithium iron phosphate batteries, ternary batteries, and lithium cobalt oxide batteries purchased on the market. According to the process roadmap and technical process, the embodiment is designed.

[0026] In the embodiment of the present invention, the first color sorting separation and the second color sorting separation are both achieved by a color sorter. The identification color of the first color sorting separation is set to yellow; the identification color of the second color sorting separation is set to white. The intensity of the magnetic separation is 1.0T. The volume ratio of water and ethanol in the stripping liquid used in the aqueous phase stripping is 1:1.

[0027] Example 1 (Comparative Example)

[0028] The raw materials are retired lithium iron phosphate batteries, sourced from a new energy enterprise in Zhejiang. After mechanical crushing, the size of the positive and negative pole pieces is 1 cm. The iron shell and other strong magnetic materials are removed by magnetic separation. The pole pieces are then roller heated at a roller temperature of 1200°C and a rotation speed of 3 min. -1 The separated material is further fed into a low-speed air jet mill at a grinding rate of 5m 3 min -1 The de-powdered positive electrode sheets were further separated from the positive electrode material through color sorting (using a color sorter with the color set to white) to obtain high-purity positive electrode material. The positive electrode material recovery rate was 53%, the positive electrode material purity was 47%, the graphite content was 52%, and the copper and aluminum impurity content was 1%.

[0029] Example 2 (Comparative Example)

[0030] The raw material is retired lithium iron phosphate batteries, which are sourced from a new energy enterprise in Zhejiang. The size of the positive and negative electrodes after mechanical crushing is 1 cm, and the crushed materials are subjected to physical air separation at a rate of 7 m s -1 , through magnetic separation to remove strong magnetic materials such as iron shells, the positive and negative electrode mixture is added to a water and ethanol solution and separated by ultrasound. The mixed solution after stripping is filtered through a 3mm mesh sieve. The filtrate contains negative electrode powder material, and the upper layer contains positive electrode sheets and copper foil. The copper foil is separated through the first color separation, and the positive electrode sheet is further added to the low-speed airflow mill at a grinding rate of 5m 3 min -1 The de-powdered cathode sheets and cathode materials are separated through a second color sorting process to obtain high-purity cathode materials. The cathode material recovery rate is 12% and the purity is 92%.

[0031] Example 3

[0032] The raw material is retired lithium iron phosphate batteries, which are sourced from a new energy enterprise in Zhejiang. The size of the positive and negative electrodes after mechanical crushing is 1 cm, and the crushed materials are subjected to physical air separation at a rate of 7 m s -1, strong magnetic materials such as iron shells are removed by magnetic separation, and the positive and negative electrode mixture is added to a water and ethanol solution, and separated by ultrasound. The stripped mixed solution is filtered through a 3mm mesh sieve. The filtrate contains negative electrode powder material, and the upper layer contains positive electrode sheets and copper foil. The copper foil is separated through the first color separation, and the positive electrode sheet is then roller heated with a roller temperature of 1200℃ and a rotation speed of 3min. -1 The separated material is further fed into a low-speed air jet mill at a grinding rate of 5m 3 min -1 The de-powdered cathode sheets and cathode materials are separated through a second color sorting process to obtain high-purity cathode materials. The cathode material recovery rate is 81% and the purity is 99.95%.

[0033] Example 4

[0034] The raw material is retired lithium iron phosphate batteries, which are sourced from a new energy enterprise in Zhejiang. The size of the positive and negative electrodes after mechanical crushing is 5mm, and the crushed materials are subjected to physical air separation at a rate of 7ms. -1 , strong magnetic materials such as iron shells are removed by magnetic separation, and the positive and negative electrode mixture is added to a water and ethanol solution, and separated by ultrasound. The stripped mixed solution is filtered through a 3mm mesh sieve. The filtrate contains negative electrode powder material, and the upper layer contains positive electrode sheets and copper foil. The copper foil is separated through the first color separation, and the positive electrode sheet is then roller heated with a roller temperature of 1200℃ and a rotation speed of 3min. -1 The separated material is further fed into a low-speed air jet mill at a grinding rate of 5m 3 min -1 The de-powdered cathode sheets and cathode materials were separated through a second color sorting process to obtain high-purity cathode materials. The cathode material recovery rate was 78% and the purity was 98.3%.

[0035] Example 5

[0036] The raw material is retired lithium iron phosphate batteries, which are sourced from a new energy enterprise in Zhejiang. The size of the positive and negative electrode pieces after mechanical crushing is 5 cm, and the crushed materials are subjected to physical air separation at a rate of 7 m s -1 , strong magnetic materials such as iron shells are removed by magnetic separation, and the positive and negative electrode mixture is added to a water and ethanol solution, and separated by ultrasound. The stripped mixed solution is filtered through a 3mm mesh sieve. The filtrate contains negative electrode powder material, and the upper layer contains positive electrode sheets and copper foil. The copper foil is separated through the first color separation, and the positive electrode sheet is then roller heated with a roller temperature of 1200℃ and a rotation speed of 3min. -1 The separated material is further fed into a low-speed air jet mill at a grinding rate of 5m 3 min-1 The de-powdered cathode sheets and cathode materials are separated through a second color sorting process to obtain high-purity cathode materials. The cathode material recovery rate is 72% and the purity is 99.95%.

[0037] Example 6

[0038] The raw material is retired lithium iron phosphate batteries, which are sourced from a new energy enterprise in Zhejiang. The size of the positive and negative electrode pieces after mechanical crushing is 1 cm, and the crushed materials are subjected to physical air separation at a rate of 4 m s -1 , strong magnetic materials such as iron shells are removed by magnetic separation, and the positive and negative electrode mixture is added to a water and ethanol solution, and separated by ultrasound. The stripped mixed solution is filtered through a 3mm mesh sieve. The filtrate contains negative electrode powder material, and the upper layer contains positive electrode sheets and copper foil. The copper foil is separated through the first color separation, and the positive electrode sheet is then roller heated with a roller temperature of 1200℃ and a rotation speed of 3min. -1 The separated material is further fed into a low-speed air jet mill at a grinding rate of 5m 3 min -1 The de-powdered cathode sheets and cathode materials are separated through a second color sorting process to obtain high-purity cathode materials. The cathode material recovery rate is 80% and the purity is 97%.

[0039] Example 7

[0040] The raw material is retired lithium iron phosphate batteries, which are sourced from a new energy enterprise in Zhejiang. The size of the positive and negative electrodes after mechanical crushing is 1 cm, and the crushed materials are subjected to physical air separation at a rate of 10 m s -1 , strong magnetic materials such as iron shells are removed by magnetic separation, and the positive and negative electrode mixture is added to a water and ethanol solution, and separated by ultrasound. The stripped mixed solution is filtered through a 3mm mesh sieve. The filtrate contains negative electrode powder material, and the upper layer contains positive electrode sheets and copper foil. The copper foil is separated through the first color separation, and the positive electrode sheet is then roller heated with a roller temperature of 1200℃ and a rotation speed of 3min. -1 The separated material is further fed into a low-speed air jet mill at a grinding rate of 5m 3 min -1 The de-powdered cathode sheets and cathode materials are separated through a second color sorting process to obtain high-purity cathode materials. The cathode material recovery rate is 79% and the purity is 96%.

[0041] Example 8

[0042] The raw materials are retired ternary batteries, which are sourced from a new energy enterprise in Zhejiang. The size of the positive and negative electrode pieces after mechanical crushing is 1 cm, and the crushed materials are subjected to physical air separation at a rate of 7 m s -1, strong magnetic materials such as iron shells are removed by magnetic separation, and the positive and negative electrode mixture is added to a water and ethanol solution and stirred for enhanced separation. The stripped mixed solution is filtered through a 3mm mesh sieve. The filtrate contains negative electrode powder material, and the upper layer contains positive electrode sheets and copper foil. The copper foil is separated through the first color separation, and the positive electrode sheet is then roller heated with a roller temperature of 1200℃ and a rotation speed of 3min. -1 The separated material is further fed into a low-speed air jet mill at a grinding rate of 5m 3 min -1 The de-powdered cathode sheets and cathode materials are separated through a second color sorting process to obtain high-purity cathode materials. The cathode material recovery rate is 72% and the purity is 99.95%.

[0043] Example 9

[0044] The raw material is retired lithium iron phosphate batteries, which are sourced from a new energy enterprise in Zhejiang. The size of the positive and negative electrodes after mechanical crushing is 1 cm, and the crushed materials are subjected to physical air separation at a rate of 7 m s -1 , strong magnetic materials such as iron shells are removed by magnetic separation, and the positive and negative electrode mixture is added to a water and ethanol solution, and separated by ultrasound. The mixed solution after stripping is filtered through a sieve with a mesh size of 1mm. The filtrate contains negative electrode powder material, and the upper layer contains positive electrode sheets and copper foil. The copper foil is separated by the first color separation, and the positive electrode sheet is then roller heated with a roller temperature of 1200℃ and a rotation speed of 3min. -1 The separated material is further fed into a low-speed air jet mill at a grinding rate of 5m 3 min -1 The de-powdered cathode sheets and cathode materials are separated through a second color sorting process to obtain high-purity cathode materials. The cathode material recovery rate is 82% and the purity is 96%.

[0045] Example 10

[0046] The raw material is retired lithium iron phosphate batteries, which are sourced from a new energy enterprise in Zhejiang. The size of the positive and negative electrodes after mechanical crushing is 1 cm, and the crushed materials are subjected to physical air separation at a rate of 7 m s -1 , strong magnetic materials such as iron shells are removed by magnetic separation, and the positive and negative electrode mixture is added to a water and ethanol solution, and separated by ultrasound. The mixed solution after stripping is filtered through a sieve with a mesh size of 4mm. The filtrate contains the negative electrode powder material, and the upper layer contains the positive electrode sheet and copper foil. The copper foil is separated by the first color separation, and the positive electrode sheet is then roller heated with a roller temperature of 1200℃ and a rotation speed of 3min. -1 The separated material is further fed into a low-speed air jet mill at a grinding rate of 5m 3 min-1 The de-powdered cathode sheets and cathode materials are separated through a second color sorting process to obtain high-purity cathode materials. The cathode material recovery rate is 74% and the purity is 99.95%.

[0047] Example 11

[0048] The raw material is retired lithium iron phosphate batteries, which are sourced from a new energy enterprise in Zhejiang. The size of the positive and negative electrodes after mechanical crushing is 1 cm, and the crushed materials are subjected to physical air separation at a rate of 7 m s -1 , strong magnetic materials such as iron shells are removed by magnetic separation, and the positive and negative electrode mixture is added to a water and ethanol solution, and separated by ultrasound. The stripped mixed solution is filtered through a 3mm mesh sieve. The filtrate contains negative electrode powder material, and the upper layer contains positive electrode sheets and copper foil. The copper foil is separated through the first color separation, and the positive electrode sheet is then roller heated with a roller temperature of 1000℃ and a rotation speed of 3min. -1 The separated material is further fed into a low-speed air jet mill at a grinding rate of 5m 3 min -1 The de-powdered cathode sheets and cathode materials are separated through a second color sorting process to obtain high-purity cathode materials. The cathode material recovery rate is 69% and the purity is 99.95%.

[0049] Example 12

[0050] The raw material is retired lithium iron phosphate batteries, which are sourced from a new energy enterprise in Zhejiang. The size of the positive and negative electrodes after mechanical crushing is 1 cm, and the crushed materials are subjected to physical air separation at a rate of 7 m s -1 , strong magnetic materials such as iron shells are removed by magnetic separation, and the positive and negative electrode mixture is added to a water and ethanol solution, and separated by ultrasound. The stripped mixed solution is filtered through a 3mm mesh sieve. The filtrate contains negative electrode powder material, and the upper layer contains positive electrode sheets and copper foil. The copper foil is separated through the first color separation, and the positive electrode sheet is then roller heated with a roller temperature of 1500℃ and a rotation speed of 3min. -1 The separated material is further fed into a low-speed air jet mill at a grinding rate of 5m 3 min -1 The de-powdered cathode sheets and cathode materials are separated through a second color sorting process to obtain high-purity cathode materials. The cathode material recovery rate is 81% and the purity is 99.95%.

[0051] Example 13

[0052] The raw material is retired lithium iron phosphate batteries, which are sourced from a new energy enterprise in Zhejiang. The size of the positive and negative electrodes after mechanical crushing is 1 cm, and the crushed materials are subjected to physical air separation at a rate of 7 m s-1 , strong magnetic materials such as iron shells are removed by magnetic separation, and the positive and negative electrode mixture is added to a water and ethanol solution, and separated by ultrasound. The stripped mixed solution is filtered through a 3mm mesh sieve. The filtrate contains negative electrode powder material, and the upper layer contains positive electrode sheets and copper foil. The copper foil is separated through the first color separation, and the positive electrode sheet is then roller heated with a roller temperature of 1200℃ and a rotation speed of 2min. -1 The separated material is further fed into a low-speed air jet mill at a grinding rate of 5m 3 min -1 The de-powdered cathode sheets and cathode materials are separated through a second color sorting process to obtain high-purity cathode materials. The cathode material recovery rate is 76% and the purity is 99.95%.

[0053] Example 14

[0054] The raw material is retired lithium iron phosphate batteries, which are sourced from a new energy enterprise in Zhejiang. The size of the positive and negative electrodes after mechanical crushing is 1 cm, and the crushed materials are subjected to physical air separation at a rate of 7 m s -1 , strong magnetic materials such as iron shells are removed by magnetic separation, and the positive and negative electrode mixture is added to a water and ethanol solution, and separated by ultrasound. The mixed solution after stripping is filtered through a 3mm mesh sieve. The filtrate contains negative electrode powder material, and the upper layer contains positive electrode sheets and copper foil. The copper foil is separated by the first color separation, and the positive electrode sheet is then roller heated with a roller temperature of 1200℃ and a rotation speed of 5min. -1 The separated material is further fed into a low-speed air jet mill at a grinding rate of 5m 3 min -1 The de-powdered cathode sheets and cathode materials are separated through a second color sorting process to obtain high-purity cathode materials. The cathode material recovery rate is 80% and the purity is 99.95%.

[0055] Example 15

[0056] The raw material is retired lithium iron phosphate batteries, which are sourced from a new energy enterprise in Zhejiang. The size of the positive and negative electrodes after mechanical crushing is 1 cm, and the crushed materials are subjected to physical air separation at a rate of 7 m s -1 , strong magnetic materials such as iron shells are removed by magnetic separation, and the positive and negative electrode mixture is added to a water and ethanol solution, and separated by ultrasound. The stripped mixed solution is filtered through a 3mm mesh sieve. The filtrate contains negative electrode powder material, and the upper layer contains positive electrode sheets and copper foil. The copper foil is separated through the first color separation, and the positive electrode sheet is then roller heated with a roller temperature of 1200℃ and a rotation speed of 3min. -1 The separated material is further fed into a low-speed air jet mill at a grinding rate of 3m3 min -1 The de-powdered cathode sheets and cathode materials are separated through a second color sorting process to obtain high-purity cathode materials. The cathode material recovery rate is 73% and the purity is 99.95%.

[0057] Example 16

[0058] The raw material is retired lithium iron phosphate batteries, which are sourced from a new energy enterprise in Zhejiang. The size of the positive and negative electrodes after mechanical crushing is 1 cm, and the crushed materials are subjected to physical air separation at a rate of 7 m s -1 , strong magnetic materials such as iron shells are removed by magnetic separation, and the positive and negative electrode mixture is added to a water and ethanol solution, and separated by ultrasound. The stripped mixed solution is filtered through a 3mm mesh sieve. The filtrate contains negative electrode powder material, and the upper layer contains positive electrode sheets and copper foil. The copper foil is separated through the first color separation, and the positive electrode sheet is then roller heated with a roller temperature of 1200℃ and a rotation speed of 3min. -1 The separated material is further fed into a low-speed airflow mill at a grinding rate of 8m 3 min -1 The de-powdered cathode sheets and cathode materials are separated through a second color sorting process to obtain high-purity cathode materials. The cathode material recovery rate is 81% and the purity is 99%.

[0059] Table 1 Separation conditions and effects of Examples 1 to 16

[0060]

[0061]

Claims

1. A method for purely physical separation of all components of waste lithium-ion batteries, characterized by: After the waste lithium-ion batteries are mechanically crushed into large-scale crushed materials, the diaphragm is removed by air separation and the iron shell is removed by magnetic separation to obtain a positive and negative electrode mixture; the positive and negative electrode mixture is aqueous-phase stripping of the negative electrode powder, and the copper foil is separated by a first color separation to obtain a positive electrode sheet; the positive electrode sheet is sequentially subjected to roller pyrolysis, low-speed airflow milling, and a second color separation to obtain high-purity positive electrode powder and aluminum foil; The scale of the large-scale crushed material is 5mm~5cm.

2. The method for purely physical separation of all components of waste lithium-ion batteries according to claim 1, characterized in that: The speed of the wind selection is 4~10m s -1 .

3. The method for purely physical separation of all components of waste lithium-ion batteries according to claim 1 or 2, characterized in that: The magnetic induction intensity of the magnetic separation is 1.0T~3.0T.

4. The method for purely physical separation of all components of waste lithium-ion batteries according to claim 1 or 2, characterized in that: The aqueous phase stripping is ultrasonic aqueous phase stripping or stirring aqueous phase stripping, and the aqueous phase stripping uses a mixed solution of water and ethanol as a stripping liquid.

5. The method for purely physical separation of all components of waste lithium-ion batteries according to claim 4, characterized in that: The positive and negative electrode mixture is filtered by using a sieve with a mesh size of 1 to 4 mm to remove the negative electrode powder in the aqueous phase.

6. The method for purely physical separation of all components of waste lithium-ion batteries according to claim 5, characterized in that: The roller pyrolysis conditions are as follows: roller heating, roller temperature is 1000~1500℃, and the rotation speed is 2~5min -1 .

7. The method for purely physical separation of all components of waste lithium-ion batteries according to claim 1 or 6, characterized in that: The grinding speed of the low-speed airflow mill is 3~8m 3 min -1 .

8. The method for purely physical separation of all components of waste lithium-ion batteries according to claim 1, characterized in that: The first color sorting and separation and the second color sorting and separation are both implemented by a color sorter. The first color sorting and separation is set to identify the color yellow; the second color sorting and separation is set to identify the color white.

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