High-pressure water jet-based power battery positive electrode material efficient recovery process

Abstract

The invention discloses a high-pressure water jet-based power battery positive electrode material efficient recovery process, which comprises the following steps: carrying out pre-safety pretreatment on a decommissioned power battery to obtain a pure positive electrode plate; carrying out standardized cutting and fixing treatment on the positive pole piece; performing double-sided impact on the fixed positive pole piece by adopting high-pressure water jet, so that the positive active material is separated from the aluminum foil current collector, and slurry containing the positive material and the clean aluminum foil current collector are obtained; carrying out neutralization and solid-liquid separation on the slurry to obtain a solid positive electrode material filter cake; and drying and screening the filter cake to obtain a crude product of the positive electrode material. The process provided by the invention can solve the problems of incomplete separation of the positive electrode material and the aluminum foil, large current collector damage, low recovery purity, complex process, environmental pollution and the like in the prior art, and realizes efficient, green and low-cost recovery of the positive electrode material.

Description

Technical Field

[0001] This invention relates to the field of power battery recycling technology, and in particular to a high-efficiency recycling process for power battery cathode materials based on high-pressure water jet. Background Technology

[0002] With the rapid development of the new energy vehicle industry, the number of retired power batteries has increased dramatically, making their efficient recycling crucial for resource conservation and environmental protection. As the most valuable component of power batteries, the recycling efficiency of cathode materials directly impacts the overall economic benefits of recycling.

[0003] Current mainstream methods for recycling cathode materials mainly include physical crushing and separation, chemical immersion, and high-temperature heat treatment. However, these methods generally suffer from problems such as incomplete separation, severe damage to the aluminum foil current collector, introduction of chemical impurities, low recycling purity, and high energy consumption. In particular, when using physical crushing methods, it is difficult to completely separate the cathode material from the aluminum foil, leading to significant challenges in subsequent purification; chemical methods are prone to causing secondary pollution.

[0004] Therefore, there is an urgent need to develop an efficient, green, and non-destructive cathode material recycling process to achieve precise separation and high-value recycling of cathode active materials and aluminum foil current collectors. Summary of the Invention

[0005] This invention aims to at least partially solve one of the technical problems in related technologies. To this end, the first objective of this invention is to propose a high-efficiency recycling process for positive electrode materials of power batteries based on high-pressure water jetting. Through pre-treatment for safety, standardized electrode cutting and fixing, double-sided high-pressure jet impact, slurry neutralization and solid-liquid separation, drying and sieving, etc., the process achieves non-destructive separation and high-purity recycling of the positive electrode material and the aluminum foil current collector. Simultaneously, the high-pressure water jet parameters are adjustable, adaptable to different types of battery electrodes, and possess good process adaptability and industrialization prospects.

[0006] To achieve the above objectives, a first aspect of the present invention proposes a high-efficiency recycling process for positive electrode materials of power batteries based on high-pressure water jet, comprising the following steps: Pre-treatment of retired power batteries is carried out to obtain pure positive electrode sheets. The positive electrode sheet is subjected to standardized cutting and fixing. High-pressure water jets are used to impact the fixed positive electrode sheet from both sides, separating the positive electrode active material from the aluminum foil current collector, resulting in a slurry containing the positive electrode material and a clean aluminum foil current collector. The slurry is neutralized and subjected to solid-liquid separation to obtain a solid positive electrode material filter cake; The filter cake is dried and sieved to obtain crude positive electrode material.

[0007] In addition, the high-efficiency recycling process for positive electrode materials of power batteries based on high-pressure water jet according to the above embodiments of the present invention may also have the following additional technical features: According to one embodiment of the present invention, the pre-safety pretreatment includes deep discharge of the retired power battery, mechanical disassembly, sorting out the positive electrode and removing the negative electrode, separator and structural components.

[0008] According to one embodiment of the present invention, the standardized cutting and fixing process includes cutting the positive electrode sheet into blanks of uniform size and fixing them using special tooling.

[0009] According to one embodiment of the present invention, the impact parameters of the high-pressure water jet include pressure, flow rate, impact angle and impact time, which are adjusted according to the electrode type.

[0010] According to one embodiment of the present invention, the formula for calculating the jet impact force is as follows: (1) in, F The force of the jet impact is measured in nanometers (N). q The jet flow rate is expressed in m³ / s. ρ This is the density of water, expressed in kg / m³. v The velocity of the water jet is expressed in m / s. β The angle between the reflected water jet and the incident direction; Failure strength of electrode materials: (2) in, It is the dimensionless material failure strength; A These are the failure surface parameters of the cathode material; N The failure surface index of the cathode material; The normalized initial static pressure; If we substitute equation (2) into equation (1) and express the normalized initial static pressure in terms of jet impact force, then the formula is: (3) in, f c It is the uniaxial compressive strength of the positive electrode material.

[0011] According to one embodiment of the present invention, the neutralization treatment uses an alkaline regulator to adjust the slurry to neutral, with a pH value of 6.5 to 7.5.

[0012] According to one embodiment of the present invention, the solid-liquid separation is carried out using a plate and frame filter press or a centrifugal separation device.

[0013] According to one embodiment of the present invention, the drying temperature is 60°C to 120°C, and the drying time is 2h to 8h; the sieving uses a standard sieve with a mesh size of 100 to 300 mesh.

[0014] According to one embodiment of the present invention, the crude cathode material is further purified by wet leaching, pyrometallurgical smelting or material regeneration processes to recover valuable metals therein or to be directly used for cathode material remanufacturing.

[0015] According to one embodiment of the present invention, the aluminum foil current collector is directly recycled and reused after cleaning.

[0016] The present invention has the following technical effects: 1. This invention uses high-pressure water jet as the core separation method, which achieves efficient and non-destructive separation of positive electrode active material and aluminum foil current collector, with thorough separation and high recovery purity.

[0017] 2. High-pressure water jet uses water as a medium, without the introduction of chemical reagents, making it green and environmentally friendly, and the separation process is controllable.

[0018] 3. The high-pressure water jet parameters are adjustable, adaptable to battery electrodes of different models and aging levels, and have good process adaptability and industrialization promotion value.

[0019] 4. This process shortens the traditional recycling process, reduces energy consumption and costs, and provides a brand-new technical path for the efficient recycling of cathode materials.

[0020] 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

[0021] Figure 1 A flowchart of a high-efficiency recycling process for positive electrode materials of power batteries based on high-pressure water jet according to an embodiment of the present invention; Figure 2 This is a schematic diagram of a high-pressure water jet separation device according to an embodiment of the present invention; Figure 3 This is a flowchart of a high-efficiency recycling process for positive electrode materials of power batteries based on high-pressure water jet according to an embodiment of the present invention. Detailed Implementation

[0022] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0023] The following description, with reference to the accompanying drawings, describes an efficient recycling process for power battery cathode materials based on high-pressure water jet, as proposed in an embodiment of the present invention.

[0024] like Figure 1 As shown in the figure, the high-efficiency recycling process for power battery cathode materials based on high-pressure water jet according to an embodiment of the present invention includes the following steps: S1 performs a pre-treatment for retired power batteries to obtain pure positive electrode sheets.

[0025] According to one embodiment of the present invention, the pre-treatment for safety includes deep discharge of the retired power battery, mechanical disassembly, sorting out the positive electrode and removing the negative electrode, separator and structural components.

[0026] Specifically, during the pre-treatment of safety, the retired power battery is first subjected to deep discharge treatment to completely eliminate residual charge; then it is mechanically disassembled to separate structural components such as the battery casing and terminals, and impurities such as negative electrode plates and separators are accurately separated through a multi-method sorting process to obtain pure positive electrode plate raw materials.

[0027] S2, standardizes the cutting and fixing of the positive electrode sheet.

[0028] According to one embodiment of the present invention, the standardized cutting and fixing process includes cutting the positive electrode sheet into blanks of uniform size and fixing them using special tooling.

[0029] Specifically, during the standardization process of the positive electrode sheet, the pure positive electrode sheet is cut into blanks of uniform size to ensure uniform force during the subsequent high-pressure water jet impact; special tooling is used to fix the electrode sheet to prevent displacement or deformation during the impact.

[0030] S3 uses high-pressure water jets to impact the fixed positive electrode sheet from both sides, separating the positive electrode active material from the aluminum foil current collector, resulting in a slurry containing the positive electrode material and a clean aluminum foil current collector.

[0031] According to one embodiment of the present invention, the impact parameters of the high-pressure water jet include pressure, flow rate, impact angle and impact time, which are adjusted according to the electrode type.

[0032] Specifically, during double-sided high-pressure water jet separation, the fixed positive electrode sheet is subjected to double-sided high-pressure water jet impact treatment. The instant the water jet contacts the surface of the positive electrode sheet, its kinetic energy is converted into dynamic pressure, generating stress waves within the positive electrode material. These stress waves are reflected and superimposed multiple times at the "positive electrode active material-aluminum foil" interface, forming localized dynamic stress concentration, which leads to the rapid generation of numerous initial microcracks at the current collector interface. After the initial cracks form, high-pressure water rapidly penetrates the pores and interface cracks within the positive electrode material, forming a water wedge effect at the crack tips. This continuously applies splitting force, causing the cracks to propagate and penetrate along the interface. Under tensile stress, the positive electrode active material undergoes brittle tensile failure, separating from the aluminum foil current collector surface. Ultimately, a slurry containing the positive electrode material and a clean aluminum foil current collector are obtained, achieving non-destructive separation of the positive electrode active material from the aluminum foil current collector. Impact parameters (such as pressure, flow rate, impact angle, and impact time) can be flexibly adjusted according to the electrode type to ensure optimal separation results. After separation, a slurry containing positive electrode material and a clean aluminum foil current collector are obtained, the latter of which can be directly recycled and reused.

[0033] According to one embodiment of the present invention, the formula for calculating the jet impact force is as follows: (1) in, F The force of the jet impact is measured in nanometers (N). q The jet flow rate is expressed in m³ / s. ρ This is the density of water, expressed in kg / m³. v The velocity of the water jet is expressed in m / s. β The angle between the reflected water jet and the incident direction; Failure strength of electrode materials: (2) in, It is the dimensionless material failure strength; A These are the failure surface parameters of the cathode material; N The failure surface index of the cathode material; The normalized initial static pressure; If we substitute equation (2) into equation (1) and express the normalized initial static pressure in terms of jet impact force, then the formula is: (3) in, f c It is the uniaxial compressive strength of the positive electrode material.

[0034] For example, such as Figure 2As shown, the positive electrode sheet is fixed on the electrode sheet fixing fixture. High-pressure water jets are sprayed through the high-pressure water jet nozzle and through the high-pressure water jet boom to impact the positive electrode sheet. The impact energy of the high-speed water jet achieves non-destructive peeling of the positive electrode active material from the aluminum foil current collector. The positive electrode active material flows into the slurry collection tank through the filter screen.

[0035] S4, neutralizes and separates the slurry into solid and liquid components to obtain a solid positive electrode material filter cake.

[0036] According to one embodiment of the present invention, the neutralization treatment uses an alkaline regulator to adjust the slurry to neutral, with a pH value of 6.5 to 7.5.

[0037] According to one embodiment of the present invention, solid-liquid separation is carried out using a plate and frame filter press or a centrifugal separation device.

[0038] Specifically, the separated slurry is subjected to acid-base neutralization treatment to adjust it to neutral to avoid corrosion of subsequent equipment; then solid-liquid separation is performed to collect the solid positive electrode material filter cake.

[0039] S5, the filter cake is dried and sieved to obtain crude positive electrode material.

[0040] Specifically, the filter cake is dried to remove moisture; then it is crushed and standardized sieved to obtain a crude cathode material with uniform particle size and high purity, which is used as a raw material for subsequent purification and regeneration.

[0041] According to one embodiment of the present invention, the drying temperature is 60°C to 120°C, and the drying time is 2h to 8h; the sieving is carried out using a standard sieve with a mesh size of 100 to 300 mesh.

[0042] According to one embodiment of the present invention, the crude cathode material is further purified by wet leaching, pyrometallurgical smelting or material regeneration processes to recover valuable metals therein or to be directly used for cathode material remanufacturing.

[0043] Specifically, depending on actual needs, crude cathode materials are purified using wet, pyrometallurgical, or regeneration processes. The purified materials are then refined and processed before being mixed with virgin cathode materials and reused in power battery production.

[0044] Taking a certain model of retired ternary lithium battery as an example, such as Figure 3 As shown, the process for recycling cathode materials using the present invention includes the following steps: (1) Perform deep discharge treatment on the battery to ensure that the residual charge is completely eliminated; (2) After mechanical disassembly, the pure positive electrode sheets are sorted out and cut into 100mm×100mm specifications; (3) Fix the electrode in a special tooling, adjust the high-pressure water jet pressure to 30MPa, the impact angle to 90°, and the double-sided impact time to 5min; (4) After impact, the slurry is collected in a neutralization tank and an alkaline regulator is added to bring the pH to 7. (5) Solid-liquid separation is performed by a plate and frame filter press to obtain a positive electrode material filter cake; (6) The filter cake was dried at 80°C for 4 hours, pulverized and passed through a 200-mesh sieve to obtain crude positive electrode material; (7) There are three processing directions for crude cathode materials: one is to directly mix them into new cathode materials to make batteries; the other is to use wet leaching process to extract valuable metals such as lithium, nickel, and cobalt; and the third is to use pyrometallurgical recovery to recover and separate effective materials.

[0045] This process, through precise control of high-pressure water jet technology and systematic process integration, provides a new approach for the efficient, green, and low-cost recycling of cathode materials from retired power batteries, and has significant prospects for industrial application.

[0046] In the description of this specification, references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," 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.

[0047] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0048] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., 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, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0049] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A high-efficiency recycling process for positive electrode materials of power batteries based on high-pressure water jet, characterized in that, Includes the following steps: Pre-treatment of retired power batteries is carried out to obtain pure positive electrode sheets. The positive electrode sheet is subjected to standardized cutting and fixing. High-pressure water jets are used to impact the fixed positive electrode sheet from both sides, separating the positive electrode active material from the aluminum foil current collector, resulting in a slurry containing the positive electrode material and a clean aluminum foil current collector. The slurry is neutralized and subjected to solid-liquid separation to obtain a solid positive electrode material filter cake; The filter cake is dried and sieved to obtain crude positive electrode material.

2. The high-efficiency recycling process for power battery cathode materials based on high-pressure water jet according to claim 1, characterized in that, The pre-treatment for safety includes deep discharge of retired power batteries, mechanical disassembly, sorting out positive electrode plates and removing negative electrode plates, separators and structural components.

3. The high-efficiency recycling process for power battery cathode materials based on high-pressure water jet according to claim 1, characterized in that, The standardized cutting and fixing process includes cutting the positive electrode sheet into blanks of uniform size and fixing them using special tooling.

4. The high-efficiency recycling process for power battery cathode materials based on high-pressure water jet according to claim 1, characterized in that, The impact parameters of the high-pressure water jet include pressure, flow rate, impact angle, and impact time, which are adjusted according to the impact force and the failure strength of the electrode material.

5. The high-efficiency recycling process for power battery cathode materials based on high-pressure water jet according to claim 4, characterized in that, The formula for calculating the jet impact force is: （1） in, F The force of the jet impact is measured in nanometers (N). q The jet flow rate is expressed in m³ / s. ρ This is the density of water, expressed in kg / m³. v The velocity of the water jet is expressed in m / s. β The angle between the reflected water jet and the incident direction; Failure strength of electrode materials: （2） in, It is the dimensionless material failure strength; A These are the failure surface parameters of the cathode material; N The failure surface index of the cathode material; The normalized initial static pressure; If we substitute equation (2) into equation (1) and express the normalized initial static pressure in terms of jet impact force, then the formula is: （3） in, f c It is the uniaxial compressive strength of the positive electrode material.

6. The high-efficiency recycling process for power battery cathode materials based on high-pressure water jet according to claim 1, characterized in that, The neutralization treatment uses an alkaline regulator to adjust the slurry to a neutral pH of 6.5 to 7.

5.

7. The high-efficiency recycling process for power battery cathode materials based on high-pressure water jet according to claim 1, characterized in that, The solid-liquid separation is carried out using a plate and frame filter press or a centrifugal separation device.

8. The high-efficiency recycling process for power battery cathode materials based on high-pressure water jet according to claim 1, characterized in that, The drying temperature is 60℃ to 120℃, and the drying time is 2h to 8h; the sieving uses a standard sieve with a mesh size of 100 to 300 mesh.

9. The high-efficiency recycling process for power battery cathode materials based on high-pressure water jet according to claim 1, characterized in that, The crude cathode material is further purified through wet leaching, pyrometallurgical smelting, or material regeneration processes to recover valuable metals or directly use them for cathode material remanufacturing.

10. The high-efficiency recycling process for power battery cathode materials based on high-pressure water jet according to claim 1, characterized in that, The aluminum foil current collector is directly recycled and reused after cleaning.

Images