Battery material recycling method, positive pole piece and battery
By using waste lithium-ion battery electrolyte to contact the positive electrode sheet of the plant material, the interface strength is reduced, and the problems of complex recycling process and environmental hazards in the prior art are solved, and efficient recycling and reuse of battery materials are achieved.
Patent Information
- Application Number
- CN202411906388.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-23
- Publication Date
- 2025-03-18
AI Technical Summary
In the existing lithium-ion battery electrolyte recycling technology, the processing process is complex and requires additional fluorine-containing waste residue, which increases costs and environmental hazards.
By obtaining the waste battery cells and the factory positive electrode sheet of the lithium-ion battery, the waste electrolyte and the battery positive electrode sheet are recycled, and the waste electrolyte is used to contact the factory positive electrode sheet to reduce its interface strength, thereby achieving efficient separation of the current collector layer and the active material layer.
It realizes efficient recycling and reuse of battery materials, simplifies processing procedures, reduces costs, and reduces the harm of waste electrolyte to the environment.
Smart Images
Figure CN119650928A_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the technical field of battery recycling, and in particular to a battery material recycling method, a positive electrode sheet and a battery. Background Art
[0002] Lithium-ion batteries have been widely used in automobiles and various electronic devices due to their advantages such as high specific energy, high battery voltage, wide operating temperature range, and long storage life. At present, the recovery of lithium-ion battery electrolyte is mainly through the alkali method and distillation method. Whether it is the alkali method or the distillation method, the fluorine-containing waste residue generated during the treatment process needs to be additionally treated, which increases the treatment process. Summary of the invention
[0003] Based on this, it is necessary to provide a battery material recycling method, a positive electrode sheet and a battery with a simple processing flow and low cost.
[0004] In a first aspect, the present application provides a battery material recycling method, comprising:
[0005] Obtain discarded lithium-ion battery cells and factory-made positive electrode plates respectively;
[0006] Recycling the waste electrolyte and the positive electrode of the waste battery cell;
[0007] The waste electrolyte is used to perform contact treatment on the positive electrode plate of the factory material; the interface strength of the positive electrode plate of the factory material after the contact treatment is less than the interface strength before the contact treatment.
[0008] In one embodiment, the waste electrolyte includes fluoride ions; the factory positive electrode plate includes an interface layer, and the material of the interface layer includes aluminum oxide;
[0009] The method of using the waste electrolyte to contact the positive electrode sheet of the factory material includes:
[0010] diluting the waste electrolyte;
[0011] The diluted waste electrolyte is contacted with the positive electrode plate of the factory material so that the fluoride ions react with the aluminum oxide to generate aluminum fluoride.
[0012] In one embodiment, the contacting treatment of the diluted waste electrolyte with the factory material positive electrode plate includes:
[0013] Spraying the diluted waste electrolyte on the positive electrode plate of the factory material; or,
[0014] The factory material positive electrode plate is immersed in the diluted waste electrolyte.
[0015] In one embodiment, the waste electrolyte includes free electrolyte;
[0016] The method of recycling the waste electrolyte and the positive electrode of the waste battery cell comprises:
[0017] The discarded battery cells are disassembled to recover the free electrolyte and the positive electrode plates of the battery cells.
[0018] In one of the embodiments, the waste electrolyte further comprises a first adhesion electrolyte;
[0019] The method of recycling the waste electrolyte and the positive electrode of the waste battery cell comprises:
[0020] Performing a first drying process on the positive electrode sheet of the battery cell to collect first volatile steam;
[0021] The first volatile vapor is condensed to recover the first adhesive electrolyte.
[0022] In one embodiment, the method further comprises:
[0023] Performing a second drying treatment on the positive electrode sheet of the factory material after the contact treatment, and collecting the second volatile steam;
[0024] The second volatile vapor is condensed to recover the second adhesion electrolyte.
[0025] In one embodiment, the method further comprises:
[0026] diluting the second adhesion electrolyte;
[0027] The diluted second adhesive electrolyte is contacted with a new factory material positive electrode plate; the interface strength of the new factory material positive electrode plate after the contact treatment is less than the interface strength before the contact treatment.
[0028] In one embodiment, the method further comprises:
[0029] The factory material positive electrode sheet after the contact treatment and the battery cell positive electrode sheet are respectively subjected to a stripping treatment to obtain separated active materials and current collectors.
[0030] In a second aspect, the present application further provides a positive electrode sheet, comprising a stacked active material layer and a current collector layer, wherein the active material layer is obtained by separating the positive electrode sheet of a battery cell obtained by the battery material recovery method provided in any of the above embodiments and the positive electrode sheet of a factory material after contact treatment; or,
[0031] The current collector layer is obtained by separating the positive electrode sheet of the battery cell obtained by the battery material recycling method provided in any of the above embodiments and the positive electrode sheet of the factory material after the contact treatment.
[0032] In a third aspect, the present application also provides a battery, comprising the positive electrode plate provided by any of the above embodiments.
[0033] In the above-mentioned battery material recycling method, positive electrode plate and battery, by obtaining the discarded battery cells and factory-made positive electrode plates of lithium-ion batteries respectively, the discarded electrolyte and the positive electrode plates of the discarded battery cells are recovered, and the factory-made positive electrode plates are contacted with the discarded electrolyte, so that the interface strength of the factory-made positive electrode plates after the contact treatment is less than the interface strength before the contact treatment. It can be understood that by using the discarded electrolyte to contact the factory-made positive electrode plates, defects are generated on the surface of the factory-made positive electrode plates, and the interface strength of the factory-made positive electrode plates is reduced, which can reduce the difficulty of stripping the factory-made positive electrode plates, thereby more efficiently separating the current collector layer and the active material layer in the factory-made positive electrode plates. The processing method is simple and low-cost, and the waste electrolyte is fully utilized to reduce the harm of the waste electrolyte to the environment. The separated current collector layer and active material layer can be used again to prepare the positive electrode plates and batteries, realizing the recycling of the current collector and active material, and saving energy and protecting the environment. BRIEF DESCRIPTION OF THE DRAWINGS
[0034] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the conventional technology, the drawings required for use in the embodiments or the conventional technology descriptions are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.
[0035] Figure 1 A schematic diagram of a process for recycling battery materials provided in one embodiment;
[0036] Figure 2 A schematic flow chart of a battery material recycling method provided in another embodiment. DETAILED DESCRIPTION
[0037] In order to facilitate understanding of the present application, the present application will be described more fully below with reference to the relevant drawings. Embodiments of the present application are provided in the drawings. However, the present application can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present application more thorough and comprehensive.
[0038] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used herein in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application.
[0039] In one embodiment, Figure 1 As shown, the present application provides a battery material recycling method, including steps 102-106.
[0040] Step 102, obtaining discarded lithium-ion battery cells and factory-made positive electrode plates respectively.
[0041] Among them, the factory-made positive electrode sheet is a positive electrode sheet that is scrapped in the front-end process of preparing the positive electrode sheet, such as coating, rolling, and slitting. The factory-made positive electrode sheet includes a current collector layer and an active material layer that are stacked. The current collector layer is used to carry the active material, and the current collector layer may include an aluminum layer. The active material layer includes a lithium-containing compound.
[0042] Step 104, recovering the waste electrolyte and the positive electrode plates of the waste battery cells.
[0043] The packaging shell of the discarded battery cell can be removed to obtain the discarded electrolyte and the battery cell positive electrode plate. The discarded electrolyte contains fluorine-containing lithium salts and organic solvents (such as ethylene carbonate, propylene carbonate, diethyl carbonate, etc.). The battery cell positive electrode plate includes a stacked current collector layer and an active material layer.
[0044] Step 106, using the waste electrolyte to perform contact treatment on the positive electrode plate of the factory material.
[0045] The interface strength of the factory material positive electrode sheet after contact treatment is less than the interface strength before contact treatment. The interface strength indicates the interface bonding strength of the factory material positive electrode sheet. The higher the interface strength, the more difficult it is to subsequently peel off the factory material positive electrode sheet. By contacting the waste electrolyte with the factory material positive electrode sheet, the waste electrolyte can react chemically with the factory material positive electrode sheet to destroy the surface of the factory material positive electrode sheet, thereby reducing the interface strength of the factory material positive electrode sheet.
[0046] In an embodiment of the present application, by respectively obtaining discarded cells and factory-made positive electrode sheets of lithium-ion batteries, recycling the discarded electrolyte and cell positive electrode sheets of the discarded cells, and using the discarded electrolyte to perform contact treatment on the factory-made positive electrode sheets, the interface strength of the factory-made positive electrode sheets after the contact treatment is less than the interface strength before the contact treatment. It can be understood that by using the discarded electrolyte to contact the factory-made positive electrode sheets, defects are generated on the surface of the factory-made positive electrode sheets, and the interface strength of the factory-made positive electrode sheets is reduced, which can reduce the difficulty of stripping the factory-made positive electrode sheets, thereby more efficiently separating the current collector layer and the active material layer in the factory-made positive electrode sheets. The processing method is simple and low-cost, and it also makes full use of the discarded electrolyte, reducing the harm of the discarded electrolyte to the environment.
[0047] In one embodiment, the waste electrolyte includes fluoride ions. The factory-made positive electrode plate also includes an interface layer, and the material of the interface layer includes aluminum oxide. The current collector layer on the factory-made positive electrode plate is usually an aluminum layer. After the factory-made positive electrode plate is scrapped, the aluminum reacts with oxygen in the air to form a dense aluminum oxide film, i.e., the interface layer, on the surface of the factory-made positive electrode plate. The presence of the interface layer will increase the difficulty of subsequent stripping of the factory-made positive electrode plate.
[0048] Furthermore, the waste electrolyte is used to contact the factory material positive electrode plate, including the steps of diluting the waste electrolyte and contacting the diluted waste electrolyte with the factory material positive electrode plate to allow fluoride ions to react with aluminum oxide to generate aluminum fluoride.
[0049] Fluoride ions react with alumina to generate aluminum fluoride, which destroys the interface layer of the positive electrode sheet of the factory material and reduces the interface strength of the positive electrode sheet of the factory material. Therefore, the waste electrode liquid can be diluted first, and the diluted waste electrolyte can be fully contacted with the positive electrode sheet of the factory material, so that the fluoride ions react with alumina to generate aluminum fluoride and destroy the interface layer. In addition, the generated aluminum fluoride can be used to make aluminum.
[0050] In one embodiment, the diluted waste electrolyte is contacted with the factory material positive electrode plate, including the step of spraying the diluted waste electrolyte on the factory material positive electrode plate. It is understood that the waste electrolyte can be sprayed on the factory material positive electrode plate to make the waste electrolyte fully contact with the factory material positive electrode plate.
[0051] In one embodiment, the diluted waste electrolyte is contacted with the factory material positive electrode plate, including the step of soaking the factory material positive electrode plate in the diluted waste electrolyte. It is understood that the factory material positive electrode plate can be soaked in the diluted waste electrolyte so that the waste electrolyte is in full contact with the factory material positive electrode plate.
[0052] In one embodiment, the waste electrolyte includes free electrolyte, which refers to electrolyte that can be directly separated from the positive electrode plate of the battery cell.
[0053] Recycling the waste electrolyte and the positive electrode of the waste battery cell includes the steps of disassembling the waste battery cell and recovering the free electrolyte and the positive electrode of the battery cell. Specifically, the waste battery cell can be disassembled by a disassembly process, the shell of the waste battery cell can be removed, and the free electrolyte and the positive electrode of the battery cell can be separated.
[0054] Furthermore, the waste electrolyte also includes a first adherent electrolyte. The first adherent electrolyte refers to an electrolyte adhered to the positive electrode plate of the battery cell. Recycling the waste electrolyte and the positive electrode plate of the waste battery cell also includes the steps of performing a first drying treatment on the positive electrode plate of the battery cell, collecting a first volatile vapor, and condensing the first volatile vapor to recover the first adherent electrolyte.
[0055] The drying temperature of the first drying treatment may be 30°C-180°C, including but not limited to 30°C, 60°C, 90°C, 120°C, 150°C, 180°C or a range between any two points, and the drying time of the first drying treatment may be 5min-60min, including but not limited to 5min, 10min, 20min, 30min, 40min, 50min, 60min or a range between any two points. The first volatile vapor includes water vapor, organic solvents and fluorine-containing compounds.
[0056] The positive electrode plate of the battery cell can be subjected to a first drying treatment based on a preset drying temperature and drying time, and the first volatile vapor can be collected and then condensed to obtain a first adherent electrolyte. After the first adherent electrolyte is mixed with a free electrolyte, a waste electrolyte can be obtained.
[0057] In one embodiment, the battery material recycling method of the present application also includes the steps of performing a second drying treatment on the positive electrode plate of the factory material after the contact treatment, collecting the second volatile vapor, and condensing the second volatile vapor to recover the second adhesion electrolyte.
[0058] The drying temperature of the second drying treatment may be 30°C-180°C, including but not limited to 30°C, 60°C, 90°C, 120°C, 150°C, 180°C or a range between any two points, and the drying time of the second drying treatment may be 5min-60min, including but not limited to 5min, 10min, 20min, 30min, 40min, 50min, 60min or a range between any two points. The second volatile vapor includes water vapor, organic solvents and fluorine-containing compounds.
[0059] The waste positive electrode sheet after the contact treatment can be subjected to a first drying treatment based on a preset drying temperature and drying time, the second volatile vapor can be collected, and then the second volatile vapor can be subjected to a condensation treatment to obtain a second adhesive electrolyte.
[0060] Furthermore, the second adhesive electrolyte can be diluted, and the diluted second adhesive electrolyte is contacted with the new factory material positive electrode plate. The interface strength of the new factory material positive electrode plate after the contact treatment is less than the interface strength before the contact treatment.
[0061] There is still a small amount of fluoride ions in the product after the waste electrolyte contacts the factory material positive electrode sheet, and the small amount of fluoride ions will chemically react with aluminum oxide. Therefore, the second adhesion electrolyte can be diluted and the diluted second adhesion electrolyte can be contacted with the new factory material positive electrode sheet to reduce the interface strength of the new factory material positive electrode sheet, reduce the difficulty of stripping the new factory material positive electrode sheet, and realize the recycling of the waste electrolyte.
[0062] In one embodiment, the battery material recycling method of the present application further includes the step of stripping the factory material positive electrode sheet and the battery cell positive electrode sheet after the contact treatment to obtain separated active materials and current collectors.
[0063] Specifically, the positive electrode sheet of the factory material and the positive electrode sheet of the battery cell can be immersed in the stripping agent solution for reaction, and after a period of time, the separated active material and the current collector are obtained. The stripping agent used in the stripping agent solution includes at least one of phosphoric acid, nitric acid, sulfuric acid, inositol hexaphosphate, inositol pentaphosphate, inositol tetraphosphate, inositol triphosphate, oxalic acid, citric acid, acetic acid, malic acid, maleic acid, valeric acid, succinic acid, gum acid, malonic acid and tartaric acid. The solvent in the stripping agent solution includes water and / or an organic solvent, and the organic solvent includes at least one of methanol, ethanol, acetone and carbonate organic compounds. The stripping time is 3min-30min, including but not limited to 3min, 6min, 9min, 12min, 15min, 18min, 21min, 24min, 27min, 30min or any range between the two. The stripping temperature can be 20℃-60℃, including but not limited to 20℃, 30℃, 40℃, 50℃, 60℃ or any range between the two.
[0064] Optionally, the positive electrode sheet of the factory material and the positive electrode sheet of the battery cell can be immersed in a mixed solution containing a stripping agent and a stripping aid to react, and after a period of time, a separated active substance and a current collector are obtained. The stripping agent includes at least one of oxalic acid, citric acid, malic acid, succinic acid, colloidal acid, malonic acid and tartaric acid. The stripping aid includes at least one of sodium fluoride, potassium fluoride, ammonium fluoride, phosphoric acid, sodium phosphate, sodium monohydrogen phosphate, sodium metaphosphate, potassium phosphate, potassium monohydrogen phosphate, potassium metaphosphate, ammonium phosphate, disodium ethylenediaminetetraacetate, tetrasodium ethylenediaminetetraacetate, inositol hexaphosphate and its salts, inositol pentaphosphate and its salts, inositol tetraphosphate and its salts, and inositol triphosphate and its salts. The mass fraction of the stripping agent in the mixed solution is 0.05% to 50%, including but not limited to 0.05%, 1%, 5%, 10%, 20%, 30%, 40%, 50% or any range between the two, and the mass fraction of the stripping aid in the mixed solution is 0.005%-10%, including but not limited to 0.005%, 0.01%, 0.05%, 1%, 2%, 3%, 4%, 5% or any range between the two. The stripping temperature is 20°C-80°C, including but not limited to 20°C, 30°C, 40°C, 50°C, 60°C, 70°C, 80°C or any range between the two. The stripping time can be 1 to 15 minutes, including but not limited to 1 minute, 5 minutes, 10 minutes, 15 minutes or any range between the two.
[0065] For a better understanding, a more specific example is given to illustrate the battery material recycling method of the present application. Figure 2 As shown, waste cells of lithium-ion batteries are obtained, and the waste cells are disassembled to obtain free electrolyte and cell positive electrode sheets. The cell positive electrode sheets are subjected to a first drying treatment, and the first volatile vapor is collected. The first volatile vapor is condensed to obtain a dried cell positive electrode sheet and a first adhesive electrolyte. The first adhesive electrolyte is mixed with the free electrolyte to obtain a waste electrolyte. The waste electrolyte is used to contact the factory positive electrode sheet. The factory positive electrode sheet after contact is subjected to a second drying treatment, and the second volatile vapor is collected. The second volatile vapor is condensed to obtain a second adhesive electrolyte and a dried factory positive electrode sheet. The second adhesive electrolyte can be mixed with the aforementioned waste electrolyte, and the mixed electrolyte can be used to contact the new factory positive electrode sheet. Finally, the dried cell positive electrode sheet and the factory positive electrode sheet are stripped to obtain separated current collectors and active substances.
[0066] In the above treatment process, the waste electrolyte in the waste battery cell is recycled to contact the factory material positive electrode sheet. The F ions in the waste electrolyte can react with the dense aluminum oxide on the surface of the factory material positive electrode sheet, destroy the aluminum oxide layer, and reduce the interface strength of the factory material positive electrode sheet, thereby reducing the difficulty of stripping the factory material positive electrode sheet and achieving efficient separation of the current collector and active material in the factory material positive electrode sheet. In addition, the waste electrolyte is fully utilized without the need to add alkali to defluorinate the waste electrolyte. The treatment process is simple and low-cost, and the harm of the waste electrolyte to the environment is reduced.
[0067] In one embodiment, the present application further provides a positive electrode sheet, comprising a stacked active material layer and a current collector layer, wherein the active material layer is obtained by separating the positive electrode sheet of a battery cell obtained by the battery material recovery method provided in any of the above embodiments and the positive electrode sheet of a factory material after contact treatment; or,
[0068] The current collector layer is obtained by separating the positive electrode sheet of the battery cell obtained by the battery material recycling method provided in any of the above embodiments and the positive electrode sheet of the factory material after the contact treatment.
[0069] In an embodiment of the present application, the positive electrode sheets of the battery cells and the current collectors and active substances in the waste factory material sheets are recovered based on the battery material recycling method, and the positive electrode sheets are formed using the recovered current collectors and active substances, thereby realizing the recycling of the current collectors and active substances, saving energy and protecting the environment.
[0070] In one embodiment, the present application also provides a battery, comprising the positive electrode plate provided in any of the above examples.
[0071] It should be understood that, although the various steps in the flowcharts involved in the above-mentioned embodiments are displayed in sequence according to the illustrated order, these steps are not necessarily executed in sequence according to the illustrated order. Unless there is a clear explanation in this article, the execution of these steps does not have a strict order restriction, and these steps can be executed in other orders. Moreover, at least a portion of the steps in the flowcharts involved in the above-mentioned embodiments may include multiple steps or multiple stages, and these steps or stages are not necessarily executed at the same time, but can be executed at different times, and the execution order of these steps or stages is not necessarily to be carried out in sequence, but can be executed in turn or alternately with other steps or at least a portion of the steps or stages in other steps.
[0072] In the description of this specification, the description with reference to the terms "some embodiments", "other embodiments", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic description of the above terms does not necessarily refer to the same embodiment or example.
[0073] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.
[0074] The above-described embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the present application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the attached claims.
Claims
1. A battery material recycling method, characterized in that: include: Obtain discarded lithium-ion battery cells and factory-made positive electrode plates respectively; Recycling the waste electrolyte and the positive electrode of the waste battery cell; The waste electrolyte is used to perform contact treatment on the positive electrode plate of the factory material; the interface strength of the positive electrode plate of the factory material after the contact treatment is less than the interface strength before the contact treatment.
2. The method according to claim 1, characterized in that The waste electrolyte includes fluoride ions; the factory positive electrode plate includes an interface layer, and the material of the interface layer includes aluminum oxide; The method of using the waste electrolyte to contact the positive electrode sheet of the factory material includes: diluting the waste electrolyte; The diluted waste electrolyte is contacted with the positive electrode plate of the factory material so that the fluoride ions react with the aluminum oxide to generate aluminum fluoride.
3. The method according to claim 2, characterized in that The step of bringing the diluted waste electrolyte into contact with the positive electrode sheet of the factory material comprises: Spraying the diluted waste electrolyte on the positive electrode plate of the factory material; or, The factory material positive electrode plate is immersed in the diluted waste electrolyte.
4. The method according to claim 1, characterized in that: The waste electrolyte includes free electrolyte; The method of recycling the waste electrolyte and the positive electrode of the waste battery cell comprises: The discarded battery cells are disassembled to recover the free electrolyte and the positive electrode plates of the battery cells.
5. The method according to claim 4, characterized in that The waste electrolyte also includes a first adhesion electrolyte; The method of recycling the waste electrolyte and the positive electrode of the waste battery cell comprises: Performing a first drying process on the positive electrode sheet of the battery cell to collect first volatile steam; The first volatile vapor is condensed to recover the first adhesive electrolyte.
6. The method according to claim 1, characterized in that The method further comprises: Performing a second drying treatment on the positive electrode sheet of the factory material after the contact treatment, and collecting the second volatile steam; The second volatile vapor is condensed to recover the second adhesion electrolyte.
7. The method according to claim 6, characterized in that The method further comprises: diluting the second adhesion electrolyte; The diluted second adhesive electrolyte is contacted with a new factory material positive electrode plate; the interface strength of the new factory material positive electrode plate after the contact treatment is less than the interface strength before the contact treatment.
8. The method according to any one of claims 1 to 7, characterized in that: The method further comprises: The factory material positive electrode sheet after the contact treatment and the battery cell positive electrode sheet are respectively subjected to a stripping treatment to obtain separated active materials and current collectors.
9. A positive electrode sheet, characterized in that: It comprises a stacked active material layer and a current collector layer, wherein the active material layer is obtained by separating the positive electrode sheet of the battery cell obtained by the method according to any one of claims 1 to 8 and the positive electrode sheet of the factory material after contact treatment; or The current collector layer is obtained by separating the positive electrode sheet of the battery cell obtained by the method according to any one of claims 1 to 8 and the positive electrode sheet of the factory material after the contact treatment.
10. A battery, characterized in that: Comprising the positive electrode sheet as claimed in claim 9.