Method for directly regenerating high-performance lithium ion cathode material
Patent Information
- Application Number
- CN202310208252.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2023-03-06
- Publication Date
- 2026-01-09
- Estimated Expiration
- 2043-03-06
AI Technical Summary
Existing lithium-ion battery recycling methods suffer from complex processes, high energy consumption, and environmental inefficiencies. In particular, pyrometallurgical and hydrometallurgical processes require strong acids, strong alkalis, and reducing agents, leading to the generation of acid and alkali wastewater and complex downstream separation processes.
A method for preparing high-performance lithium-ion cathode materials through direct regeneration involves pulverizing waste cathode sheets, immersing them in a lithium source solution, heating and stirring them while introducing carbon dioxide, filtering them, drying them, and calcining them in an air or oxygen atmosphere. The amount of aluminum is controlled to replenish lithium and repair the structure, avoiding the use of strong acids, strong alkalis, and reducing agents.
It achieves a simple recycling process, with no secondary pollution, reduces the generation of acid and alkaline wastewater, enables large-scale industrial production, and improves the electrochemical performance and thermal stability of cathode materials through the utilization of aluminum.
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Abstract
Description
TECHNICAL FIELD
[0001] The application belongs to the technical field of battery recycling, and particularly relates to a method for directly regenerating high-performance lithium ion positive electrode materials. BACKGROUND
[0002] At present, the recycling methods for waste lithium ion batteries mainly include pyrometallurgy and hydrometallurgy. Both pyrometallurgy and hydrometallurgy need to effectively decompose the positive electrode materials of waste lithium ion batteries, extract valuable metals, and prepare lithium ion battery positive electrode materials. The difference between them lies in the decomposition method. Pyrometallurgy uses high-temperature reduction roasting, and hydrometallurgy uses acid (alkali) and reducing agent leaching. The processes of pyrometallurgy and hydrometallurgy are complex, and there are obvious shortcomings in energy consumption and environmental friendliness. SUMMARY
[0003] The present application aims to solve at least one of the technical problems existing in the prior art. To this end, the present application provides a method for directly regenerating high-performance lithium ion positive electrode materials, which is simple in process, does not produce secondary pollution, does not need strong acid, strong alkali and reducing agent for leaching, reduces the generation of acid and alkali wastewater, and reduces the complex component separation process at the back end.
[0004] The present application aims to provide a method for directly regenerating high-performance lithium ion positive electrode materials, comprising the following steps:
[0005] Discharge the waste lithium ion battery, disassemble it, and obtain the waste positive electrode sheet;
[0006] Crush and sieve the waste positive electrode sheet to obtain undersize material; the undersize material is waste positive electrode black powder containing a small amount of aluminum powder; the content of aluminum powder is less than 2wt%;
[0007] Immerse the waste positive electrode black powder in a lithium source solution, heat and stir, then pass carbon dioxide, and filter to obtain filter residue;
[0008] Dry and calcine the filter residue to obtain the high-performance lithium ion positive electrode material.
[0009] Preferably, the crushing includes primary crushing and secondary crushing; the waste positive electrode sheet is sieved through a 5-80 mesh sieve after primary crushing, and then sieved through a 100-200 mesh sieve after secondary crushing.
[0010] Preferably, the specific process of discharging includes: soaking the waste lithium ion battery in a solution for 36-48h to discharge the battery to below 1V.
[0011] Preferably, the solution is selected from water, a sodium chloride solution or a sodium sulfate solution.
[0012] Preferably, the mechanical crushing device used in the crushing is one of a toothed crusher, a hammer crusher, a knife crusher, a turbine crusher, a pressure grinding crusher or a milling crusher; the mechanical crushing device mechanically crushes the waste positive plate into debris and powder through crushing, breaking and grinding.
[0013] Preferably, the waste lithium ion battery is a waste lithium cobalt oxide battery, and in the filter residue, aluminum accounts for 0.5%-6% of the total molar mass of lithium and cobalt. More preferably, aluminum accounts for about 2.1% of the total molar mass of lithium and cobalt.
[0014] Preferably, the waste lithium ion battery is a waste lithium cobalt oxide battery, and in the filter residue, the molar mass ratio of lithium to cobalt is (1-1.1):1.
[0015] Preferably, the waste lithium ion battery is a waste lithium cobalt oxide battery, and in the filter residue, aluminum accounts for 0.5%-6% of the total molar mass of lithium and cobalt. More preferably, aluminum accounts for about 2.1% of the total molar mass of lithium and cobalt.
[0016] Preferably, the waste lithium ion battery is a waste lithium cobalt oxide battery, and in the filter residue, the molar mass ratio of lithium to cobalt is (1-1.1):1.
[0017] Preferably, the waste lithium cobalt oxide battery has a molar ratio of nickel, cobalt and manganese of one of 5:2:3, 6:2:2 or 8:1:1.
[0018] Preferably, the lithium source solution is a lithium hydroxide solution.
[0019] Preferably, the concentration of the lithium hydroxide solution is 2g / L-6g / L.
[0020] Preferably, the parameters of the heating and stirring include: the temperature of the heating is 40℃-100℃, the time of the stirring is 10min-240min, and the rate of the stirring is 50rpm-600rpm. More preferably, the temperature of the heating is 90℃-95℃, the time of the stirring is 120min-180min, and the rate of the stirring is 300rpm-500rpm.
[0021] Preferably, the temperature of the drying is 50℃-100℃, and the time of the drying is 1h-20h. More preferably, the temperature of the drying is 70℃-100℃, and the time of the drying is 10h-15h.
[0022] Preferably, the calcination temperature is 700-1000℃, the heating rate is 5-30℃ / min, and the calcination time is 10-40h. More preferably, the calcination temperature is 850-950℃, the heating rate is 5-10℃ / min, and the calcination time is 15-24h.
[0023] Preferably, the calcination atmosphere is air or oxygen.
[0024] Compared with the prior art, the present application has the following advantages:
[0025] (1) The method for directly regenerating high-performance lithium ion positive electrode material provided by the present application is simple in process and does not produce secondary pollution. In the whole recycling process, no strong acid, strong base and reducing agent are needed for leaching, thereby reducing the generation of acid and alkali wastewater, reducing the complex component separation process at the rear end and wastewater treatment cost, and enabling large-scale industrial production.
[0026] (2) The present application can realize one-step lithium supplementation and aluminum element. By fully utilizing the characteristics that aluminum can be dissolved in a lithium source solution, one-step lithium supplementation and aluminum immersion under normal pressure in a low-temperature (below 100℃) liquid phase are realized.
[0027] (3) By controlling the amount of aluminum in the waste positive electrode black powder, the present application can effectively utilize the aluminum powder in the waste positive electrode black powder, and then moderately supplement the deficient elements, such as lithium element by immersing in a lithium source solution or nickel salt, cobalt salt or manganese salt by moderately supplementing into the waste positive electrode black powder, to directly regenerate and repair the structure of the positive electrode material, thereby recovering its electrochemical performance, realizing the effective doping of aluminum ions in the regenerated positive electrode material, and modifying and adjusting the phase structure of the positive electrode material, so that the positive electrode material can overcome the severe structural change and collapse in the cycle, greatly improving the electrochemical performance and thermal stability of the positive electrode material. BRIEF DESCRIPTION OF DRAWINGS
[0028] Figure 1 is the process flow chart of the present application;
[0029] Figure 2 is the cycle performance comparison chart of the positive electrode material of Example 2 and the control group. DETAILED DESCRIPTION
[0030] In order to make those skilled in the art more clearly understand the technical solutions described in the present application, the following examples are given for illustration. It should be pointed out that the following examples do not constitute a limitation on the scope of protection required by the present application.
[0031] The raw materials, reagents and devices used in the following examples, if not specifically stated, can be obtained from conventional commercial channels or can be obtained by existing known methods.
[0032] Reference Figure 1 The embodiment of the present application provides a method for directly regenerating high-performance lithium ion positive electrode material, comprising the following steps:
[0033] Battery discharging and manual disassembly: the waste lithium ion battery is discharged and manually disassembled to obtain the waste positive electrode sheet;
[0034] Mechanical treatment: the waste positive electrode sheet is subjected to primary crushing and secondary crushing, the primary crushed product is sieved through a 5-80 mesh sieve, and the secondary crushed product is sieved through a 100-200 mesh sieve to obtain the sieve-up material and the sieve-down material; the sieve-up material is aluminum scrap, and the sieve-down material is the waste positive electrode black powder containing less than 2wt% aluminum powder;
[0035] Lithium supplementing and aluminum supplementing: the waste positive electrode black powder is immersed in a lithium source solution, heated and stirred, and then carbon dioxide is introduced, and the filter residue is obtained by filtration;
[0036] Regeneration of the positive electrode material: the filter residue is dried, and then is heated to 700-1000℃ at a heating rate of 5-30℃ / min in an air atmosphere or an oxygen atmosphere, and is calcined for 10-40h to obtain the high-performance lithium ion positive electrode material.
[0037] The method for directly regenerating high-performance lithium ion positive electrode material is described below with specific examples:
[0038] Example 1
[0039] A method for directly regenerating high-performance lithium ion positive electrode material, comprising the following steps:
[0040] (1) 2kg of waste lithium cobalt oxide soft pack battery is soaked in water, and is discharged for 36 hours to make the battery discharged to below 1V, and after natural air drying, manual disassembly is performed to obtain the waste positive electrode sheet;
[0041] (2) the waste positive electrode sheet is subjected to primary crushing by using a knife-type crusher, and is sieved through a 5 mesh vibrating screen to obtain the primary sieve-up material and the primary sieve-down material, and then the primary sieve-down material is subjected to secondary crushing and is sieved through a 200 mesh vibrating screen to obtain the secondary sieve-up material and the secondary sieve-down material; wherein the primary sieve-up material and the secondary sieve-up material are aluminum scrap, and the secondary sieve-down material is the waste positive electrode black powder containing less than 2wt% aluminum powder;
[0042] (3) After analysis, the molar content of lithium in the waste positive electrode black powder obtained in step (2) is 3.5%, the molar content of cobalt is 48%, and the molar content of aluminum is 1.4%. According to the normal molar mass ratio of lithium to cobalt in lithium cobalt oxide battery (1-1.1):1, and aluminum accounting for about 2.1% of the total molar mass of lithium and cobalt, the concentration of lithium hydroxide solution required is calculated to be 2.2g / L, then the waste positive electrode black powder obtained in step (2) is immersed in a lithium hydroxide solution with a concentration of 2.2g / L, after the immersion is completed, carbon dioxide is introduced, and stirring is continued, and the filter residue is obtained after sufficient precipitation, filtration; wherein the immersion conditions are: constant temperature of 90℃, stirring rate of 300rpm, and immersion time of 120min;
[0043] (4) The filter residue is dried at 100℃ for 10h, then the dried filter residue is moved into a muffle furnace, the temperature rising rate is set to 5℃ / min, the temperature is raised to 850℃ and kept for 24h, then naturally cooled to obtain the regenerated high-performance lithium ion positive electrode material.
[0044] Example 2
[0045] A method for directly regenerating and preparing a high-performance lithium ion positive electrode material, comprising the following steps:
[0046] (1) 2kg of waste nickel-cobalt-manganese ternary lithium battery is soaked in water, and discharged for 48 hours to make the battery discharge to below 1V, and after natural air drying, manual disassembly is performed to obtain a waste positive electrode sheet;
[0047] (2) The waste positive electrode sheet is subjected to primary crushing with a knife-type crusher, and the primary crushed product is passed through a 80-mesh vibrating screen to obtain primary sieve residue and primary sieve undersize, then the primary sieve undersize is subjected to secondary crushing, and the secondary crushed product is passed through a 100-mesh vibrating screen to obtain secondary sieve residue and secondary sieve undersize; wherein the primary sieve residue and the secondary sieve residue are aluminum scraps; the secondary sieve undersize is a waste positive electrode black powder containing less than 2wt% aluminum powder;
[0048] (3) Analysis shows that the molar content of lithium in the waste positive electrode black powder obtained in step (2) is 5.2%, the molar content of nickel is 73.2%, the molar content of cobalt is 8.3%, the molar content of manganese is 9.1%, and the molar content of aluminum is 2.0%. According to the normal molar mass ratio of nickel, cobalt and manganese in the nickel-cobalt-manganese ternary lithium battery, the shortage elements are added, 0.9% of cobalt is added, the aluminum accounts for about 3.6% of the total molar mass of (nickel, cobalt and manganese), and the total molar mass ratio of lithium to (nickel, cobalt, manganese and aluminum) is (1-1.1):1, the concentration of lithium hydroxide solution required is calculated to be 6.0g / L, then the waste positive electrode black powder obtained in step (2) is immersed in the lithium hydroxide solution with a concentration of 6.0g / L, after the immersion is completed, carbon dioxide is introduced, and stirring is continued, and the filter residue is obtained after sufficient precipitation and filtration; wherein the immersion conditions are: constant temperature of 95℃, stirring rate of 500rpm, and immersion time of 180min;
[0049] (4) The filter residue is dried at 70℃ for 15h, and then the dried filter residue is moved into a muffle furnace, the temperature rising rate is set to 10℃ / min, the temperature is raised to 950℃, and then the temperature is kept for 15h, and then the temperature is naturally cooled to obtain the regenerated high-performance lithium ion positive electrode material.
[0050] Performance test
[0051] The regenerated high-performance lithium ion positive electrode materials prepared in Example 1 and Example 2 are assembled into CR2032 type button cells respectively, and the capacity retention rate of the cells is tested under the conditions of 25℃ and 55℃, 0.5C rate, 3.0V-4.3V charge-discharge cycle, and compared with the same type of commercially available positive electrode material (control group), and the results are shown in Table 1 and Figure 2
[0052] Table 1
[0053]
[0054] As can be seen from Table 1 and Figure 2 , the cycle performance of the regenerated high-performance lithium ion positive electrode materials prepared in Example 1 and Example 2 is obviously better than that of the same type of commercially available positive electrode material.
[0055] Comparative Example 1
[0056] The difference between Example 1 and Comparative Example 1 is that in the method of Comparative Example 1, the primary crushing and the secondary crushing are both passed through an 80-mesh oscillating screen, and the aluminum powder content in the waste positive electrode black powder is greater than 2wt%.
[0057] Comparative Example 2
[0058] The difference between Example 1 and Comparative Example 2 is that in the method of Comparative Example 2, the calcination temperature is 600℃.
[0059] Comparative Example 3
[0060] The difference from Example 1 is that in the method of Comparative Example 3, the calcination temperature is 1200℃.
[0061] The regenerated lithium-ion positive electrode materials prepared in Comparative Examples 1-3 were respectively assembled into CR2032 type button cells for testing. The test cells were cycled for 100 cycles at a rate of 0.5C and a voltage of 3.0V-4.3V in an environment of 25℃, and the capacity retention rates were as follows:
[0062] Comparative Example 1: 49.7%; Comparative Example 2: 33.5%; Comparative Example 3: 25.63%.
[0063] It can be seen that the cycle performance of the regenerated lithium-ion positive electrode materials prepared in Comparative Examples 1-3 is significantly reduced compared with the regenerated lithium-ion positive electrode material prepared in Example 1.
[0064] The above describes the preferred embodiments of the present application, but the present application is not limited to the described embodiments, and those skilled in the art can make various equivalent modifications or replacements without departing from the spirit of the present application. These equivalent modifications or replacements are all included in the scope defined by the claims of the present application.
Claims
1. A method for directly regenerating high performance lithium-ion cathode materials, characterized in that, The method comprises the following steps: Discharge and disassemble the waste lithium ion battery to obtain a waste positive plate; Crush and sieve the waste positive plate to obtain undersize, which is waste positive black powder containing a small amount of aluminum powder, wherein the content of aluminum powder is less than 2wt%; Immerse the waste positive black powder in a lithium source solution, heat and stir, then pass carbon dioxide, and filter to obtain a filter residue; Dry and calcine the filter residue to obtain the high-performance lithium ion positive material; The crushing comprises primary crushing and secondary crushing; sieve the waste positive plate after primary crushing through a 5-80 mesh sieve, and sieve the waste positive plate after secondary crushing through a 100-200 mesh sieve; The lithium source solution is a lithium hydroxide solution; The waste lithium ion battery is a waste lithium cobaltate battery, and in the filter residue, aluminum accounts for 0.5%-6% of the total molar mass of lithium and cobalt; or, the waste lithium ion battery is a waste nickel-cobalt-manganese ternary lithium battery, and in the filter residue, aluminum accounts for 0.5%-6% of the total molar mass of nickel, cobalt and manganese.
2. The method of claim 1, wherein the high performance lithium-ion cathode material is directly prepared by the method. The waste lithium ion battery is a waste lithium cobaltate battery, and in the filter residue, the molar mass ratio of lithium to cobalt is (1-1.1):
1.
3. The method for directly regenerating high performance lithium-ion cathode material according to claim 1, characterized in that, The waste lithium ion battery is a waste nickel-cobalt-manganese ternary lithium battery, and in the filter residue, the total molar mass ratio of lithium to nickel, cobalt, manganese and aluminum is (1-1.1):
1.
4. The method of claim 1, wherein the high performance lithium-ion cathode material is directly prepared by the regeneration. The parameters of the heating and stirring include: the temperature of heating is 40℃-100℃, the time of stirring is 10min-240min, and the rate of stirring is 50rpm-600rpm.
5. The method of claim 1, wherein the high performance lithium-ion cathode material is directly prepared by the regeneration. The temperature of the drying is 50℃-100℃, and the time of the drying is 1h-20h.
6. The method of claim 1, wherein the high performance lithium-ion cathode material is directly prepared by the regeneration. The temperature of the calcination is 700℃-1000℃, the rate of the temperature rising is 5℃ / min-30℃ / min, and the time of the calcination is 10h-40h.