A positive electrode black powder and a method for recovering the same

Abstract

The application provides a positive electrode black powder and a recovery method thereof. The positive electrode black powder provided by the application comprises a ternary material with a layered structure, and satisfies: H (003) / H (200) ≥ 2, wherein H (003) is the peak intensity of a 003 characteristic diffraction peak in an X-ray diffraction spectrum of the positive electrode black powder, and H (200) is the peak intensity of a 200 characteristic diffraction peak in the X-ray diffraction spectrum of the positive electrode black powder. By controlling the ratio of the peak intensity of the 003 characteristic diffraction peak to the peak intensity of the 200 characteristic diffraction peak in the X-ray diffraction spectrum of the positive electrode black powder within a certain range, the application improves the efficiency of wet recovery of leaching lithium, is beneficial to simplifying the subsequent recovery process, and reduces the recovery cost.

Description

Technical Field

[0001] This application relates to the field of secondary battery recycling technology, and in particular to a positive electrode black powder and its recycling method. Background Technology

[0002] With the large-scale application of lithium batteries in new energy vehicles and energy storage, a large number of retired lithium batteries are generated, causing significant environmental damage. Resource recycling of retired lithium batteries can avoid environmental pollution and resource waste while also bringing substantial economic benefits. In the process of recycling retired lithium batteries, separating the cathode black powder and aluminum foil to obtain cathode black powder with high dispersibility and low impurity content is a key step in improving the recovery rate of lithium, nickel, cobalt, and manganese metals. Summary of the Invention

[0003] The purpose of this application is to provide a cathode black powder and a method for its recycling, so as to improve the efficiency of wet recycling of leached lithium, simplify subsequent recycling processes, and reduce recycling costs.

[0004] To achieve the above objectives, a first aspect of this application provides a cathode black powder, the cathode black powder comprising a ternary material having a layered structure, the cathode black powder satisfying: H (003) / H (200) ≥2, where H (003) H represents the peak intensity of the 003 characteristic diffraction peak in the X-ray diffraction pattern of the cathode black powder. (200) The peak intensity is the 200 characteristic diffraction peak in the X-ray diffraction pattern of the cathode black powder.

[0005] As an embodiment of this application, the positive electrode black powder satisfies: 0.05° ≤ F (003) ≤0.2°, where F (003) The full width at half maximum (FWHM) of the 003 characteristic diffraction peak in the X-ray diffraction pattern of the cathode black powder.

[0006] As an embodiment of this application, the positive electrode black powder satisfies: 0.3°≤F (200) ≤1°, where F (200) The full width at half maximum (FWHM) of the 200 characteristic diffraction peak in the X-ray diffraction pattern of the cathode black powder.

[0007] As an embodiment of this application, the particle size distribution diagram of the positive electrode black powder has at least two characteristic peaks, and at least one characteristic peak exists above 20 μm.

[0008] As an embodiment of this application, the volume percentage H of the characteristic peak with the largest particle size in the particle size distribution diagram of the cathode black powder is... max Satisfy: 1% ≤ H max ≤5%.

[0009] As an embodiment of this application, the cathode black powder contains impurity elements, including at least one of Al, Cu, Fe, Mg, B, Ca, Zn, Sb, W, Bi, Cr, Sr, Y, W, Zr, Ti, La, Nb, Mo, and V, and the total content C of the impurity elements satisfies: C≤3wt%.

[0010] As an embodiment of this application, the specific surface area B of the positive electrode black powder satisfies: 1m 2 / g≤B≤10m 2 / g.

[0011] As an embodiment of this application, the resistivity R of the 20KN positive electrode black powder satisfies: 50Ω*cm≤R≤300Ω*cm.

[0012] As an embodiment of this application, the compacted density D of the 30KN cathode black powder satisfies: 2.5 g / cm³. 3 ≤D≤4g / cm 3 .

[0013] A second aspect of this application provides a method for recovering cathode black powder, comprising the following steps:

[0014] S1. Discharge and disassemble retired lithium-ion batteries to obtain positive electrode plates;

[0015] S2. Place the positive electrode sheet into a laser cleaning machine and clean each surface of the positive electrode sheet for 0.5h to 4h under the conditions of laser wavelength of 337nm~1064nm and cleaning power of 100W~2000W. Then, sieve to obtain positive electrode black powder.

[0016] The cathode black powder comprises a ternary material with a layered structure, and the cathode black powder satisfies: H (003) / H (200) ≥2, where H (003) H represents the peak intensity of the 003 characteristic diffraction peak in the X-ray diffraction pattern of the cathode black powder. (200) The peak intensity is the 200 characteristic diffraction peak in the X-ray diffraction pattern of the cathode black powder.

[0017] Compared with the prior art, the beneficial effects of this application are:

[0018] This application controls the peak intensity H of the 003 characteristic diffraction peak in the X-ray diffraction pattern of the cathode black powder. (003) Peak intensity H of the 200 characteristic diffraction peak (200) Satisfy: H (003) / H (200) ≥2 improves the efficiency of wet lithium leaching recovery, which helps to simplify subsequent recovery processes and reduce recovery costs. Attached Figure Description

[0019] Figure 1 The X-ray diffraction pattern (also known as XRD pattern) of the cathode black powder prepared in Example 1;

[0020] Figure 2 This is a particle size distribution diagram of the positive electrode black powder prepared in Example 1. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions in the embodiments of this application will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0022] In this application, the technical features described in an open-ended manner include both closed technical solutions consisting of the listed features and open technical solutions that include the listed features.

[0023] In this application, numerical ranges are referred to as continuous unless otherwise specified, and include the minimum and maximum values ​​of the range, as well as every value between the minimum and maximum values. Furthermore, when the range refers to integers, it includes every integer between the minimum and maximum values ​​of the range. Additionally, when multiple ranges are provided to describe a feature or characteristic, the ranges may be merged. In other words, unless otherwise specified, all ranges disclosed herein should be understood to include any and all subranges to which they are incorporated.

[0024] Unless otherwise specified, all reagents or instruments used in this application are commercially available products.

[0025] An embodiment of this application provides a cathode black powder, which comprises a ternary material with a layered structure, and the cathode black powder satisfies: H (003) / H (200) ≥2, where H (003) H represents the peak intensity of the 003 characteristic diffraction peak in the X-ray diffraction pattern of the cathode black powder. (200) The peak intensity is the 200 characteristic diffraction peak in the X-ray diffraction pattern of the cathode black powder.

[0026] The inventors of this application have discovered that the ratio of the peak intensity of the 003 characteristic diffraction peak to the peak intensity of the 200 characteristic diffraction peak in the X-ray diffraction pattern of cathode black powder can reflect the content of aluminum impurities in the cathode black powder. By controlling the ratio within a certain range, it is beneficial to simplify the subsequent recycling process, reduce recycling costs, and improve the efficiency of wet lithium leaching. The method for obtaining the X-ray diffraction pattern of cathode black powder in this application is as follows: the sample to be tested is ground into powder for 15 minutes and pressed into a uniform thin sheet. Then, the sample is loaded onto the sample stage of the X-ray diffractometer, and the X-ray diffractometer is started to obtain the corresponding X-ray diffraction pattern. The parameters of the X-ray diffractometer are as follows: target material: Cu target; X-ray wavelength: 1.5406; scanning mode: continuous scanning; start angle & end angle: 10°~90°; scanning speed: 10° / min; step size: 0.01°.

[0027] In some embodiments, the positive electrode black powder satisfies: 3.37 ≥ H (003) / H (200) ≥2. For example, H (003) / H (200) It can be 2, 2.12, 2.29, 2.46, 2.94, 3.22, 3.37, or a value within the range formed by any two of the above points.

[0028] In some embodiments, the positive electrode black powder satisfies: 0.05° ≤ F (003) ≤0.2°, where F (003) The full width at half maximum (FWHM) of the 003 characteristic diffraction peak in the X-ray diffraction pattern of the cathode black powder is given. For example, the FWHM of the 003 characteristic diffraction peak in the X-ray diffraction pattern of the cathode black powder can be 0.05°, 0.1°, 0.15°, 0.2°, or a value within the range formed by any two of the above points.

[0029] In some embodiments, the positive electrode black powder satisfies: 0.3° ≤ F (200) ≤1°, where F (200) The full width at half maximum (FWHM) of the 200 characteristic diffraction peak in the X-ray diffraction pattern of the cathode black powder is given. For example, the FWHM of the 200 characteristic diffraction peak in the X-ray diffraction pattern of the cathode black powder can be 0.3°, 0.35°, 0.4°, 0.45°, 0.5°, 0.55°, 0.6°, 0.65°, 0.7°, 0.75°, 0.8°, 0.85°, 0.9°, 0.95°, 1.0°, or a value within the range formed by any two of the above points.

[0030] Half-peak width F of positive black powder (003) and F (200) It can reflect the crystallinity of the positive electrode active material and aluminum impurities in the black powder respectively. The higher the value, the cleaner the binder is removed and the higher the subsequent leaching efficiency.

[0031] In some embodiments, the particle size distribution diagram of the cathode black powder contains at least two characteristic peaks, and at least one characteristic peak is present above 20 μm. When the particle size distribution diagram of the cathode black powder meets the above conditions, it indicates high particle dispersibility and high subsequent leaching efficiency.

[0032] In some embodiments, the volume percentage H of the largest characteristic peak in the particle size distribution diagram of the cathode black powder is... max Satisfy: 1% ≤ H max ≤5%. For example, the volume percentage H of the largest characteristic peak in the particle size distribution diagram of cathode black powder. max It can be a value within the range of 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, 5%, or any two of the above. The volume percentage H of the largest characteristic peak in the particle size distribution diagram of the cathode black powder. max Within the above range, the particles are well dispersed, resulting in high subsequent leaching efficiency.

[0033] In some embodiments, the cathode black powder contains impurity elements, including at least one selected from Al, Cu, Fe, Mg, B, Ca, Zn, Sb, W, Bi, Cr, Sr, Y, W, Zr, Ti, La, Nb, Mo, and V. In some embodiments, the impurity element includes at least one selected from Al, Cu, Fe, B, Sb, W, Sr, Y, Ti, and Zr.

[0034] In some embodiments, the total content C of the impurity elements satisfies the following condition: C ≤ 3 wt%. For example, the total content C of the impurity elements... I The total content of impurity elements in the cathode black powder can be 0.5wt%, 1wt%, 1.5wt%, 2wt%, 2.5wt%, 3wt%, or any value within the range of any two of the above points. When the total content of impurity elements in the cathode black powder is within the above range, it is beneficial to simplify the subsequent recovery process and improve the purity of the recovered product.

[0035] In some embodiments, the specific surface area B of the positive electrode black powder satisfies: 1m² 2 / g≤B≤10m 2 / g. For example, the specific surface area B of the positive electrode black powder can be 1m². 2 / g、2m 2 / g、3m 2 / g、4m 2 / g、5m 2 / g、6m 2 / g、7m 2 / g、8m 2 / g、9m 2 / g, 10m 2 / g or a value within the range defined by any two of the above points. A specific surface area B of the cathode black powder within the above range is beneficial for subsequent leaching of lithium metal elements.

[0036] In some embodiments, the powder resistivity R of the 20KN cathode black powder satisfies: 50Ω*cm ≤ R ≤ 300Ω*cm. The powder resistivity R of the 20KN cathode black powder can be 50Ω*cm, 100Ω*cm, 120Ω*cm, 150Ω*cm, 180Ω*cm, 200Ω*cm, 250Ω*cm, 280Ω*cm, 300Ω*cm, or a value within the range formed by any two of the above points. A powder resistivity of the cathode black powder within the above range is beneficial for subsequent lithium metal leaching.

[0037] In some embodiments, the compacted density D of the 30KN cathode black powder satisfies: 2.5 g / cm³. 3 ≤D≤4g / cm 3 For example, the compacted density D of the 30KN positive electrode black powder can be 2.5 g / cm³. 3 2.8g / cm 3 3g / cm 3 3.2g / cm 3 3.5g / cm 3 3.8g / cm 3 4g / cm 3 Or a value within the range defined by any two of the above points. A compacted density of the cathode black powder within the above range is beneficial for subsequent lithium metal leaching.

[0038] Embodiments of this application also provide a method for recovering cathode black powder, comprising the following steps:

[0039] S1. Discharge and disassemble retired lithium-ion batteries to obtain positive electrode plates;

[0040] S2. Place the positive electrode sheet into a laser cleaning machine and clean each surface of the positive electrode sheet for 0.5h to 4h under the conditions of laser wavelength of 337nm~1064nm and cleaning power of 100W~2000W. Then, sieve to obtain positive electrode black powder.

[0041] The cathode black powder comprises a ternary material with a layered structure, and the cathode black powder satisfies: H (003) / H (200) ≥2, where H (003) H represents the peak intensity of the 003 characteristic diffraction peak in the X-ray diffraction pattern of the cathode black powder. (200) The peak intensity is the 200 characteristic diffraction peak in the X-ray diffraction pattern of the cathode black powder.

[0042] This application utilizes laser cleaning to recover cathode black powder. Laser cleaning eliminates the need for cleaning media, significantly reducing damage to the aluminum foil, and resulting in low aluminum impurity content in the cathode black powder. Furthermore, laser cleaning removes the cathode black powder from the surface of the current collector aluminum foil through vaporization, shock waves, and thermoelasticity. The cathode black powder recovery rate is high, and its dispersibility is excellent, significantly improving the efficiency of subsequent wet leaching.

[0043] In some embodiments, the cleaning power is 100–2000 W. For example, the cleaning power can be 100 W, 150 W, 200 W, 300 W, 500 W, 1000 W, 1500 W, 2000 W, or a value within a range consisting of any two of the above. Laser cleaning power affects recovery efficiency and the aluminum impurity content in the black powder; a suitable power range is beneficial for improving recovery efficiency and reducing the aluminum impurity content in the black powder.

[0044] In some embodiments, the laser wavelength is 337–1064 nm. For example, the laser wavelength can be 337 nm, 488 nm, 514 nm, 543 nm, 550 nm, 570 nm, 659 nm, 694 nm, 1064 nm, or a value within the range of any two of the above. If the laser wavelength is too large, the positive electrode black powder cannot be effectively peeled off from the aluminum foil, resulting in a low positive electrode black powder recovery rate. If the laser wavelength is too small, the aluminum foil breaks and mixes with the positive electrode active material, leading to an excessively high aluminum impurity content in the black powder. A suitable laser wavelength can selectively vaporize and decompose the binder, achieving separation of the positive electrode black powder and the aluminum foil without causing significant damage to the aluminum foil.

[0045] In some embodiments, the laser cleaning time is 0.5-4 hours. For example, the laser cleaning time can be 0.5 hours, 0.75 hours, 1 hour, 1.5 hours, 2 hours, 2.5 hours, 3 hours, 3.5 hours, 4 hours, or a value within a range consisting of any two of the above. A suitable cleaning time can improve the recovery rate of the cathode black powder without causing significant damage to the aluminum foil.

[0046] The following are specific embodiments of this application, and the technical solutions of this application are further described in conjunction with the embodiments. However, this application is not limited to these embodiments. Unless otherwise specified, the reagents, methods, and equipment used in this application are all conventional reagents, methods, and equipment in this technical field.

[0047] Example 1

[0048] Example 1 provides a method for recovering cathode black powder, comprising the following steps:

[0049] (1) After the retired ternary lithium battery is fully discharged using a discharge device, it is automatically disassembled to obtain positive electrode, negative electrode and separator respectively.

[0050] (2) The above positive electrode sheet is placed in a laser cleaning machine and cleaned for 0.5 hours on each side under the conditions of laser wavelength 1064nm and cleaning power 100W to obtain a mixture of black powder and aluminum foil;

[0051] (3) Add the mixture obtained in step 2 to a vibrating screen with a screen size of 0.1 mm and a screening time of 0.5 h to obtain positive electrode black powder.

[0052] The recovery methods of the positive electrode black powder in Examples 2 to 8 are basically the same as those in Example 1, except that the laser cleaning power is different, as shown in Table 1.

[0053] The recovery methods for the positive electrode black powder in Examples 9 to 16 are basically the same as those in Example 1, except that the laser cleaning wavelengths are different, as detailed in Table 1.

[0054] The recovery methods for the positive electrode black powder in Examples 17-24 are basically the same as those in Example 1, except that the laser cleaning time is different, as shown in Table 1.

[0055] Comparative Example 1

[0056] The method for recovering the positive electrode black powder in Comparative Example 1 is basically the same as that in Example 1, except that the laser power is 2500W, the laser wavelength is 248nm, and the cleaning time is 7h.

[0057] Comparative Example 2

[0058] The method for recovering the cathode black powder in Comparative Example 2 is basically the same as that in Example 1, except that the laser power is 3000W, the laser wavelength is 2100nm, and the cleaning time is 5h.

[0059] The physical properties of the cathode black powder in Examples 1-24 and Comparative Examples 1-2 are shown in Table 1, where H (003) / H (200) F (003) F (200) The results can be obtained from XRD test patterns. Taking Example 1 as an example, the test patterns are detailed below. Figure 1 The test spectra of other embodiments and comparative examples are similar and will not be listed one by one. The results are detailed in Table 1.

[0060] Test case

[0061] A mixed solution of 1M sulfuric acid and 0.5M hydrogen peroxide was used as the leaching agent. The recovered cathode black powder was chemically leached at 60℃, a solid-liquid ratio of 100g / L, a stirring speed of 1000rpm, and a reaction time of 30min. The leaching efficiencies of lithium, nickel, cobalt, and manganese are shown in Table 2.

[0062] Table 1

[0063]

[0064] Table 1 (continued)

[0065]

[0066]

[0067]

[0068] Table 2

[0069] serial number Li (wt%) Ni (wt%) Co (wt%) Mn (wt%) Example 1 92 83 82 81 Example 2 93 87 86 86 Example 3 94 88 87 97 Example 4 95 91 90 89 Example 5 99 99 99 99 Example 6 99 99 99 99 Example 7 99 99 99 99 Example 8 99 99 99 99 Example 9 85 75 76 75 Example 10 95 86 86 86 Example 11 96 87 87 87 Example 12 97 90 91 89 Example 13 98 91 92 90 Example 14 99 93 93 93 Example 15 99 95 95 95 Example 16 99 99 99 99 Example 17 93 83 83 83 Example 18 94 85 84 85 Example 19 95 86 86 86 Example 20 96 87 87 87 Example 21 97 88 88 88 Example 22 98 90 90 90 Example 23 99 95 95 95 Example 24 99 99 99 99 Comparative Example 1 78 55 56 55 Comparative Example 2 80 60 61 59

[0070] As can be seen from the above embodiments and comparative examples, this application improves the efficiency of wet lithium leaching recovery by controlling the ratio of the peak intensity of the 003 characteristic diffraction peak to the peak intensity of the 200 characteristic diffraction peak in the X-ray diffraction pattern of the cathode black powder within a certain range, which is beneficial to simplifying the subsequent recovery process and reducing the recovery cost.

[0071] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application and are not intended to limit the scope of protection of this application. Although this application has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of this application without departing from the substance and scope of the technical solutions of this application.

Claims

1. A positive electrode black powder, characterized in that, The cathode black powder comprises a ternary material with a layered structure, and the cathode black powder satisfies: H (003) / H (200) ≥2, where H (003) H represents the peak intensity of the 003 characteristic diffraction peak in the X-ray diffraction pattern of the cathode black powder. (200) The peak intensity of the 200 characteristic diffraction peak in the X-ray diffraction pattern of the cathode black powder; The particle size distribution diagram of the cathode black powder contains at least two characteristic peaks, and at least one characteristic peak is present above 20 μm; the volume percentage H of the largest characteristic peak in the particle size distribution diagram of the cathode black powder is... max Satisfy: 1≤H max ≤4.

3.

2. The positive electrode black powder according to claim 1, characterized in that, The positive electrode black powder satisfies: 0.05°≤F (003) ≤0.2°, where F (003) The full width at half maximum (FWHM) of the 003 characteristic diffraction peak in the X-ray diffraction pattern of the cathode black powder.

3. The positive electrode black powder according to claim 1, characterized in that, The positive electrode black powder satisfies: 0.3°≤F (200) ≤1°, where F (200) The full width at half maximum (FWHM) of the 200 characteristic diffraction peak in the X-ray diffraction pattern of the cathode black powder.

4. The positive electrode black powder according to claim 1, characterized in that, The cathode black powder contains impurity elements, including at least one of Al, Cu, Fe, Mg, B, Ca, Zn, Sb, W, Bi, Cr, Sr, Y, Zr, Ti, La, Nb, Mo, and V, and the total content C of the impurity elements satisfies: C≤3 wt%.

5. The positive electrode black powder according to claim 1, characterized in that, The specific surface area B of the cathode black powder satisfies: 1m 2 / g≤B≤10m 2 / g.

6. The positive electrode black powder according to claim 1, characterized in that, The resistivity R of the 20KN positive electrode black powder satisfies: 50 Ω*cm≤R≤300 Ω*cm.

7. The positive electrode black powder according to claim 1, characterized in that, The compacted density D of the 30KN positive electrode black powder satisfies: 2.5 g / cm³ ≤ D ≤ 4 g / cm³.

8. A method for recovering cathode black powder, characterized in that, Includes the following steps: S1. Discharge and disassemble retired lithium-ion batteries to obtain positive electrode plates; S2. Place the positive electrode sheet in a laser cleaning machine and clean each surface of the positive electrode sheet for 0.5 h to 4 h under the conditions of laser wavelength of 337 nm to 1064 nm and cleaning power of 100 W to 2000 W. Then, sieve to obtain positive electrode black powder. The cathode black powder comprises a ternary material with a layered structure, and the cathode black powder satisfies: H (003) / H (200) ≥2, where H (003) H represents the peak intensity of the 003 characteristic diffraction peak in the X-ray diffraction pattern of the cathode black powder. (200) The peak intensity of the 200 characteristic diffraction peak in the X-ray diffraction pattern of the cathode black powder; The particle size distribution diagram of the cathode black powder contains at least two characteristic peaks, and at least one characteristic peak is present above 20 μm; the volume percentage H of the largest characteristic peak in the particle size distribution diagram of the cathode black powder is... max Satisfy: 1≤H max ≤4.3.

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