Method and device for regenerating retired lithium battery ternary material into sodium battery material

Abstract

The invention discloses a method and a device for regenerating an ex-service lithium battery ternary material into a sodium battery material, the method comprises the following steps: assembling the ex-service lithium battery ternary material, a diaphragm, an electrolyte and a sodium sheet into a half battery, and in the charging and discharging process, sodium ions gradually replace lithium ions, so that the ex-service lithium battery ternary material is converted into a sodium battery positive electrode material. On the basis, a direct regeneration device for preparing the sodium battery positive electrode material by taking the retired lithium battery ternary positive electrode material as a raw material is designed, and large-batch recovery of the retired lithium battery ternary material is realized.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of battery recycling, and particularly relates to a method and device for regenerating retired lithium battery ternary materials into sodium battery materials. BACKGROUND

[0002] In recent years, with the continuous improvement of global environmental protection awareness, the application range of lithium ion batteries is continuously expanding, especially in the field of new energy vehicles. The increasing number of new energy vehicles leads to a sharp increase in the number of retired ternary lithium ion batteries. Retired ternary lithium batteries contain toxic organic solvents and heavy metals, which need to be properly treated. At the same time, the retired lithium battery ternary cathode contains lithium, cobalt and other metal resources, which have high recycling value. Therefore, it is necessary to efficiently recycle the retired ternary lithium battery.

[0003] The cost of the cathode material accounts for a large part of the cost of the lithium ion battery, and one of the focuses of recycling the retired lithium battery ternary battery is to efficiently recycle the cathode material. The current cathode recovery methods are mainly divided into: hydrometallurgy, pyrometallurgy and direct regeneration.

[0004] The hydrometallurgical recovery process soaks the retired lithium battery cathode in acid or ammonia solution, leaches the metal elements of the cathode material, and then purifies and separates the leaching solution to obtain the final product. The core of hydrometallurgy is chemical reagent leaching, which has the problems of excessive use of chemical reagents and complex process, resulting in high recovery cost of hydrometallurgy, and easy to cause secondary pollution to the environment.

[0005] Pyrometallurgy is the main means for treating retired lithium battery cathode materials, mainly using the battery components to undergo a series of physical and chemical reactions at high temperatures to convert metal oxides into valuable metal alloys. The pyrometallurgical process is simple, but has the problems of high energy consumption and waste gas emission.

[0006] Both hydrometallurgy and pyrometallurgy have significant drawbacks, while direct regeneration technology does not destroy the cathode structure and does not separate and purify elements, which is considered by the industry as a feasible direction for future recycling of retired lithium ion batteries. It simplifies the process flow of recycling, avoids the use of a large amount of chemical reagents and waste gas emission problems.

[0007] The current direct regeneration technology is to supplement the lost elements and restore the crystal structure. The focus of supplementing the lost elements is to supplement lithium elements, and the lithium element has low reserves and uneven distribution, which increases the cost of direct regeneration. SUMMARY

[0008] In order to solve the problem of recycling the positive electrode material of the retired ternary lithium ion battery and the problem of lithium resource shortage, the present application provides a method and device for preparing ternary sodium ion positive electrode material from retired ternary lithium ion battery positive electrode material as raw material. The method and device for preparing ternary sodium ion battery positive electrode material from retired ternary lithium battery positive electrode powder material as raw material regenerate the sodium battery positive electrode material from the retired ternary lithium battery positive electrode material, change from supplementing lithium elements to supplementing sodium elements, realize efficient recycling of the retired ternary lithium battery material, and avoid the problem of lithium element shortage.

[0009] The object of the present application is achieved by the following technical solutions.

[0010] A method for regenerating retired lithium battery ternary material into sodium battery material, comprising the following steps:

[0011] S1, the retired ternary lithium battery positive electrode material is coated by stirring to obtain a positive electrode sheet;

[0012] S2, the positive electrode sheet obtained in step S1 is assembled into a half battery with electrolyte, a separator and a sodium sheet;

[0013] S3, the half battery obtained in step S2 is subjected to a charging and discharging process, and is cycled for a certain number of cycles; wherein the current size is 0.1-1.0C, and the voltage range is 2-4.3V or 2-4.5V;

[0014] S4, the battery obtained in step S3 is disassembled to obtain a ternary sodium ion battery positive electrode material prepared from retired ternary lithium ion battery positive electrode material.

[0015] Preferably, the number of cycles of the charging and discharging process is 25-35 cycles.

[0016] Preferably, the retired ternary lithium battery positive electrode material is one or more of lithium battery ternary materials, and is further preferably NCM811, NCM622 or NCM523.

[0017] Preferably, the electrolyte is one or more of lithium ion electrolyte and sodium ion electrolyte, and is further preferably LB-200, LB-276, LB-107, NC-004 or NP-005.

[0018] Preferably, the separator is one or more of glass fiber, 2325 and 3501 separator.

[0019] Preferably, the positive electrode sheet is obtained by stirring and coating the retired lithium battery positive electrode material, N-methyl pyrrolidone (NMP), conductive carbon and polyvinylidene fluoride (PVDF).

[0020] Preferably, the thickness of the stirring coating is 50-200 um, the model of the battery shell is 2025 battery shell, and the diameter of the sodium sheet is 12-16 mm.

[0021] The ternary sodium-ion battery cathode material prepared by the method described in any of the above has a chemical formula of Na 0.5 Li x Ni y Mn z Co m O2, wherein 0 < x < 0.1, 0 < y < 1, 0 < z < 1, and 0 < m < 1; the ternary sodium-ion battery cathode material belongs to the hexagonal system and has a space group of R-3m; further preferably, the sodium battery cathode material has an O3-type layered structure of the R-3m space group.

[0022] On the basis of half-cell theory, in order to improve the efficiency of preparing a sodium battery cathode material from a retired ternary lithium battery cathode material, a device for preparing a sodium battery cathode material from a retired lithium battery cathode material is designed, and the device can regenerate a large amount of retired ternary lithium battery cathode material into a sodium battery cathode material.

[0023] A device for regenerating a retired lithium battery ternary material into a sodium battery material, comprising a shell 1, a positive electrode bin 4 and a negative electrode bin 7 placed in the shell 1, a separator 6 placed between the positive electrode bin 4 and the negative electrode bin 7, a positive electrode bin cover 5 and a negative electrode bin cover 8 respectively arranged on the upper part of the positive electrode bin 4 and the negative electrode bin 7, and an electric wire 3 connected to the positive electrode bin cover 5 and the negative electrode bin cover 8; the electric wire 3 is used to connect a power supply; the positive electrode bin 4 is used to place a retired ternary lithium-ion battery cathode material; the negative electrode bin 7 is used to place a sodium metal sheet; and a drainage port 9 is used to replace electrolyte.

[0024] Preferably, the shell 1 is a cuboid and is provided with a shell cover 2, and the bottom of the shell 1 is provided with a drainage port 9; the positive electrode bin and the negative electrode bin are both cuboids, and the separator 6 is arranged on one side of the positive electrode bin 4 and opposite to the negative electrode bin.

[0025] Preferably, in the device for preparing a sodium battery cathode material from a retired ternary lithium battery cathode material, except the electric wire and the separator, the rest is made of stainless steel.

[0026] A method for regenerating a retired lithium battery ternary material into a sodium battery material, which adopts the device described above, places a retired lithium battery cathode material in the positive electrode bin, adds a sodium-ion electrolyte, and places a sodium sheet in the negative electrode bin, and covers the shell cover; then the positive electrode bin is connected to a positive electrode, the negative electrode bin is connected to a negative electrode, the device is subjected to a charge-discharge test, and a ternary sodium-ion battery cathode material is obtained.

[0027] Preferably, the size of the charge-discharge test current is 0.1-1.0 C.

[0028] Preferably, the charge-discharge test voltage range is 2-4.3V or 2-4.5V.

[0029] Preferably, the number of cycles of the charge-discharge process is 25-35 cycles.

[0030] The retired ternary lithium battery positive electrode material is stirred and coated, and then assembled into a half battery with an electrolyte, a separator and a sodium sheet. After a certain number of cycles, the retired ternary lithium battery positive electrode material is regenerated into a sodium battery positive electrode material. The working principle is as follows: during the charging process, lithium ions are released from the retired ternary lithium battery positive electrode material into the electrolyte, and during the discharging process, the priority of sodium ions in the electrolyte to be inserted into the positive electrode material is higher than that of lithium ions due to the influence of the electrolyte and the sodium sheet, so that a large amount of sodium ions can be inserted into the positive electrode material, and only a small amount of lithium ions can be inserted into the positive electrode material. With the circulation, the content of sodium ions in the positive electrode material increases, and the content of lithium ions decreases. After a certain number of cycles, only sodium ions exist in the positive electrode material, realizing the regeneration of the retired ternary lithium battery positive electrode into a sodium battery positive electrode material.

[0031] Compared with the prior art, the present application has the following advantages and beneficial effects:

[0032] (1) The present application fills the gap in the field of preparing sodium battery positive electrode materials from retired ternary lithium battery positive electrode materials, and changes the supplement of lithium elements in direct regeneration technology to the supplement of sodium elements, which avoids the problem of lithium element shortage and efficiently recycles the retired ternary lithium battery positive electrode material.

[0033] (2) The sodium battery positive electrode material prepared by the present application has a first cycle specific capacity of 100-130mAh / g in the voltage range of 2-4.0V, which is higher than that of general P2 type sodium ion battery positive electrode materials, and has high cycle stability, with a specific capacity of 90-120mAh / g.

[0034] (3) The method for preparing sodium battery positive electrode materials from retired lithium battery positive electrodes is applicable to all existing retired ternary lithium battery positive electrode materials, is environmentally friendly, has good controllability, and can realize large-scale production. BRIEF DESCRIPTION OF DRAWINGS

[0035] Figure 1 X-ray diffraction patterns of the retired 811 lithium battery positive electrode material powder and the sodium battery positive electrode material in Example 1;

[0036] Figure 2 Scanning electron microscope images of the sodium battery positive electrode material prepared in Example 1;

[0037] Figure 3 Cycle-specific capacity graph of the sodium battery positive electrode material half battery prepared in Example 1;

[0038] Figure 4 Cycle-specific capacity graph of the sodium full cell made from the sodium cathode material of Example 1;

[0039] Figure 5 X-ray diffraction patterns of the retired lithium cathode 622 material powder and the sodium cathode material of Example 2;

[0040] Figure 6 Scanning electron microscope image of the sodium cathode material made from Example 2;

[0041] Figure 7 Cycle-specific capacity graph of the sodium half cell made from the sodium cathode material of Example 2;

[0042] Figure 8 Direct regeneration device diagram for preparing the sodium cathode material from the retired ternary lithium cathode material in Example 3, the label description is as follows: 1, shell; 2, shell cover; 3, wire; 4, positive electrode bin; 5, positive electrode bin cover; 6, separator; 7, negative electrode bin; 8, negative electrode bin cover; 9, drain;

[0043] Figure 9 X-ray diffraction pattern of the sodium cathode material made from Example 3;

[0044] Figure 10 Scanning electron microscope image of the sodium cathode material made from Example 3;

[0045] Figure 11 Cycle-specific capacity graph of the sodium half cell made from the sodium cathode material of Example 3;

[0046] Figure 12 X-ray diffraction pattern of the sodium cathode material made from Example 4;

[0047] Figure 13 X-ray diffraction patterns of the sodium cathode materials made from Comparative Example 1, Comparative Example 2 and Comparative Example 3;

[0048] Figure 14 X-ray diffraction pattern of the sodium cathode material made from Comparative Example 4. DETAILED DESCRIPTION

[0049] In order to more clearly illustrate the specific embodiments of the present application or the technical solutions in the prior art, the specific embodiments will be explained below in combination with the required use of the accompanying drawings. The following described drawings are only some embodiments of the present application, and for those skilled in the art, other drawings can be obtained from the drawings without any creative labor, and other embodiments can be obtained.

[0050] Unless otherwise defined, all terms used in the description employed herein are to be understood as having the meanings that are commonly understood by those of ordinary skill in the art. The terminology used in the description herein is for the purpose of describing only the particular embodiments and is not intended to be limiting of the present application.

[0051] The present application provides a direct regeneration method and device for preparing sodium battery cathode material from retired lithium battery cathode material. Based on waste retired lithium battery cathode material, high-value sodium battery cathode material is directly regenerated. The lithium battery ternary cathode material before regeneration has the problems of lithium element and transition metal element loss, and its chemical formula is Li x Ni y Co z Mn m O q , wherein 0 < x < 1.03, 0 < y < 0.95, 0 < z < 0.95, 0 < m < 0.95. After direct regeneration by the present application, the chemical formula of the obtained sodium battery cathode material is Na 0.5 Li x Ni y Mn z Co m O2, wherein 0 < x < 0.1, 0 < y < 1, 0 < z < 1, 0 < m < 1.

[0052] The raw materials used in the following examples and comparative examples are all commercially available.

[0053] Example 1

[0054] Retired lithium battery 811 cathode material powder (Li 0.97 Ni 0.78 Co 0.09 Mn 0.09 O2), conductive carbon, polyvinylidene fluoride (PVDF) and N-methyl pyrrolidone (NMP) were weighed according to the mass ratio of 8:1:1:50 for slurry coating, and a cathode sheet was obtained. The cathode sheet was assembled with a glass fiber separator, a sodium ion electrolyte (1M NaClO4 in EC:PC = 1:1 Vol% with 5% FEC) and a metal sodium sheet into a half battery. The battery was cycled at a current density of 0.1C at 2-4.5V for 25 cycles, and the sodium battery cathode material was obtained by disassembling the battery.

[0055] Figure 1The XRD patterns of the retired lithium battery 811 positive electrode material powder and the sodium battery positive electrode material in this embodiment are shown in the figure, and there are obvious differences between the XRD patterns of the retired lithium battery 811 positive electrode material powder and the sodium battery positive electrode material. The sodium battery positive electrode material appears a (003) plane characteristic peak belonging to the sodium battery O3 positive electrode material at 16°, and there is no (003) plane characteristic peak belonging to the lithium battery positive electrode material at 18°, which proves that this method can prepare a sodium battery positive electrode material from the retired lithium battery 811 ternary positive electrode material as raw material.

[0056] Figure 2 The scanning electron microscope image of the sodium battery positive electrode material is shown in the figure. The prepared sodium battery positive electrode material is composed of secondary particles composed of primary particles, and the morphology is spherical. According to the inductively coupled plasma atomic emission spectrometry (ICP) test results, the chemical formula of the sodium battery positive electrode material is Na 0.5 Li 0.04 Ni 0.78 Co 0.08 Mn 0.09 O2.

[0057] Figure 3 The cycle-specific capacity graph of the sodium battery positive electrode material half-cell in this embodiment is shown in the figure. The sodium battery positive electrode material prepared in this embodiment is made into a sodium ion button half-cell for electrochemical performance test (electrolyte is 1M NaClO4 in EC:PC=1:1Vol% with 5% FEC), and cycled at a current density of 1.0C in the voltage range of 2-4.0V. The first cycle specific capacity is 121.07mAh / g, and after 150 cycles, the specific capacity is 117.78mAh / g, and the capacity retention rate is 97.28%.

[0058] Figure 4 The cycle-specific capacity graph of the sodium battery positive electrode material full cell in this embodiment is shown in the figure. The sodium battery positive electrode is reassembled with a separator, a sodium ion electrolyte (1M NaPF6 in DMC:EC=1:1Vol% with 5% FEC) and hard carbon (hard carbon has been electrochemically pre-sodiumized) into a full cell, and cycled at a current density of 0.1C in the voltage range of 2-4.2V. The first cycle specific capacity is 167.25mAh / g, and after 80 cycles, the specific capacity is 123.91mAh / g, and the capacity retention rate is 74.09%.

[0059] Example 2

[0060] The retired lithium battery 622 positive electrode material powder (Li 0.96 Ni 0.58 Co 0.19 Mn 0.18The positive electrode sheet was obtained by slurry coating with O2), NMP, conductive carbon and PVDF, and the positive electrode sheet was assembled with a glass fiber separator, a sodium ion electrolyte (1M NaClO4 in EC:PC=1:1 Vol% with 5% FEC) and a metal sodium sheet into a half battery. The half battery was cycled at a current density of 1C in the range of 2-4.5V for 30 cycles, and the battery was disassembled to obtain the sodium battery positive electrode material.

[0061] Figure 5 The XRD patterns of the retired lithium battery 622 positive electrode material powder and the sodium battery positive electrode material in the present embodiment are shown in the figure, and the XRD patterns of the retired lithium battery 622 positive electrode material powder and the sodium battery positive electrode material are obviously different. The sodium battery positive electrode material appears a (003) face characteristic peak belonging to the sodium battery O3 positive electrode material at 16°, and no (003) face characteristic peak belonging to the lithium battery positive electrode material appears at 18°, proving that this method can prepare a sodium battery positive electrode material from a retired lithium battery 622 ternary positive electrode material.

[0062] Figure 6 The scanning electron microscope image of the sodium battery positive electrode material is shown in the figure. The prepared sodium battery positive electrode material is composed of secondary particles composed of primary particles, and the morphology is spherical. According to the ICP test results, the chemical formula of the sodium battery positive electrode material is Na 0.5 Li 0.03 Ni 0.56 Co 0.17 Mn 0.18 O2.

[0063] Figure 7 The cycle-specific capacity graph of the sodium battery positive electrode material half battery in the present embodiment is shown in the figure. The sodium battery positive electrode material prepared in the present embodiment was made into a sodium ion button half battery for electrochemical performance test (electrolyte: 1M NaClO4 in EC:PC=1:1 Vol% with 5% FEC). In the voltage range of 2-4.0V, the first cycle specific capacity was 112.40mAh / g, and the specific capacity was 93.42mAh / g after 200 cycles, and the capacity retention rate was 83.11% at a current density of 1.0C.

[0064] Example 3

[0065] Figure 8 The direct regeneration device for preparing a sodium battery positive electrode material from a retired lithium battery ternary positive electrode material in the present embodiment is shown in the figure. The retired lithium battery 811 positive electrode material powder (Li 0.97 Ni 0.78 Co 0.09 Mn 0.09 O2) was placed in

[0066] In the positive electrode compartment, sodium ion electrolyte (1M NaClO4 in EC:PC = 1:1 Vol% with 5% FEC) was added, and a sodium sheet was placed in the negative electrode compartment, and the shell cover was covered. The positive electrode compartment was connected to the positive electrode, and the negative electrode compartment was connected to the negative electrode. The device was subjected to charge and discharge test, and the sodium battery positive electrode material was obtained by cycling at a current density of 0.1C in 2-4.5V for 25 cycles.

[0067] Figure 9 The XRD pattern of the sodium battery positive electrode material prepared in this example is shown in the figure. The sodium battery positive electrode material has a (003) face characteristic peak at 16°, which belongs to the sodium battery O3 positive electrode material, and no (003) face characteristic peak at 18°, which belongs to the lithium battery positive electrode material, proving that this device can prepare sodium battery positive electrode material from retired lithium battery ternary positive electrode material.

[0068] Figure 10 The scanning electron microscope image of the sodium battery positive electrode material is shown in the figure. The prepared sodium battery positive electrode material is composed of secondary particles composed of primary particles, and the morphology is spherical. According to the ICP test results, the chemical formula of the sodium battery positive electrode material is Na 0.5 Li 0.07 Ni 0.76 Co 0.07 Mn 0.08 O2.

[0069] Figure 11 The cycle-specific capacity graph of the sodium battery positive electrode material half-cell in this example is shown in the figure. The sodium battery positive electrode material prepared in this example was made into a sodium ion button half-cell for electrochemical performance test (electrolyte: 1M NaClO4 in EC:PC = 1:1 Vol% with 5% FEC). In the voltage range of 2-4.0V, the first cycle specific capacity was 118.22mAh / g at a current density of 1.0C, and the specific capacity was 102.54mAh / g after 100 cycles, with a capacity retention rate of 86.74%.

[0070] Example 4

[0071] According to the mass ratio of 8:1:1:50, the retired lithium battery 622 positive electrode material powder (Li 0.96 Ni 0.58 Co 0.19 Mn 0.18 O2), NMP, conductive carbon and PVDF were stirred and coated to obtain a positive electrode sheet. The positive electrode sheet was assembled with a glass fiber separator, a sodium ion electrolyte (1M NaClO4 in EC:PC = 1:1 Vol% with 5% FEC) and a metal sodium sheet to form a half-cell. The battery was cycled at a current density of 1C in 2-4.3V for 30 cycles, and the sodium battery positive electrode material was obtained by disassembling the battery.

[0072] Figure 12 The XRD patterns of the retired Li 622 cathode material powder and the sodium cathode material prepared in this example are shown in the figure. The XRD patterns of the retired Li 622 cathode material powder and the sodium cathode material are obviously different. The sodium cathode material appears a (003) plane characteristic peak belonging to sodium O3 cathode material at 16°, and no (003) plane characteristic peak belonging to lithium cathode material appears at 18°, proving that this method can prepare sodium cathode material from retired Li 622 ternary cathode material.

[0073] The scanning electron microscope image of the sodium cathode material prepared in this example is similar to that of Example 2. Figure 6 According to the scanning electron microscope image, the prepared sodium cathode material is composed of secondary particles composed of primary particles, and the morphology is spherical. According to the ICP test results, the chemical formula of the sodium cathode material is Na 0.5 Li 0.06 Ni 0.53 Co 0.18 Mn 0.20 O2. The electrochemical performance of the sodium cathode material prepared in this example is close to that of Example 2.

[0074] Comparative Example 1

[0075] The retired Li 811 cathode material powder (Li 0.97 Ni 0.78 Co 0.09 Mn 0.09 O2), NMP, conductive carbon and PVDF were weighed according to the mass ratio of 8:1:1:50, and then stirred and coated to obtain a cathode sheet. The cathode sheet, glass fiber separator, sodium ion electrolyte (1M NaClO4 in EC:PC = 1:1 Vol% with 5% FEC) and metal lithium sheet were assembled into a half battery. The battery was cycled at a current density of 0.1C at 2-4.5V for 25 cycles, and then disassembled to obtain a sodium cathode material.

[0076] Figure 13 The XRD pattern of the sodium cathode material prepared in this example is shown in the figure. The sodium cathode material appears a (003) plane characteristic peak belonging to sodium O3 cathode material at 16°, but the diffraction intensity is very weak, and the amount of sodium ion intercalation is very small. However, a (003) plane characteristic peak belonging to lithium cathode material also appears at 18°, and the diffraction intensity is very strong, indicating that the content of lithium ions in the cathode material is high, proving that the main body of the material is still a lithium ternary material. According to the ICP test results, the chemical formula of the sodium cathode material is Na 0.04 Li 0.96 Ni 0.76 Co 0.07 Mn 0.08 O2.

[0077] Comparative Example 2

[0078] The retired lithium battery 811 positive electrode material powder (Li 0.97 Ni 0.78 Co 0.09 Mn 0.09 O2), NMP, conductive carbon and PVDF were weighed according to a mass ratio of 8:1:1:50, and slurry coating was performed to obtain a positive electrode sheet. The positive electrode sheet was assembled with a glass fiber separator, a sodium ion electrolyte (1M NaClO4 in EC:PC=1:1 Vol% with 5% FEC) and a metal sodium sheet to form a half battery. The half battery was cycled at a current density of 0.1C at 2-4.0V for 25 cycles, and the battery was disassembled to obtain a sodium battery positive electrode material.

[0079] Figure 13 The XRD pattern of the sodium battery positive electrode material prepared by the present comparative example is shown in the figure. The sodium battery positive electrode material has two adjacent diffraction peaks at 16°, and the right diffraction peak belongs to the characteristic peak of the sodium battery O3 positive electrode material. The material has double phase, and there is a heterogeneous phase, which is not conducive to the electrochemical performance of the material. According to the ICP test results, the chemical formula of the sodium battery positive electrode material is Na 0.2 Li 0.76 Ni 0.76 Co 0.07 Mn 0.08 O2.

[0080] Comparative Example 3

[0081] A direct regeneration device for preparing a sodium battery positive electrode material from a retired lithium battery ternary positive electrode material was used to prepare a sodium battery positive electrode material. The retired lithium battery 811 positive electrode material powder (Li 0.97 Ni 0.78 Co 0.09 Mn 0.09 O2) was placed in the positive electrode bin, sodium ion electrolyte (1M NaClO4 in EC:PC=1:1 Vol% with 5% FEC) was added, and lithium sheet was placed in the negative electrode bin, and the shell cover was covered. The positive electrode bin was connected to the positive electrode, and the negative electrode bin was connected to the negative electrode. The device was tested for charging and discharging at a current density of 0.1C at 2-4.5V for 25 cycles to obtain a sodium battery positive electrode material.

[0082] Figure 13The XRD pattern of the sodium battery cathode material prepared in the present comparative example is shown in the figure. The sodium battery cathode material has no (003) face characteristic peak of the sodium battery O3 cathode material at 16°, and a (003) face characteristic peak of the lithium battery cathode material appears at 18°, and the diffraction intensity is strong. The content of lithium ions in the cathode material is high, which proves that the material is still a lithium battery ternary cathode material, and there is almost no sodium ion insertion. According to the ICP test results, the chemical formula of the sodium battery cathode material is Na 0.02 Li 0.95 Ni 0.76 Co 0.07 Mn 0.08 O2.

[0083] Comparative Example 4

[0084] The retired lithium battery 811 cathode material powder (Li 0.97 Ni 0.78 Co 0.09 Mn 0.09 O2), NMP, conductive carbon and PVDF were weighed according to the mass ratio of 8:1:1:50, and then stirred and coated to obtain a cathode sheet. The cathode sheet, glass fiber separator, sodium ion electrolyte (1M NaClO4 in EC:PC = 1:1 Vol% with 5% FEC) and metal sodium sheet were assembled into a half battery. The battery was cycled at a current density of 2.0C and a voltage of 2-4.5V. During the battery cycling process, overcharging occurred in multiple batteries, and the battery could not be stably cycled for 25 cycles.

[0085] Figure 14 The XRD pattern of the sodium battery cathode material prepared in the present comparative example is shown in the figure. The sodium battery cathode material has two adjacent diffraction peaks at 16°, and the right diffraction peak belongs to the characteristic peak of the sodium battery O3 cathode material. The material has double phase, and there is a heterogeneous phase, which is not conducive to the electrochemical performance of the material. According to the ICP test results, the chemical formula of the sodium battery cathode material is Na 0.18 Li 0.76 Ni 0.76 Co 0.07 Mn 0.08 O2.

[0086] The above embodiments can also be changed and modified by those skilled in the art in the art according to the disclosure of the above specification. Therefore, the present application is not limited to the specific embodiments disclosed and described above, and some modifications and changes of the application should also fall within the protection scope of the claims of the present application. In addition, although some specific terms are used in the present specification, these terms are only for convenience of explanation and do not constitute any limitation on the present application.

Claims

1. A method for regenerating retired lithium-ion battery ternary materials into sodium-ion battery materials, characterized in that, Includes the following steps: S1. The retired ternary lithium battery cathode material is coated by stirring to obtain the cathode sheet; S2. Assemble the positive electrode obtained in step S1 with electrolyte, separator and sodium plate into a half cell; S3. Perform a charge and discharge process on the half-cell obtained in step S2; wherein the current is 0.1 to 1.0C and the voltage range is 2 to 4.3V or 2 to 4.5V. S4. Disassemble the battery obtained in step S3 to obtain the positive electrode material of ternary sodium-ion battery.

2. The method according to claim 1, characterized in that, The number of cycles in the charging and discharging process is 25 to 35.

3. The method according to claim 1, characterized in that, The retired ternary lithium battery cathode material is one or more ternary lithium battery materials, preferably NCM811, NCM622 or NCM523.

4. The method according to claim 1, characterized in that, The electrolyte is one or more of lithium-ion electrolyte and sodium-ion electrolyte, preferably LB-200, LB-276, LB-107, NC-004 or NP-005.

5. The method according to claim 1, characterized in that, The diaphragm is one or more of glass fiber, 2325 and 3501 diaphragms.

6. The method according to claim 1, characterized in that, The thickness of the slurry coating is 50–200 μm, and the diameter of the sodium sheet is 12–16 mm.

7. The ternary sodium-ion battery cathode material prepared by the method according to any one of claims 1-6, characterized in that, The chemical formula of the ternary sodium-ion battery cathode material is Na 0.5 Li x Ni y Mn z Co m O2, where 0 < x < 0.1, 0 < y < 1, 0 < z < 1, 0 < m < 1; the ternary sodium-ion battery cathode material has an O3-type layered structure with the R-3m space group.

8. A device for regenerating retired lithium-ion battery ternary materials into sodium-ion battery materials, characterized in that, Includes an outer shell (1), a positive electrode compartment (4) and a negative electrode compartment (7) placed inside the outer shell (1), a diaphragm (6) placed between the positive electrode compartment (4) and the negative electrode compartment (7), and a positive electrode compartment cover (5) and a negative electrode compartment cover (8) respectively provided on the upper part of the positive electrode compartment (4) and the negative electrode compartment (7), and both the positive electrode compartment cover (5) and the negative electrode compartment cover (8) are connected to wires (3).

9. The apparatus for regenerating decommissioned lithium-ion battery ternary materials into sodium-ion battery materials according to claim 8, characterized in that, The outer shell (1) is a cuboid and is provided with an outer shell cover (2). The bottom of the outer shell (1) is provided with a drain outlet (9). The positive electrode compartment and the negative electrode compartment are both cuboids. The diaphragm (6) is provided on one side of the positive electrode compartment (4) and is opposite to the negative electrode compartment.

10. A method for regenerating retired lithium-ion battery ternary materials into sodium-ion battery materials, characterized in that, Using the apparatus described in claim 8 or 9, retired lithium battery positive electrode material is placed in the positive electrode chamber, sodium ion electrolyte is added, and sodium sheet is placed in the negative electrode chamber, and the outer casing is closed; then the positive electrode chamber is connected to the positive electrode, the negative electrode chamber is connected to the negative electrode, and the apparatus is charged and discharged to obtain ternary sodium ion battery positive electrode material.

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