Recycling method of lithium ion battery and spin capacitor

Abstract

The embodiment of the invention provides a recycling method of a lithium ion battery and a spin capacitor. The method comprises the following steps: recycling a positive electrode material of the lithium ion battery; the method comprises the following steps: reducing a positive electrode material through electrochemical discharge to obtain a nano composite material which comprises transition metal nano particles and lithium compound nano particles; wherein the nano composite material is used for preparing a first electrode of the spin capacitor. In the embodiment of the invention, the positive electrode material of the lithium ion battery can be converted into the nano composite material consisting of the transition metal nano particles and the lithium compound nano particles, and the nano composite material can be used as an electrode material of a spin capacitor, so that the direct recovery of the positive electrode material of the lithium ion battery is realized. The spin capacitor prepared from the recycled lithium ion battery positive electrode material shows good performance, opens up a new recycling thought, and provides new possibility for finding industrial recycling of battery positive electrodes.

Description

Technical Field

[0001] The present application relates to the technical field of lithium ion battery recycling, and specifically to a lithium ion battery recycling method and a spin capacitor. Background Art

[0002] The continued popularity of lithium-ion batteries has led to the problem of waste batteries becoming more prominent in recent years, and more and more researchers have devoted themselves to the issue of recycling waste batteries. Among them, the positive electrode has the most recycling value.

[0003] The current mainstream recycling methods include pyrometallurgy, hydrometallurgy and direct recycling. Pyrometallurgy is the high-temperature recycling of heavy metal alloys, which consumes a lot of energy; hydrometallurgy is the chemical method of recycling metal elements, which is complicated and difficult to industrialize. These two methods emphasize the extraction and reuse of metal elements, not from the perspective of the whole material, and do not consider the inherent characteristics of the material, resulting in a waste of resources.

[0004] It should be pointed out that the information disclosed in the background technology section of this application is only intended to deepen the understanding of the general background technology of this application, and should not be regarded as an admission or suggestion in any form that the information constitutes prior art already known to those skilled in the art. Summary of the invention

[0005] In view of this, the present application provides a method for recycling ion batteries and a spin capacitor, so as to solve the problem in the prior art that when recycling the positive electrode of lithium ion electrons, the inherent characteristics of the material are not fully considered from the perspective of the material as a whole, resulting in waste of resources.

[0006] In a first aspect, an embodiment of the present application provides a method for recycling a lithium-ion battery, comprising:

[0007] Recycling of cathode materials for lithium-ion batteries;

[0008] Reducing the positive electrode material by electrochemical discharge to obtain a nanocomposite material, wherein the nanocomposite material includes transition metal nanoparticles and lithium compound nanoparticles;

[0009] The nanocomposite material is used to prepare a first electrode of a spin capacitor, and the first electrode is one of two electrodes of the spin capacitor.

[0010] In a possible implementation, the positive electrode material includes at least one of the following materials:

[0011] Lithium iron phosphate, lithium cobalt oxide, lithium manganese oxide and nickel-cobalt-manganese ternary materials.

[0012] In a possible implementation, the recycling of the positive electrode material of the ion battery includes:

[0013] Recycling a positive electrode sheet of a lithium-ion battery, wherein the positive electrode sheet comprises a current collector and a positive electrode material coated on a surface of the current collector;

[0014] The positive electrode material coated on the surface of the current collector is scraped off to obtain the positive electrode material of the lithium ion battery.

[0015] In a possible implementation, the recycling of positive electrode materials of ion batteries includes: recycling positive electrode plates of lithium ion batteries, wherein the positive electrode plates include a current collector and positive electrode materials coated on the surface of the current collector;

[0016] The method of reducing the positive electrode material by electrochemical discharge to obtain the nanocomposite material comprises: reducing the positive electrode material coated on the surface of the current collector by electrochemical discharge to obtain the nanocomposite material coated on the surface of the current collector.

[0017] In a second aspect, an embodiment of the present application provides a method for recycling a lithium-ion battery, comprising:

[0018] Discharging the lithium-ion battery so that the positive electrode material of the lithium-ion battery is reduced to a nanocomposite material through electrochemical discharge, wherein the nanocomposite material includes transition metal nanoparticles and lithium compound nanoparticles;

[0019] Recovering the nanocomposite material from the lithium-ion battery;

[0020] The nanocomposite material is used to prepare a first electrode of a spin capacitor, and the first electrode is one of two electrodes of the spin capacitor.

[0021] In a possible implementation, the positive electrode material includes at least one of the following materials:

[0022] Lithium iron phosphate, lithium cobalt oxide, lithium manganese oxide and nickel-cobalt-manganese ternary materials.

[0023] In a possible implementation, the step of recovering the nanocomposite material in the lithium-ion battery includes:

[0024] A positive electrode sheet of a lithium-ion battery is recycled, wherein the positive electrode sheet comprises a current collector and the nanocomposite material coated on the surface of the current collector.

[0025] In a possible implementation, after recycling the positive electrode sheet of the lithium-ion battery, the method further includes:

[0026] The nanocomposite material coated on the surface of the current collector is scraped off to obtain the nanocomposite material in the lithium ion battery.

[0027] In a third aspect, an embodiment of the present application provides a spin capacitor, including:

[0028] A first electrode, wherein the first electrode comprises a nanocomposite material generated by using a cathode material recycled from a lithium-ion battery, wherein the nanocomposite material comprises transition metal nanoparticles and lithium compound nanoparticles;

[0029] The second electrode includes at least one of the following materials: metallic lithium, a lithium compound, and a carbon material.

[0030] In a fourth aspect, an embodiment of the present application provides a spin capacitor, including:

[0031] A first electrode, the first electrode comprising a nanocomposite material recovered from a lithium-ion battery, the nanocomposite material comprising transition metal nanoparticles and lithium compound nanoparticles;

[0032] The second electrode includes at least one of the following materials: metallic lithium, a lithium compound, and a carbon material.

[0033] In the embodiment of the present application, the positive electrode material of the lithium-ion battery can be converted into a nanocomposite material composed of transition metal nanoparticles and lithium compound nanoparticles, and the nanocomposite material can be used as the electrode material of the spin capacitor, thereby realizing the direct recycling of the positive electrode material of the lithium-ion battery. The spin capacitor prepared by using the recycled positive electrode material of the lithium-ion battery shows good performance, opens up new recycling ideas, and provides new possibilities for finding industrial recycling of battery positive electrodes. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be 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 paying creative labor.

[0035] Figure 1 A schematic diagram of a lithium-ion battery recycling method provided in an embodiment of the present application;

[0036] Figure 2 A schematic diagram of a waste lithium-ion battery cell provided in an embodiment of the present application;

[0037] Figure 3 A schematic diagram of scraping off the positive electrode material from the positive electrode sheet of a lithium-ion battery provided in an embodiment of the present application;

[0038] Figure 4 A schematic flow chart of another lithium-ion battery recycling method provided in an embodiment of the present application;

[0039] Figure 5 The cyclic voltammetry curve of the spin capacitor prepared in the embodiment of the present application;

[0040] Figure 6 The constant current charge and discharge curve of the spin capacitor prepared in the embodiment of the present application;

[0041] Figure 7 This is the MH curve of the spin capacitor prepared in the embodiment of the present application under a magnetic field of 50000 Oe. DETAILED DESCRIPTION

[0042] In order to better understand the technical solution of the present application, the embodiments of the present application are described in detail below with reference to the accompanying drawings.

[0043] It should be clear that the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present application.

[0044] The terms used in the embodiments of the present application are only for the purpose of describing specific embodiments, and are not intended to limit the present application. The singular forms "a", "said" and "the" used in the embodiments of the present application and the appended claims are also intended to include plural forms, unless the context clearly indicates other meanings.

[0045] It should be understood that the term "and / or" used in this article is only a description of the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0046] The spin capacitor effect originates from the formation of a double-layer capacitor between the spin charge of the ferromagnetic metal interface and lithium ions under the action of an electric field. This effect is the source of the extra capacity of transition metal compounds as electrode materials in energy storage devices, and has the characteristics of large capacity and fast storage. The applicant has found through research that by discharging waste lithium-ion batteries to near 0 volts, the positive electrode material of the lithium-ion battery can be converted into a nanocomposite material composed of transition metal nanoparticles and lithium compound nanoparticles. The nanocomposite material can be directly used to prepare a spin capacitor, realizing the direct recycling of the positive electrode material of the lithium-ion battery. The spin capacitor prepared using the positive electrode material of the recycled lithium-ion battery has shown good performance, opened up new ideas for recycling, and provided new possibilities for finding industrial recycling of battery positive electrodes.

[0047] See also Figure 1 , is a schematic diagram of a lithium ion battery recycling method provided in an embodiment of the present application. Figure 1 As shown, it mainly includes the following steps.

[0048] Step S101: Recovering the positive electrode material of the lithium-ion battery.

[0049] Specifically, the cells of waste lithium-ion batteries (such as Figure 2 As shown in the figure, the positive electrode sheet of the waste lithium-ion battery is disassembled and separated. The positive electrode sheet of the lithium-ion battery includes a current collector and a positive electrode material coated on the surface of the current collector. The positive electrode material coated on the surface of the current collector is scraped off to obtain the positive electrode material of the lithium-ion battery (as shown in the figure). Figure 3 shown).

[0050] In practical applications, since the positive electrode of the lithium-ion battery has a higher working potential (for example, more than 3v), the material (for example, aluminum) selected for the current collector of the positive electrode sheet can usually only be used at a higher potential. However, in the spin capacitor provided in the embodiment of the present application, the nanocomposite material usually works at a lower potential (for example, 0-1.7v), which causes the current collector of the positive electrode sheet in the lithium-ion battery to be not applicable in the spin capacitor. Therefore, in the embodiment of the present application, it is necessary to scrape off the positive electrode material coated on the surface of the current collector, and only recycle the positive electrode material of the positive electrode sheet, without recycling the current collector of the positive electrode sheet. In a possible implementation, after scraping off the positive electrode material on the current collector surface of the positive electrode sheet, the scraped positive electrode material needs to be dried. Specifically, it can be dried for 12 hours at a temperature of 60°C in a vacuum drying oven. Of course, those skilled in the art can adjust the drying temperature and duration according to the state of the collected positive electrode material, and the embodiment of the present application does not specifically limit this.

[0051] It is understandable that different types of lithium-ion batteries may have different corresponding positive electrode materials. Exemplarily, the recycled positive electrode material may include at least one of the following materials: lithium iron phosphate, lithium cobalt oxide, lithium manganese oxide, and nickel cobalt manganese oxide.

[0052] In some application scenarios, the material selected for the current collector of the positive electrode sheet (for example, titanium) may be used both at a higher potential and at a lower potential. It is understandable that the current collector and the positive electrode material of the positive electrode sheet can be used at the same time. In other words, the positive electrode sheet of the lithium-ion battery is directly recycled. It is understandable that in the embodiment of the present application, since there is no need to scrape the positive electrode material off the current collector of the positive electrode sheet, the recycling process is simpler.

[0053] Step S102: reducing the positive electrode material by electrochemical discharge to obtain a nanocomposite material, wherein the nanocomposite material includes transition metal nanoparticles and lithium compound nanoparticles.

[0054] In one possible implementation, when only the positive electrode material in the positive electrode plate of the lithium-ion battery is recovered, the recovered positive electrode material can be coated on a new current collector. The material selected for the new current collector (for example, copper) can be used at a lower potential. After the recovered positive electrode material is coated on the new current collector, a new electrode plate is obtained. The new electrode plate is reduced by electrochemical discharge, and the positive electrode material in the new electrode plate is converted into a nanocomposite material. In a specific implementation, the new electrode plate can be used as the positive electrode of the lithium-ion battery and assembled with the negative electrode (for example, lithium) of the lithium-ion battery to form a new lithium-ion battery. The assembled new lithium-ion battery is discharged to near 0v (for example, discharged to a range of 0-0.6v, wherein the discharge degree of the lithium-ion battery affects the reduction degree of the positive electrode material, and the higher the discharge degree, the higher the reduction degree of the positive electrode material), and the positive electrode material in the new electrode plate is reduced to a nanocomposite material composed of transition metal nanoparticles and lithium compound nanoparticles, and the nanocomposite material has a spin capacitor interface and can be used to prepare a spin capacitor.

[0055] In a possible implementation, when the positive electrode of a lithium-ion battery is directly recycled, the recycled positive electrode can be directly used as the positive electrode of the lithium-ion battery and assembled with the negative electrode (e.g., lithium) of the lithium-ion battery to form a new lithium-ion battery. The assembled new lithium-ion battery is discharged to near 0V (e.g., within the range of 0-0.6V), and the positive electrode material in the new electrode is reduced to a nanocomposite material composed of transition metal nanoparticles and lithium compound nanoparticles. The nanocomposite material has a spin capacitor interface and can be used to prepare a spin capacitor.

[0056] It should be noted that some waste lithium-ion batteries (i.e., lithium-ion batteries to be recycled) usually cannot be discharged to near 0V. Therefore, it is necessary to first recycle the positive electrode plates of the lithium-ion batteries, and then assemble them into new lithium-ion batteries, and then discharge them to near 0V through the new lithium-ion batteries.

[0057] Of course, in some possible implementations, the discharge reduction of the positive electrode material may be achieved by other methods, and the embodiments of the present application do not impose specific limitations on this.

[0058] In a possible implementation, the cathode material of the recycled lithium-ion battery is lithium iron phosphate, and after the lithium iron phosphate is discharged and reduced, the obtained nanocomposite material is a composite material of Fe and Li3PO4.

[0059] In a possible implementation, the cathode material of the recycled lithium-ion battery is lithium cobalt oxide, and after the lithium cobalt oxide is discharged and reduced, the obtained nanocomposite material is a composite material of Co and Li2O.

[0060] In a possible implementation, the positive electrode material of the recycled lithium-ion battery is lithium manganese oxide, and after the lithium manganese oxide is discharged and reduced, the obtained nanocomposite material is a composite material of Mn and Li2O.

[0061] In one possible implementation, the cathode material of the recycled lithium-ion battery is lithium nickel cobalt manganese oxide. After the lithium nickel cobalt manganese oxide is discharged and reduced, the lithium compound nanoparticles in the obtained nanocomposite material are Li2O, and the transition metal nanoparticles are related to the ratio of nickel, cobalt and manganese in the lithium nickel cobalt manganese oxide.

[0062] The nanocomposite material obtained in the embodiment of the present application has a spin capacitor interface and can be directly used for a spin capacitor. Specifically, the nanocomposite material is used to prepare a first electrode of a spin capacitor, and the first electrode is one of the two electrodes of the spin capacitor. The other electrode of the spin capacitor (i.e., the second electrode) can generally be made of metallic lithium, a lithium compound and / or a carbon material.

[0063] In an embodiment of the present application, the positive electrode material of the lithium-ion battery can be converted into a nanocomposite material composed of transition metal nanoparticles and lithium compound nanoparticles. The nanocomposite material can be directly used to prepare a spin capacitor, thereby realizing direct recovery of the positive electrode material of the lithium-ion battery.

[0064] It can be understood that in the above embodiment, since some waste lithium-ion batteries (i.e., lithium-ion batteries to be recycled) usually cannot be discharged to near 0V, it is necessary to first recycle the positive electrode plates of the lithium-ion batteries and then assemble them into new lithium-ion batteries, which are then discharged to near 0V.

[0065] In some possible application scenarios, the waste lithium-ion battery may also be directly discharged to near 0V, and the current collector of the positive electrode plate can be used at a lower potential. It is understandable that at this time, the positive electrode material can be directly reduced to a nanocomposite material by discharging in the waste lithium-ion battery, and then the nanocomposite material can be recycled. This is described in detail below in conjunction with a specific implementation method.

[0066] See also Figure 4 , is a schematic flow chart of another lithium-ion battery recycling method provided in an embodiment of the present application. Figure 4 As shown, it mainly includes the following steps.

[0067] Step S401: performing a discharge process on a lithium-ion battery, so that the positive electrode material of the lithium-ion battery is reduced to a nano-composite material through electrochemical discharge, wherein the nano-composite material includes transition metal nanoparticles and lithium compound nanoparticles.

[0068] In an embodiment of the present application, the waste lithium-ion battery is discharged to near 0 volts, so that the positive electrode material of the lithium-ion battery is reduced to a nanocomposite material through electrochemical discharge.

[0069] Step S402: Recovering the nanocomposite material in the lithium-ion battery.

[0070] Specifically, after the positive electrode material of the lithium ion battery is discharged and reduced to the nano composite material, the nano composite material in the lithium ion battery is recovered.

[0071] In a possible implementation, the positive electrode sheet of the lithium-ion battery is recycled, and the positive electrode sheet includes a current collector and a nanocomposite material coated on the surface of the current collector. It is understandable that the positive electrode sheet of the lithium-ion battery recycled at this time can be directly used as the first electrode of the spin capacitor. In other words, the positive electrode sheet only needs to be simply cut or spliced ​​to serve as the first electrode of the spin capacitor.

[0072] In a possible implementation, after obtaining the positive electrode sheet of the lithium-ion battery, it is necessary to scrape off the nanocomposite material coated on the positive electrode sheet to obtain the nanocomposite material in the lithium-ion battery. It is understandable that since the nanocomposite material is obtained here, when preparing the spin capacitor, it is also necessary to coat the nanocomposite material on a current collector (e.g., copper foil) to obtain the first electrode of the spin capacitor.

[0073] It should be noted that the embodiments of the present application are Figure 1 The difference of the embodiment shown is that the positive electrode material in the waste lithium-ion battery is first reduced to a nanocomposite material, and then the nanocomposite material is directly recycled. It can be understood that this method saves the step of rebuilding the lithium-ion discharge platform, and the process is simpler.

[0074] For details about the embodiments of this application, please refer to Figure 1 For the sake of brevity, the description of the illustrated embodiment will not be repeated here.

[0075] Corresponding to the above embodiment, the embodiment of the present application further provides a spin capacitor, which includes a first electrode and a second electrode. The first electrode includes a nanocomposite material generated by using a positive electrode material recycled from a lithium-ion battery, and the nanocomposite material includes transition metal nanoparticles and lithium compound nanoparticles; the second electrode includes at least one of the following materials: metallic lithium, lithium compound, and carbon material.

[0076] Corresponding to the above embodiment, the embodiment of the present application also provides another spin capacitor, which includes a first electrode and a second electrode. The first electrode includes a nanocomposite material recovered from a lithium-ion battery, the nanocomposite material includes transition metal nanoparticles and lithium compound nanoparticles; the second electrode includes at least one of the following materials: metallic lithium, lithium compound and carbon material.

[0077] like Figure 5 As shown, the prepared spin capacitor was subjected to cyclic voltammetry test at different scan rates between 0.01-1.7 V. The electrochemical curve had no redox peak and was overall a smooth rectangle, showing obvious pseudocapacitive behavior, indicating that the entire charge and discharge capacity is mainly dominated by surface diffusion, that is, the capacitive contribution is the main factor.

[0078] like Figure 6 As shown in Figure 2, the specific capacity of the prepared spin capacitor was tested under cyclic voltammetry. The electrode was tested at a current density of 100 mA g -1 Under the condition of the first discharge and conversion reaction, the specific capacity is stable at 200mAhg in the subsequent cycles. -1 In the voltage range of 0.01-1.7 V, there is no obvious redox platform and no electrochemical reaction is involved, indicating that the capacity storage originates from diffusion-controlled capacitive behavior.

[0079] like Figure 7 As shown in the figure, under a magnetic field of 50000Oe, the magnetization intensity of the positive electrode material before discharge is very low and is linear as a whole, indicating that the material is an intrinsic paramagnetic substance of the positive electrode material. After the electrochemical discharge process, due to the conversion to a transition metal with ferromagnetism, the magnetization intensity can reach 127.0emu g -1 Fe , and the curve shows the superparamagnetism unique to nanoscale transition metals, indicating that nanometal particles are generated through discharge.

[0080] The above is only a specific implementation of the present application. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. The protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A method for recycling lithium-ion batteries, characterized in that: include: Recycling of cathode materials for lithium-ion batteries; Reducing the positive electrode material by electrochemical discharge to obtain a nanocomposite material, wherein the nanocomposite material includes transition metal nanoparticles and lithium compound nanoparticles; The nanocomposite material is used to prepare a first electrode of a spin capacitor, and the first electrode is one of two electrodes of the spin capacitor.

2. The method according to claim 1, characterized in that The positive electrode material includes at least one of the following materials: Lithium iron phosphate, lithium cobalt oxide, lithium manganese oxide and nickel-cobalt-manganese ternary materials.

3. The method according to claim 1, characterized in that The positive electrode material of the recycled ion battery comprises: Recycling a positive electrode sheet of a lithium-ion battery, wherein the positive electrode sheet comprises a current collector and a positive electrode material coated on a surface of the current collector; The positive electrode material coated on the surface of the current collector is scraped off to obtain the positive electrode material of the lithium ion battery.

4. The method according to claim 1, characterized in that: The positive electrode material for recycling ion batteries comprises: recycling positive electrode plates of lithium ion batteries, wherein the positive electrode plates comprise a current collector and positive electrode materials coated on the surface of the current collector; The method of reducing the positive electrode material by electrochemical discharge to obtain the nanocomposite material comprises: reducing the positive electrode material coated on the surface of the current collector by electrochemical discharge to obtain the nanocomposite material coated on the surface of the current collector.

5. A method for recycling lithium-ion batteries, characterized in that: include: Discharging the lithium-ion battery so that the positive electrode material of the lithium-ion battery is reduced to a nanocomposite material through electrochemical discharge, wherein the nanocomposite material includes transition metal nanoparticles and lithium compound nanoparticles; Recovering the nanocomposite material from the lithium-ion battery; The nanocomposite material is used to prepare a first electrode of a spin capacitor, and the first electrode is one of two electrodes of the spin capacitor.

6. The method according to claim 5, characterized in that The positive electrode material includes at least one of the following materials: Lithium iron phosphate, lithium cobalt oxide, lithium manganese oxide and nickel-cobalt-manganese ternary materials.

7. The method according to claim 5, characterized in that The method of recovering the nanocomposite material in the lithium-ion battery comprises: A positive electrode sheet of a lithium-ion battery is recycled, wherein the positive electrode sheet comprises a current collector and the nanocomposite material coated on the surface of the current collector.

8. The method according to claim 7, characterized in that After the positive electrode sheet of the lithium-ion battery is recovered, the method further comprises: The nanocomposite material coated on the surface of the current collector is scraped off to obtain the nanocomposite material in the lithium ion battery.

9. A spin capacitor, characterized in that: include: A first electrode, wherein the first electrode comprises a nanocomposite material generated by using a cathode material recycled from a lithium-ion battery, wherein the nanocomposite material comprises transition metal nanoparticles and lithium compound nanoparticles; The second electrode includes at least one of the following materials: metallic lithium, a lithium compound, and a carbon material.

10. A spin capacitor, characterized in that: include: A first electrode, the first electrode comprising a nanocomposite material recovered from a lithium-ion battery, the nanocomposite material comprising transition metal nanoparticles and lithium compound nanoparticles; The second electrode includes at least one of the following materials: metallic lithium, a lithium compound, and a carbon material.

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