Electrochemistry-based waste battery recycling and lithium extracting system and method

Abstract

The invention provides a waste battery recycling and lithium extracting system and method based on electrochemistry, and belongs to the field of battery energy storage. The waste battery recycling and lithium extracting system based on electrochemistry comprises an electrolytic bath; the electrolyte diaphragm divides the electrolytic cell into a first reaction tank and a second reaction tank, the first reaction tank contains an organic electrolyte and accommodates the positive electrode of the waste lithium battery, and the second reaction tank contains a first organic solvent; the carbon material current collector is arranged in the second reaction tank; wherein the positive electrode of the waste lithium battery is subjected to oxidation reaction to release lithium positive ions, the lithium positive ions enter the second reaction tank through the electrolyte diaphragm, the nitrogen dioxide gas introduced into the second reaction tank is reduced, and the recycled product lithium nitrate is obtained in the second reaction tank. According to the invention, collaborative recovery of the positive electrode of the waste lithium battery and the nitrogen dioxide gas can be realized.

Description

Technical Field

[0001] At least one embodiment of the present invention relates to waste battery recycling, and more particularly to an electrochemical-based waste battery recycling and lithium extraction system and method. Background Art

[0002] Lithium batteries are important energy storage devices that are widely used in electric vehicles, portable electronic devices, and renewable energy storage systems. The rapid growth in their production and use has aroused widespread attention to lithium battery recycling technology. In particular, the positive electrode materials of lithium batteries play an important role in the overall cost and performance of batteries. These positive electrode materials usually contain rare metals and precious metals and have high economic value. With the surge in the use of lithium batteries, the number of waste lithium batteries has also increased year by year. How to effectively recycle the valuable materials in these waste batteries to avoid waste of resources and environmental pollution has become an environmental and industrial problem that needs to be solved urgently around the world. Summary of the invention

[0003] In view of this, in order to at least partially solve the above-mentioned technical problems, the present invention provides a system and method for recycling and extracting lithium from waste batteries based on electrochemistry.

[0004] According to an embodiment of one aspect of the present invention, a waste battery recycling and lithium extraction system based on electrochemistry is provided, comprising:

[0005] An electrolytic cell; an electrolyte diaphragm, which divides the electrolytic cell into a first reaction cell and a second reaction cell, wherein the first reaction cell contains an organic electrolyte and accommodates a positive electrode of a waste lithium battery, and the second reaction cell contains a first organic solvent, and the second reaction cell is suitable for introducing nitrogen dioxide gas; a carbon material current collector, which is placed in the second reaction cell; wherein the positive electrode of the waste lithium battery undergoes an oxidation reaction to release lithium positive ions, and the lithium positive ions enter the second reaction cell through the electrolyte diaphragm, and the nitrogen dioxide gas introduced into the second reaction cell is reduced, and a recovered product, lithium nitrate, is obtained in the second reaction cell.

[0006] According to another embodiment of the present invention, there is provided a method for recovering lithium from waste batteries based on electrochemistry, comprising:

[0007] placing an organic electrolyte in a first reaction tank, and placing a first organic solvent in a second reaction tank;

[0008] Placing the positive electrode of the waste lithium battery in a first reaction tank, and placing the carbon material current collector in a second reaction tank; and

[0009] The positive electrode of the waste lithium battery and the carbon material current collector are respectively connected to the two ends of the electrochemical workstation, and nitrogen dioxide gas is introduced into the second reaction tank to cause an oxidation reaction at the positive electrode of the waste lithium battery to release lithium positive ions. The lithium positive ions enter the second reaction tank through the electrolyte diaphragm, and the nitrogen dioxide gas introduced into the second reaction tank is reduced to obtain a recovered product, lithium nitrate, in the second reaction tank.

[0010] According to the electrochemical waste battery recycling and lithium extraction system provided by the above embodiment of the present invention, the positive electrode of the waste lithium battery undergoes an oxidation reaction in the organic electrolyte of the first reaction tank to release lithium positive ions, and the lithium positive ions enter the second reaction tank through the electrolyte diaphragm, and the nitrogen dioxide gas introduced into the second reaction tank is reduced, and the recovered product lithium nitrate is obtained in the second reaction tank. The positive electrode of the waste lithium battery undergoes electrochemical lithium removal and the nitrogen dioxide gas undergoes electrochemical reduction, so as to achieve the coordinated recovery of the two pollutants, the positive electrode of the waste lithium battery and the nitrogen dioxide gas, and the recycling and lithium extraction system of the present application can achieve a higher lithium recovery efficiency.

[0011] According to the electrochemical-based waste battery recycling and lithium extraction system provided by the above embodiment of the present invention, the reduction potential is higher than the oxidation potential. The recycling and lithium extraction system can also realize the function of power generation and has the advantages of low energy consumption and being green and pollution-free. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings of the embodiments will be briefly introduced below. Obviously, the drawings in the following description only relate to some embodiments of the present invention, but are not intended to limit the present invention.

[0013] Figure 1 A schematic diagram of an electrochemical waste battery lithium recovery and extraction system provided in an embodiment of the present invention;

[0014] Figure 2 A schematic flow chart of a method for recovering lithium from waste batteries based on electrochemistry provided in an embodiment of the present invention.

[0015] Figure 3 The XRD test diagram of the recovered product provided in Example 1 of the present invention;

[0016] Figure 4 A graph showing the recovery performance test results of the waste battery recovery and lithium extraction system provided in Example 1 of the present invention;

[0017] Figure 5 A graph showing the recovery performance test results of the waste battery recovery and lithium extraction system provided in Example 2 of the present invention; and

[0018] Figure 6 This is a graph showing the recovery performance test results of the waste battery recovery and lithium extraction system provided in Example 3 of the present invention.

[0019] Description of reference numerals:

[0020] 1-Electrolyzer;

[0021] 11- first reaction tank;

[0022] 12- second reaction tank;

[0023] 2-Electrolyte separator;

[0024] 3- Waste lithium battery positive electrode;

[0025] 4-carbon material current collector;

[0026] 5-Electrochemical workstation;

[0027] 6- Active materials. DETAILED DESCRIPTION

[0028] In order to make the purpose, technical scheme and advantages of the present invention more clear, the present invention is further described in detail below in conjunction with specific embodiments and with reference to the accompanying drawings. However, the present invention can be implemented in different forms and should not be construed as being limited to the embodiments set forth herein. On the contrary, providing these embodiments will make the invention thorough and complete and fully convey the scope of the present invention to those skilled in the art. In the accompanying drawings, for clarity, the sizes and relative sizes of layers and regions may be exaggerated, and the same reference numerals throughout represent the same elements.

[0029] The terms used herein are only for describing specific embodiments and are not intended to limit the present invention. The terms "comprise", "include", etc. used herein indicate the existence of the features, steps, operations and / or components, but do not exclude the existence or addition of one or more other features, steps, operations or components.

[0030] The recycling technology of lithium batteries mainly includes physical, chemical and biological methods, among which the recycling of positive electrode materials is the focus of research. Existing recycling technologies mainly focus on extracting key metals such as lithium, cobalt, nickel and aluminum through high-temperature smelting, hydrometallurgy, mechanical crushing and other methods. Although these technologies have made certain progress in recycling efficiency and cost control, they still face a series of challenges such as complex technology, high energy consumption and environmental pollution. Therefore, the development of efficient, green and economical lithium battery positive electrode recycling technology is not only crucial to the recycling of resources, but also of great significance to the realization of sustainable development.

[0031] In view of this, the present invention provides a waste battery recycling and lithium extraction system and method based on electrochemistry, so as to at least partially solve the high energy consumption and high pollution problems existing in the recycling methods of related research.

[0032] Figure 1A schematic diagram of an electrochemical-based waste battery lithium recovery and extraction system provided in an embodiment of the present invention.

[0033] According to an exemplary embodiment of the present invention, the present invention provides a waste battery recycling and lithium extraction system based on electrochemistry, referring to Figure 1 As shown, including:

[0034] Electrolytic cell 1;

[0035] The electrolyte diaphragm 2 separates the electrolytic cell 1 into a first reaction cell 11 and a second reaction cell 12, wherein the first reaction cell 11 contains an organic electrolyte and accommodates the waste lithium battery positive electrode 3, and the second reaction cell 12 contains a first organic solvent, and the second reaction cell 12 is suitable for introducing nitrogen dioxide gas;

[0036] The carbon material current collector 4 is placed in the second reaction tank 12;

[0037] The positive electrode 3 of the waste lithium battery undergoes an oxidation reaction to release lithium ions, and the lithium ions enter the second reaction tank 12 through the electrolyte diaphragm 2. The nitrogen dioxide gas introduced into the second reaction tank 12 is reduced to nitrite (NO2 - ), NO2 - Oxidized to NO3 in the environment - , and the recovered product lithium nitrate is obtained in the second reaction tank 12.

[0038] In some embodiments, the waste lithium battery positive electrode 3 includes one or more of a lithium iron phosphate positive electrode, a lithium cobalt oxide positive electrode, and a nickel-cobalt-manganese ternary positive electrode.

[0039] According to an embodiment of the present invention, the organic electrolyte includes an organic lithium salt and a second organic solvent.

[0040] In some embodiments, the organic lithium salt includes one or more of lithium hexafluorophosphate, lithium perchlorate, lithium tetrafluoroborate, lithium bis(difluoromethylsulfonyl imide), lithium bis(trifluoromethylsulfonyl imide), lithium bis(fluorosulfonyl imide), lithium bis(oxalatoborate), lithium difluorooxalatoborate, and lithium hexafluoroarsenate.

[0041] In some embodiments, the second organic solvent includes one or more of ethylene carbonate, propylene carbonate, fluoroethylene carbonate, dimethyl carbonate, diethyl carbonate, ethyl methyl carbonate, methyl propyl carbonate, and vinylene carbonate.

[0042] In some embodiments, the first organic solvent includes one or more of ethylene carbonate, propylene carbonate, fluoroethylene carbonate, dimethyl carbonate, diethyl carbonate, ethyl methyl carbonate, methyl propyl carbonate, and vinylene carbonate.

[0043] In some embodiments, the electrolyte separator 2 is a solid electrolyte, including one or more of an oxide electrolyte or a sulfide electrolyte.

[0044] In some embodiments, the oxide electrolyte includes one of a lithium lanthanum zirconium tantalum oxide electrolyte, a lithium aluminum germanium phosphate electrolyte, a lithium aluminum titanium phosphate electrolyte, a lithium lanthanum zirconium oxide electrolyte, a lithium lanthanum titanium oxide electrolyte, and a lithium lanthanum zirconium niobium oxide electrolyte.

[0045] In some embodiments, the sulfide electrolyte includes a lithium germanium phosphorus sulfur electrolyte.

[0046] In some embodiments, the carbon material current collector 4 includes one or more of carbon felt, carbon paper, carbon cloth, graphite felt, graphene film, graphene mesh, carbon nanotube film, carbon nanotube paper, conductive activated carbon film, mesoporous carbon film, conductive graphite plate and conductive graphite mesh.

[0047] According to an embodiment of the present invention, the positive electrode of the waste lithium battery undergoes an oxidation reaction in the organic electrolyte of the first reaction tank to release lithium positive ions, and the lithium positive ions enter the second reaction tank through the electrolyte diaphragm, and the nitrogen dioxide gas introduced into the second reaction tank is reduced to obtain the recovered product lithium nitrate in the second reaction tank. The positive electrode of the waste lithium battery undergoes electrochemical lithium removal and the nitrogen dioxide gas undergoes electrochemical reduction, thereby achieving the coordinated recovery of two pollutants, the positive electrode of the waste lithium battery and the nitrogen dioxide gas.

[0048] Figure 2 A schematic flow chart of a method for recovering lithium from waste batteries based on electrochemistry provided in an embodiment of the present invention.

[0049] According to an exemplary embodiment of the present invention, the present invention provides a method for recycling and extracting lithium from waste batteries, referring to Figure 2 As shown, it includes: operation S01 to operation S03.

[0050] In operation S01 , an electrolyte membrane 2 is placed in an electrolytic cell 1 , the electrolytic cell 1 is divided into a first reaction cell 11 and a second reaction cell 12 , an organic electrolyte is placed in the first reaction cell 11 , and a first organic solvent is placed in the second reaction cell 12 .

[0051] According to an embodiment of the present invention, the above-mentioned method for recycling and extracting lithium from waste batteries further includes preparing an organic electrolyte.

[0052] In some embodiments, the organic lithium salt is dissolved in the second organic solvent to obtain an organic electrolyte. The concentration of the organic electrolyte is any value between 0 and 0.1 mg / L, for example, 0.01 mg / L, 0.05 mg / L, 0.08 mg / L, 0.1 mg / L, preferably 0.1 mg / L.

[0053] According to an embodiment of the present invention, the process of mixing the organic lithium salt with the second organic solvent to form an organic electrolyte is performed in a glove box with an argon atmosphere.

[0054] According to an embodiment of the present invention, the above waste battery recycling and lithium extraction method further includes preparing an electrolyte membrane. Specifically, the electrolyte powder is punched into an electrolyte sheet; and the electrolyte sheet is sintered at 800°C to 1000°C for 5 to 10 hours to obtain the electrolyte membrane.

[0055] In some embodiments, the lithium aluminum titanium phosphorus electrolyte powder is punched into an electrolyte sheet with a diameter of 14 mm, and then sintered at 800° C. to 1000° C. for 5-10 hours to obtain the desired electrolyte membrane.

[0056] In operation S02 , the positive electrode 3 of the waste lithium battery is placed in the first reaction tank 11 , and the carbon material current collector 4 is placed in the second reaction tank 12 .

[0057] Operation S03, connect the waste lithium battery positive electrode 3 and the carbon material collector 4 to the two ends of the electrochemical workstation respectively, and introduce nitrogen dioxide gas into the second reaction tank, so that the waste lithium battery positive electrode 3 undergoes an oxidation reaction to release lithium positive ions, and the lithium positive ions enter the second reaction tank through the electrolyte membrane 2, and the nitrogen dioxide gas introduced into the second reaction tank 12 is reduced, and the recovered product lithium nitrate is obtained in the second reaction tank 12.

[0058] According to an embodiment of the present invention, the process of releasing lithium positive ions by oxidation reaction of the positive electrode 3 of the waste lithium battery is as shown in formula (1):

[0059]

[0060] According to an embodiment of the present invention, nitrogen dioxide gas is reduced to nitrite (NO2 - ) is shown in formula (2).

[0061] Formula (2)

[0062] According to an embodiment of the present invention, the energy requirement for the lithium recovery process is -64.6Wh / kg LEP The positive electrode 3 of the waste lithium battery undergoes oxidation reaction to release lithium ions, and its oxidation potential is E0=0.5V vs.RHE; nitrogen dioxide is reduced to nitrite (NO2 - ), its reduction potential E0 = 0.88V vs. RHE, the reduction potential is higher than the oxidation potential, which indicates that the recovery and lithium extraction system of the present invention can achieve the function of power generation while synergistically recovering two pollutants.

[0063] The following schematically illustrates the designed system and method for recycling and extracting lithium from waste batteries based on electrochemistry. It should be noted that the example is only a specific embodiment of the present invention and cannot limit the scope of protection of the present invention.

[0064] Example 1

[0065] Prepare an organic electrolyte. Specifically, in a glove box filled with argon, prepare an organic electrolyte containing lithium hexafluorophosphate, dimethyl carbonate and ethylene glycol dimethyl ether, wherein the concentration of lithium hexafluorophosphate is 1 mol / L, and the volume ratio of solvent dimethyl carbonate and ethylene glycol dimethyl ether is 50:50. Stir the prepared electrolyte thoroughly to obtain the desired organic electrolyte.

[0066] Preparation of electrolyte membrane: Specifically, 1 g of lithium aluminum titanium phosphorus electrolyte powder was punched into an electrolyte sheet with a diameter of 14 mm. The electrolyte sheet was transferred to a muffle furnace and sintered at 850° C. for 10 hours to obtain the desired electrolyte membrane.

[0067] Electrochemical-based lithium recovery process for waste batteries.

[0068] Specifically, refer to Figure 1 As shown, in a glove box filled with argon, an electrolyte membrane 2 is placed in an electrolytic cell 1, and the electrolytic cell 1 is divided into a first reaction cell 11 and a second reaction cell 12. An organic electrolyte is placed in the first reaction cell 11, and an organic solution of ethylene carbonate is placed in the second reaction cell 12. A lithium iron phosphate cathode of a waste lithium battery is placed in the first reaction cell 11, and a carbon material current collector 4 (conductive graphite plate) is placed in the second reaction cell 12, and then the electrolytic cell 1 is transferred outside the glove box.

[0069] The waste lithium battery positive electrode 3 and the carbon material current collector 4 are respectively connected to the two ends of the electrochemical workstation 5. The nitrogen dioxide gas (active material) is introduced into the second reaction tank. After the reaction occurs, the recovered product in the second electrolytic tank is recovered and the performance of the recovered product is tested.

[0070] Figure 3 This is the XRD test diagram of the recovered product provided in Example 1 of the present invention.

[0071] refer to Figure 3 As shown, the XRD test results of the recovered product obtained by the electrochemical waste battery recovery and lithium extraction process of the present invention show that the recovered product obtained is lithium nitrate.

[0072] Figure 4 This is a graph showing the recovery performance test results of the waste battery recovery and lithium extraction system provided in Example 1 of the present invention.

[0073] refer to Figure 4As shown, the recovery rate of lithium iron phosphate from waste batteries is 96.23%, which indicates that the waste battery recovery and lithium extraction system of the present invention achieves a higher recovery rate.

[0074] Example 2

[0075] The waste batteries are recycled using the same process as the electrochemical waste battery recycling and lithium extraction process in Example 1. The difference is that the waste batteries are cobalt oxide lithium positive electrodes.

[0076] Figure 5 This is a graph showing the recovery performance test results of the waste battery recovery and lithium extraction system provided in Example 2 of the present invention.

[0077] refer to Figure 5 As shown, the recovery rate of lithium cobalt oxide from waste batteries is 36%.

[0078] Example 3

[0079] The waste batteries are recycled using the same process as the electrochemical waste battery recycling and lithium extraction process in Example 1. The difference is that the waste batteries are nickel-cobalt-manganese ternary positive electrodes.

[0080] Figure 6 This is a graph showing the recovery performance test results of the waste battery recovery and lithium extraction system provided in Example 3 of the present invention.

[0081] refer to Figure 6 As shown, the recovery rate of nickel-cobalt-manganese ternary positive electrode of waste batteries is 58%.

[0082] The ordinal numbers used in the specification and claims, such as "first", "second", "third", etc., to modify the corresponding elements, do not themselves mean that the elements have any ordinal numbers, nor do they represent the order of one element and another element, or the order in the manufacturing method. The use of these ordinal numbers is only used to clearly distinguish a component with a certain name from another component with the same name.

[0083] The specific embodiments described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A waste battery recycling and lithium extraction system based on electrochemistry, characterized in that: include: Electrolyzer (1); An electrolyte diaphragm (2) is used to separate the electrolytic cell (1) into a first reaction cell (11) and a second reaction cell (12), wherein the first reaction cell (11) contains an organic electrolyte and accommodates a positive electrode (3) of a waste lithium battery, and the second reaction cell (12) contains a first organic solvent, and the second reaction cell (12) is suitable for introducing nitrogen dioxide gas; A carbon material current collector (4) is placed in the second reaction tank (12); The positive electrode (3) of the waste lithium battery undergoes an oxidation reaction to release lithium ions, and the lithium ions enter the second reaction tank through the electrolyte diaphragm (2). The nitrogen dioxide gas introduced into the second reaction tank (12) undergoes reduction, and the recovered product lithium nitrate is obtained in the second reaction tank (12).

2. The waste battery recycling and lithium extraction system according to claim 1 is characterized in that: The waste lithium battery positive electrode (3) comprises one or more of a lithium iron phosphate positive electrode, a lithium cobalt oxide positive electrode and a nickel-cobalt-manganese ternary positive electrode.

3. The waste battery recycling and lithium extraction system according to claim 1 is characterized in that: The organic electrolyte comprises an organic lithium salt, The organic lithium salt includes one or more of lithium hexafluorophosphate, lithium perchlorate, lithium tetrafluoroborate, lithium bis(difluoromethylsulfonyl imide), lithium bis(trifluoromethylsulfonyl imide), lithium bis(fluorosulfonyl imide), lithium bis(oxalatoborate), lithium difluorooxalatoborate and lithium hexafluoroarsenate.

4. The waste battery recycling and lithium extraction system according to claim 3 is characterized in that: The organic electrolyte further includes a second organic solvent, and the second organic solvent includes one or more of ethylene carbonate, propylene carbonate, fluoroethylene carbonate, dimethyl carbonate, diethyl carbonate, ethyl methyl carbonate, methyl propyl carbonate and vinylene carbonate.

5. The waste battery recycling and lithium extraction system according to claim 1 is characterized in that: The first organic solvent includes one or more of ethylene carbonate, propylene carbonate, fluoroethylene carbonate, dimethyl carbonate, diethyl carbonate, ethyl methyl carbonate, methyl propyl carbonate and vinylene carbonate.

6. The waste battery recycling and lithium extraction system according to claim 1 is characterized in that: The electrolyte membrane (2) comprises one or more of an oxide electrolyte and a sulfide electrolyte.

7. The waste battery recycling and lithium extraction system according to claim 1 is characterized in that: The carbon material current collector (4) comprises one or more of carbon felt, carbon paper, carbon cloth, graphite felt, graphene film, graphene mesh, carbon nanotube film, carbon nanotube paper, conductive activated carbon film, mesoporous carbon film, conductive graphite plate and conductive graphite mesh.

8. A method for recovering and extracting lithium from waste batteries based on electrochemistry, which is implemented by using the system for recovering and extracting lithium from waste batteries based on electrochemistry as described in any one of claims 1 to 7, characterized in that: include: Placing an organic electrolyte in a first reaction tank (11), and placing a first organic solvent in a second reaction tank (12); Placing the positive electrode (3) of the waste lithium battery in the first reaction tank (11), and placing the carbon material current collector (4) in the second reaction tank (12); and The positive electrode (3) of the waste lithium battery and the carbon material current collector (4) are respectively connected to the two ends of an electrochemical workstation, and nitrogen dioxide gas is introduced into the second reaction tank, so that the positive electrode (3) of the waste lithium battery undergoes an oxidation reaction to release lithium positive ions, and the lithium positive ions enter the second reaction tank through the electrolyte diaphragm (2), and the nitrogen dioxide gas introduced into the second reaction tank (12) is reduced, and a recovered product lithium nitrate is obtained in the second reaction tank (12).

9. The method for recovering lithium from waste batteries according to claim 8, characterized in that: Also includes: preparing the organic electrolyte, The concentration of the organic electrolyte is 0-0.1 mg / L, and is not 0.

10. The method for recovering lithium from waste batteries according to claim 8, characterized in that: Also included is the preparation of an electrolyte separator, comprising: Punching the electrolyte powder into electrolyte sheets; The electrolyte membrane is obtained by sintering the electrolyte sheet at 800° C. to 1000° C. for 5 to 10 hours.

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