Electrochemical-based waste battery recycling and lithium extraction system and method

Abstract

The present invention provides an electrochemically based waste battery lithium recovery system and method, belonging to the field of battery energy storage. The electrochemically based waste battery lithium recovery system comprises: an electrolytic cell; an electrolyte membrane that separates the electrolytic cell into a first reaction cell and a second reaction cell, wherein the first reaction cell contains an organic electrolyte and accommodates the positive electrode of the waste lithium battery, and the second reaction cell contains a first organic solvent; and a carbon material current collector placed in the second reaction cell. The positive electrode of the waste lithium battery undergoes an oxidation reaction to release lithium ions, which then pass through the electrolyte membrane into the second reaction cell. Nitrogen dioxide gas introduced into the second reaction cell undergoes reduction, and lithium nitrate is recovered as a product in the second reaction cell. The present invention enables the coordinated recovery of the positive electrode of the waste lithium battery and nitrogen dioxide gas.

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, as essential energy storage devices widely used in electric vehicles, portable electronic devices, and renewable energy storage systems, have seen rapid growth in production and use, sparking widespread interest in lithium battery recycling technologies. In particular, the cathode materials of lithium batteries, which often contain rare and precious metals and possess high economic value, play a crucial role in the overall cost and performance of the battery. As lithium battery usage surges, the number of used lithium batteries is also increasing year by year. How to effectively recover the valuable materials from these used batteries while avoiding resource waste and environmental pollution has become a pressing global environmental and industrial issue. 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 an electrochemical-based waste battery recycling and lithium extraction system and method.

[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 membrane, which separates the electrolytic cell into a first reaction cell and a second reaction cell, wherein the first reaction cell contains an organic electrolyte and accommodates the positive electrode of the 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 membrane, and the nitrogen dioxide gas introduced into the second reaction cell is reduced, and the 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 the first reaction tank and the carbon material current collector in the 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. 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.

[0010] According to the electrochemically based waste battery lithium recovery and extraction system provided by the above-mentioned 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. The lithium positive ions enter the second reaction tank through the electrolyte membrane. 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 delithiation and the nitrogen dioxide gas undergoes electrochemical reduction, achieving the coordinated recovery of two pollutants, the positive electrode of the waste lithium battery and the nitrogen dioxide gas. In addition, the lithium recovery and extraction system of the present application can achieve a high 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, 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-based waste battery lithium recovery and extraction system provided in an embodiment of the present invention;

[0014] Figure 2 A schematic flow chart of an electrochemical-based method for recycling and extracting lithium from waste batteries provided in an embodiment of the present invention.

[0015] Figure 3 The XRD test pattern 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] To make the objectives, technical solutions, and advantages of the present invention more clearly understood, the present invention will be further described in detail below with reference to specific embodiments and the accompanying drawings. However, the present invention can be implemented in various forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided to make the present invention thorough and complete and to fully convey the scope of the present invention to those skilled in the art. In the drawings, the dimensions and relative dimensions of layers and regions may be exaggerated for clarity, and like reference numerals denote like elements throughout.

[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 presence of the features, steps, operations and / or components, but do not exclude the presence or addition of one or more other features, steps, operations or components.

[0030] Lithium battery recycling technologies mainly include physical, chemical, and biological methods, among which the recovery of cathode 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, and mechanical crushing. Although these technologies have made certain progress in recycling efficiency and cost control, they still face a series of challenges such as technical complexity, high energy consumption, and environmental pollution. Therefore, the development of efficient, green, and economical lithium battery cathode recycling technology is not only crucial for the recycling of resources, but also of great significance for achieving sustainable development.

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

[0032] Figure 1Schematic 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 Shown, including:

[0034] electrolytic cell 1;

[0035] The electrolyte membrane 2 divides 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 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 oxidation reaction to release lithium ions, which pass through the electrolyte membrane 2 and enter the second reaction tank 12. The nitrogen dioxide gas introduced into the second reaction tank 12 is reduced to nitrite (NO2 - ), NO2 - Oxidized to NO3 in the environment - , 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(difluoromethanesulfonyl imide), lithium bis(trifluoromethanesulfonyl 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 and 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 a used lithium battery undergoes an oxidation reaction in the organic electrolyte of a first reaction tank, releasing lithium ions. The lithium ions then pass through the electrolyte membrane into a second reaction tank, where nitrogen dioxide gas introduced into the second reaction tank undergoes reduction, resulting in the recovery of lithium nitrate as a product. Electrochemical delithiation of the used lithium battery's positive electrode and electrochemical reduction of the nitrogen dioxide gas achieve the synergistic recovery of both the used lithium battery's positive electrode and the nitrogen dioxide gas.

[0048] Figure 2 A schematic flow chart of an electrochemical-based method for recycling and extracting lithium from waste batteries 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 , the electrolyte membrane 2 is placed in the 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 solution having a concentration of any value between 0 and 0.1 mg / L, such as 0.01 mg / L, 0.05 mg / L, 0.08 mg / L, or 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 and the second organic solvent to form the organic electrolyte is performed in a glove box with an argon atmosphere.

[0054] According to an embodiment of the present invention, the above-mentioned 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, 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 waste lithium battery positive electrode 3 is placed in the first reaction tank 11 , and the carbon material current collector 4 is placed in the second reaction tank 12 .

[0057] In operation S03, the positive electrode 3 of the waste lithium battery and the carbon material current collector 4 are respectively connected to the two ends of the 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. 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 the positive electrode 3 of the waste lithium battery undergoing oxidation reaction to release lithium positive ions is shown in formula (1):

[0059]

[0060] According to an embodiment of the present invention, nitrogen dioxide gas is reduced to nitrite (NO2 - The process of ) 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 shows that the recovery and lithium extraction system of the present invention can achieve the function of power generation while synergistically recovering the two pollutants.

[0063] The following schematically illustrates the designed electrochemical-based waste battery recycling and lithium extraction system and method. It should be noted that this example is only a specific embodiment of the present invention and does not limit the scope of protection of the present invention.

[0064] Example 1

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

[0066] Prepare the electrolyte membrane. Specifically, 1g 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, dividing the electrolytic cell 1 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 from a used 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. The electrolytic cell 1 is then transferred outside the glove box.

[0069] Connect the waste lithium battery positive electrode 3 and the carbon material current collector 4 to the two ends of the electrochemical workstation 5. 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 its performance is tested.

[0070] Figure 3 This is the XRD test pattern 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-based waste battery lithium recovery and 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 in FIG, the recovery rate of lithium iron phosphate from waste batteries is 96.23%, which indicates that the waste battery recycling and lithium extraction system of the present invention achieves a high recovery rate.

[0074] Example 2

[0075] The waste batteries are recycled using the same process as the electrochemical-based waste battery lithium recovery process in Example 1. The difference is that the waste batteries have a cobalt oxide lithium positive electrode.

[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 were recycled using the same process as the electrochemical-based waste battery lithium recovery process in Example 1. The difference was that the waste batteries used a nickel-cobalt-manganese ternary positive electrode.

[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 in the figure, the recovery rate of nickel-cobalt-manganese ternary positive electrode of waste batteries is 58%.

[0082] The use of ordinal numbers such as "first," "second," and "third" in the specification and claims to modify corresponding elements does not in itself mean that the elements have any ordinal number, nor does it represent the order of one element relative to another or the order in the manufacturing method. The use of such ordinal numbers is only used to clearly distinguish one element with a certain name from another element 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 are only specific embodiments of the present invention and are 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: electrolytic cell (1); An electrolyte diaphragm (2) is provided 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 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; 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 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) undergoes reduction, and the recovered product lithium nitrate is obtained in the second reaction tank (12); The electrochemical-based waste battery recycling and lithium extraction system has a reduction potential higher than an oxidation potential, thereby achieving a power generation function.

2. The waste battery recycling and lithium extraction system according to claim 1, characterized in that: 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.

3. The waste battery recycling and lithium extraction system according to claim 1, characterized in that: The organic electrolyte includes 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, characterized in that: The organic electrolyte further includes a second organic solvent, which 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, characterized in that: The electrolyte membrane (2) includes one or more of an oxide electrolyte and a sulfide electrolyte.

7. The waste battery recycling and lithium extraction system according to claim 1, 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, implemented 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 waste lithium battery positive electrode (3) 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 the 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 the 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, wherein: 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, wherein: Also included is the preparation of an electrolyte separator, comprising: Punching the electrolyte powder into electrolyte sheets; The electrolyte separator is obtained by sintering the electrolyte sheet at 800° C. to 1000° C. for 5 to 10 hours.

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