Device and method for extracting lithium from salt lake

Abstract

Provided in the present disclosure are a device and method for extracting lithium from a salt lake. The device comprises a power supply, a lithium-extracting compartment, a lithium-removing compartment and an electrolyte compartment. The method comprises the following steps: (1) mixing a lithium-removing material and an electrolyte to prepare a lithium-removing flowing slurry, and mixing a lithium-intercalated material and lithium-containing salt lake brine to prepare a lithium-intercalated flowing slurry; (2) injecting an electrolyte into the electrolyte compartment, making the lithium-removing flowing slurry flow through the lithium-removing compartment, making the lithium-intercalated flowing slurry flow through the lithium-extracting compartment, and energizing same to carry out a lithium-extracting reaction; and (3) collecting the liquid flowing out of the lithium-extracting compartment, filtering same and then mixing same with the electrolyte, making the mixture flow through the lithium-removing compartment, continuing to carry out the lithium-extracting reaction, and collecting the liquid in the electrolyte compartment to obtain a lithium-rich solution. The device for extracting lithium from a salt lake of the present disclosure has a simple structure, and the method reduces the impurity-removing pressure of an ion exchange membrane and prolongs the service life of the ion exchange membrane; in addition, the obtained lithium-rich solution has a low impurity concentration, and the effect of impurity removal is better.

Description

Device and method for extracting lithium from salt lake Technical Field

[0001] The present invention belongs to the technical field of lithium extraction from salt lakes, and relates to a device and a method for extracting lithium from salt lakes. Background Art

[0002] With the increasing consumption of non-renewable energy sources such as oil and coal, the development and utilization of new energy sources has become an inevitable trend. As a prime example of this development and utilization, new energy vehicles have experienced rapid growth in recent years and are expected to eventually surpass the market share of traditional fuel vehicles, gradually replacing them. As an essential metal in new energy vehicles, lithium is experiencing increasing market demand, but the difficulty of mining existing lithium mines makes it difficult to meet market demand. In addition to lithium ore, brines, particularly salt lake brines, contain significant lithium resources in ionic form, offering a natural advantage over extracting lithium from ore.

[0003] In addition to lithium ions, brine also contains calcium, magnesium, sodium, potassium and other ions. In particular, magnesium ions and lithium ions are located on the diagonal position of the periodic table and have similar properties, which restricts the development and utilization of salt lake lithium resources.

[0004] CN 102382984 A proposes a new electrochemical deintercalation method for lithium extraction. This technology uses delithiated lithium-ion cathode materials as the electrode material, salt lake brine as the catholyte, and an electrolyte free of calcium and magnesium ions as the anolyte to achieve lithium extraction. This method uses fixed electrodes, which has drawbacks such as high operational difficulty and limited contact area between the electrodes and the brine.

[0005] CN109487081A discloses a mobile electrode lithium extraction unit device, but the mobile electrode lithium extraction unit device proposed therein is relatively complex, and the impurity removal pressure of the cation exchange membrane is high.

[0006] The method for extracting lithium from salt lakes described in the above scheme has the problems of difficult operation, complex equipment or poor impurity removal effect, which limits its application in practice.

[0007] Summary of the Invention

[0008] The following is a summary of the subject matter described in detail herein. This summary is not intended to limit the scope of the claims.

[0009] The purpose of the present disclosure is to provide a device and method for extracting lithium from salt lakes. The device for extracting lithium from salt lakes disclosed in the present disclosure has a simple structure and does not require two devices for lithium extraction and lithium removal. The method reduces the impurity removal pressure of the ion exchange membrane, extends the service life of the ion exchange membrane, and at the same time, the impurity concentration of the obtained lithium-rich solution is low, and the impurity removal effect is better.

[0010] To achieve this purpose, the present disclosure adopts the following technical solutions:

[0011] In the first aspect, the present disclosure provides a device for extracting lithium from a salt lake, the device comprising a power supply, a lithium extraction cabin, a lithium stripping cabin and an electrolyte cabin, the electrolyte cabin being placed between the lithium extraction cabin and the lithium stripping cabin, an anion exchange membrane being arranged between the electrolyte cabin and the lithium extraction cabin, a monovalent cation exchange membrane being arranged between the electrolyte cabin and the lithium stripping cabin, the lithium extraction cabin being parallel to the direction of the anion exchange membrane and having a baffle arranged on a side away from the electrolyte cabin, the lithium stripping cabin being parallel to the direction of the monovalent cation exchange membrane and having a baffle arranged on a side away from the electrolyte cabin, no baffles being arranged on both sides of the lithium extraction cabin perpendicular to the direction of the anion exchange membrane, and no baffles being arranged on both sides of the lithium stripping cabin perpendicular to the direction of the monovalent cation exchange membrane.

[0012] During use, the device disclosed herein removes impurities from the cation exchange membrane after the impurity removal step. The device utilizes the selectivity of the lithium ion screen for primary impurity removal, followed by secondary impurity removal using the monovalent cation exchange membrane. This reduces the impurity removal pressure on the cation exchange membrane and extends its service life. Separate brine and electrolyte flow paths are unnecessary, eliminating the need for extensive cleaning of the electrolytic cell when switching between brine and electrolyte.

[0013] In one embodiment, a cathode current collector is provided in the lithium extraction compartment.

[0014] In one embodiment, the cathode current collector comprises any one of aluminum foil, copper foil, nickel mesh or nickel sheet, or a combination of at least two thereof.

[0015] In one embodiment, the cathode current collector is connected to the negative electrode of the power supply.

[0016] In one embodiment, the cathode current collector is not attached to the anion exchange membrane.

[0017] In one embodiment, an anode current collector is disposed in the lithium de-ion compartment.

[0018] In one embodiment, the anode current collector includes any one of aluminum foil, copper foil, nickel mesh, or nickel sheet, or a combination of at least two thereof.

[0019] In one embodiment, the anode current collector is connected to a positive electrode of a power source.

[0020] In one embodiment, the anode current collector is not attached to a monovalent cation exchange membrane.

[0021] In one embodiment, the material of the anion exchange membrane includes polystyrene, polypropylene or polyamide.

[0022] In one embodiment, the components of the monovalent cation exchange membrane include an organic base material and polypyrrole.

[0023] In one embodiment, the organic base material includes any one of polytetrafluoroethylene, polychlorotrifluoroethylene, polyvinylidene fluoride, styrene-butadiene rubber, polyaniline or polyacrylonitrile, or a combination of at least two thereof.

[0024] In a second aspect, the present disclosure provides a method for extracting lithium from a salt lake, the method using the apparatus described in the first aspect, the method comprising the following steps:

[0025] (1) mixing a delithiation material and an electrolyte to form a delithiation flow slurry, and mixing a lithium insertion material and lithium-containing salt lake brine to form a lithium insertion flow slurry;

[0026] (2) injecting the electrolyte into the electrolyte chamber, connecting the cathode current collector to the negative electrode of the power supply, connecting the anode current collector to the positive electrode of the power supply, flowing the lithium-removing flow slurry through the lithium-removing chamber, and flowing the lithium-inserting flow slurry through the lithium-extracting chamber, and applying power to carry out the lithium-extracting reaction;

[0027] (3) Collect the liquid flowing out of the lithium extraction chamber, filter it, mix it with the electrolyte, and flow it through the lithium removal chamber to continue the lithium extraction reaction. Collect the liquid in the electrolyte chamber to obtain a lithium-rich solution.

[0028] In the method for extracting lithium from salt lakes disclosed in the present invention, salt lake brine and lithium-intercalated active substances are in the same compartment and are not separated by a cation exchange membrane. The first step of impurity removal is performed using the selectivity of the lithium ion sieve. The electrolyte and salt lake brine are separated by an anion exchange membrane to ensure that the cations in the brine do not enter the electrolyte. A portion of the electrolyte and the delithiation active substance are in the same delithiation compartment, and a portion of the electrolyte is separated from the active substance by a monovalent cation exchange membrane. The delithiation active substance removes lithium in the electrolyte, so that the electrolyte in the delithiation compartment is converted into a lithium-rich solution. Under the action of the electric potential, lithium ions move toward the anode through the monovalent cation exchange membrane and enter the electrolyte in the middle compartment, but are blocked by the anion membrane and do not enter the brine tank, thus obtaining a pure lithium-rich solution.

[0029] In one embodiment, the active material in the delithiation material in step (1) comprises any one of lithium-rich lithium titanate, lithium iron phosphate or lithium manganese oxide, or a combination of at least two thereof.

[0030] In one embodiment, the solute in the electrolyte includes any one of sodium chloride, potassium chloride, sodium sulfate, potassium sulfate, sodium nitrate or potassium nitrate, or a combination of at least two thereof.

[0031] In one embodiment, the active material in the lithium intercalation material includes any one of lithium-poor lithium titanate, lithium iron phosphate, or lithium manganese oxide, or a combination of at least two thereof.

[0032] The lithium-poor state described in the present disclosure refers to the state of lithium titanate, lithium iron phosphate, lithium manganese oxide, etc. after lithium ions are removed, and the lithium-rich state refers to the state of lithium titanate, lithium iron phosphate, lithium manganese oxide, etc. after lithium ions are embedded.

[0033] In one embodiment, the lithium-removing material and the lithium-inserting material in step (1) both contain a conductive agent.

[0034] In one embodiment, the conductive agent includes any one of conductive carbon black, conductive acetylene black, graphene, or carbon nanotubes, or a combination of at least two thereof.

[0035] In one embodiment, the mass ratio of the active material to the conductive agent in the lithium-removing material and the lithium-intercalating material is (85-95):(5-15), for example: 85:15, 88:12, 90:10, 92:7 or 95:5.

[0036] In one embodiment, the solid content of the lithium-removing mobile slurry and the lithium-inserting mobile slurry in step (1) is 10-50%, for example, 10%, 20%, 30%, 40% or 50%.

[0037] In one embodiment, the concentration of the electrolyte in step (2) is 0.3 to 2 mol / L, for example, 0.3 mol / L, 0.5 mol / L, 1 mol / L, 1.5 mol / L or 2 mol / L.

[0038] In one embodiment, the concentration of electrolyte in the electrolyte compartment is lower than the concentration of electrolyte in the delithiation compartment.

[0039] In one embodiment, the flow rate of the lithium removal flow slurry and the lithium insertion flow slurry in step (2) is 1 to 5 mL / min, for example, 1 mL / min, 2 mL / min, 3 mL / min, 4 mL / min or 5 mL / min.

[0040] In one embodiment, the voltage of the power supply in step (2) is 0.1 to 1.5 V, for example, 0.1 V, 0.5 V, 1 V, 1.2 V or 1.5 V.

[0041] Compared with the prior art, the present disclosure has the following beneficial effects:

[0042] (1) The device for extracting lithium from salt lakes disclosed in the present invention has a simple structure, does not require two devices for lithium extraction and lithium removal, has independent flow paths for brine and electrolyte, does not require large-scale cleaning of the electrolytic cell when switching brine / electrolyte, and has good application prospects.

[0043] (2) The method for extracting lithium from salt lakes disclosed in the present invention not only simplifies the use of the device, but also reduces the impurity removal pressure of the ion exchange membrane, prolongs the service life of the ion exchange membrane, and at the same time obtains a lower impurity concentration in the lithium-rich solution (electrolyte in the electrolyte tank) and a better impurity removal effect.

[0044] (3) The initial lithium ion extraction efficiency of the method for extracting lithium from salt lakes disclosed in the present invention can reach more than 70 μmol / min. After 48 hours, the lithium ion extraction efficiency is still maintained at more than 64 μmol / min. After 48 hours, the lithium ion extraction efficiency decreases and remains below 7 μmol / min. This proves that the method disclosed in the present invention has less pressure on the ion exchange membrane and the service life of the membrane is extended. At the same time, the present application obtains Mg in the electrolyte 2+ The ion concentration can reach below 0.015g / L, and the impurity content is low.

[0045] Still other aspects will become apparent upon reading and understanding the accompanying drawings and detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] The accompanying drawings are used to provide a further understanding of the technical solution of this article and constitute a part of the specification. Together with the embodiments of this application, they are used to explain the technical solution of this article and do not constitute a limitation on the technical solution of this article.

[0047] Figure 1 is a schematic diagram of the device used for lithium extraction from salt lakes according to an embodiment of the present disclosure, 1-lithiation-removing flowing slurry, 2-baffle, 3-current collector, 4-anion exchange membrane, 5-cation exchange membrane, 6-lithiation-intercalating flowing slurry. DETAILED DESCRIPTION

[0048] The technical solution of the present disclosure is further described below through specific implementation methods. It should be understood by those skilled in the art that the embodiments are only used to help understand the present disclosure and should not be regarded as specific limitations of the present disclosure.

[0049] A schematic diagram of a device for extracting lithium from salt lakes according to an embodiment of the present disclosure is shown in FIG1 , wherein:

[0050] 1 is the lithium-deionized flow slurry, 2 is the baffle, 3 is the current collector, 4 is the anion exchange membrane (made of polystyrene), 5 is the cation exchange membrane (made of polytetrafluoroethylene and polypyrrole), and 6 is the lithium-embedded flow slurry.

[0051] Example 1

[0052] This embodiment provides a method for extracting lithium from a salt lake, the method comprising the following steps:

[0053] (1) mixing lithium-rich lithium manganese oxide and conductive carbon black in a mass ratio of 93:7 to obtain a delithiation material, mixing lithium-poor lithium manganese oxide and conductive carbon black in a mass ratio of 93:7 to obtain a delithiation material, mixing the delithiation material and an electrolyte (0.8 mol / L sodium chloride solution) to prepare a delithiation flowable slurry, and mixing the lithium flowable slurry and lithium-containing salt lake brine to prepare a lithium flowable slurry, wherein the solid content of the delithiation flowable slurry and the lithium flowable slurry is 40%;

[0054] (2) Sodium chloride with a concentration of 0.4 mol / L was injected into the electrolyte tank, the cathode current collector was connected to the negative electrode of the power supply, and the anode current collector was connected to the positive electrode of the power supply (nickel sheets were used for both the cathode current collector and the anode current collector), and the lithium-removing flow slurry was passed through the lithium-removing tank at a flow rate of 2 mL / min, and the lithium-inserting flow slurry was passed through the lithium-extracting tank at a flow rate of 2 mL / min, and a voltage of 1.2 V was applied to carry out the lithium-extracting reaction;

[0055] (3) Collect the liquid flowing out of the lithium extraction chamber, filter it, mix it with the electrolyte, and flow it through the lithium removal chamber to continue the lithium extraction reaction. Collect the liquid in the electrolyte chamber to obtain a lithium-rich solution.

[0056] Example 2

[0057] This embodiment provides a method for extracting lithium from a salt lake, the method comprising the following steps:

[0058] (1) mixing lithium-rich lithium manganese oxide and conductive acetylene black in a mass ratio of 95:5 to obtain a delithiation material, mixing lithium-poor lithium manganese oxide and conductive acetylene black in a mass ratio of 95:5 to obtain a delithiation material, mixing the delithiation material and an electrolyte (0.6 mol / L sodium chloride solution) to prepare a delithiation flowable slurry, and mixing the lithium flowable slurry and lithium-containing salt lake brine to prepare a lithium flowable slurry, wherein the solid content of the delithiation flowable slurry and the lithium flowable slurry is 40%;

[0059] (2) Sodium chloride with a concentration of 0.4 mol / L was injected into the electrolyte tank, the cathode current collector was connected to the negative electrode of the power supply, and the anode current collector was connected to the positive electrode of the power supply (nickel sheets were used for both the cathode current collector and the anode current collector), and the lithium-removing flow slurry was passed through the lithium-removing tank at a flow rate of 2 mL / min, and the lithium-inserting flow slurry was passed through the lithium-extracting tank at a flow rate of 4 mL / min, and a voltage of 1.2 V was applied to carry out the lithium-extracting reaction;

[0060] (3) Collect the liquid flowing out of the lithium extraction chamber, filter it, mix it with the electrolyte, and flow it through the lithium removal chamber to continue the lithium extraction reaction. Collect the liquid in the electrolyte chamber to obtain a lithium-rich solution.

[0061] Example 3

[0062] This embodiment provides a method for extracting lithium from a salt lake, the method comprising the following steps:

[0063] (1) mixing lithium-rich lithium manganese oxide and conductive carbon black in a mass ratio of 90:10 to obtain a delithiation material, mixing lithium-poor lithium manganese oxide and conductive carbon black in a mass ratio of 90:10 to obtain a delithiation material, mixing the delithiation material and an electrolyte (0.6 mol / L sodium chloride solution) to prepare a delithiation flowable slurry, and mixing the lithium flowable slurry and lithium-containing salt lake brine to prepare a lithium flowable slurry, wherein the solid content of the delithiation flowable slurry and the lithium flowable slurry is 40%;

[0064] (2) Sodium chloride with a concentration of 0.4 mol / L was injected into the electrolyte tank, the cathode current collector was connected to the negative electrode of the power supply, and the anode current collector was connected to the positive electrode of the power supply (nickel sheets were used for both the cathode current collector and the anode current collector), and the lithium-removing flow slurry was passed through the lithium-removing tank at a flow rate of 1 mL / min, and the lithium-inserting flow slurry was passed through the lithium-extracting tank at a flow rate of 4 mL / min, and a voltage of 1.2 V was applied to carry out the lithium-extracting reaction;

[0065] (3) Collect the liquid flowing out of the lithium extraction chamber, filter it, mix it with the electrolyte, and flow it through the lithium removal chamber to continue the lithium extraction reaction. Collect the liquid in the electrolyte chamber to obtain a lithium-rich solution.

[0066] Example 4

[0067] This embodiment provides a method for extracting lithium from a salt lake, the method comprising the following steps:

[0068] (1) mixing lithium-rich lithium manganese oxide and graphene in a mass ratio of 85:15 to obtain a delithiation material, mixing lithium-poor lithium manganese oxide and graphene in a mass ratio of 85:15 to obtain a delithiation material, mixing the delithiation material and an electrolyte (0.6 mol / L sodium chloride solution) to prepare a delithiation flowable slurry, and mixing the lithium flowable slurry and lithium-containing salt lake brine to prepare a lithium flowable slurry, wherein the solid content of the delithiation flowable slurry and the lithium flowable slurry is 40%;

[0069] (2) Sodium chloride with a concentration of 0.4 mol / L was injected into the electrolyte tank, the cathode current collector was connected to the negative electrode of the power supply, and the anode current collector was connected to the positive electrode of the power supply (nickel sheets were used for both the cathode current collector and the anode current collector), and the lithium-removing flow slurry was passed through the lithium-removing tank at a flow rate of 2 mL / min, and the lithium-inserting flow slurry was passed through the lithium-extracting tank at a flow rate of 5 mL / min, and a voltage of 1.2 V was applied to carry out the lithium-extracting reaction;

[0070] (3) Collect the liquid flowing out of the lithium extraction chamber, filter it, mix it with the electrolyte, and flow it through the lithium removal chamber to continue the lithium extraction reaction. Collect the liquid in the electrolyte chamber to obtain a lithium-rich solution.

[0071] Example 5

[0072] This embodiment provides a method for extracting lithium from a salt lake, the method comprising the following steps:

[0073] (1) mixing lithium-rich lithium manganese oxide and carbon nanotubes in a mass ratio of 93:7 to obtain a delithiation material, mixing lithium-poor lithium manganese oxide and carbon nanotubes in a mass ratio of 93:7 to obtain a delithiation material, mixing the delithiation material and an electrolyte (0.6 mol / L sodium chloride solution) to prepare a delithiation flowable slurry, and mixing the lithium flowable slurry and lithium-containing salt lake brine to prepare a lithium flowable slurry, wherein the solid content of the delithiation flowable slurry and the lithium flowable slurry is 40%;

[0074] (2) Sodium chloride with a concentration of 0.4 mol / L was injected into the electrolyte tank, the cathode current collector was connected to the negative electrode of the power supply, and the anode current collector was connected to the positive electrode of the power supply (nickel sheets were used for both the cathode current collector and the anode current collector), and the lithium-removing flow slurry was passed through the lithium-removing tank at a flow rate of 2 mL / min, and the lithium-inserting flow slurry was passed through the lithium-extracting tank at a flow rate of 5 mL / min, and a voltage of 0.5 V was applied to carry out the lithium-extracting reaction;

[0075] (3) Collect the liquid flowing out of the lithium extraction chamber, filter it, mix it with the electrolyte, and flow it through the lithium removal chamber to continue the lithium extraction reaction. Collect the liquid in the electrolyte chamber to obtain a lithium-rich solution.

[0076] Example 6

[0077] This embodiment provides a method for extracting lithium from a salt lake, the method comprising the following steps:

[0078] (1) mixing lithium-rich lithium manganese oxide and conductive carbon black in a mass ratio of 93:7 to obtain a delithiation material, mixing lithium-poor lithium manganese oxide and conductive carbon black in a mass ratio of 93:7 to obtain a delithiation material, mixing the delithiation material and an electrolyte (0.6 mol / L sodium chloride solution) to prepare a delithiation flowable slurry, and mixing the lithium flowable slurry and lithium-containing salt lake brine to prepare a lithium flowable slurry, wherein the solid content of the delithiation flowable slurry and the lithium flowable slurry is 40%;

[0079] (2) Sodium chloride with a concentration of 0.4 mol / L was injected into the electrolyte tank, the cathode current collector was connected to the negative electrode of the power supply, and the anode current collector was connected to the positive electrode of the power supply (nickel sheets were used for both the cathode current collector and the anode current collector), and the lithium-removing flow slurry was passed through the lithium-removing tank at a flow rate of 2 mL / min, and the lithium-inserting flow slurry was passed through the lithium-extracting tank at a flow rate of 5 mL / min, and a voltage of 1.5 V was applied to carry out the lithium-extracting reaction;

[0080] (3) Collect the liquid flowing out of the lithium extraction chamber, filter it, mix it with the electrolyte, and flow it through the lithium removal chamber to continue the lithium extraction reaction. Collect the liquid in the electrolyte chamber to obtain a lithium-rich solution.

[0081] Example 7

[0082] The only difference between this embodiment and embodiment 1 is that the concentration of the electrolyte in the electrolyte tank and the electrolyte in the lithium removal tank is 0.5 mol / L, and the other conditions and parameters are exactly the same as those in embodiment 1.

[0083] Comparative Example 1

[0084] In this comparative example, the mobile electrode lithium extraction unit of CN 109487081A was used to extract lithium.

[0085] Performance testing:

[0086] The lithium ion extraction efficiency was calculated by measuring the change rate of lithium ions in the electrolyte compartment based on ICP. The test results are shown in Table 1:

[0087] Table 1

[0088] As can be seen from Table 1, from Examples 1-6, the initial lithium ion extraction efficiency of the method for extracting lithium from salt lakes disclosed in the present invention can reach more than 70 μmol / min, and the lithium ion extraction efficiency remains above 64 μmol / min after 48 hours. After 48 hours, the lithium ion extraction efficiency decreases and remains below 7 μmol / min, proving that the method disclosed in the present invention puts less pressure on the ion exchange membrane and extends the service life of the membrane. At the same time, the present invention obtains Mg in the electrolyte 2+ The ion concentration can reach below 0.015g / L, and the impurity content is low.

[0089] By comparing Example 1 and Example 7, it can be seen that in the method for extracting lithium from salt lakes described in the present disclosure, the concentration of the electrolyte in the electrolyte compartment must be lower than the concentration of the electrolyte in the delithiation compartment, so that the solutions in the delithiation compartment and the electrolyte compartment form a concentration gradient. Driven by the concentration gradient, the lithium ions in the delithiation compartment can pass through the ion exchange membrane and be immersed in the electrolyte, thereby achieving lithium enrichment (sodium ions will also be immersed in the electrolyte and can be removed by simple methods in the subsequent process).

[0090] By comparing Example 1 and Comparative Example 1, it can be seen that the method disclosed in the present invention not only simplifies the use of the device, but also reduces the impurity removal pressure of the ion exchange membrane, extends the service life of the ion exchange membrane, and at the same time obtains a lower impurity concentration in the lithium-rich solution (electrolyte in the electrolyte tank) and a better impurity removal effect.

Claims

1. A device for extracting lithium from a salt lake, the device comprising a power supply, a lithium extraction cabin, a lithium stripping cabin and an electrolyte cabin, the electrolyte cabin being placed between the lithium extraction cabin and the lithium stripping cabin, an anion exchange membrane being arranged between the electrolyte cabin and the lithium extraction cabin, a monovalent cation exchange membrane being arranged between the electrolyte cabin and the lithium stripping cabin, the lithium extraction cabin being parallel to the direction of the anion exchange membrane and having a baffle arranged on a side away from the electrolyte cabin, the lithium stripping cabin being parallel to the direction of the monovalent cation exchange membrane and having a baffle arranged on a side away from the electrolyte cabin, no baffle being arranged on both sides of the lithium extraction cabin perpendicular to the direction of the anion exchange membrane, and no baffle being arranged on both sides of the lithium stripping cabin perpendicular to the direction of the monovalent cation exchange membrane.

2. The device according to claim 1, wherein: A cathode current collector is arranged in the lithium extraction chamber.

3. The device as claimed in claim 2, wherein: The cathode current collector comprises any one of aluminum foil, copper foil, nickel mesh or nickel sheet, or a combination of at least two thereof; Optionally, the cathode current collector is connected to the negative electrode of the power supply; Optionally, the cathode current collector is not attached to the anion exchange membrane.

4. The device according to claim 1, wherein: An anode current collector is arranged in the lithium removal chamber.

5. The device according to claim 4, wherein: The anode current collector comprises any one of aluminum foil, copper foil, nickel mesh or nickel sheet, or a combination of at least two thereof; Optionally, the anode current collector is connected to the positive electrode of a power source; Optionally, the anode current collector is not attached to a monovalent cation exchange membrane.

6. The device according to any one of claims 1 to 5, wherein: The material of the anion exchange membrane includes polystyrene, polypropylene or polyamide; Optionally, the components of the monovalent cation exchange membrane include an organic base material and polypyrrole; Optionally, the organic base material includes any one of polytetrafluoroethylene, polychlorotrifluoroethylene, polyvinylidene fluoride, styrene-butadiene rubber, polyaniline or polyacrylonitrile, or a combination of at least two thereof.

7. A method for extracting lithium from a salt lake, the method using the device according to any one of claims 1 to 6, the method comprising the following steps: (1) mixing a lithium removal material and an electrolyte to form a lithium removal flow slurry, and mixing a lithium insertion material and lithium-containing salt lake brine to form a lithium insertion flow slurry; (2) injecting electrolyte into the electrolyte tank, connecting the cathode current collector to the negative electrode of the power supply, connecting the anode current collector to the positive electrode of the power supply, flowing the lithium-removing slurry through the lithium-removing tank, flowing the lithium-inserting slurry through the lithium-extracting tank, and applying power to carry out lithium-extracting reaction; (3) collecting the liquid flowing out of the lithium extraction chamber, filtering it, mixing it with the electrolyte, and flowing it through the lithium removal chamber to continue the lithium extraction reaction, and collecting the liquid in the electrolyte chamber to obtain a lithium-rich solution.

8. The method of claim 7, wherein: The active material in the lithium-removing material in step (1) includes any one of lithium-rich lithium titanate, lithium iron phosphate or lithium manganese oxide, or a combination of at least two thereof; Optionally, the solute in the electrolyte includes any one of sodium chloride, potassium chloride, sodium sulfate, potassium sulfate, sodium nitrate or potassium nitrate, or a combination of at least two thereof; Optionally, the active material in the lithium insertion material includes any one of lithium-deficient lithium titanate, lithium iron phosphate or lithium manganese oxide, or a combination of at least two thereof.

9. The method according to claim 7 or 8, wherein: In step (1), both the lithium-removing material and the lithium-inserting material contain a conductive agent; Optionally, the conductive agent includes any one of conductive carbon black, conductive acetylene black, graphene or carbon nanotubes, or a combination of at least two thereof; Optionally, the mass ratio of the active material to the conductive agent in the lithium-removing material and the lithium-inserting material is (85-95):(5-15).

10. The method according to any one of claims 7 to 9, wherein: The solid content of the lithium-removing flowing slurry and the lithium-inserting flowing slurry in step (1) is 10-50%.

11. The method according to any one of claims 7 to 10, wherein: The concentration of the electrolyte in step (2) is 0.3-2 mol / L; Optionally, the concentration of the electrolyte in the electrolyte compartment is lower than the concentration of the electrolyte in the de-lithiation compartment.

12. The method according to any one of claims 7 to 11, wherein: The flow rate of the lithium-removing flowing slurry and the lithium-inserting flowing slurry in step (2) is 1 to 5 mL / min.

13. The method according to any one of claims 7 to 12, wherein: The voltage of the power supply in step (2) is 0.1 to 1.5V.

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