Ceramic membrane electrolytic cell for electro-deintercalation of lithium from salt lake, electrolytic device and method for electro-deintercalation of lithium from salt lake

Abstract

The present invention provides a ceramic membrane electrolytic cell for lithium extraction from salt lakes by electro-deintercalation, an electrolytic device and a method for extracting lithium from salt lakes by electro-deintercalation, and relates to the technical field of lithium extraction from salt lakes. The present invention forms a ceramic membrane electrolytic cell by using a lithium ion conductor ceramic membrane as the bottom wall and the side wall, so that the ceramic membrane electrolytic cell has the advantages of preferentially selecting Li + The ceramic membrane electrolytic cell provided by the present invention can be set in the brine of the electrolysis device for extracting lithium from salt lakes. Water is added to the ceramic membrane electrolytic cell, and the lithium-intercalated electrode is placed as the cathode. Under the action of the electric field, Li in the brine is + It moves toward the cathode, preferentially passes through the ceramic membrane electrolyzer and is separated from other impurity cations, and is initially enriched in pure water, reducing the impact of impurity cations on the electrical deintercalation process. The preparation method of lithium-ion ceramic membrane is simple, easy to scale up, and low in cost.

Description

Technical Field

[0001] The present disclosure relates to the technical field of lithium extraction from salt lakes, and in particular to a ceramic membrane electrolytic cell for electro-deintercalation of lithium from salt lakes, and an electrolytic device and method for electro-deintercalation of lithium from salt lakes. Background Art

[0002] Methods for extracting lithium from salt lake brine include evaporation crystallization, electrodialysis, extraction, precipitation, adsorption, and ion exchange. The extraction method is easy to operate and has high selectivity, which is conducive to industrial production, but the large amount of organic reagents used will corrode equipment and pollute the environment. The adsorption method is low in cost and high in efficiency, but the permeability and solubility of the adsorbent are poor, and a large amount of acidic solution is required, resulting in the generation of a large amount of waste liquid, which limits its industrial application. Traditional lithium extraction methods have problems such as high cost, high energy consumption, and low separation efficiency. At present, electro-deintercalation is considered to be a salt lake lithium extraction technology with great development potential due to its good selectivity, high recovery rate, and pollution-free nature.

[0003] The LiFePO4 / FePO4 “rocking chair” structure electrode system is used to achieve simultaneous extraction and recovery of lithium on different electrodes. In the actual production process, the salt lake brine contains Na + , K + Mg 2+ The coexistence of multiple cations such as lithium ions will inevitably participate in electrochemical reactions and be embedded in electrode materials, which not only reduces the purity of lithium ions but also reduces the exchange capacity of the electrode for lithium.

[0004] In view of this, the present disclosure is proposed. Summary of the Invention

[0005] The purpose of the present disclosure includes providing a ceramic membrane electrolytic cell for extracting lithium from salt lakes through electro-deintercalation.

[0006] The purpose of the present disclosure includes providing an electrolysis device for extracting lithium from salt lakes through electro-deintercalation.

[0007] The present disclosure also aims to provide a method for extracting lithium from salt lakes through electro-deintercalation.

[0008] In order to achieve at least one of the above-mentioned objectives of the present disclosure, the following technical solutions may be adopted:

[0009] In a first aspect, the present disclosure provides a ceramic membrane electrolytic cell for extracting lithium from salt lakes by electro-deintercalation, which includes a bottom wall and multiple side walls, wherein the multiple side walls are connected to the bottom wall to form a trough-like structure, and the bottom wall and the side walls are both made of lithium ion conductor ceramic materials.

[0010] In some embodiments of the present disclosure, the lithium ion conductor ceramic material includes lithium zirconium oxide or lithium titanium oxide.

[0011] In some embodiments of the present disclosure, the method for preparing the ceramic membrane electrolyzer includes:

[0012] mixing lanthanum zirconium oxide or lanthanum titanium oxide and a lithium source and grinding them uniformly to obtain a mixture, pre-sintering the mixture and then cooling it to room temperature to obtain a pre-sintered material;

[0013] Grinding the pre-sintered material again to obtain a mother powder;

[0014] Placing the mother powder in an electrolytic cell-shaped mold and pressing it to obtain a green blank;

[0015] The green body is sintered to obtain the ceramic membrane electrolytic cell.

[0016] In some embodiments of the present disclosure, the lanthanum zirconium oxide or the lanthanum titanium oxide and the lithium source are ball-milled at a rotation speed of 150-200 r / min for 2-3 hours to obtain a mixed material.

[0017] In some embodiments of the present disclosure, the pre-sintering comprises heating the material to 800-1000° C. at a heating rate of 3-7° C. / min, holding the temperature for 3-5 hours, and then cooling the material to room temperature in the furnace.

[0018] In some embodiments of the present disclosure, the pre-sintered material is ball-milled again at a rotation speed of 150-200 / min for 2-3 hours to obtain the mother powder.

[0019] In some embodiments of the present disclosure, sintering the green blank includes: heating the temperature to 1200-1400° C. at a heating rate of 3-7° C. / min, keeping the temperature for 8-12 minutes, and then cooling the green blank with the furnace.

[0020] In some embodiments of the present disclosure, the bottom wall and the side wall are both membrane-like structures with a thickness of 1-10 mm.

[0021] In some embodiments of the present disclosure, the thickness of the bottom wall and the side wall is 1-5 mm.

[0022] In a second aspect, the present disclosure provides an electrolysis device for extracting lithium from salt lakes through electro-deintercalation, which includes the ceramic membrane electrolytic cell described in the above embodiment.

[0023] In some embodiments of the present disclosure, the electrolysis device for extracting lithium from a salt lake by electro-deintercalation further includes an electrolysis outer cell, a cation exchange membrane, a first electrode, and a second electrode. The cation exchange membrane vertically divides the electrolysis outer cell into a cathode chamber and an anode chamber. The ceramic membrane electrolysis cell is placed in the cathode chamber. One of the first electrode and the second electrode is provided in the ceramic membrane electrolysis cell, and the other of the first electrode and the second electrode is provided in the anode chamber.

[0024] In some embodiments of the present disclosure, the first electrode is a lithium-intercalated electrode.

[0025] In some embodiments of the present disclosure, the method for preparing the lithium-intercalated electrode includes:

[0026] The electrode active material, conductive carbon black, PVDF and N-methylpyrrolidone are mixed and ground into a slurry, the slurry is coated on a current collector, and the slurry is dried to obtain a lithium extraction electrode;

[0027] The lithium-extracting electrode is placed in a NaCl solution to delithiate and form a lithium-intercalated electrode.

[0028] In some embodiments of the present disclosure, the masses of the conductive carbon black, the PVDF, and the N-methylpyrrolidone are 5-15%, 10-15%, and 150-200% of the mass of the electrode active material, respectively.

[0029] In some embodiments of the present disclosure, the electrode active material includes LiMn2O4, LiFePO4, LiNi x Co y Mn z One of O2 and its doped derivatives, wherein 0 <x,y<1,x+y+z=1。

[0030] In some embodiments of the present disclosure, the current collector includes titanium mesh, carbon fiber cloth, carbon fiber felt, porous carbon substrate, or titanium plate, and the thickness of the current collector is 0.1-2 mm.

[0031] In some embodiments of the present disclosure, a voltage of 1-1.2 V is applied during the delithiation, the concentration of the NaCl solution is 0.4-0.6 mol / L, and the delithiation time is 4-10 h.

[0032] In some embodiments of the present disclosure, the second electrode is an inert electrode.

[0033] In some embodiments of the present disclosure, the second electrode is placed in a 0.4-0.6 mol / L LiCl solution for cyclic voltammetry scanning activation before use.

[0034] In a third aspect, the present disclosure provides a method for extracting lithium from a salt lake by electro-deintercalation, which is carried out using the electrolysis device for extracting lithium from a salt lake by electro-deintercalation as described in the above embodiment.

[0035] In some embodiments of the present disclosure, the cathode chamber is filled with brine, and the anode chamber and the ceramic membrane electrolyzer are both filled with water. The first electrode is inserted into the ceramic membrane electrolyzer as a cathode, and the second electrode is inserted into the anode chamber as an anode. A voltage is applied to both ends of the first electrode and the second electrode to perform electrolysis to extract lithium. During the electrolysis to extract lithium, the lithium ions in the brine are embedded in the first electrode to obtain a lithium-rich electrode. After the lithium extraction process is completed, the brine is replaced with a recovery liquid, and a reverse voltage is applied. The lithium-rich electrode serves as an anode and the second electrode serves as a cathode. The lithium ions in the lithium-rich electrode are released into the recovery liquid to enrich the lithium in the brine in the recovery liquid.

[0036] In some embodiments of the present disclosure, the brine includes one or more of sulfate brine, chloride brine, and carbonate brine.

[0037] In some embodiments of the present disclosure, the concentration of impurity cations in the brine is greater than 200 g / L.

[0038] In some embodiments of the present disclosure, the water includes at least one of pure water, high-purity water, ultrapure water, deionized water, distilled water, and double-distilled water.

[0039] In some embodiments of the present disclosure, the recovery liquid is a 40-60 mmol / L lithium chloride solution.

[0040] In some embodiments of the present disclosure, the voltage applied to both ends of the first electrode and the second electrode is 1.5-4.5V.

[0041] In some embodiments of the present disclosure, the time for electrolytic lithium extraction is 0.5-3 hours.

[0042] Compared with the prior art, the present invention has the following advantages:

[0043] Lithium ion conductor ceramic membrane is a lithium solid compound with the ability to conduct lithium rapidly. The holes in its crystal structure are just enough for lithium ions to pass through. + The present invention forms a ceramic membrane electrolytic cell by using a lithium ion conductor ceramic membrane as the bottom wall and the side wall, so that the ceramic membrane electrolytic cell has the advantage of preferentially selecting the permeability of Li + The ceramic membrane electrolytic cell provided by the present invention can be set in the brine of the electrolysis device for extracting lithium from salt lakes. Water is added to the ceramic membrane electrolytic cell, and the lithium-intercalated electrode is placed as the cathode. Under the action of the electric field, Li in the brine is +It moves toward the cathode, preferentially passes through the ceramic membrane electrolyzer and is separated from other impurity cations, and is initially enriched in water, which helps to reduce the impact of impurity cations on the electrical deintercalation process. The preparation method of lithium-ion ceramic membrane is simple, easy to mass produce, and low cost.

[0044] In the process of electro-deintercalation and lithium extraction, hydrogen is generated at the cathode under the action of the electric field. At the same time, lithium ions preferentially enter the water through the ceramic membrane electrolyzer and are embedded in the electrode under the action of the electric field. At this time, the solution of the ceramic membrane electrolyzer is a lithium-containing aqueous solution. There are fewer coexisting impurity cations in the solution of the ceramic membrane electrolyzer, and the viscosity of the solution is lower than that of brine. Therefore, lithium extraction can be carried out at a higher potential without the occurrence of impurity ions embedded in the electrode, thereby improving the purity of the recovered lithium and the lithium exchange capacity of the electrode, thereby improving the efficiency of lithium extraction. In addition, as lithium ions are continuously consumed, the rate of cross-membrane transport of lithium ions from brine to the ceramic membrane electrolyzer can be increased, further improving the lithium extraction efficiency and shortening the lithium extraction time. In addition, in the present disclosure, by setting the electrolyte in the anode chamber to water and using a cation exchange membrane to separate the anode chamber from the brine, the generation of chlorine can be avoided during lithium extraction at high potential. Hydrolysis occurs at the anode to produce oxygen, and the generated hydrogen ions enter the brine through the cation exchange membrane, increasing the acidity of the brine, thereby avoiding the formation of impurities such as magnesium hydroxide precipitated on the lithium ion ceramic membrane during the lithium extraction process to hinder the passage of lithium ions. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] In order to more clearly illustrate the technical solutions of the embodiments of the present disclosure, the following briefly introduces the drawings required for use in the embodiments. It should be understood that the following drawings only illustrate certain embodiments of the present disclosure and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without creative work.

[0046] Figure 1 This is a diagram showing the working principle of the method for extracting lithium from salt lakes by electro-deintercalation provided in the present disclosure.

[0047] Icons: 100-electrolysis device for extracting lithium from salt lakes through electro-deintercalation; 101-ceramic membrane electrolytic cell; 102-electrolysis outer cell; 103-cation exchange membrane; 104-first electrode; 105-second electrode. DETAILED DESCRIPTION

[0048] The embodiments of the present disclosure will be described in detail below with reference to the examples. However, those skilled in the art will appreciate that the following examples are intended only to illustrate the present disclosure and should not be construed as limiting the scope of the present disclosure. Where specific conditions are not specified in the examples, the experiments were performed under conventional conditions or the conditions recommended by the manufacturer. Where the manufacturer of the reagents or instruments is not specified, all are commercially available conventional products.

[0049] The endpoints of the ranges and any values ​​disclosed in this disclosure are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoints of each range, the endpoints of each range and individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, and these numerical ranges should be considered to be specifically disclosed herein.

[0050] In a first aspect, the present disclosure provides a ceramic membrane electrolytic cell, which can be used in preparing an electrolytic device for extracting lithium from salt lakes through electro-deintercalation.

[0051] In the present disclosure, a ceramic membrane electrolyzer includes a bottom wall and a plurality of side walls, wherein the plurality of side walls are connected to the bottom wall to form a trough-like structure, and both the bottom wall and the side walls are made of a lithium-ion conductive ceramic material. The bottom wall and the side walls in the present disclosure are both thin-film-like. Generally speaking, a lithium-ion conductive ceramic membrane is a membrane structure that can serve as a separator between a cathode chamber and an anode chamber. However, in the present disclosure, the lithium-ion conductive ceramic membrane is innovatively prepared into a trough-like structure to form a ceramic membrane electrolyzer, and the ceramic membrane electrolyzer is placed in brine.

[0052] Among them, lithium ion conductor ceramic materials include garnet-type ceramic materials or Li 3x La 2 / 3-x TiO type ceramic material. Garnet type ceramic material is made of lithium zirconium oxide, Li 3x La 2 / 3-x TiO-type ceramic materials are made of lithium titanium oxide.

[0053] Specifically, the preparation method of the ceramic membrane electrolyzer includes:

[0054] (1) Lanthanum zirconium oxide or lanthanum titanium oxide and a lithium source are mixed and ground uniformly to obtain a mixture, and the mixture is pre-sintered and then cooled to room temperature to obtain a pre-sintered material.

[0055] The lanthanum zirconium oxide is specifically lanthanum oxide and zirconium oxide, and the lanthanum titanium oxide is specifically lanthanum oxide and titanium oxide. The lithium source can be, for example, lithium hydroxide, with the mass fractions of lithium hydroxide, lanthanum oxide, and zirconium oxide being 10-30%:40-60%:20-40%, respectively. The mass fractions of lithium hydroxide, lanthanum oxide, and titanium oxide are also 10-30%:40-60%:20-40%, respectively. The lanthanum zirconium oxide or lanthanum titanium oxide and the lithium source are ball milled at 150-200 rpm for 2-3 hours to obtain a mixture. Pre-sintering involves heating the mixture to 800-1000°C at a rate of 3-7°C / min, holding the mixture for 3-5 hours, and then cooling the mixture to room temperature in the furnace.

[0056] In some embodiments, the ball milling speed can be, for example, any one of 150, 160, 170, 180, 190, 200 r / min or a range value between any two of them; the ball milling time can be, for example, any one of 2, 2.2, 2.5, 2.7, 2.8, 3 h or a range value between any two of them; the pre-sintering heating rate can be, for example, any one of 3, 4, 5, 6, 7 ° C / min or a range value between any two of them; the pre-sintering temperature can be, for example, any one of 800, 850, 900, 950, 1000 ° C or a range value between any two of them; the pre-sintering holding time can be, for example, any one of 3, 3.5, 4, 4.5, 5 h or a range value between any two of them.

[0057] (2) Grind the pre-sintered material again to obtain mother powder.

[0058] The pre-sintered material is ball-milled again at a rotation speed of 150-200 r / min for 2-3 hours to obtain a mother powder of a lithium ion conductor ceramic material.

[0059] In some embodiments, the rotation speed of the pre-sintered material during the re-ball milling is, for example, any one of 150, 160, 170, 180, 190, and 200 r / min, or a range between any two of them; the ball milling time can be, for example, any one of 2, 2.2, 2.5, 2.7, 2.8, and 3 h, or a range between any two of them.

[0060] (3) The mother powder is placed in an electrolytic cell-shaped mold and pressed to obtain a green blank.

[0061] (4) Sintering the green body to obtain a ceramic membrane electrolytic cell.

[0062] The green body is sintered including: heating to 1200-1400°C at a heating rate of 3-7°C / min, keeping warm for 8-12 minutes and then cooling with the furnace. The thickness of the prepared lithium ion conductor ceramic membrane is 1-10mm, and the thickness of the lithium ion conductor ceramic membrane is 1-5mm.

[0063] In some embodiments, the sintering heating rate can be, for example, any one of 3, 4, 5, 6, or 7°C / min, or a range between any two of them; the sintering temperature can be, for example, any one of 1200, 1250, 1300, 1350, or 1400°C, or a range between any two of them; the sintering holding time can be, for example, any one of 8, 9, 10, 11, or 12 minutes, or a range between any two of them.

[0064] Also, see Figure 1, the present disclosure correspondingly further provides an electrolysis device 100 for electro-extracting lithium from salt lakes. In addition to including the above-mentioned ceramic membrane electrolytic cell 101, the electrolysis device 100 for electro-extracting lithium from salt lakes further includes an outer electrolytic cell 102, a cation exchange membrane 103, a first electrode 104, and a second electrode 105. The cation exchange membrane 103 vertically divides the outer electrolytic cell 102 into a cathode chamber and an anode chamber. The ceramic membrane electrolytic cell 101 is placed in the cathode chamber, and the cathode chamber is filled with brine. Both the anode chamber and the ceramic membrane electrolytic cell 101 are filled with water. One of the first electrode 104 and the second electrode 105 is disposed in the ceramic membrane electrolytic cell 101, and the other of the first electrode 104 and the second electrode 105 is disposed in the anode chamber.

[0065] Among them, the first electrode 104 is a lithium-inserted electrode, and the second electrode 105 is an inert electrode.

[0066] The preparation method of the lithium-inserted electrode includes:

[0067] (1) Mix the electrode active material, conductive carbon black, PVDF, and N-methylpyrrolidone and grind them into a slurry state, coat the slurry state on the current collector, and dry it to obtain a lithium extraction electrode.

[0068] The masses of the conductive carbon black, PVDF, and N-methylpyrrolidone are 5-15%, 10-15%, and 150-200% of the mass of the electrode active material respectively. The electrode active material includes one of LiMn2O4, LiFePO4, LiNi x Co y Mn z O2 and its doped derivatives, where 0 < x, y < 1 and x + y + z = 1. The current collector includes a titanium mesh, a carbon fiber cloth, a carbon fiber felt, a porous carbon substrate, or a titanium plate, and the thickness of the current collector is 0.1-2 mm.

[0069] (2) Place the lithium extraction electrode in a NaCl solution to de-lithiate and form a lithium-inserted electrode.

[0070] When de-lithiating, apply a voltage of 1-1.2 V, the concentration of the NaCl solution is 0.4-0.6 mol / L, and the de-lithiation time is 4-10 h.

[0071] In some embodiments, the voltage applied during de-lithiation is any one of 1, 1.1, 1.2 V or a range value between any two of them; the concentration of the NaCl solution is any one of 0.4, 0.5, 0.6 mol / L or a range value between any two of them; the de-lithiation time is any one of 4, 5, 6, 7, 8, 9, 10 h or a range value between any two of them.

[0072] The inert electrodes include but are not limited to activated carbon electrodes, platinum electrodes and graphite electrodes. Before use, the second electrode is placed in a 0.4-0.6 mol / L LiCl solution for cyclic voltammetry scanning activation.

[0073] In addition, the present disclosure also provides a method for extracting lithium from a salt lake by electro-deintercalation, which is performed using the electrolysis device 100 for extracting lithium from a salt lake by electro-deintercalation according to the above embodiment.

[0074] Specifically, the method for extracting lithium from a salt lake by electro-deintercalation provided by the present disclosure includes filling a cathode chamber with brine, filling an anode chamber and a ceramic membrane electrolytic cell 101 with water, inserting a first electrode 104 as a cathode into the ceramic membrane electrolytic cell 101, and inserting a second electrode 105 as an anode into the anode chamber, applying a voltage (1.5-4.5V) to both ends of the first electrode 104 and the second electrode 105 for electrolytic lithium extraction for 0.5-3h, and during the electrolytic lithium extraction, lithium ions in the brine are intercalated into the first electrode 104 to obtain a lithium-rich electrode, and after the lithium extraction process is completed, the brine is replaced with a recovery liquid (40-60mmol / L lithium chloride solution), and a reverse voltage is applied, the lithium-rich electrode serves as the anode, and the second electrode 105 serves as the cathode, and the lithium ions in the lithium-rich electrode are deintercalated into the recovery liquid so that the lithium in the brine is enriched in the recovery liquid.

[0075] In some embodiments, the voltage applied to both ends of the first electrode 104 and the second electrode 105 is any one of 1.5, 2, 2.5, 3, 3.5, 4, 4.5 V or a range of values ​​between any two of them; the time for electrolytic lithium extraction is any one of 0.5, 0.8, 1, 1.5, 2, 2.5, 3 h or a range of values ​​between any two of them.

[0076] Since in the actual production process, salt lake brine contains Na + , K + Mg 2+ The coexistence of various cations such as magnesium and lithium will inevitably participate in the electrochemical reaction and be embedded in the electrode material. The extent to which the coexisting cations are embedded in the electrode reaction depends on the electrode potential in the actual electrolyte solution and the concentration of the coexisting cations in the brine. Most of my country's salt lakes are high magnesium-lithium ratio salt lakes with a low concentration of lithium ions. In order to improve the efficiency of lithium extraction, the electrode potential is usually increased during the electro-deintercalation and lithium extraction. However, as the electrode potential increases, the coexisting impurity cations in the brine are more easily embedded in the electrode, which not only reduces the purity of lithium ions, but also reduces the exchange capacity of the electrode for lithium. Furthermore, in the existing electro-deintercalation and lithium extraction methods of salt lakes, the voltage applied to the electrodes usually does not exceed 1.2V, while in the present application, a voltage of 1.5-4.5V can be applied to both ends of the two electrodes, which significantly increases the electrode potential and improves the efficiency of lithium extraction. In addition, in the existing electro-deintercalation and lithium extraction methods of salt lakes, the higher the concentration of coexisting cations in the brine, the easier it is to embed into the electrode. Specifically, the embedding potential order of cations in the brine is ER ,Li + >E R ,Na + >E R ,Mg 2+ >E R ,K + Therefore, sodium ions and magnesium ions are the main factors affecting the embedding of lithium ions in brine, and other impurity cations are mainly adsorbed on the electrode surface to affect the embedding of lithium. Therefore, it is necessary to control the concentration of impurity cations in the brine, especially the concentration of sodium ions and magnesium ions, resulting in a small range of brines for which it is applicable. The method for extracting lithium from salt lakes by electro-deintercalation provided by the present disclosure can be used for brines with a co-existing cation concentration greater than 200 g / L. It can be seen that the concentration requirement of co-existing impurity cations in brines applicable to the present disclosure is lower, which greatly expands the scope of application of the method for extracting lithium from salt lakes by electro-deintercalation.

[0077] Lithium ion conductor ceramic membrane is a lithium solid compound with the ability to conduct lithium rapidly. The holes in its crystal structure are just enough for lithium ions to pass through. + The present invention forms a ceramic membrane electrolytic cell by using a lithium ion conductor ceramic membrane as the bottom wall and the side wall, so that the ceramic membrane electrolytic cell has the advantage of preferentially selecting the permeability of Li + The ceramic membrane electrolytic cell provided by the present disclosure can be set in the brine of the electrolysis device 100 for extracting lithium from a salt lake by electro-deintercalation. Water is added to the ceramic membrane electrolytic cell, and a lithium-intercalated electrode is placed therein as a cathode. Under the action of the electric field, Li in the brine is + It moves toward the cathode, preferentially passes through the ceramic membrane electrolyzer and is separated from other impurity cations, and is initially enriched in water, which helps to reduce the impact of impurity cations on the electrical deintercalation process. The preparation method of lithium-ion ceramic membrane is simple, easy to mass produce, and low cost.

[0078] In addition, with respect to the method for extracting lithium from salt lakes by electro-deintercalation provided in the present invention, hydrogen is generated at the cathode under the action of the electric field, while lithium ions preferentially enter the water through the ceramic membrane electrolytic cell and are embedded in the electrode under the action of the electric field. At this time, the solution of the ceramic membrane electrolytic cell is a lithium-containing aqueous solution. There are fewer coexisting impurity cations in the solution of the ceramic membrane electrolytic cell, and the viscosity of the solution is lower than that of the brine. Therefore, lithium extraction can be carried out at a higher potential without generating impurity ions embedded in the electrode, thereby improving the purity of the recovered lithium and increasing the lithium extraction exchange capacity of the electrode, thereby improving the efficiency of lithium extraction. In addition, as lithium ions are continuously consumed, the rate of cross-membrane transport of lithium ions from brine to the ceramic membrane electrolytic cell can be increased, further improving the lithium extraction efficiency and shortening the lithium extraction time.

[0079] Furthermore, in the present application, the anode chamber is water, and a cation exchange membrane is used to separate the anode chamber from the brine. This can avoid the generation of chlorine when lithium is extracted at high potential. Hydrolysis occurs at the anode to produce oxygen, and the generated hydrogen ions enter the brine through the cation exchange membrane, increasing the acidity of the brine and avoiding the formation of impurities such as magnesium hydroxide precipitated on the lithium ion ceramic membrane during the lithium extraction process to hinder the passage of lithium ions.

[0080] The features and performance of the present disclosure are further described in detail below with reference to the embodiments.

[0081] Example 1

[0082] This embodiment provides a method for extracting lithium from a salt lake by electro-deintercalation, which comprises the following steps:

[0083] (1) Preparation of a lithium extraction electrode: LiFePO4 active material, conductive carbon black, and PVDF were added to N-methylpyrrolidone and repeatedly ground into a slurry. The slurry was coated on a titanium mesh and dried to prepare a lithium extraction electrode. The mass of conductive carbon black, PVDF, and N-methylpyrrolidone was 10%, 12%, and 150% of the mass of the electrode active material, respectively.

[0084] (2) Electrode activation: The prepared lithium-extraction electrode was placed in a 0.5 mol / L NaCl solution at a voltage of 1.1 V to delithiate for 7 h to form a lithiated FePO4 electrode. The activated carbon electrode was activated by cyclic voltammetry scanning in a 0.5 mol / L LiCl solution.

[0085] (3) Preparation of ceramic membrane electrolytic cell: lithium hydroxide, lanthanum oxide and titanium oxide were weighed in order according to the mass fraction of 20%, 50% and 30% respectively, and dry ball milled at a speed of 170r / min for 2 hours using zirconium oxide balls and polyurethane ball milling jars. The powder and the zirconium oxide balls used for ball milling were then separated using a screen. The separated powder was placed in a tube furnace for pre-sintering, heated to 950°C at a speed of 5°C / min, kept at this temperature for 3 hours, and then cooled to room temperature with the furnace. A second dry ball milling was performed at a speed of 170r / min for 2 hours. After ball milling, the balls were separated to obtain mother powder. The mother powder was placed in an electrolytic cell-shaped mold and pressed into a blank. The blank was subjected to a second sintering, heated to 1300°C at a speed of 5°C / min, kept at this temperature for 10 minutes, and then cooled with the furnace to obtain LLTO with a thickness of 3mm.

[0086] (4) Preparation of an electrolytic device for lithium extraction from a salt lake by electro-deintercalation: The outer electrolytic cell is vertically divided into a cathode chamber and an anode chamber by using a cation exchange membrane. The cathode chamber is filled with brine, and the anode chamber and the ceramic membrane electrolytic cell are both filled with pure water. The ceramic membrane electrolytic cell is placed in the cathode chamber, and the lithium extraction electrode is placed as the cathode in the ceramic membrane electrolytic cell, and the activated carbon is placed as the anode in the anode chamber. Figure 1As shown, the composition of the brine is: 0.35g / L Li, 105.65g / L Na, 107.97g / L Mg, 8.45g / L K, 2.76g / L Ca, 10.54g / L SO4 2- .

[0087] (5) Lithium extraction by electrolysis: A voltage of 3 V is applied to both ends of the electrode for electrolysis for 1.5 h. During the electrolysis, the lithium ions in the brine are embedded in the first electrode to obtain a lithium-rich electrode LiFePO4. After the lithium extraction process is completed, the brine is replaced with a recovery liquid (50 mmol / L lithium chloride solution). A reverse voltage is applied, and the LiFePO4 electrode is used as the anode and the activated carbon electrode is used as the cathode. After 1.5 h of electrolysis, the lithium ions in the electrode material are released into the recovery liquid.

[0088] Example 2

[0089] This embodiment provides a method for extracting lithium from a salt lake by electro-deintercalation, which comprises the following steps:

[0090] (1) Preparation of a lithium-extraction electrode: LiFePO4 active material, conductive carbon black, and PVDF were added to N-methylpyrrolidone and repeatedly ground into a slurry. The slurry was coated on a titanium mesh and dried to produce a lithium-extraction electrode. The mass of conductive carbon black, PVDF, and N-methylpyrrolidone was 15%, 10%, and 200% of the mass of the electrode active material, respectively.

[0091] (2) Electrode activation: The prepared lithium-extraction electrode was placed in a 0.5 mol / L NaCl solution at a voltage of 1.2 V to delithiate for 4 h to form a lithium-intercalated FePO4 electrode, and the activated carbon electrode was activated by cyclic voltammetry scanning in a 0.5 mol / L LiCl solution.

[0092] (3) Preparation of ceramic membrane electrolytic cell: lithium hydroxide, lanthanum oxide and titanium oxide were weighed in order according to the mass fraction of 20%, 50% and 30% respectively, and dry ball milled for 2 hours at 170r / min using zirconium oxide balls and polyurethane ball milling jars. The powder and the zirconium oxide balls used for ball milling were then separated using a screen. The separated powder was placed in a tube furnace for pre-sintering, heated to 950°C at 5°C / min, kept warm for 3 hours, and then cooled to room temperature with the furnace. A second dry ball milling was performed at 170r / min for 2 hours. After ball milling, the balls were separated to obtain mother powder. The mother powder was placed in an electrolytic cell-shaped mold and pressed into a green blank. The green blank was subjected to a second sintering, heated to 1300°C at 5°C / min, kept warm for 10 minutes, and then cooled with the furnace to obtain LLTO with a thickness of 5mm.

[0093] (4) Preparation of an electrolytic device for lithium extraction from a salt lake by electro-deintercalation: The outer electrolytic cell is vertically divided into a cathode chamber and an anode chamber by using a cation exchange membrane. The cathode chamber is filled with brine, and the anode chamber and the ceramic membrane electrolytic cell are both filled with pure water. The ceramic membrane electrolytic cell is placed in the cathode chamber, and the lithium extraction electrode is placed as the cathode in the ceramic membrane electrolytic cell, and the activated carbon is placed as the anode in the anode chamber. Figure 1 As shown, the composition of the brine is: 0.35g / L Li, 105.65g / L Na, 107.97g / L Mg, 8.45g / L K, 2.76g / L Ca, 10.54g / L SO4 2- .

[0094] (5) A voltage of 4.5 V is applied to both ends of the electrode for electrolysis for 0.5 h, and then the brine is replaced with the recovery liquid, and a reverse voltage is applied. The LiFePO4 electrode serves as the anode and the activated carbon electrode serves as the cathode. After electrolysis for 0.5 h, the lithium ions in the electrode material are released into the recovery liquid.

[0095] Example 3

[0096] This embodiment provides a method for extracting lithium from a salt lake by electro-deintercalation, which comprises the following steps:

[0097] (1) Preparation of a lithium extraction electrode: LiFePO4 active material, conductive carbon black, and PVDF were added to N-methylpyrrolidone and repeatedly ground into a slurry. The slurry was coated on a titanium mesh and dried to produce a lithium extraction electrode. The mass of conductive carbon black, PVDF, and N-methylpyrrolidone was 5%, 15%, and 150% of the mass of the electrode active material, respectively.

[0098] (2) Electrode activation: The prepared lithium-extraction electrode was placed in a 0.5 mol / L NaCl solution at a voltage of 1.0 V to delithiate for 10 h to form a lithium-intercalated FePO4 electrode, and the activated carbon electrode was activated by cyclic voltammetry scanning in a 0.5 mol / L LiCl solution.

[0099] (3) Preparation of ceramic membrane electrolytic cell: lithium hydroxide, lanthanum oxide and titanium oxide were weighed in order according to the mass fraction of 20%, 50% and 30% respectively, and dry ball milled at a speed of 175r / min for 2 hours using zirconium oxide balls and polyurethane ball milling jars. The powder and the zirconium oxide balls used for ball milling were then separated using a screen. The separated powder was placed in a tube furnace for pre-sintering, heated to 950°C at 5°C / min, kept warm for 3 hours, and then cooled to room temperature with the furnace. A second dry ball milling was performed at a speed of 170r / min for 2 hours. After ball milling, the balls were separated to obtain mother powder. The mother powder was placed in an electrolytic cell-shaped mold and pressed into a blank. The blank was sintered for a second time, heated to 1300°C at 5°C / min, kept warm for 10 minutes, and then cooled with the furnace to obtain LLTO with a thickness of 1mm.

[0100] (4) Preparation of an electrolytic device for lithium extraction from a salt lake by electro-deintercalation: The outer electrolytic cell is vertically divided into a cathode chamber and an anode chamber by using a cation exchange membrane. The cathode chamber is filled with brine, and the anode chamber and the ceramic membrane electrolytic cell are both filled with pure water. The ceramic membrane electrolytic cell is placed in the cathode chamber, and the lithium extraction electrode is placed as the cathode in the ceramic membrane electrolytic cell, and the activated carbon is placed as the anode in the anode chamber. Figure 1 As shown, the composition of the brine is: 0.35g / L Li, 105.65g / L Na, 107.97g / L Mg, 8.45g / L K, 2.76g / L Ca, 10.54g / L SO4 2- .

[0101] (5) Apply a voltage of 1.5 V at both ends of the electrode for electrolysis for 3 hours, then replace the brine with the recovery liquid, apply a reverse voltage, use the LiFePO4 electrode as the anode, and the activated carbon electrode as the cathode. After electrolysis for 3 hours, the lithium ions in the electrode material are released into the recovery liquid.

[0102] Example 4

[0103] This embodiment provides a method for extracting lithium from a salt lake by electro-deintercalation, which comprises the following steps:

[0104] (1) Preparation of a lithium extraction electrode: LiFePO4 active material, conductive carbon black, and PVDF were added to N-methylpyrrolidone and repeatedly ground into a slurry. The slurry was coated on a titanium mesh and dried to produce a lithium extraction electrode. The mass of conductive carbon black, PVDF, and N-methylpyrrolidone was 10%, 12%, and 150% of the mass of the electrode active material, respectively.

[0105] (2) Electrode activation: The prepared lithium-extraction electrode was placed in a 0.5 mol / L NaCl solution at a voltage of 1.1 V to delithiate for 7 h to form a lithium-intercalated FePO4 electrode, and the activated carbon electrode was activated by cyclic voltammetry scanning in a 0.5 mol / L LiCl solution.

[0106] (3) Preparation of ceramic membrane electrolytic cell: lithium hydroxide, lanthanum oxide and zirconium oxide were weighed in order according to the mass fraction of 25%, 50% and 25% respectively, and ball milled at a speed of 200r / min for 2 hours using zirconium oxide balls and polyurethane ball milling jars. The powder and the zirconium oxide balls used for ball milling were then separated using a screen. The separated powder was placed in a tube furnace and heated to 800℃ at 5℃ / min for pre-sintering. After keeping the temperature for 4 hours, it was cooled to room temperature with the furnace and ball milled at a speed of 200r / min for 2 hours. After ball milling, the ball material was separated to obtain mother powder. The mother powder was placed in an electrolytic cell-shaped mold and pressed into a blank. The blank was subjected to secondary sintering, heated to 1200℃ at 5℃ / min, kept at this temperature for 25 minutes, and then cooled with the furnace to obtain LLZO with a thickness of 3mm.

[0107] (4) Preparation of an electrolytic device for lithium extraction from a salt lake by electro-deintercalation: The outer electrolytic cell is vertically divided into a cathode chamber and an anode chamber by using a cation exchange membrane. The cathode chamber is filled with brine, and the anode chamber and the ceramic membrane electrolytic cell are both filled with pure water. The ceramic membrane electrolytic cell is placed in the cathode chamber, and the lithium extraction electrode is placed as the cathode in the ceramic membrane electrolytic cell, and the activated carbon is placed as the anode in the anode chamber. Figure 1 As shown, the composition of the brine is: 0.35g / L Li, 105.65g / L Na, 107.97g / L Mg, 8.45g / L K, 2.76g / L Ca, 10.54g / L SO4 2- .

[0108] (5) Apply 3V voltage at both ends of the electrode for electrolysis for 1.5 hours, then replace the brine with the recovery liquid, apply reverse voltage, use the LiFePO4 electrode as the anode, and the activated carbon electrode as the cathode. After electrolysis for 1.5 hours, the lithium ions in the electrode material are released into the recovery liquid.

[0109] Example 5

[0110] This embodiment is basically the same as embodiment 1, with the only difference being that, in this embodiment, the electrode active material is LiMn2O4, the prepared lithium-intercalated electrode is a lithium-intercalated Mn2O4 electrode, and the second electrode is a platinum electrode.

[0111] Example 6

[0112] This embodiment is basically the same as embodiment 1, except that in this embodiment, the electrode active material is LiNi x Co y Mn z O2, the prepared lithium-intercalated electrode is lithium-intercalated Ni x Co y Mn z O2 electrode, the second electrode is a graphite electrode.

[0113] Example 7

[0114] This embodiment is basically the same as embodiment 1, with the only difference being that, in this embodiment, the thickness of the bottom wall and the side wall of the ceramic membrane electrolytic cell used is 5 mm.

[0115] Example 8

[0116] This embodiment is basically the same as embodiment 1, with the only difference being that, in this embodiment, the thickness of the bottom wall and the side wall of the ceramic membrane electrolytic cell used is 8 mm.

[0117] Comparative Example 1

[0118] The difference between this comparative example and Example 1 is that in this comparative example, no ceramic membrane electrolytic cell is used for lithium extraction, that is, step (3) in Example 1 is omitted, and in steps (4) and (5), the cathode lithium-intercalated LiFePO4 is directly inserted into the brine, and a voltage of 3 V is applied across the electrodes for electrolysis for 1.5 h to extract lithium.

[0119] Comparative Example 2

[0120] The difference between this comparative example and Example 1 is that in this comparative example, no ceramic membrane electrolytic cell is used for lithium extraction, that is, step (3) in Example 1 is omitted. At the same time, in steps (4) and (5), the cathode lithium-intercalated LiFePO4 is directly inserted into the brine, and a voltage of 1 V is applied across the electrodes for electrolysis for 1.5 hours to extract lithium.

[0121] Comparative Example 3

[0122] The difference between this comparative example and Example 1 is that in this comparative example, the voltage applied across the electrodes in step (5) of Example 1 is replaced with 1.2V.

[0123] Comparative Example 4

[0124] The difference between this comparative example and Example 1 is that the ceramic membrane electrolytic cell used in this comparative example adopts Li9SiAlO8 material.

[0125] Comparative Example 5

[0126] The difference between this comparative example and Example 1 is that the thickness of the bottom wall and the side wall of the ceramic membrane electrolytic cell used in this comparative example is 15 mm.

[0127] Comparative Example 6

[0128] The difference between this comparative example and Example 1 is that in this comparative example, the pure water contained in the anode chamber in step (4) of Example 1 is replaced with 50 mmol / L lithium chloride solution.

[0129] Experimental example: performance testing

[0130] The main indicators of lithium extraction obtained after lithium extraction experiments on the electrodes obtained in the examples and comparative examples are shown in the following table.

[0131]

[0132] It can be found from the examples that a ceramic membrane electrolytic cell prepared using a lithium ion ceramic membrane is placed in the cathode chamber, and the brine in the cathode chamber and the electrolyte (water) in the ceramic membrane electrolytic cell are separated. Lithium extraction can be carried out at a higher potential, and the recovery rate of lithium ions reaches more than 92%, the purity of lithium ions reaches more than 95%, and the exchange capacity of lithium ions reaches more than 29.5 mg (Li) / g (LiFePO4). Compared with the use of ordinary electrical deintercalation and lithium extraction in Comparative Example 1, the lithium ion purity, recovery rate and electrode exchange capacity are significantly improved.

[0133] It can be seen from the data of Comparative Example 1 that when lithium is extracted without using a ceramic membrane electrolytic cell, the impurity cations in the brine will be embedded in the electrode, resulting in a significant decrease in the lithium ion concentration, purity and electrode adsorption capacity in the recovered liquid, especially the purity can only reach 65%.

[0134] It can be seen from the data of Comparative Examples 1 and 2 that Comparative Example 2 reduces the lithium extraction voltage, but the lithium ion concentration, purity and electrode adsorption capacity of the recovered liquid are better than those of Comparative Example 1, but are still significantly worse than those of Example 1. This may be because, as the electrode potential increases, the coexisting impurity cations in the brine are more easily embedded in the electrode, which not only reduces the purity of lithium ions, but also reduces the exchange capacity of the electrode for lithium. Therefore, when lithium extraction is not performed using a ceramic membrane electrolytic cell, lithium extraction can only be performed at a lower potential, while Example 1 of the present application can perform lithium extraction at a higher potential, which is beneficial to improving the lithium extraction efficiency. At the same time, it can also avoid the coexisting impurity cations in the brine from being embedded in the electrode, thereby improving the purity of lithium ions and the electrode adsorption capacity.

[0135] From the data of Comparative Example 3, it can be seen that the scheme of Example 1 can still maintain good purity when lithium is extracted at a lower voltage, but the lithium ion concentration in the recovered liquid and the electrode adsorption capacity are significantly reduced.

[0136] From the data of Comparative Example 4, it can be seen that the use of Li 3x La 2 / 3-x TiO-type lithium ion ceramic membrane is superior to monoclinic structure Li9SiAlO8 as cathode electrolyzer.

[0137] It can be seen from the data of Comparative Example 5 that when the thickness of the ceramic membrane electrolytic cell exceeds the range value of this application, the lithium ion concentration in the recovered liquid and the electrode adsorption capacity will be significantly reduced.

[0138] The data from Comparative Example 6 show that while similar lithium extraction performance can be achieved by replacing the pure water in the anode chamber with lithium chloride, the anode in Comparative Example 6 produces chlorine as a side reaction, which corrodes the electrode. This reduces the efficiency of lithium extraction to a certain extent, primarily manifested in lower electrode adsorption capacity and lower lithium ion concentration in the recovered liquid compared to Example 1.

[0139] In summary, the present disclosure provides a ceramic membrane electrolyzer, which is made of lithium ion conductor ceramic material. The lithium ion conductor ceramic material is a lithium solid lithium compound with the ability to rapidly conduct lithium. The holes contained in its crystal structure are just enough for lithium ions to pass through. + The present invention forms a ceramic membrane electrolytic cell by using a lithium ion conductor ceramic membrane as the bottom wall and the side wall, so that the ceramic membrane electrolytic cell has the advantage of preferentially selecting the permeability of Li + The ceramic membrane electrolytic cell provided by the present disclosure can be set in the brine of the electrolysis device 100 for extracting lithium from a salt lake by electro-deintercalation. Water is added to the ceramic membrane electrolytic cell, and a lithium-intercalated electrode is placed therein as a cathode. Under the action of the electric field, Li in the brine is + It moves toward the cathode, preferentially passes through the ceramic membrane electrolyzer and is separated from other impurity cations, and is initially enriched in pure water, reducing the impact of impurity cations on the electrical deintercalation process. The preparation method of lithium-ion ceramic membrane is simple, easy to scale up, and low in cost.

[0140] Under the action of the electric field, the cathode produces hydrogen, and at the same time, the lithium ion ceramic membrane electrolyzer enters the water and embeds the electrode under the action of the electric field. At this time, the solution of the ceramic membrane electrolyzer is a lithium-containing aqueous solution. The coexisting impurity cations in the solution of the ceramic membrane electrolyzer are relatively small, and the viscosity of the solution is lower than that of the brine. Therefore, lithium can be extracted at a higher potential without the occurrence of impurity ions embedded in the electrode, thereby improving the purity of the recovered lithium and increasing the lithium extraction exchange capacity of the electrode, thereby improving the efficiency of lithium extraction. In addition, as lithium ions are continuously consumed, the rate of lithium ion transport from brine to the ceramic membrane electrolyzer across the membrane can be increased, further improving the lithium extraction efficiency and shortening the lithium extraction time. In addition, in the present disclosure, by setting the electrolyte in the anode chamber to pure water and separating it from the brine with a cation exchange membrane, the generation of chlorine can be avoided during high potential lithium extraction. Hydrolysis occurs at the anode to produce oxygen, and the generated hydrogen ions enter the brine through the cation exchange membrane, increasing the acidity of the brine and avoiding the formation of impurities such as magnesium hydroxide precipitated on the lithium ion ceramic membrane during the lithium extraction process to hinder the passage of lithium ions.

[0141] The above describes in detail the optional embodiments of the present disclosure, but the present disclosure is not limited thereto. Within the technical concept of the present disclosure, various simple variations of the technical solution of the present disclosure can be made, including combining the various technical features in any other appropriate manner. These simple variations and combinations should also be regarded as the contents disclosed by the present disclosure and fall within the scope of protection of the present disclosure.

[0142] Industrial Applicability

[0143] In summary, the present disclosure provides a ceramic membrane electrolyzer, which is made of lithium ion conductor ceramic material. The lithium ion conductor ceramic material is a lithium solid lithium compound with the ability to rapidly conduct lithium. The holes contained in its crystal structure are just enough for lithium ions to pass through. + The present invention forms a ceramic membrane electrolytic cell by using a lithium ion conductor ceramic membrane as the bottom wall and the side wall, so that the ceramic membrane electrolytic cell has the advantage of preferentially selecting the permeability of Li + The ceramic membrane electrolytic cell provided by the present invention can be set in the brine of the electrolysis device for extracting lithium from salt lakes. Water is added to the ceramic membrane electrolytic cell, and the lithium-intercalated electrode is placed as the cathode. Under the action of the electric field, Li in the brine is + They move toward the cathode, preferentially passing through the ceramic membrane electrolyzer and separated from other impurity cations, and are initially enriched in pure water, reducing the influence of impurity cations on the electrical deintercalation process. The preparation method of the lithium-ion ceramic membrane is simple, easy to scale up, and low in cost. Under the action of the electric field, hydrogen is generated at the cathode, and at the same time, the lithium-ion ceramic membrane electrolyzer enters the water and embeds into the electrode under the action of the electric field. At this time, the solution of the ceramic membrane electrolyzer is a lithium-containing aqueous solution. The solution of the ceramic membrane electrolyzer contains fewer coexisting impurity cations, and the viscosity of the solution is lower than that of brine. Therefore, lithium can be extracted at a higher potential without the occurrence of impurity ions embedded in the electrode, thereby improving the purity of the recovered lithium and the lithium extraction exchange capacity of the electrode, thereby improving the efficiency of lithium extraction. In addition, as lithium ions are continuously consumed, the rate of lithium ion transport across the membrane from brine to the ceramic membrane electrolyzer can be increased, further improving the efficiency of lithium extraction and shortening the time of lithium extraction. In addition, in the present disclosure, by setting the electrolyte in the anode chamber to pure water and separating it from the brine using a cation exchange membrane, the generation of chlorine can be avoided during lithium extraction at high potential. Hydrolysis occurs at the anode to produce oxygen, and the generated hydrogen ions enter the brine through the cation exchange membrane, increasing the acidity of the brine, thereby avoiding the formation of impurities such as magnesium hydroxide precipitated on the lithium ion ceramic membrane during the lithium extraction process to hinder the passage of lithium ions.

Claims

1. An electrolysis device for extracting lithium from salt lakes by electro-deintercalation, characterized in that: It includes a ceramic membrane electrolytic cell for lithium extraction from salt lakes through electro-deintercalation, an electrolytic outer cell, a cation exchange membrane, a first electrode, and a second electrode. The cation exchange membrane vertically divides the electrolytic outer cell into a cathode chamber and an anode chamber. The ceramic membrane electrolytic cell is placed in the cathode chamber. One of the first and second electrodes is provided in the ceramic membrane electrolytic cell, and the other of the first and second electrodes is provided in the anode chamber. The ceramic membrane electrolytic cell includes a bottom wall and multiple side walls. The multiple side walls are connected to the bottom wall to form a trough-like structure. The bottom wall and the side walls are both made of lithium ion conductor ceramic materials.

2. The electrolysis device for extracting lithium from salt lakes by electro-deintercalation according to claim 1, characterized in that: The lithium ion conductor ceramic material includes lithium zirconium oxide or lithium titanium oxide.

3. The electrolysis device for extracting lithium from salt lakes by electro-deintercalation according to claim 2, characterized in that: The preparation method of the ceramic membrane electrolyzer comprises: mixing lanthanum zirconium oxide or lanthanum titanium oxide and a lithium source and grinding them uniformly to obtain a mixture, pre-sintering the mixture and then cooling it to room temperature to obtain a pre-sintered material; Grinding the pre-sintered material again to obtain a mother powder; Placing the mother powder in an electrolytic cell-shaped mold and pressing it to obtain a green blank; The green body is sintered to obtain the ceramic membrane electrolytic cell.

4. The electrolysis device for extracting lithium from salt lakes by electro-deintercalation according to claim 3, characterized in that: The lanthanum zirconium oxide or the lanthanum titanium oxide and the lithium source are ball-milled at a rotation speed of 150-200 r / min for 2-3 hours to obtain a mixed material.

5. The electrolysis device for extracting lithium from salt lakes by electro-deintercalation according to any one of claims 3 to 4, characterized in that: The pre-sintering includes heating the temperature to 800-1000° C. at a heating rate of 3-7° C. / min, keeping the temperature for 3-5 hours, and then cooling the temperature to room temperature in the furnace.

6. The electrolysis device for extracting lithium from salt lakes by electro-deintercalation according to claim 3, characterized in that: The pre-sintered material is ball-milled again at a rotation speed of 150-200 r / min for 2-3 hours to obtain the mother powder.

7. The electrolysis device for extracting lithium from salt lakes by electro-deintercalation according to claim 3, characterized in that: The sintering of the green blank includes: heating the temperature to 1200-1400° C. at a heating rate of 3-7° C. / min, keeping the temperature for 8-12 minutes, and then cooling the green blank with the furnace.

8. The electrolysis device for extracting lithium from salt lakes by electro-deintercalation according to claim 3, characterized in that: The bottom wall and the side wall are both membrane-like structures with a thickness of 1-10 mm.

9. The electrolysis device for extracting lithium from salt lakes by electro-deintercalation according to claim 3, characterized in that: The thickness of the bottom wall and the side wall is 1-5 mm.

10. The electrolysis device for extracting lithium from salt lakes by electro-deintercalation according to claim 1, characterized in that: The first electrode is a lithium-intercalated electrode.

11. The electrolysis device for extracting lithium from salt lakes by electro-deintercalation according to claim 10, characterized in that: The preparation method of the lithium-intercalated electrode includes: mixing and grinding an electrode active material, conductive carbon black, PVDF and N-methylpyrrolidone into a slurry, coating the slurry on a current collector, and drying to obtain a lithium-extraction electrode; placing the lithium-extraction electrode in a NaCl solution to delithiate and form a lithium-intercalated electrode.

12. The electrolysis device for extracting lithium from salt lakes by electro-deintercalation according to claim 11, characterized in that: The masses of the conductive carbon black, the PVDF and the N-methylpyrrolidone are 5-15%, 10-15% and 150-200% of the mass of the electrode active material respectively.

13. The electrolysis device for extracting lithium from salt lakes according to any one of claims 11 to 12, characterized in that: The electrode active material includes LiMn2O4, LiFePO4, LiNi x Co y Mn z One of O2 and its doped derivatives, wherein 0 <x,y<1,x+y+z=1。 14. The electrolysis device for extracting lithium from salt lakes according to claim 11, characterized in that: The current collector includes titanium mesh, carbon fiber cloth, carbon fiber felt, porous carbon substrate, or titanium plate, and the thickness of the current collector is 0.1-2 mm.

15. The electrolysis device for extracting lithium from salt lakes according to claim 11, characterized in that: During the delithiation, a voltage of 1-1.2 V is applied, the concentration of the NaCl solution is 0.4-0.6 mol / L, and the delithiation time is 4-10 h.

16. The electrolysis device for extracting lithium from salt lakes according to claim 1, characterized in that: The second electrode is an inert electrode.

17. The electrolysis device for extracting lithium from salt lakes by electro-deintercalation according to claim 1, characterized in that: Before use, the second electrode is placed in a 0.4-0.6 mol / L LiCl solution and activated by cyclic voltammetry scanning.

18. A method for extracting lithium from salt lakes by electro-deintercalation, characterized in that: The method is carried out using the electrolysis device for extracting lithium from salt lakes by electro-deintercalation according to any one of claims 1 to 17.

19. The method for extracting lithium from salt lakes by electro-deintercalation according to claim 18, characterized in that: The cathode chamber is filled with brine, and the anode chamber and the ceramic membrane electrolytic cell are both filled with water. The first electrode is inserted into the ceramic membrane electrolytic cell as a cathode, and the second electrode is inserted into the anode chamber as an anode. Voltage is applied to both ends of the first electrode and the second electrode to perform electrolysis to extract lithium. During the electrolysis to extract lithium, the lithium ions in the brine are embedded in the first electrode to obtain a lithium-rich electrode. After the lithium extraction process is completed, the brine is replaced with a recovery liquid, and a reverse voltage is applied. The lithium-rich electrode serves as an anode and the second electrode serves as a cathode. The lithium ions in the lithium-rich electrode are released into the recovery liquid to enrich the lithium in the brine in the recovery liquid.

20. The method for extracting lithium from salt lakes by electro-deintercalation according to claim 19, characterized in that: The brine includes one or more of sulfate brine, chloride brine and carbonate brine.

21. The method for extracting lithium from salt lakes by electro-deintercalation according to any one of claims 19-20, characterized in that: The concentration of impurity cations in the brine is greater than 200 g / L.

22. The method for extracting lithium from salt lakes by electro-deintercalation according to claim 19, characterized in that: The water includes at least one of pure water, high-purity water, ultrapure water, deionized water, distilled water and double-distilled water.

23. The method for extracting lithium from salt lakes by electro-deintercalation according to claim 19, characterized in that: The recovery liquid is a 40-60 mmol / L lithium chloride solution.

24. The method for extracting lithium from salt lakes by electro-deintercalation according to claim 19, characterized in that: The voltage applied to both ends of the first electrode and the second electrode is 1.5-4.5V.

25. The method for extracting lithium from salt lakes by electro-deintercalation according to claim 19, characterized in that: The time for electrolytic lithium extraction is 0.5-3h.

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