WO2024250154A1 - Ceramic membrane electrolytic bath for extracting lithium from salt lake by means of electrical de-intercalation, and electrolysis device and method for extracting lithium from salt lake by means of electrical de-intercalation - Google Patents

Abstract

The present disclosure relates to the technical field of lithium extraction from a salt lake, and provides a ceramic membrane electrolytic bath for extracting lithium from a salt lake by means of electrical de-intercalation, and an electrolysis device and method for extracting lithium from a salt lake by means of electrical de-intercalation. In the present disclosure, a lithium ion conductor ceramic membrane is used as a bottom wall and a side wall, so as to form a ceramic membrane electrolytic bath, such that the ceramic membrane electrolytic bath has the effect of preferentially selectively permeating Li⁺. The ceramic membrane electrolytic bath provided in the present disclosure can be arranged in brine of an electrolysis device for extracting lithium from a salt lake by means of electrical de-intercalation; water is added to the ceramic membrane electrolytic bath; a lithium-intercalated electrode is placed as a cathode therein; and Li⁺ in the brine moves towards the cathode under the action of an electric field, is preferentially separated from other impurity cations by means of the ceramic membrane electrolytic bath and is preliminarily enriched in pure water, thereby reducing the influence of the impurity cations on the electrical de-intercalation process. The preparation method for a lithium-ion ceramic membrane is simple and easy for large-scale production, and has a low cost.

Description

A ceramic membrane electrolytic cell for extracting lithium from a salt lake by electro-deintercalation, an electrolytic device and a method for extracting lithium from a salt lake by electro-deintercalation Technical Field

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

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, highly selective, and conducive to industrial production, but the large amount of organic reagents used will corrode equipment and pollute the environment. The adsorption method is cost-effective and efficient, 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 no pollution.

The LiFePO ₄ /FePO ₄ "rocking chair" structure electrode system is used to achieve simultaneous extraction and recovery of lithium on different electrodes. In the actual production process, salt lake brine contains multiple cations such as Na ⁺ , K ⁺ , Mg ²⁺ , which will inevitably participate in the electrochemical reaction and embed into the electrode material, which not only reduces the purity of lithium ions, but also reduces the exchange capacity of the electrode for lithium.

In view of this, the present disclosure is proposed.

Summary of the invention

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

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

The present disclosure also aims to provide a method for extracting lithium from salt lakes by electro-deintercalation.

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

In a first aspect, the present disclosure provides a ceramic membrane electrolytic cell for extracting lithium from a salt lake 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 both the bottom wall and the side walls are made of lithium ion conductor ceramic materials.

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

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

The lanthanum zirconium oxide or lanthanum titanium oxide and the lithium source are mixed and ground evenly to obtain a mixed material, and the mixed material is pre-sintered and then cooled 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 blank is sintered to obtain the ceramic membrane electrolytic cell.

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.

In some embodiments of the present disclosure, 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.

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.

In some embodiments of the present disclosure, sintering the green billet comprises: 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 with the furnace.

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

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

In a second aspect, the present disclosure provides an electrolytic device for extracting lithium from a salt lake through electro-deintercalation, which comprises the ceramic membrane electrolytic cell described in the above embodiment.

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

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

In some embodiments of the present disclosure, the method for preparing the lithium-intercalated electrode comprises:

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 dried to obtain a lithium extraction electrode;

The lithium extraction electrode is placed in a NaCl solution to de-lithiate and form a lithium insertion electrode.

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.

In some embodiments of the present disclosure, _the electrode active material includes one of _LiMn2O4 , LiFePO4, _{LiNixCoyMnzO2} and doped derivatives _thereof , wherein 0< _x , y<1, x+y+ _z = ₁ .

In some embodiments of the present disclosure, 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.

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.

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

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.

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.

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 electrolytic lithium extraction. During the electrolytic lithium extraction, 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.

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

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

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.

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

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.

In some embodiments of the present disclosure, the time for electrolysis to extract lithium is 0.5-3h.

Compared with the prior art, the beneficial effects of the present invention include:

The lithium ion conductor ceramic membrane is a lithium solid lithium-containing compound with the ability to conduct lithium rapidly. The holes contained in its crystal structure are just enough for lithium ions to pass through, and it has a preferential permeability to Li ⁺ . The present invention forms a ceramic membrane electrolytic cell by using the lithium ion conductor ceramic membrane as the bottom wall and the side wall, so that the ceramic membrane electrolytic cell has the effect of preferentially permeating Li ⁺ . The ceramic membrane electrolytic cell provided by the present invention can be arranged in the brine of an electrolytic device 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, the Li ⁺ in the brine moves toward the cathode, preferentially passes through the ceramic membrane electrolytic cell and is separated from other impurity cations, and is initially enriched in the water, which is beneficial to reducing the influence of impurity cations on the electro-deintercalation process. The preparation method of the lithium ion ceramic membrane is simple, easy to mass produce, and has low cost.

In the process of lithium extraction, the cathode produces hydrogen under the action of the electric field, and lithium ions preferentially pass through the ceramic. The 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 less, 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 the exchange capacity of the electrode for lithium extraction, thereby improving the efficiency of lithium extraction. In addition, with the continuous consumption of lithium ions, the rate of lithium ion transport from brine to the ceramic membrane electrolyzer across the membrane can be increased, further improving the efficiency of lithium extraction 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 when extracting lithium at a high potential, the anode undergoes hydrolysis 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 during the lithium extraction process, which are precipitated on the lithium ion ceramic membrane to hinder the passage of lithium ions.

BRIEF DESCRIPTION OF THE DRAWINGS

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

FIG1 is a diagram showing the working principle of the method for extracting lithium from salt lakes by electro-deintercalation provided in the present invention.

Icons: 100 - electrolytic device for extracting lithium from salt lakes by electro-deintercalation; 101 - ceramic membrane electrolytic cell; 102 - electrolytic outer cell; 103 - cation exchange membrane; 104 - first electrode; 105 - second electrode.

DETAILED DESCRIPTION

The embodiments of the present disclosure will be described in detail below in conjunction with the examples, but those skilled in the art will appreciate that the following examples are only used to illustrate the present disclosure and should not be considered to limit the scope of the present disclosure. Where specific conditions are not specified in the examples, they are carried out under conventional conditions or conditions recommended by the manufacturer. Where the manufacturers of the reagents or instruments used are not specified, they are all conventional products that can be purchased commercially.

The endpoints and any values of the ranges 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 endpoint values of each range, the endpoint values of each range and the individual point values, and the individual point values can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed in this article.

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 a salt lake through electro-deintercalation.

In the present disclosure, the ceramic membrane electrolyzer includes a bottom wall and a plurality of side walls, the plurality of 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. The bottom wall and the side walls in the present disclosure are both thin-film-shaped. Generally speaking, The lithium ion conductor ceramic membrane is a membrane structure that can be used as a partition membrane between the cathode chamber and the anode chamber. However, the present disclosure innovatively prepares the lithium ion conductor ceramic membrane into a trough-shaped structure to form a ceramic membrane electrolytic cell, and places the ceramic membrane electrolytic cell in brine.

The lithium ion conductor ceramic material includes a garnet type ceramic material or a Li _3x La _2/3-x TiO type ceramic material. The garnet type ceramic material is made of lithium zirconium oxide, and the Li _3x La _2/3-x TiO type ceramic material is made of lithium titanium oxide.

Specifically, the preparation method of the ceramic membrane electrolyzer includes:

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

The lanthanum zirconium oxide is specifically lanthanum oxide and zirconium oxide, the lanthanum titanium oxide is specifically lanthanum oxide and titanium oxide, the lithium source can be, for example, lithium hydroxide, the mass fractions of lithium hydroxide, lanthanum oxide and zirconium oxide are 10-30%: 40-60%: 20-40% respectively, and the mass fractions of lithium hydroxide, lanthanum oxide and titanium oxide are 10-30%: 40-60%: 20-40% respectively. The lanthanum zirconium oxide or lanthanum titanium oxide and the lithium source are ball milled at a speed of 150-200r/min for 2-3h to obtain a mixed material. The pre-sintering includes heating to 800-1000°C at a heating rate of 3-7°C/min, keeping the temperature for 3-5 hours and then cooling to room temperature with the furnace.

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.

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

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.

In some embodiments, the rotation speed of the pre-sintered material for ball milling again is, for example, any one of 150, 160, 170, 180, 190, 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, 3 h or a range between any two of them.

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

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

The sintering of the green blank includes: heating to 1200-1400°C at a heating rate of 3-7°C/min, keeping the temperature 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.

In some embodiments, the heating rate of sintering can be, for example, any one of 3, 4, 5, 6, 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, 1400 ° C or a range between any two of them; the sintering holding time can be, for example, 8, 9, 10, 11, 12 minutes. Either one or a range of values between any two.

In addition, please refer to Figure 1. The present disclosure also provides an electrolytic device 100 for extracting lithium from a salt lake by electro-deintercalation. In addition to the above-mentioned ceramic membrane electrolytic cell 101, the electrolytic device 100 for extracting lithium from a salt lake also includes an electrolytic outer cell 102, a cation exchange membrane 103, a first electrode 104 and a second electrode 105. The cation exchange membrane 103 vertically divides the electrolytic outer cell 102 into a cathode chamber and an anode chamber. The ceramic membrane electrolytic cell 101 is placed in the cathode chamber, and brine is contained in the cathode chamber. The anode chamber and the ceramic membrane electrolytic cell 101 are both filled with water. One of the first electrode 104 and the second electrode 105 is provided in the ceramic membrane electrolytic cell 101, and the other of the first electrode 104 and the second electrode 105 is provided in the anode chamber.

The first electrode 104 is a lithium-intercalated electrode, and the second electrode 105 is an inert electrode.

The preparation method of the lithium-intercalated electrode comprises:

(1) 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 dried to obtain a lithium extraction electrode.

The mass of conductive carbon black, _PVDF and N- _{methylpyrrolidone} is 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, _{LiNixCoyMnzO2} and _their doped derivatives, wherein 0<x, y<1, x+y+z=1. 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 0.1-2mm.

(2) The lithium-extracting electrode is placed in a NaCl solution to de-lithiate and form a lithium-intercalated electrode.

During 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.

In certain embodiments, the voltage applied during delithiation is any one of 1, 1.1, and 1.2 V or a range between any two of them; the concentration of the NaCl solution is any one of 0.4, 0.5, and 0.6 mol/L or a range between any two of them; and the delithiation time is any one of 4, 5, 6, 7, 8, 9, and 10 h or a range between any two of them.

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

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.

Specifically, the method for extracting lithium from a salt lake by electro-deintercalation provided by the present invention 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 is used as an anode, and the second electrode 105 is used as a cathode, and the lithium ions in the lithium-rich electrode are deintercalated into the recovery liquid to enrich the lithium in the brine in the recovery liquid.

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

Since in the actual production process, salt lake brine contains Na ⁺ , K ⁺ , Mg ²⁺ and other cations coexisting, it is inevitable that they will participate in the electrochemical reaction and be embedded in the electrode material. The degree of the coexisting cations embedding 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 China's salt lakes are high magnesium-lithium ratio salt lakes, and the concentration of lithium ions is low. 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, the voltage applied to the electrode in the existing electro-deintercalation salt lake lithium extraction method is usually no more than 1.2V, while in this application, a voltage of 1.5-4.5V can be applied to both ends of the two electrodes, which significantly improves the electrode potential and improves the efficiency of lithium extraction. In addition, in the existing method for extracting lithium from salt lakes by electro-deintercalation, 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 ⁺ > _ER , Na ⁺ > _ER , ^Mg2+ > _ER , K ⁺ , so it is mainly sodium ions and magnesium ions in the brine that have a greater impact on the embedding of lithium ions, and other impurity cations are mainly adsorbed on the electrode surface to affect the embedding of lithium. For this reason, 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 targeted. The method for extracting lithium from salt lakes by electro-deintercalation provided in the present disclosure can be used for brine with a coexisting cation concentration greater than 200 g/L. It can be seen that the concentration requirement of coexisting impurity cations in the brine 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.

The lithium ion conductor ceramic membrane is a lithium solid lithium-containing compound with the ability to conduct lithium rapidly. The holes contained in its crystal structure are just enough for lithium ions to pass through, and it has a preferential permeability to Li ⁺ . The present disclosure forms a ceramic membrane electrolytic cell by using the lithium ion conductor ceramic membrane as the bottom wall and the side wall, so that the ceramic membrane electrolytic cell has the effect of preferentially permeating Li ⁺ . The ceramic membrane electrolytic cell provided by the present disclosure can be arranged 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, the Li ⁺ in the brine moves toward the cathode, preferentially passes through the ceramic membrane electrolytic cell and is separated from other impurity cations, and is initially enriched in the water, which is beneficial to reducing the influence of impurity cations on the electro-deintercalation process. The preparation method of the lithium ion ceramic membrane is simple, easy to mass produce, and low in cost.

In addition, with respect to the method for extracting lithium from salt lakes by electro-deintercalation provided in the present invention, under the action of the electric field, hydrogen is generated at the cathode, and 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 electric 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 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.

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. The production of chlorine can be avoided when extracting lithium. 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 during the lithium extraction process that precipitate on the lithium ion ceramic membrane and hinder the passage of lithium ions.

The features and performance of the present invention are further described in detail below in conjunction with the embodiments.

Example 1

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

(1) Preparation of lithium extraction electrode: _LiFePO4 active material, conductive carbon black and PVDF are added to N-methylpyrrolidone and repeatedly ground into a slurry, the slurry is coated on a titanium mesh, and dried to obtain a lithium extraction electrode. The mass of conductive carbon black, PVDF and N-methylpyrrolidone is 10%, 12% and 150% of the mass of the electrode active material, respectively.

(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 FePO ₄ electrode. The activated carbon electrode was activated by cyclic voltammetry scanning in a 0.5 mol/L LiCl solution.

(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 a speed of 170r/min using zirconium oxide balls and polyurethane ball mills. 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. Secondary dry ball milling was performed at a speed of 170r/min for 2 hours. After ball milling, the ball material was separated to obtain the 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 1300°C at 5°C/min, kept warm for 10 minutes, and then cooled with the furnace to obtain LLTO with a thickness of 3mm.

(4) Preparation of an electrolytic device for extracting lithium from salt lakes by electro-deintercalation: The outer electrolytic cell is vertically divided into a cathode chamber and an anode chamber by 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 in the ceramic membrane electrolytic cell as the cathode, and the activated carbon is placed in the anode chamber as the anode, as shown in Figure 1. The composition of the brine is: 0.35 g/L Li, 105.65 g/L Na, 107.97 g/L Mg, 8.45 g/L K, 2.76 g/L Ca, ^10.54 g/L _SO42- .

(5) Lithium extraction by electrolysis: A voltage of 3 V was applied to both ends of the electrodes for electrolysis for 1.5 h. During the lithium extraction by electrolysis, the lithium ions in the brine were embedded in the first electrode to obtain a lithium-rich electrode LiFePO ₄ . After the lithium extraction process was completed, the brine was replaced with a recovery solution (50 mmol/L lithium chloride solution) and a reverse voltage was applied. The LiFePO ₄ electrode was used as the anode and the activated carbon electrode was used as the cathode. After 1.5 h of electrolysis, the lithium ions in the electrode material were released into the recovery solution.

Example 2

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

(1) Preparation of lithium extraction electrode: _LiFePO4 active material, conductive carbon black and PVDF are added to N-methylpyrrolidine The ketone is repeatedly ground into a slurry, the slurry is coated on a titanium mesh, and dried to obtain a lithium extraction electrode. The mass of conductive carbon black, PVDF and N-methylpyrrolidone is 15%, 10% and 200% of the mass of the electrode active material respectively.

(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 FePO ₄ electrode, and the activated carbon electrode was activated by cyclic voltammetry scanning in a 0.5 mol/L LiCl solution.

(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 a speed of 170r/min using zirconium oxide balls and polyurethane ball mills. 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. Secondary dry ball milling was performed at a speed of 170r/min for 2 hours. After ball milling, the ball material was separated to obtain the 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 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.

(4) Preparation of an electrolytic device for extracting lithium from salt lakes by electro-deintercalation: The outer electrolytic cell is vertically divided into a cathode chamber and an anode chamber by 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 in the ceramic membrane electrolytic cell as the cathode, and the activated carbon is placed in the anode chamber as the anode, as shown in Figure 1. The composition of the brine is: 0.35 g/L Li, 105.65 g/L Na, 107.97 g/L Mg, 8.45 g/L K, 2.76 g/L Ca, ^10.54 g/L _SO42- .

(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 a 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.

Example 3

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

(1) Preparation of lithium extraction electrode: _LiFePO4 active material, conductive carbon black and PVDF are added to N-methylpyrrolidone and repeatedly ground into a slurry, the slurry is coated on a titanium mesh, and dried to obtain a lithium extraction electrode. The mass of conductive carbon black, PVDF and N-methylpyrrolidone is 5%, 15% and 150% of the mass of the electrode active material, respectively.

(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 FePO ₄ electrode, and the activated carbon electrode was activated by cyclic voltammetry scanning in a 0.5 mol/L LiCl solution.

(3) Preparation of ceramic membrane electrolyzer: 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 powders were then separated from the zirconium oxide balls used for ball milling using a sieve and the separated powders were pre-sintered in a tube furnace. The temperature was raised to 950℃ at 5℃/min, kept at this temperature for 3 hours, and then cooled to room temperature with the furnace. Secondary 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 twice, heated to 1300℃ at 5℃/min, kept at this temperature for 10 minutes, and then cooled with the furnace to obtain LLTO with a thickness of 1mm.

(4) Preparation of an electrolytic device for extracting lithium from salt lakes by electro-deintercalation: The outer electrolytic cell is vertically divided into a cathode chamber and an anode chamber by 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 in the ceramic membrane electrolytic cell as the cathode, and the activated carbon is placed in the anode chamber as the anode, as shown in Figure 1. The composition of the brine is: 0.35 g/L Li, 105.65 g/L Na, 107.97 g/L Mg, 8.45 g/L K, 2.76 g/L Ca, ^10.54 g/L _SO42- .

(5) A voltage of 1.5 V is applied to both ends of the electrode for electrolysis for 3 h, and then the brine is replaced with a recovery liquid, and a reverse voltage is applied. The _LiFePO4 electrode is used as the anode and the activated carbon electrode is used as the cathode. After electrolysis for 3 h, the lithium ions in the electrode material are released into the recovery liquid.

Example 4

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

(1) Preparation of lithium extraction electrode: _LiFePO4 active material, conductive carbon black and PVDF are added to N-methylpyrrolidone and repeatedly ground into a slurry, the slurry is coated on a titanium mesh, and dried to obtain a lithium extraction electrode. The mass of conductive carbon black, PVDF and N-methylpyrrolidone is 10%, 12% and 150% of the mass of the electrode active material, respectively.

(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 FePO ₄ electrode, and the activated carbon electrode was activated by cyclic voltammetry scanning in a 0.5 mol/L LiCl solution.

(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 zirconium oxide balls and polyurethane ball mills were used to ball mill at a speed of 200r/min for 2 hours, and then the powder and the zirconium oxide balls used for ball milling were separated by a screen. The separated powder was placed in a tubular furnace and heated to 800°C at 5°C/min for pre-sintering. After keeping warm 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 the 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°C at 5°C/min, kept warm for 25 minutes, and then cooled with the furnace to obtain LLZO with a thickness of 3mm.

(4) Preparation of an electrolytic device for extracting lithium from salt lakes by electro-deintercalation: The outer electrolytic cell is vertically divided into a cathode chamber and an anode chamber by 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 in the ceramic membrane electrolytic cell as the cathode, and the activated carbon is placed in the anode chamber as the anode, as shown in Figure 1. The composition of the brine is: 0.35 g/L Li, 105.65 g/L Na, 107.97 g/L Mg, 8.45 g/L K, 2.76 g/L Ca, ^10.54 g/L _SO42- .

(5) A voltage of 3 V is applied to both ends of the electrode for electrolysis for 1.5 h, and then the brine is replaced with a 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 1.5 h, the lithium ions in the electrode material are released into the recovery liquid.

Example 5

This embodiment is substantially the same as Embodiment 1, except that, in this embodiment, the electrode active material is LiMn ₂ O ₄ , the prepared lithium-intercalated electrode is a lithium-intercalated Mn ₂ O ₄ electrode, and the second electrode is a platinum electrode.

Example 6

This embodiment is substantially the same as Embodiment 1, except that, in this embodiment, the electrode active material is LiNi _x Co _y Mn _z O ₂ , the prepared lithium-intercalated electrode is a lithium-intercalated Ni _x Co _y Mn _z O ₂ electrode, and the second electrode is a graphite electrode.

Example 7

This embodiment is basically the same as Embodiment 1, except that, in this embodiment, the thickness of the bottom wall and the side wall of the ceramic membrane electrolytic cell used is 5 mm.

Example 8

This embodiment is basically the same as Embodiment 1, except that, in this embodiment, the thickness of the bottom wall and the side wall of the ceramic membrane electrolytic cell used is 8 mm.

Comparative Example 1

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.

Comparative Example 2

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 1 V is applied across the electrodes for electrolysis for 1.5 h to extract lithium.

Comparative Example 3

The difference between this comparative example and Example 1 is that in this comparative example, the step (5) in Example 1 is applied to both ends of the electrode. The applied voltage is replaced with 1.2V.

Comparative Example 4

The difference between this comparative example and Example 1 is that the ceramic membrane electrolytic cell used in this comparative example adopts Li ₉ SiAlO ₈ material.

Comparative Example 5

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.

Comparative Example 6

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.

Experimental example: performance testing

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.

It can be found from the examples that the ceramic membrane electrolyzer prepared using the lithium ion ceramic membrane is placed in the cathode chamber and The brine in the cathode chamber is separated from the electrolyte (water) in the ceramic membrane electrolytic cell, so lithium can be extracted at a higher potential. 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 (LiFePO ₄ ). Compared with the ordinary electrical deintercalation and lithium extraction in Comparative Example 1, the lithium ion purity, recovery rate and electrode exchange capacity are significantly improved.

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

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 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 electrolyzer, 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.

It can be seen from the data of Comparative Example 3 that the scheme of Example 1 can still maintain a 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.

It can be seen from the data of Comparative Example 4 that the use of Li _3x La _2/3-x TiO type lithium ion ceramic membrane as the cathode electrolytic cell is superior to the monoclinic structure Li ₉ SiAlO ₈ .

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 the present application, the lithium ion concentration in the recovered liquid and the electrode adsorption capacity will be significantly reduced.

From the data of Comparative Example 6, it can be seen that although similar lithium extraction indicators can be obtained by replacing the pure water in the anode chamber with lithium chloride, the anode of Comparative Example 6 will produce chlorine as a side reaction, which will corrode the electrode. To a certain extent, the efficiency of lithium extraction will be reduced, which is mainly reflected in the lower electrode adsorption capacity and the concentration of lithium ions obtained in the recovered liquid compared with Example 1.

In summary, the present disclosure provides a ceramic membrane electrolytic cell, which is made of lithium ion conductor ceramic material, and the lithium ion conductor ceramic material is a lithium solid lithium-containing compound with the ability to conduct lithium rapidly. The holes contained in its crystal structure can just allow lithium ions to pass through, and it has a preferential permeability to Li ⁺ . The present disclosure forms a ceramic membrane electrolytic cell by using a lithium ion conductor ceramic membrane as a bottom wall and a side wall, so that the ceramic membrane electrolytic cell has the effect of preferentially permeating Li ⁺ . The ceramic membrane electrolytic cell provided by the present disclosure can be arranged in the brine of an 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 moves toward the cathode, preferentially passes through the ceramic membrane electrolytic cell and is separated from other impurity cations, and is initially enriched in pure water, thereby reducing the influence of impurity cations on the electro-deintercalation process. The preparation method of the lithium ion ceramic membrane is simple, easy to mass produce, and low in cost.

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 Into the electrode, 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 less, and the viscosity of the solution is lower than that of the brine, so lithium can be extracted at a higher potential, and the impurity ions will not be embedded in the electrode, which improves the purity of the recovered lithium, and at the same time improves the exchange capacity of the electrode for lithium extraction, thereby improving the efficiency of lithium extraction. In addition, with the continuous consumption of lithium ions, the rate of lithium ion transport from brine to the ceramic membrane electrolyzer across the membrane can be increased, further improving the efficiency of lithium extraction 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 when extracting lithium at a high potential, the anode undergoes hydrolysis 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 during the lithium extraction process. Precipitation on the lithium ion ceramic membrane hinders the passage of lithium ions.

The optional implementation modes of the present disclosure are described in detail above, but the present disclosure is not limited thereto. Within the technical concept of the present disclosure, the technical solution of the present disclosure can be subjected to a variety of simple modifications, including combining various technical features in any other suitable manner, and these simple modifications and combinations should also be regarded as the contents disclosed by the present disclosure and belong to the protection scope of the present disclosure.

Industrial Applicability

In summary, the present disclosure provides a ceramic membrane electrolytic cell, which is prepared from a lithium ion conductor ceramic material, and the lithium ion conductor ceramic material is a lithium solid lithium-containing compound with the ability to conduct lithium rapidly. The holes contained in its crystal structure can just allow lithium ions to pass through, and it has a preferential permeability to Li ⁺ . The present disclosure forms a ceramic membrane electrolytic cell by using a lithium ion conductor ceramic membrane as a bottom wall and a side wall, so that the ceramic membrane electrolytic cell has the effect of preferentially permeating Li ⁺ . The ceramic membrane electrolytic cell provided by the present disclosure can be arranged in the brine of an electrolysis device 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 moves toward the cathode, preferentially passes through the ceramic membrane electrolytic cell and is separated from other impurity cations, and is initially enriched in pure water, thereby reducing the influence of impurity cations on the electro-deintercalation process. The preparation method of the lithium ion ceramic membrane is simple, easy to mass produce, and low in cost. 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 less, and the viscosity of the solution is lower than that of the brine. Therefore, lithium can be extracted at a higher potential without the situation of impurity ions being embedded in the electrode, thereby improving the purity of the recovered lithium and the exchange capacity of the electrode for lithium extraction, thereby improving the efficiency of lithium extraction. In addition, with the continuous consumption of lithium ions, the rate of lithium ion transport from brine to the ceramic membrane electrolyzer across the membrane 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 with a cation exchange membrane, the generation of chlorine can be avoided when extracting lithium at a high potential, the anode undergoes hydrolysis 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 during the lithium extraction process, which are precipitated on the lithium ion ceramic membrane to hinder the passage of lithium ions.

Claims (27)

A ceramic membrane electrolytic cell for lithium extraction from salt lakes by electro-deintercalation is characterized in that it comprises 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 the bottom wall and the side walls are both made of lithium ion conductor ceramic materials. The ceramic membrane electrolyzer for lithium extraction from salt lakes by electro-deintercalation according to claim 1 is characterized in that the lithium ion conductor ceramic material comprises lithium zirconium oxide or lithium titanium oxide. The ceramic membrane electrolytic cell for lithium extraction from salt lakes by electro-deintercalation according to claim 2, characterized in that the preparation method of the ceramic membrane electrolytic cell comprises: The lanthanum zirconium oxide or lanthanum titanium oxide and the lithium source are mixed and ground evenly to obtain a mixed material, and the mixed material is pre-sintered and then cooled 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 blank is sintered to obtain the ceramic membrane electrolytic cell. The ceramic membrane electrolytic cell for lithium extraction from salt lakes by electro-deintercalation according to claim 3 is 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. The ceramic membrane electrolytic cell for lithium extraction from salt lakes according to any one of claims 3-4 is characterized in that the pre-sintering includes heating to 800-1000°C at a heating rate of 3-7°C/min, keeping the temperature for 3-5 hours, and then cooling to room temperature with the furnace. The ceramic membrane electrolyzer for lithium extraction from salt lakes according to any one of claims 3 to 5 is characterized in that the pre-sintered material is ball-milled again at a rotation speed of 150 to 200 r/min for 2 to 3 hours to obtain the mother powder. The ceramic membrane electrolytic cell for lithium extraction from salt lakes according to any one of claims 3 to 6 is characterized in that sintering the green billet comprises: 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 with the furnace. The ceramic membrane electrolytic cell for lithium extraction from salt lakes by electro-deintercalation according to any one of claims 3 to 7 is characterized in that both the bottom wall and the side walls are membrane structures with a thickness of 1 to 10 mm. The ceramic membrane electrolytic cell for lithium extraction from salt lakes by electro-deintercalation according to any one of claims 3 to 8, characterized in that the thickness of the bottom wall and the side wall is 1 to 5 mm. An electrolytic device for extracting lithium from a salt lake by electro-deintercalation, characterized in that it comprises a ceramic membrane electrolytic cell for extracting lithium from a salt lake by electro-deintercalation according to any one of claims 1 to 9. The electrolytic device for extracting lithium from a salt lake by electro-deintercalation according to claim 10 is characterized in that the electrolytic device for extracting lithium from a salt lake by electro-deintercalation also includes 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, the ceramic membrane electrolytic cell is provided with one of the first electrode and the second electrode, and the anode chamber is provided with The other of the first electrode and the second electrode. The electrolytic device for extracting lithium from salt lakes by electro-deintercalation according to claim 11, characterized in that the first electrode is a lithium intercalation electrode. The electrolytic device for extracting lithium from salt lakes by electro-deintercalation according to claim 12 is characterized in that the method for preparing the lithium-intercalated electrode comprises: mixing and grinding the 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-extracting electrode; placing the lithium-extracting electrode in a NaCl solution to delithiate to form a lithium-intercalated electrode. The electrolytic device for extracting lithium from salt lakes by electro-deintercalation according to claim 13, 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. The electrolytic device for extracting lithium from salt _lakes by electro-deintercalation according to any one of claims 13-14, characterized in that the electrode active material comprises one of _LiMn2O4 , _LiFePO4 , _{LiNixCoyMnzO2} and their doped derivatives, wherein 0<x, _{y < 1} , x+y+z=1. The electrolytic device for extracting lithium from salt lakes by electro-deintercalation according to any one of claims 13 to 15 is characterized in that the current collector comprises 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 to 2 mm. The electrolysis device for extracting lithium from salt lakes by electro-deintercalation according to any one of claims 13 to 16 is characterized in that a voltage of 1 to 1.2 V is applied during the delithiation, the concentration of the NaCl solution is 0.4 to 0.6 mol/L, and the delithiation time is 4 to 10 h. The electrolysis device for extracting lithium from salt lakes by electro-deintercalation according to any one of claims 11 to 17, characterized in that the second electrode is an inert electrode. The electrolysis device for extracting lithium from salt lakes by electro-deintercalation according to any one of claims 11 to 18 is characterized in that the second electrode is placed in a 0.4-0.6 mol/L LiCl solution for cyclic voltammetry scanning activation before use. A method for extracting lithium from a salt lake by electro-deintercalation, characterized in that it is carried out using the electrolysis device for extracting lithium from a salt lake by electro-deintercalation as described in any one of claims 10 to 19. The method for extracting lithium from salt lakes by electro-deintercalation according to claim 20 is characterized in that the cathode chamber is filled with brine, 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, and a voltage is applied to both ends of the first electrode and the second electrode to electrolyze lithium. During the electrolysis of 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 deintercalated into the recovery liquid to enrich the lithium in the brine in the recovery liquid. The method for extracting lithium from salt lakes by electro-deintercalation according to claim 21 is characterized in that the brine comprises one or more of sulfate brine, chloride brine and carbonate brine. The method for extracting lithium from salt lakes by electro-deintercalation according to any one of claims 21-22, characterized in that the concentration of impurity cations in the brine is greater than 200 g/L. The method for extracting lithium from salt lakes by electro-deintercalation according to any one of claims 21 to 23, characterized in that the water comprises at least one of pure water, high-purity water, ultrapure water, deionized water, distilled water and double-distilled water. The method for extracting lithium from salt lakes by electro-deintercalation according to any one of claims 21 to 24, characterized in that the recovered liquid is a 40-60 mmol/L lithium chloride solution. The method for extracting lithium from a salt lake by electro-deintercalation according to any one of claims 21 to 25, characterized in that the voltage applied to both ends of the first electrode and the second electrode is 1.5-4.5V. The method for extracting lithium from salt lakes by electro-deintercalation according to any one of claims 21 to 26, characterized in that the time for electrolytic lithium extraction is 0.5-3h.