Lithium extraction deintercalation tank and use thereof

Abstract

Provided in the present disclosure are a lithium extraction deintercalation tank and the use thereof. Partition plates with openings are arranged in main tanks, and the openings of adjacent partition plates are staggered up and down to form a plurality of connected "pipelined" lithium extraction tanks; a solution to be subjected to lithium extraction is led "zigzag" to the plurality of lithium extraction tanks, such that the concentration of lithium ions in said solution is gradually reduced in a flow direction; and lithium extraction electrodes containing different lithium ion sieve materials are correspondingly provided according to changes in the concentration, and the lithium extraction electrodes are configured to be different constant-current sections having operating currents decreasing progressively in sequence and / or different constant-voltage sections having operating voltages decreasing progressively in sequence, so as to perform electrolytic lithium extraction, thereby realizing a simple, flexible and efficient lithium extraction mode.

Description

A lithium extraction and deintercalation tank and its application Technical Field

[0001] The present disclosure belongs to the field of electrochemistry, for example, a lithium extraction and deintercalation cell and its application. Background Art

[0002] With the rapid development of new energy vehicles, demand for lithium in power batteries has grown rapidly in recent years. As a key new energy material and strategic reserve resource, lithium, hailed as the "energy metal of the 21st century," has garnered significant global attention for its development and utilization. According to relevant statistics, global lithium resources total 40 million tons, of which approximately 70% resides in brines (including salt lake brines, underground brines, and concentrated seawater). Due to the limited mining of high-quality solid mineral resources, and the cost and scale advantages of lithium extraction from brine, the development and utilization of brine lithium resources has become an inevitable trend.

[0003] Electrochemical lithium extraction technology, as a new lithium separation and extraction technology, has the advantages of being green and efficient. However, at present, there is relatively little research on electrochemical lithium extraction devices and methods. Due to the low lithium ion concentration, high mineralization, and high viscosity of brine, the lithium extraction rate during the electrochemical deintercalation method of salt lake lithium extraction is relatively low. In addition, the devices used for electrochemical deintercalation of lithium from salt lakes have problems such as large inter-electrode spacing, insufficient brine flow, and poor solution mass transfer, which also seriously affect the lithium extraction rate during the electrochemical deintercalation method of salt lake lithium extraction. In related technologies, to meet the needs of large-scale industrial production, each lithium extraction and deintercalation tank contains up to 100 or more cation and cation deintercalation units. Depending on the treatment of the lithium solution to be extracted, the maximum operating current peak of a single cation and cation deintercalation unit can reach 20 to 60A. The operating current output requirement of the power supply of the entire lithium extraction and deintercalation tank is 2000 to 6000A. With the in-depth research and development of the technology, this current will be even higher. For a 2-meter-long lithium extraction and deintercalation cell, the applied operating voltage between each pair of cathode and anode cells cannot exceed 1V or lower. Therefore, related technologies typically use a constant current-constant voltage power supply mode to ensure that the operating voltage during lithium extraction is within a safe range. However, this power supply method makes it difficult to fully utilize the efficiency of each electrode plate, and thus cannot achieve the goal of efficient lithium extraction.

[0004] CN115276141A discloses a power supply method and system for an electrochemical deintercalation tank power supply, which provides a constant current to each working unit in the electrochemical deintercalation working group based on a preset constant current segment sequence, and collects the working voltage of each working unit in the electrochemical deintercalation working group in real time. When the working voltage of any working unit reaches a preset voltage threshold, it switches to the next constant current segment, or when a preset delay is reached, it switches to the next constant current segment. Because the constant current segment sequence includes multiple constant current segments, each constant current segment corresponds to a different current, which ensures the safety of the working unit while allowing the working unit to fully exert its efficiency. However, the process is very cumbersome, and it is difficult to control the boundaries of the conversion of different constant current segments, making it difficult to achieve large-scale production in industry.

[0005] Therefore, it is still necessary to develop new technical solutions for electrochemical lithium extraction from brine to solve the defects and problems existing in electrochemical lithium extraction technology.

[0006] Summary of the Invention

[0007] The following is a summary of the subject matter described in detail herein. This summary is not intended to limit the scope of the claims.

[0008] In view of the problems existing in the related art, the purpose of the present disclosure is to provide a lithium extraction and deintercalation tank and its application. By arranging a partition with openings in the main tank, and the openings of adjacent partitions are staggered up and down to form multiple connected, "assembly line" lithium extraction tanks, the lithium solution to be extracted is allowed to flow into the multiple lithium extraction tanks in a "bend-flow" manner, so that the lithium ion concentration in the lithium solution to be extracted gradually decreases along the flow direction. According to the change in concentration, lithium extraction electrodes containing different lithium ion sieve materials are correspondingly arranged, and the lithium extraction electrodes are set to different constant current sections with successively decreasing working currents and / or different constant voltage sections with successively decreasing working voltages to perform electrolytic lithium extraction, thereby realizing a simple, flexible and efficient lithium extraction method.

[0009] To achieve this goal, the present disclosure adopts the following technical solutions:

[0010] In a first aspect, the present disclosure provides a lithium extraction and deintercalation cell, comprising a cathode main cell, an anode main cell, and a diaphragm disposed between the cathode main cell and the anode main cell;

[0011] A separator is provided in the cathode main tank, and the separator divides the cathode main tank into at least two lithium extraction tanks;

[0012] The lithium extraction tank is provided with lithium extraction electrodes, and the anode main tank is provided with deintercalation electrodes corresponding to the number of the lithium extraction electrodes, and the lithium extraction electrodes are electrically connected to the deintercalation electrodes via an external power supply;

[0013] The separators are provided with openings, and the openings between two adjacent separators are staggered up and down along the height direction of the lithium extraction tank, so that the lithium solution to be extracted flows in the cathode main tank in a baffled manner.

[0014] The present disclosure adopts a "production line" type lithium extraction tank setting method, in which multiple lithium extraction tanks are connected, and each two tanks are separated by a partition. The first partition is provided with a hole (i.e., an opening) near the bottom or near the top for the lithium extraction solution to be tested (such as brine) to enter, the second partition is provided with a hole near the top or near the bottom, the third partition is provided with a hole near the bottom or near the top, and so on, so that the holes between the connected partitions are staggered up and down along the height direction of the partition, and the lithium extraction solution to be extracted is circulated to the last lithium extraction tank in a "baffled" manner, so that the lithium extraction solution to be extracted flows more fully, thereby improving the mass transfer effect of the solution, especially suitable for lithium extraction from brine with high viscosity.

[0015] The following are optional technical solutions of the present disclosure, but are not intended to limit the technical solutions provided by the present disclosure. Through the following technical solutions, the technical objectives and beneficial effects of the present disclosure can be better achieved and realized.

[0016] As an optional technical solution of the present disclosure, the separator is provided in the anode main tank, dividing the anode main tank into deintercalation tanks corresponding to each lithium extraction tank, and the number of deintercalation electrodes in the deintercalation tank is the same as the number of lithium extraction electrodes in the corresponding lithium extraction tank.

[0017] In the present disclosure, deintercalation electrodes corresponding to the number of lithium extraction electrodes can be installed in the anode main cell. Alternatively, a separator can be used to divide the anode main cell into multiple deintercalation cells. Each deintercalation cell and the corresponding lithium extraction cell are connected by a separator for mass transfer, and the deintercalation electrode in each deintercalation cell corresponds to the lithium extraction electrode in the corresponding lithium extraction cell. In other words, the anode separator and the cathode separator can be the same or different, and are not limited to the same separator. In fact, the anode does not need to be equipped with a separator. In particular, when the cathode main cell is an independent unit or each lithium extraction cell uses an independent power supply, the anode main cell can be equipped with a separator.

[0018] In one embodiment, the first lithium extraction tank and the first deintercalation tank are both provided with a liquid inlet, and the last lithium extraction tank and the last deintercalation tank are both provided with a liquid outlet.

[0019] When lithium is extracted using the lithium extraction and deintercalation cell disclosed in the present disclosure, when the extracted lithium flows through the last lithium extraction cell, the lithium ion extraction rate has reached the target requirement. Therefore, the solution at this time can be discharged to facilitate the replenishment of new solution from the liquid inlet. This flow process can be carried out continuously by controlling the liquid inlet speed, which can support continuous and large-scale lithium extraction work.

[0020] In one embodiment, the number of the lithium extraction tanks is 10 to 20, for example, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19 or 20.

[0021] As an optional technical solution of the present disclosure, the lithium extraction tank is divided into a high concentration tank, a medium concentration tank and a low concentration tank according to the change of the lithium ion concentration in the lithium solution to be extracted in the cathode main tank.

[0022] The lithium ion concentration in the lithium solution to be extracted in a zigzag flow continuously decreases along the flow direction. Therefore, the present disclosure divides the lithium extraction tanks, and the lithium ion sieve material on the electrode plate in each lithium extraction tank is selected according to the concentration range of the brine passing through the tank. The interval segment with high lithium ion concentration in the brine adopts a lithium ion sieve material with good selectivity, high adsorption capacity and stable chemical properties, the interval segment with medium lithium ion concentration in the brine adopts a lithium ion sieve material with good chemical stability but high capacity, and the interval segment with low lithium ion concentration in the brine adopts a lithium ion sieve material with high ion diffusion coefficient but low capacity.

[0023] As an optional technical solution of the present disclosure, the concentration of lithium ions in the high concentration tank is greater than 0.1g / L, for example, 0.12g / L, 0.17g / L, 0.2g / L, 0.25g / L, 0.3g / L, 0.35g / L, 0.4g / L, 0.45g / L or 0.5g / L, etc., and the concentration of lithium ions in the medium concentration tank is 0.01 to 0.1g / L, for example, 0.01g / L, 0.02g / L, 0.03g / L, etc. / L, 0.04g / L, 0.05g / L, 0.06g / L, 0.07g / L, 0.08g / L, 0.09g / L or 0.1g / L, etc. The concentration of lithium ions in the low-concentration tank is less than 0.01g / L, for example, 0.008g / L, 0.006g / L, 0.004g / L or 0.002g / L, etc., but is not limited to the listed values, and other values ​​not listed within the above numerical range are equally applicable.

[0024] As an optional technical solution of the present disclosure, the number of the high-concentration tanks is 2 to 8, for example, 2, 3, 4, 5, 6, 7 or 8, the number of the medium-concentration tanks is 1 to 9, for example, 1, 2, 3, 4, 5, 6, 7, 8 or 9, and the number of the low-concentration tanks is 1 to 9, for example, 1, 2, 3, 4, 5, 6, 7, 8 or 9.

[0025] As an optional technical solution of the present disclosure, the high-concentration tank is provided with a first lithium ion sieve material, the medium-concentration tank is provided with a second lithium ion sieve material, and the low-concentration tank is provided with a third lithium ion sieve material;

[0026] Comparing the adsorption capacity per unit mass, the first lithium ion sieve material>the second lithium ion sieve material>the third lithium ion sieve material;

[0027] Comparing the ion diffusion coefficient per unit mass, the first lithium ion sieve material is less than the second lithium ion sieve material and is less than the third lithium ion sieve material.

[0028] As an optional technical solution of the present disclosure, the adsorption capacity of the first lithium ion sieve material is 35-38 mg / g, for example, 35 mg / g, 35.3 mg / g, 35.6 mg / g, 35.9 mg / g, 36.2 mg / g, 36.5 mg / g, 36.8 mg / g, 37.1 mg / g, 37.4 mg / g, 37.7 mg / g or 38 mg / g, and the adsorption capacity of the second lithium ion sieve material is 30-33 mg / g, for example, 30 mg / g, 30.3 mg / g, 30.6 mg / g, 30.9 mg / g, 31.2 mg / g, 31.6 mg / g, 31.7 mg / g, 31.8 mg / g, 31.9 mg / g, 31.9 mg / g, 31.9 mg / g, 31.1 mg / g, 31.2 mg / g, 31.3 mg / g, 31.7 mg / g, 31.8 mg / g, 31.9 mg / g, 31.9 mg / g, 31.9 mg / g, 31.9 mg / g, 31.1 mg / g, 31.1 mg / g, The adsorption capacity of the third lithium ion sieve material is 12-15 mg / g, such as 12 mg / g, 12.3 mg / g, 12.6 mg / g, 12.9 mg / g, 13.2 mg / g, 13.5 mg / g, 13.8 mg / g, 14.1 mg / g, 14.4 mg / g, 14.7 mg / g or 15 mg / g, but is not limited to the listed values, and other values ​​not listed within the above numerical range are also applicable.

[0029] As a preferred technical solution of the present disclosure, the ion diffusion coefficient of the first lithium ion sieve material is 10 -10 ~10 -11 cm 2 / s, for example 10 -10 cm 2 / s, 9*10 -11 cm 2 / s, 8*10 -11 cm 2 / s, 7*10 -11 cm 2 / s, 6*10 -11 cm 2 / s, 5*10 -11 cm 2 / s, 4*10 -11 cm 2 / s, 3*10 -11 cm 2 / s, 2*10 -11 cm 2 / s or 10-11 cm 2 / s, etc., the ion diffusion coefficient of the second lithium ion sieve material is 10 -9 ~10 -10 cm 2 / s, for example 10 -9 cm 2 / s, 9*10 -10 cm 2 / s, 8*10 -10 cm 2 / s, 7*10 -10 cm 2 / s, 6*10 -10 cm 2 / s, 5*10 -10 cm 2 / s, 4*10 -10 cm 2 / s, 3*10 -10 cm 2 / s, 2*10 -10 cm 2 / s or 10 -10 cm 2 / s, etc., the ion diffusion coefficient of the third lithium ion sieve material is 10 -7 ~10 -8 cm 2 / s, for example 10 -7 cm 2 / s, 9*10 -8 cm 2 / s, 8*10 -8 cm 2 / s, 7*10 -8 cm 2 / s, 6*10 -8 cm 2 / s, 5*10 -8 cm 2 / s, 4*10 -8 cm 2 / s, 3*10 -8 cm 2 / s, 2*10 -8 cm 2 / s or 10 -8 cm 2 / s, etc., but are not limited to the listed values. Other values ​​not listed within the above value range are also applicable.

[0030] As an optional technical solution of the present disclosure, the first lithium ion sieve material, the second lithium ion sieve material and the third lithium ion sieve material are physical adsorption materials or electrochemical adsorption materials.

[0031] In one embodiment, when the first lithium ion sieve material, the second lithium ion sieve material and the third lithium ion sieve material are electrochemical adsorption materials, the first lithium ion sieve material, the second lithium ion sieve material and the third lithium ion sieve material are respectively arranged on the lithium extraction electrodes in the corresponding lithium extraction tanks.

[0032] As an optional technical solution of the present disclosure, when the first lithium ion sieve material, the second lithium ion sieve material and the third lithium ion sieve material are physical adsorption materials:

[0033] The first lithium ion sieve material includes a manganese dioxide adsorbent; the second lithium ion sieve material includes a lithium silicate adsorbent; and the third lithium ion sieve material includes an aluminum hydroxide-based adsorbent.

[0034] As an optional technical solution of the present disclosure, when the first lithium ion sieve material, the second lithium ion sieve material and the third lithium ion sieve material are electrochemical adsorption materials:

[0035] The first lithium ion sieve material includes a manganese oxide lithium ion sieve, such as lithium manganate LiMn2O4, Li 1.33 Mn 1.67 O4 or Li 1.6 Mn 1.6 O4; the second lithium ion sieve material includes any one of lithium cobaltate, lithium vanadate or lithium iron phosphate or a combination of at least two thereof, typical but non-limiting examples of the combination include a combination of lithium cobaltate and lithium iron phosphate, a combination of lithium cobaltate and lithium vanadate or a combination of lithium vanadate and lithium iron phosphate; the third lithium ion sieve material includes a titanium oxide lithium ion sieve, such as lithium titanate Li2TiO3 and / or Li4Ti5O 12 .

[0036] It should be noted that the lithium ion sieve material in the present disclosure needs to be selected according to the concentration range of the brine passing through the corresponding lithium extraction tank. The specific selection requirements are as described above. Those skilled in the art can make reasonable choices and adjustments based on the actual working conditions or implementation conditions. This application does not limit the first, second and third lithium ion sieve materials to the specific substances listed above.

[0037] As an optional technical solution of the present disclosure, each of the lithium extraction tanks is equipped with a current and / or voltage monitor for monitoring the corresponding lithium extraction electrode.

[0038] In one embodiment, the current and / or voltage monitor is electrically connected to the host, and the electrical connection refers to connection with the host through an electrical signal transmission line, and information communication is carried out by transmitting electrical signals to each other through the line. The host is used to analyze, store and display the working status and replacement information of the lithium extraction electrode.

[0039] As an optional technical solution of the present disclosure, the opening on the partition is arranged near the top end or the bottom end of the partition.

[0040] In one embodiment, along the height direction of the partition, the distance between the edge of the opening and the top or bottom end of the partition is 5% to 10% of the height of the partition, for example, 5%, 5.5%, 6%, 6.5%, 7%, 7.5%, 8%, 8.5%, 9%, 9.5% or 10%, etc., but is not limited to the listed values, and other values ​​not listed within the above numerical range are also applicable.

[0041] In one embodiment, the radius of the opening is 3 to 8 cm, for example, 3 cm, 3.5 cm, 4 cm, 4.5 cm, 5 cm, 5.5 cm, 6 cm, 6.5 cm, 7 cm, 7.5 cm or 8 cm, but is not limited to the listed values. Other values ​​not listed within the above numerical range are also applicable.

[0042] As an optional technical solution of the present disclosure, the following steps are included:

[0043] The lithium solution to be extracted and hot gas are introduced into the first lithium extraction tank at the same time, and flow in a zigzag manner in the cathode main tank to perform decreasing constant current electrolysis and / or decreasing constant voltage electrolysis to extract lithium.

[0044] As the fresh lithium solution to be extracted is passed into the lithium extraction tank, hot air is introduced simultaneously. This not only increases the temperature during the lithium extraction process, but also stirs the solution to be extracted, further promoting the flow and mass transfer of the solution to be extracted, effectively improving the lithium extraction efficiency of the lithium extraction tank. It should be noted that since the lithium desorption rate in the anode main tank is much faster than the lithium extraction rate in the cathode main tank, the anode main tank does not need to be equipped with a partition or hot air.

[0045] As an optional technical solution disclosed in the present invention, the decreasing constant current electrolytic lithium extraction includes that during the electrolytic lithium extraction process, the working current of the lithium extraction electrode itself in the lithium extraction tank remains unchanged, and along the flow direction of the lithium solution to be extracted, the working current of the lithium extraction electrode decreases successively or decreases in stages.

[0046] In one embodiment, in the decreasing constant current electrolysis lithium extraction, the difference in working current between two adjacent lithium extraction electrodes is 0.5 to 7 A, for example, 0.5 A, 1 A, 1.5 A, 2 A, 2.5 A, 3 A, 3.5 A, 4 A, 4.5 A, 5 A, 5.5 A, 6 A, 6.5 A or 7 A, but is not limited to the listed values. Other values ​​not listed within the above numerical range are also applicable.

[0047] In one embodiment, the various lithium extraction electrodes in the decreasing constant current electrolysis lithium extraction are electrically connected in parallel, or each lithium extraction electrode is individually controlled by an independent power supply to achieve constant current.

[0048] As an optional technical solution disclosed in the present invention, the decreasing constant voltage electrolytic lithium extraction includes that during the process of electrolytic lithium extraction, the working voltage of the lithium extraction electrode itself in the lithium extraction tank remains unchanged, and along the flow direction of the lithium solution to be extracted, the working voltage of the lithium extraction electrode decreases successively or in stages.

[0049] In one embodiment, in the decreasing constant-voltage electrolysis lithium extraction, the difference in the operating voltages of two adjacent lithium extraction electrodes is 0.05 to 0.15 V, for example, 0.05 V, 0.06 V, 0.07 V, 0.08 V, 0.09 V, 0.1 V, 0.11 V, 0.12 V, 0.13 V, 0.14 V or 0.15 V, etc., but is not limited to the listed values, and other values ​​not listed within the above numerical range are also applicable.

[0050] One of the objectives of the present disclosure is to gradually reduce the concentration of the lithium solution to be extracted along the flow direction by dividing the lithium extraction solution into sections with separators. Therefore, the operating parameters of the lithium extraction electrode should be adjusted according to the actual concentration of the lithium solution to be extracted within the lithium extraction tank. If the lithium ion concentration in two or three adjacent tanks or a certain section of the lithium extraction tank does not change significantly, the lithium extraction tank can also be segmented or zoned. Taking decreasing constant current electrolysis as an example, the operating current of the lithium extraction electrode in each segment of the lithium extraction tank is the same, and the operating current of the lithium extraction electrode between adjacent segments decreases along the flow direction of the solution. Regardless of the method, the operating current in the first lithium extraction tank is determined by the initial concentration of the lithium solution to be extracted. The higher the concentration, the larger the initial current value. The number of lithium extraction tanks set and the amplitude of the operating current change need to be adjusted according to the actual lithium extraction goals and effects, so that the lithium ion concentration in the solution of the last lithium extraction tank is reduced to below the target requirement. Therefore, the key to the present disclosure is to maintain the overall downward trend of the operating current of the lithium extraction electrode along the flow direction of the solution. Similarly, the change of the operating voltage in decreasing constant voltage electrolysis can also be performed in a segmented manner.

[0051] In one embodiment, the lithium extraction electrodes in the decreasing constant voltage electrolysis lithium extraction are electrically connected in series.

[0052] In a second aspect, the present disclosure provides an application of the lithium extraction and deintercalation cell as described in the first aspect for lithium extraction, and the application of the lithium extraction and deintercalation cell for lithium extraction includes: dividing the cathode main cell into a front section and a rear section along the flow direction of the lithium solution to be extracted, the lithium extraction cell in the front section performs the decreasing constant current electrolysis to extract lithium, and the lithium extraction cell in the rear section performs the decreasing constant pressure lithium extraction.

[0053] The lithium extraction tank disclosed herein is preferably configured to operate in a high-to-low constant current mode or a constant current mode followed by a constant voltage mode from front to back (i.e., from the cathode main tank liquid inlet to the liquid outlet). Compared to the related art power supply methods of first applying constant current and then constant voltage to a single electrode, or performing segmented constant current, this application is more flexible and energy-efficient, avoiding the tedious operation of switching power supply modes for each electrode.

[0054] In one embodiment, the ratio of the number of lithium extraction tanks in the front section to the number of lithium extraction tanks in the back section is greater than or equal to 2, for example, 2, 3, 4, 5, 6, 7 or 8, but is not limited to the listed values. Other values ​​not listed within the above numerical range are also applicable.

[0055] As an optional technical solution of the present disclosure, the lithium solution to be extracted includes brine.

[0056] In one embodiment, the concentration of lithium ions in the brine is 0.2 to 0.8 g / L, for example, 0.2 g / L, 0.25 g / L, 0.3 g / L, 0.35 g / L, 0.4 g / L, 0.45 g / L, 0.5 g / L, 0.55 g / L, 0.6 g / L, 0.65 g / L, 0.7 g / L, 0.75 g / L or 0.8 g / L, etc., but is not limited to the listed values, and other values ​​not listed within the above numerical range are also applicable.

[0057] In one embodiment, the flow rate of the lithium solution to be extracted is 1 to 5 L / h, for example, 1 L / h, 1.5 L / h, 2 L / h, 2.5 L / h, 3 L / h, 3.5 L / h, 4 L / h, 4.5 L / h or 5 L / h, but is not limited to the listed values. Other values ​​not listed within the above numerical range are also applicable.

[0058] In one embodiment, the temperature of the hot air is 35-40°C, such as 35°C, 36°C, 37°C, 38°C, 39°C or 40°C, but is not limited to the listed values. Other values ​​not listed within the above range are also applicable.

[0059] In one embodiment, the hot gas comprises air and / or an inert gas.

[0060] In one embodiment, the flow ratio of the hot gas to the lithium solution to be extracted is 1:(1-2), for example, 1:1, 1:1.1, 1:1.2, 1:1.3, 1:1.4, 1:1.5, 1:1.6, 1:1.7, 1:1.8, 1:1.9 or 1:2, etc., but is not limited to the listed values, and other values ​​not listed within the above numerical range are also applicable.

[0061] In one embodiment, the application further includes introducing pure water and / or sodium chloride solution into the anode main tank while simultaneously introducing the lithium solution to be extracted and hot gas into the first lithium extraction tank.

[0062] When a separator is also provided in the anode main tank, pure water and / or sodium chloride solution is introduced from the liquid inlet of the first de-embedding tank.

[0063] As an optional technical solution of the present disclosure, during the process of electrolytic lithium extraction, the current and / or voltage of the lithium extraction electrode in the lithium extraction tank is monitored, and when it exceeds a preset value, the corresponding lithium extraction electrode is replaced.

[0064] The present disclosure has at least the following beneficial effects:

[0065] (1) The lithium extraction and deintercalation tank disclosed in the present invention is connected by arranging multiple lithium extraction tanks in an "assembly line" manner, so that the lithium solution to be extracted in the lithium extraction tank flows in a "bend-type" manner and the lithium ion concentration is distributed from high to low. Therefore, the lithium ion sieve material of the corresponding lithium extraction electrode is set according to the different lithium ion concentrations in each lithium extraction tank, and resources are reasonably allocated, thereby reducing costs while efficiently extracting lithium;

[0066] (2) The lithium extraction and deintercalation tank disclosed in the present invention is used for lithium extraction. In the application of lithium extraction electrodes matching different working currents and / or voltages, a decreasing constant current electrolysis for lithium extraction is performed, or a decreasing constant current electrolysis for lithium extraction is performed in the front section and a decreasing constant voltage electrolysis for lithium extraction is performed in the back section. Compared with the related art of first applying a constant current and then a constant voltage to one electrode or applying a segmented constant current power supply to one electrode, the setting of this solution is more flexible and avoids the tedious operation of changing the power supply mode of the electrode.

[0067] (3) The lithium extraction and deintercalation cell disclosed in the present invention is used for lithium extraction. In the process of introducing fresh lithium solution to be extracted, hot gas is also introduced. Combined with the "baffled" flow mode, the flow of the lithium solution to be extracted is sufficient, the mass transfer effect of the solution is improved, and the lithium extraction efficiency of the electrolytic cell is effectively improved.

[0068] Still other aspects will become apparent upon reading and understanding the accompanying drawings and detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0069] The accompanying drawings are used to provide a further understanding of the technical solution of this article and constitute a part of the specification. Together with the embodiments of this application, they are used to explain the technical solution of this article and do not constitute a limitation on the technical solution of this article.

[0070] FIG1 is a schematic diagram of the cathode main tank in the lithium extraction and deintercalation tank of Example 1;

[0071] FIG2 is a schematic diagram of the cathode main tank in the lithium extraction and deintercalation tank of Example 2;

[0072] FIG3 is a schematic top view of the lithium extraction and deintercalation tank of Example 1 and Example 2;

[0073] FIG4 is a schematic top view of the lithium extraction and deintercalation cell of Example 4;

[0074] In the figure: 1- cathode main tank, 11- liquid inlet, 12- liquid outlet, 2- partition, 21- opening, 3- diaphragm, 4- lithium extraction electrode, 5- deintercalation electrode, 6- lithium solution to be extracted, 7- external power supply, 8- anode main tank. DETAILED DESCRIPTION

[0075] The technical solution of the present disclosure will be further described below with reference to the accompanying drawings and through specific embodiments. It should be understood by those skilled in the art that the embodiments are only used to help understand the present disclosure and should not be regarded as specific limitations of the present disclosure.

[0076] Example 1

[0077] This embodiment provides a lithium extraction and deintercalation cell and its application, as shown in Figures 1 and 3:

[0078] The lithium extraction and deintercalation cell comprises a cathode main cell 1, an anode main cell 8, and a diaphragm 3 disposed between the cathode main cell 1 and the anode main cell 8; a separator 2 is disposed in the cathode main cell 1, the separator 2 dividing the cathode main cell 1 into 15 sequentially connected lithium extraction cells; a separator 2 is also disposed in the anode main cell 8, the separator 2 dividing the anode main cell 8 into 15 sequentially connected deintercalation cells corresponding to the lithium extraction cells; the first lithium extraction cell and the first deintercalation cell are both provided with a liquid inlet 11, and the last lithium extraction cell and the last deintercalation cell are both provided with a liquid outlet 12;

[0079] The lithium extraction tank is provided with a lithium extraction electrode 4, and the lithium extraction electrodes 4 are electrically connected in parallel; the deintercalation tank is provided with a deintercalation electrode 5, and the deintercalation electrodes 5 are electrically connected in parallel, and the lithium extraction electrode 4 and the deintercalation electrode 5 are electrically connected via an external power supply 7;

[0080] The separator 2 is provided with openings 21, and the openings 21 between two adjacent separators 2 are staggered up and down along the height direction of the lithium extraction tank or the deintercalation tank. The opening 21 of the first separator 2 is set at a position 10 cm away from the top of the separator 2 and is a circle with a radius of 5 cm. The opening 21 of the second separator 2 is set at a position 10 cm away from the bottom of the separator 2 and is a circle with a radius of 5 cm. The opening 21 of the third separator 2 is the same as the first separator 2, and so on. A total of 15 separators 2 are provided, so that the lithium solution 6 to be extracted flows in the cathode main tank 1 and the anode main tank 8 in a baffled manner;

[0081] Along the flow direction of the lithium solution 6 to be extracted, the lithium extraction tank is divided into 5 high-concentration tanks, 5 medium-concentration tanks and 5 low-concentration tanks according to the change of the lithium ion concentration in the lithium extraction tank; the lithium ion sieve material of the lithium extraction electrode 4 in the high-concentration tank is LiMn2O4 with high adsorption capacity and good selectivity; the lithium ion sieve material of the lithium extraction electrode 4 in the medium-concentration tank is lithium iron phosphate with good chemical stability, relatively low ion diffusion coefficient and high capacity; the lithium ion sieve material of the lithium extraction electrode 4 in the low-concentration tank is Li2TiO3 with high diffusion coefficient, good stability but low capacity;

[0082] A voltage monitor is installed in each lithium extraction tank for monitoring the corresponding lithium extraction electrode 4 ; the voltage monitor is electrically connected to a host, which is used to analyze, store and display the working status and replacement information of the lithium extraction electrode 4 .

[0083] The application of the lithium extraction and deintercalation tank in this embodiment includes the following steps:

[0084] The lithium solution 6 to be extracted and hot air are introduced simultaneously from the first lithium extraction tank and flow in a zigzag manner in the cathode main tank 1. At the same time, pure water is introduced from the first deintercalation tank and flows in a zigzag manner in the anode main tank 8. The lithium solution 6 to be extracted is brine with a lithium ion concentration of 0.5 g / L and a flow rate of 3 L / h. The hot air is hot air with a temperature of 37° C. and a flow rate of 4.5 L / h.

[0085] The working current of the lithium extraction electrode 4 is set according to Table 1, wherein the lithium extraction electrode 4 in the first lithium extraction tank is the first lithium extraction electrode 4, and its working current is recorded as A1. The second lithium extraction tank is adjacent to the first lithium extraction tank in the direction close to the anode area, and its working current is recorded as A2. A1>A2, and so on, to perform decreasing constant current electrolysis to extract lithium;

[0086] Table 1

[0087] When the real-time working voltage of the lithium extraction electrode 4 in a lithium extraction tank exceeds the set safety constant voltage of 0.8V, the voltage monitor will sound an alarm and a new lithium extraction electrode 4 will be replaced accordingly until the electrolytic lithium extraction is completed.

[0088] Example 2

[0089] This embodiment provides a lithium extraction and deintercalation cell and its application, as shown in Figures 2 and 3:

[0090] The lithium extraction and deintercalation cell comprises a cathode main cell 1, an anode main cell 8, and a diaphragm 3 between the cathode main cell 1 and the anode main cell 8; a separator 2 is provided in the cathode main cell 1, and the separator 2 divides the cathode main cell 1 into 15 sequentially connected lithium extraction cells; a separator 2 is also provided in the anode main cell 8, and the separator 2 divides the anode main cell 8 into 15 sequentially connected deintercalation cells corresponding to the lithium extraction cells; a lithium extraction electrode 4 is provided in the lithium extraction cell, and a deintercalation electrode 5 is provided in the deintercalation cell, and the lithium extraction electrode 4 and the deintercalation electrode 5 are electrically connected via an external power supply 7; the first lithium extraction cell and the first deintercalation cell are both provided with a liquid inlet 11, and the last lithium extraction cell and the last deintercalation cell are both provided with a liquid outlet 12;

[0091] The separator 2 is provided with openings 21, and the openings 21 between two adjacent separators 2 are staggered up and down along the height direction of the lithium extraction tank or the deintercalation tank. The opening 21 of the first separator 2 is set at a position 10 cm away from the top of the separator 2 and is a circle with a radius of 5 cm. The opening 21 of the second separator 2 is set at a position 10 cm away from the bottom of the separator 2 and is a circle with a radius of 5 cm. The opening 21 of the third separator 2 is the same as the first separator 2, and so on. A total of 15 separators 2 are provided, so that the lithium solution 6 to be extracted flows in the cathode main tank 1 and the anode main tank 8 in a baffled manner;

[0092] Along the flow direction of the lithium solution 6 to be extracted, the lithium extraction tank is divided into 5 high-concentration tanks, 5 medium-concentration tanks and 5 low-concentration tanks according to the change of the lithium ion concentration in the lithium extraction tank; the lithium ion sieve material of the lithium extraction electrode 4 in the high-concentration tank is LiMn2O4 with high adsorption capacity and good selectivity; the lithium ion sieve material of the lithium extraction electrode 4 in the medium-concentration tank is lithium iron phosphate with good chemical stability, relatively low ion diffusion coefficient and high capacity; the lithium ion sieve material of the lithium extraction electrode 4 in the low-concentration tank is Li2TiO3 with high diffusion coefficient, good stability but low capacity;

[0093] Along the flow direction of the lithium extraction solution 6 to be extracted, the lithium extraction electrode 4 in the first lithium extraction tank is the first lithium extraction electrode 4, the lithium extraction electrode 4 in the second lithium extraction tank is the second lithium extraction electrode 4, and so on; at the same time, the cathode main tank 1 is divided into a front section and a rear section, the front section includes the first lithium extraction electrode 4 to the tenth lithium extraction electrode 4, and the rear section includes the eleventh lithium extraction electrode 4 to the fifteenth lithium extraction electrode 4; the lithium extraction electrodes 4 in the front section are electrically connected in parallel, and the lithium extraction electrodes 4 in the rear section are electrically connected in series;

[0094] A voltage monitor is installed in each lithium extraction tank for monitoring the corresponding lithium extraction electrode 4 ; the voltage monitor is electrically connected to a host, which is used to analyze, store and display the working status and replacement information of the lithium extraction electrode 4 .

[0095] The application of the lithium extraction and deintercalation tank in this embodiment includes the following steps:

[0096] The lithium solution 6 to be extracted and hot air are introduced simultaneously from the first lithium extraction tank and flow in a zigzag manner in the cathode main tank 1. At the same time, a sodium chloride solution is introduced from the first deintercalation tank and flows in a zigzag manner in the anode main tank 8. The lithium solution 6 to be extracted is brine with a lithium ion concentration of 0.5 g / L and a flow rate of 3 L / h. The hot air is hot air with a temperature of 40° C. and a flow rate of 6 L / h.

[0097] The working current and working voltage of the lithium extraction electrode 4 are set according to Table 2, wherein the working current of the first lithium extraction electrode 4 is recorded as A1, the working current of the second lithium extraction electrode 4 is recorded as A2, A1>A2, and so on. The working voltage of the eleventh lithium extraction electrode 4 is recorded as V1, the working voltage of the twelfth lithium extraction electrode 4 is recorded as V2, and so on. The lithium extraction tank in the front section performs the said decreasing constant current electrolysis to extract lithium, and the lithium extraction tank in the said rear section performs the said decreasing constant voltage lithium extraction;

[0098] Table 2

[0099] When the real-time working voltage of the lithium extraction electrode 4 in a lithium extraction tank exceeds the set safety constant voltage of 0.8V, the voltage monitor will sound an alarm and a new lithium extraction electrode 4 will be replaced accordingly until the electrolytic lithium extraction is completed.

[0100] Example 3

[0101] This embodiment provides a lithium extraction and deintercalation cell and its application. The lithium extraction and deintercalation cell is exactly the same as that in Example 1. The difference between the cell and Example 1 is as follows:

[0102] The working voltage of the lithium extraction electrode 4 is set according to Table 3, wherein the lithium extraction electrode 4 in the first lithium extraction tank is the first lithium extraction electrode 4, and its working voltage is recorded as V1, and the lithium extraction electrode 4 in the second lithium extraction tank is the second lithium extraction electrode 4, and its working voltage is recorded as V2, V1>V2, and so on, to perform decreasing constant voltage electrolysis to extract lithium;

[0103] Table 3

[0104] Except for the above, other conditions are exactly the same as those in Example 1.

[0105] Example 4

[0106] This embodiment provides a lithium extraction and deintercalation cell and its application. As shown in FIG4 , no separator 2 is provided in the anode main cell 8 of the lithium extraction and deintercalation cell. Apart from this, other conditions are exactly the same as those in Example 1.

[0107] Comparative Example 1

[0108] This comparative example provides a lithium extraction and deintercalation cell and its use. The lithium extraction and deintercalation cell is exactly the same as that in Example 1. The difference between the application and Example 1 is that the operating current of all lithium extraction electrodes 4 is set to 25A, and other conditions are exactly the same as those in Example 1.

[0109] Comparative Example 2

[0110] This comparative example provides a lithium extraction and deintercalation cell and its application. The lithium extraction and deintercalation cell is exactly the same as that in Example 1. The difference between the application and Example 1 is that the operating current of all lithium extraction electrodes 4 is set to 1A, and other conditions are exactly the same as those in Example 1.

[0111] Comparative Example 3

[0112] This comparative example provides a lithium extraction and deintercalation cell and its use. The difference between the lithium extraction and deintercalation cell and Example 1 is that the openings 21 of all the separators 2 are uniformly set to a position 10 cm near the bottom of the separator 2, and are circular with a radius of 5 cm, so that the lithium solution 6 to be extracted is not allowed to flow in a baffled manner. Apart from this, the other conditions and application parameters of the lithium extraction and deintercalation cell are exactly the same as those of Example 1.

[0113] Comparative Example 4

[0114] This comparative example provides a lithium extraction and deintercalation cell and its application. The difference between the lithium extraction and deintercalation cell and Example 1 is that the lithium ion sieve material of all lithium extraction electrodes 4 is set to LiMn2O4. Apart from this, the other conditions and application parameters of the lithium extraction and deintercalation cell are exactly the same as those in Example 1.

[0115] Comparative Example 5

[0116] This comparative example provides a lithium extraction and deintercalation cell and its use. The difference between the lithium extraction and deintercalation cell and Example 1 is that the lithium ion sieve material of all lithium extraction electrodes 4 is set to Li2TiO3. Apart from this, the other conditions and application parameters of the lithium extraction and deintercalation cell are exactly the same as those of Example 1.

[0117] Comparative Example 6

[0118] This comparative example provides a lithium extraction and deintercalation cell and its application. The lithium extraction and deintercalation cell differs from Example 1 in that no hot air is used and only the lithium solution 6 to be extracted is introduced. Apart from this, the other conditions and application parameters of the lithium extraction and deintercalation cell are exactly the same as those of Example 1.

[0119] After the same amount of brine was introduced to extract lithium, the concentration of lithium ions remaining in the last lithium extraction tank in the example and comparative example solutions was tested, and the lithium extraction rate was calculated. The results are shown in Table 4.

[0120] Table 4

[0121] As can be seen from Table 1:

[0122] It can be seen from the residual lithium ion concentrations of Examples 1-3 that the power supply method of the electrolytic cell of this scheme is preferably power supply at different constant current segments. It can be seen from Example 1 compared to Example 4 that whether the anode has a partition has no effect on the results of this scheme; compared to Comparative Example 1, Example 1 uses a continuous high current as the power supply method, and the electrode plate easily exceeds the safety voltage, affecting lithium extraction, and the energy consumption and cost will be higher; Comparative Example 2 uses a low current, and the lithium extraction efficiency is extremely low; Comparative Example 3 has openings at the bottom, which will cause the brine in the lithium extraction tank to flow too fast and lithium cannot be extracted normally; compared to Comparative Examples 4-5, Example 1 uses a lithium ion sieve with a higher capacity at low concentrations, which will affect the lithium extraction efficiency, while using a lithium ion sieve with a lower capacity in high-concentration brine will increase the number of times the lithium ion sieve is replaced, and the operation is cumbersome; compared to Comparative Example 6, the introduction of hot air to increase the temperature of the lithium extraction environment can better improve the lithium extraction efficiency.

Claims

1. A lithium extraction and deintercalation cell, comprising: an anode main tank, wherein a de-embedding electrode is arranged in the anode main tank; A cathode main tank, wherein a partition is arranged in the cathode main tank, and the partition divides the cathode main tank into at least two lithium extraction tanks; the partition is provided with openings, and the openings between two adjacent partitions are staggered up and down along the height direction of the lithium extraction tank, so that the lithium solution to be extracted flows in the cathode main tank in a baffled manner; the lithium extraction tank is provided with lithium extraction electrodes, and the number of the lithium extraction electrodes corresponds to the number of the deintercalation electrodes; the lithium extraction electrodes are electrically connected to the deintercalation electrodes through an external power supply; A diaphragm is arranged between the anode main tank and the cathode main tank.

2. The lithium extraction and deintercalation cell according to claim 1, wherein: The separator is arranged in the anode main tank, dividing the anode main tank into deintercalation tanks corresponding to each of the lithium extraction tanks, and the number of deintercalation electrodes in the deintercalation tanks is the same as the number of lithium extraction electrodes in the corresponding lithium extraction tanks; Optionally, the first lithium extraction tank and the first deintercalation tank are both provided with a liquid inlet, and the last lithium extraction tank and the last deintercalation tank are both provided with a liquid outlet; Optionally, the number of the lithium extraction tanks is 10 to 20.

3. The lithium extraction and deintercalation cell according to claim 1 or 2, wherein: According to the change of lithium ion concentration in the lithium solution to be extracted in the cathode main tank, the lithium extraction tank is divided into a high concentration tank, a medium concentration tank and a low concentration tank.

4. The lithium extraction and deintercalation cell according to claim 3, wherein: The concentration of lithium ions in the high-concentration tank is greater than 0.1 g / L; the concentration of lithium ions in the medium-concentration tank is 0.01-0.1 g / L; the concentration of lithium ions in the low-concentration tank is less than 0.01 g / L.

5. The lithium extraction and deintercalation cell according to claim 3 or 4, wherein: The number of the high-concentration tanks is 2 to 8; the number of the medium-concentration tanks is 1 to 9; and the number of the low-concentration tanks is 1 to 9.

6. The lithium extraction and deintercalation cell according to any one of claims 3 to 5, wherein: The high-concentration tank is provided with a first lithium ion sieve material, the medium-concentration tank is provided with a second lithium ion sieve material, and the low-concentration tank is provided with a third lithium ion sieve material; Comparing the adsorption capacity per unit mass, the first lithium ion sieve material>the second lithium ion sieve material>the third lithium ion sieve material; Comparing the ion diffusion coefficient per unit mass, the first lithium ion sieve material is less than the second lithium ion sieve material and less than the third lithium ion sieve material; Optionally, the adsorption capacity of the first lithium ion sieve material is 35-38 mg / g; The adsorption capacity of the second lithium ion sieve material is 30-33 mg / g; the adsorption capacity of the third lithium ion sieve material is 12-15 mg / g; Optionally, the ion diffusion coefficient of the first lithium ion sieve material is 10 -10 ~10 -11 cm 2 / s; the ion diffusion coefficient of the second lithium ion sieve material is 10 -9 ~10 -10 cm 2 / s; the ion diffusion coefficient of the third lithium ion sieve material is 10 -7 ~10 -8 cm 2 / s.

7. The lithium extraction and deintercalation cell according to claim 6, wherein: The first lithium ion sieve material, the second lithium ion sieve material and the third lithium ion sieve material are physical adsorption materials or electrochemical adsorption materials; Optionally, when the first lithium ion sieve material, the second lithium ion sieve material and the third lithium ion sieve material are electrochemical adsorption materials, the first lithium ion sieve material, the second lithium ion sieve material and the third lithium ion sieve material are respectively arranged on lithium extraction electrodes in corresponding lithium extraction tanks.

8. The lithium extraction and deintercalation cell according to claim 7, wherein: When the first lithium ion sieve material, the second lithium ion sieve material and the third lithium ion sieve material are physical adsorption materials: The first lithium ion sieve material includes a manganese dioxide adsorbent; the second lithium ion sieve material includes a lithium silicate adsorbent; and the third lithium ion sieve material includes an aluminum hydroxide-based adsorbent.

9. The lithium extraction and deintercalation cell according to claim 7, wherein: When the first lithium ion sieve material, the second lithium ion sieve material and the third lithium ion sieve material are electrochemical adsorption materials: The first lithium ion sieve material includes a manganese oxide lithium ion sieve; the second lithium ion sieve material includes any one of lithium cobalt oxide, lithium vanadate or lithium iron phosphate or a combination of at least two; the third lithium ion sieve material includes a titanium oxide lithium ion sieve; Optionally, the manganese oxide lithium ion sieve includes LiMn2O4, Li 1.33 Mn 1.67 O4 or Li 1.6 Mn 1.6 At least one of O4; Optionally, the titanium oxide lithium ion sieve comprises Li2TiO3 and / or Li4Ti5O 12 .

10. The lithium extraction and deintercalation cell according to any one of claims 1 to 9, wherein: Each of the lithium extraction tanks is equipped with a current and / or voltage monitor for monitoring the corresponding lithium extraction electrode; Optionally, the current and / or voltage monitor is electrically connected to a host, and the host is used to analyze, store and display the working status and replacement information of the lithium extraction electrode.

11. The lithium extraction and deintercalation cell according to any one of claims 1 to 10, wherein: The opening on the partition is arranged near the top end or the bottom end of the partition; Optionally, along the height direction of the partition, the distance between the edge of the opening and the top or bottom of the partition accounts for 5% to 10% of the height of the partition; Optionally, the radius of the opening is 3 to 8 cm.

12. An application of the lithium extraction and deintercalation cell according to any one of claims 1 to 11, comprising the following steps: The lithium solution to be extracted and hot gas are introduced into the first lithium extraction tank at the same time, and flow in a zigzag manner in the cathode main tank to perform decreasing constant current electrolysis and / or decreasing constant voltage electrolysis for lithium extraction.

13. The use according to claim 12, wherein: The decreasing constant current electrolysis for lithium extraction includes that during the process of electrolysis for lithium extraction, the working current of the lithium extraction electrode in the lithium extraction tank remains unchanged, and the working current of the lithium extraction electrode decreases successively or in stages along the flow direction of the lithium solution to be extracted; Optionally, in the decreasing constant current electrolysis for lithium extraction, the difference in working current between two adjacent lithium extraction electrodes is 0.5 to 7A; Optionally, the lithium extraction electrodes in the decreasing constant current electrolysis lithium extraction are electrically connected in parallel.

14. The use according to claim 12 or 13, wherein: The decreasing constant-voltage electrolysis for lithium extraction includes that, during the process of electrolysis for lithium extraction, the working voltage of the lithium extraction electrode in the lithium extraction tank remains unchanged, and the working voltage of the lithium extraction electrode decreases sequentially or in stages along the flow direction of the lithium solution to be extracted; Optionally, in the decreasing constant-voltage electrolysis for lithium extraction, the difference in working voltages between two adjacent lithium extraction electrodes is 0.05 to 0.15 V; Optionally, the lithium extraction electrodes in the decreasing constant-voltage electrolysis lithium extraction are electrically connected in series.

15. The use according to any one of claims 12 to 14, wherein: The cathode main tank is divided into a front section and a rear section along the flow direction of the lithium solution to be extracted, the lithium extraction tank in the front section is subjected to the decreasing constant current electrolysis to extract lithium, and the lithium extraction tank in the rear section is subjected to the decreasing constant pressure electrolysis to extract lithium; Optionally, the ratio of the number of lithium extraction tanks in the front section to the number of lithium extraction tanks in the back section is greater than or equal to 2.

16. The use according to any one of claims 12 to 15, wherein: The lithium solution to be extracted includes brine; Optionally, the concentration of lithium ions in the brine is 0.2 to 0.8 g / L; Optionally, the flow rate of the lithium solution to be extracted is 1 to 5 L / h; Optionally, the temperature of the hot air is 35-40°C; Optionally, the hot gas comprises air and / or an inert gas; Optionally, the flow ratio of the hot gas to the lithium solution to be extracted is 1:(1-2); Optionally, the application further comprises: when the lithium solution to be extracted and hot gas are simultaneously introduced into the first lithium extraction tank, pure water and / or sodium chloride solution is introduced into the anode main tank.

17. The use according to any one of claims 12 to 16, wherein: During the process of electrolytic lithium extraction, the current and / or voltage of the lithium extraction electrode in the lithium extraction tank is monitored, and when it exceeds a preset value, the corresponding lithium extraction electrode is replaced.

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