Electrochemical pelletizing electrode deintercalation lithium extraction membrane stack electrolysis equipment

Abstract

The application discloses an electrochemical granulation electrode deintercalation lithium extraction membrane stack electrolysis equipment, which comprises an electrolysis tank and an electrode assembly; the electrolysis tank comprises a first side plate, a piece of side plate rubber pad, a plurality of tank bodies, another piece of side plate rubber pad, a second side plate and a first tank body rubber pad, an anion membrane and a second tank body rubber pad arranged in sequence between two adjacent tank bodies; the tank bodies are divided into anode tanks and cathode tanks, the anode tanks and the cathode tanks are arranged alternately in an X direction from the first side plate to the second side plate, and the number of the anode tanks is equal to that of the cathode tanks; and an elastic porous pad is laid on the inner cavity bottom wall of the tank body. The electrolysis equipment can realize efficient extraction of lithium resources in salt lake brine, has the advantages of high lithium recovery rate and current efficiency, and is convenient to install, maintain and observe and monitor in the lithium extraction process.

Description

Technical Field

[0001] This invention relates to the field of lithium extraction from salt lakes. Specifically, it relates to an electrochemical granulation electrode lithium extraction membrane stack electrolysis device. Background Technology

[0002] The rapid development of the new energy vehicle industry in recent years, coupled with the booming energy storage market, has led to a dramatic increase in the demand for lithium from both sectors. As more and more companies enter the lithium battery industry, lithium prices have fallen from nearly 600,000 yuan / ton in 2019 to 200,000 yuan / ton in 2021, and are expected to continue declining to 100,000 yuan / ton in 2023. This price is unbearable for most ore-based lithium extraction companies. However, for companies extracting lithium from salt lakes, this price still offers some profit margin. Furthermore, salt lake resources are vast and account for over 60% of lithium resources. Therefore, salt lake lithium extraction has attracted significant attention and importance from companies.

[0003] Currently, the main lithium extraction technologies applied to industrial production in salt lakes include solar pond methods, adsorption methods, and extraction methods. However, these technologies all have certain limitations. Solar pond methods rely on sunlight, resulting in production volumes significantly affected by seasonality, and are also time-consuming and inefficient. Adsorption methods suffer from low adsorption capacity, high adsorbent prices, and high freshwater consumption. Extraction methods, which often employ organic extractants and acid / alkaline treatment processes, are prone to environmental pollution. The rocking chair-type coated electrode electrochemical lithium extraction method also has some problems, such as the high cost of titanium mesh electrode carriers, complex equipment that is difficult to disassemble and assemble, and the time-consuming and inconsistent coating process on the electrodes. Summary of the Invention

[0004] Therefore, the technical problem to be solved by the present invention is to provide an electrochemical granulation electrode deintercalation and extraction lithium membrane stack electrolysis device, which is convenient to disassemble and maintain, has low cost, and has high lithium extraction efficiency.

[0005] To solve the above-mentioned technical problems, the present invention provides the following technical solution:

[0006] An electrochemical granulation electrode lithium extraction membrane stack electrolysis device includes an electrolytic cell and an electrode assembly. The electrolytic cell includes a first side plate, a side plate pad, multiple tanks, another side plate pad, a second side plate, and a first tank pad, an anion exchange membrane, and a second tank pad arranged sequentially between adjacent tanks. The tanks are divided into anode tanks and cathode tanks. In the X direction from the first side plate to the second side plate, the anode tanks and cathode tanks are arranged alternately, and the number of anode tanks and cathode tanks is equal. An elastic porous pad is laid on the bottom wall of the inner cavity of the tank. The liquid inlet of the tank is located below the elastic porous pad, and the liquid outlet is opened on the side wall of the tank.

[0007] The electrode assembly includes a current collector, a carrier frame fixedly mounted on one side of the current collector, a fixing frame that fixes the current collector and the carrier frame together, and granulated active material filled in the carrier frame. The carrier frame has multiple perforations arranged in a matrix. The electrode assembly is placed in the anode tank and cathode tank respectively, with the top of the carrier frame lower than the outlet and the bottom of the carrier frame higher than the inlet. When used for lithium extraction, the lithium-rich solution or brine flows through the inner cavity of the electrolytic cell in a "bottom-in, top-out" manner. The perforations on the carrier frame facilitate the entry of the solution from the inner cavity of the cell into the carrier frame and ensure sufficient contact with the granulated active material. The elastic porous pad supports the electrode assembly and guides the solution, allowing the solution to flow evenly and smoothly into the carrier frame through the perforations.

[0008] In the aforementioned electrochemical granulation electrode lithium extraction membrane stack electrolysis equipment, the number of tanks is an even number greater than or equal to 2 and less than or equal to 260; the side plate pads, the tanks, the first tank pads, and the second tank pads are all U-shaped; and the anion exchange membrane separates the inner cavities of two adjacent tanks.

[0009] The aforementioned electrochemical granulation electrode lithium extraction membrane stack electrolysis equipment features a U-shaped tank with an open top. The inner cavity of the tank is formed by two parallel and opposing vertical plates and a bottom plate sandwiched between the vertical plates and perpendicular to them. The two vertical plates are designated as a first vertical plate and a second vertical plate, respectively. The lower surfaces of the bottom plate, the first vertical plate, and the second vertical plate are located in the same plane. The open-top design of the tank facilitates observation and monitoring during the lithium extraction process.

[0010] In the aforementioned electrochemical granulation electrode lithium extraction membrane stack electrolysis equipment, adjacent tanks, the first side plate and the tank adjacent to the first side plate, and the second side plate and the tank adjacent to the second side plate are all connected by connecting plates. The connecting plates protrude along the outer edges of the U-shaped end faces of the tanks, the outer edges of the first and second side plates, respectively. Multiple threaded holes for bolts to pass through are machined on the connecting plates. An anode tank, a cathode tank, and the tank gasket and anion exchange membrane between them together form a tank unit. Multiple tank units can be interconnected through the connecting plates and threaded holes. This modularizes the entire electrolysis equipment, allowing for increased lithium extraction capacity by increasing the number of tank units. Furthermore, the modules are clearly spaced, making maintenance and repair convenient and efficient.

[0011] In the aforementioned electrochemical granulation electrode lithium extraction membrane stack electrolysis equipment, the length of the connecting plate protruding from the edge of the tank, the length of the connecting plate protruding from the edge of the first side plate, and the length of the connecting plate protruding from the edge of the second side plate are all 10-30 mm; the thickness of the connecting plate is 3 mm-10 mm; the diameter of the threaded hole is 4-7 mm; the material of the connecting plate is one of acrylic, PVC, PP, and PE; the material of the bolt is one of carbon steel, stainless steel, and alloy steel, and the model is one of M4, M5, and M6.

[0012] In the aforementioned electrochemical granulation electrode lithium extraction membrane stack electrolysis equipment, the liquid outlet is located at the upper part of the second vertical plate; the bottom plate of the tank contains a main liquid inlet channel and a branch liquid inlet channel; the main liquid inlet channel is perpendicular to the first vertical plate and extends towards the second vertical plate, and is a horizontal pipe with a single-end opening; the opening of the main liquid inlet channel is the liquid inlet.

[0013] The inlet branch channel is conductively connected between the main inlet channel and the bottom wall of the inner cavity of the tank. There are multiple inlet branch channels, which are evenly arranged along the extension direction of the main inlet channel. The axis of the inlet branch channel is perpendicular to the axis of the main inlet channel. The even distribution of the inlet branch channels at the bottom of the tank allows the lithium-rich solution and brine to enter the inner cavity of the tank evenly, reducing concentration polarization during electrolysis.

[0014] The diameter of the main inlet channel is larger than the diameter of the branch inlet channels. The diameter of the branch inlet channels is smaller than the diameter of the main inlet channel, and the branch inlet channels are evenly distributed along the direction of extension of the main inlet channel, which is conducive to the uniform flow of lithium-rich solution and brine into the inner cavity of the tank.

[0015] In the aforementioned electrochemical granulation electrode lithium extraction membrane electrolysis equipment, the height of the tank is 200–330 mm, and the width of the tank in the X direction is 10–30 mm. Taking the direction from the first vertical plate to the second vertical plate as the Y direction, the width of the tank in the Y direction is 200–300 mm, and the width of the inner cavity of the tank in the Y direction is 150–200 mm. When the width of the tank in the X direction is within this range, the distance between the anode electrode assembly in the anode tank and the cathode electrode assembly in the cathode tank is more suitable. If the distance between the cathode electrode assembly and the anode electrode assembly is too large, the resistance of the reaction system will be too high, the polarization of the electro-deintercalation process will be too large, and the lithium extraction efficiency will be reduced. If the distance between the cathode electrode assembly and the anode is too small, the amount of granulated active material that can be filled in the electrode assembly is small, which can easily lead to problems such as the electrode assembly being too small and difficult to process.

[0016] In the aforementioned electrochemical granulation electrode lithium extraction membrane stack electrolysis equipment, the thickness of the side plate gasket is 2–5 mm, and the thickness of the anion exchange membrane is 0.1–0.5 mm with a resistance of less than 50 Ω / cm. 2 The thickness of the first and second tank body rubber pads is 2-5 mm; the thickness of the elastic porous pad is 3-5 mm, the pore size of the elastic porous pad is 0.05-2 mm, and the porosity is 70%-80%; the anion exchange membrane is a Zhejiang Lanran anion exchange membrane or a Seter anion exchange membrane; the side plate rubber pad, the first tank body rubber pad, and the second tank body rubber pad are made of one of silicone rubber, nitrile rubber, and neoprene rubber; the elastic porous pad is foam or recycled foam. If the elastic porous pad is too thick, it will occupy more space in the tank cavity, resulting in a reduction in the amount of granulating active material contained in the tank cavity. If the elastic porous pad is too thin, or has too large or too many pores, it will be difficult to uniformly guide the liquid entering the tank cavity; if the elastic porous pad has too small or too few pores, the solvent will make it difficult for lithium-rich solutions and brine to enter the tank cavity.

[0017] In the aforementioned electrochemical granulation electrode lithium extraction membrane electrolysis equipment, the granulation active material in the anode tank is Li. x FePO4 or Li x Mn₂O₄, x > 0.4 and < 1 or less, the granulation active material in the cathode cell is Li y FePO4 or Li y Mn₂O₄, y is greater than or equal to 0.4 and less than 1, and x is greater than y; the granulation active material is short cylindrical particles with a diameter of 1-3 mm and a column length of 3-5 mm; the filler density of the granulation active material in the carrier frame is 0.7-0.86 g / cm³. 3 The diameter of the permeation holes is 0.5–1.5 mm. The granulated active material in the anode tank is lithium-deficient, while the granulated active material in the cathode tank is lithium-rich. When the values ​​of x and y are within the above ranges, although the lithium-deficient capacity is sacrificed, a longer cycle life is ensured. When the loading amount and packing density of the granulated active material are within the above ranges, the lithium-rich solution and brine can fully wet the surface of the granulated active material, and the carrier frame can hold as much granulated active material as possible, which is beneficial to improving the lithium extraction efficiency.

[0018] In the aforementioned electrochemical granulation electrode lithium extraction membrane stack electrolysis equipment, the current collector is a graphite plate or graphite carbon felt with a thickness of 2-3 mm; the carrier frame is made of PVC, PE, or PP; the electrode assemblies on both sides of the anion exchange membrane are arranged in a mirror-symmetrical manner, and the carrier frame in the tank adjacent to the first side plate is in close proximity to the anion exchange membrane. The current collector material is reasonably priced, readily available, and does not exhibit passivation due to exposure to air. The thickness of the current collector ensures sufficient strength while minimizing its volume within the tank cavity, thus increasing the space occupied by the active material. The mirror-symmetrical arrangement of the electrode assemblies on both sides of the anion exchange membrane, and the carrier frame in the tank adjacent to the first side plate, ensures that the granulated active material is located between the two current collectors and within the electric field range in a pair of anode and cathode tanks, resulting in better lithium extraction performance.

[0019] The technical solution of the present invention achieves the following beneficial technical effects:

[0020] 1. The electrochemical granulation, deintercalation, and extraction lithium membrane stack electrolytic cell equipment of the present invention, through the adoption of a U-shaped tank design, achieves a bottom-in, top-out circulation of the solution. Simultaneously, by laying an elastic porous pad at the bottom of the tank and controlling the height of the carrier frame, the phenomenon of the carrier frame affecting the inflow and outflow of the tank solution is prevented, ensuring uniform inflow of lithium-rich solution and brine, reducing concentration polarization during electrolysis, thus not only improving electrolysis efficiency but also helping to maintain solution stability and extending the service life of the equipment. Furthermore, by controlling the pore size of the carrier frame, leakage of granulation active material is effectively prevented while ensuring sufficient solution wetting, ensuring the stability and efficiency of the electrolysis process. In addition, the use of graphite plates as current collectors is not only affordable and readily available but also avoids passivation caused by metal exposure to air, improving the reliability and service life of the equipment.

[0021] 2. This invention employs a unique U-shaped tank connection design, using bolts to connect two adjacent U-shaped tanks and utilizing U-shaped tank gaskets to ensure the stability and sealing of the equipment structure. Simultaneously, high-quality materials such as acrylic, PVC, PP, or PE boards are used for the connecting plates, and high-strength materials such as carbon steel, stainless steel, or alloy steel are used for the bolts, guaranteeing the durability and safety of the equipment. These material choices and structural design collectively improve the conductivity and performance of the equipment. Furthermore, the modular design of the equipment makes it easy to expand and maintain; adding tank units can improve lithium extraction efficiency, adapting to different production scales. The electrolysis equipment in this invention has a clear overall structure and well-defined intervals, allowing operators and maintenance personnel to quickly locate and handle problems, greatly improving the equipment's operating efficiency and stability.

[0022] 3. This invention achieves optimized cycle life by precisely controlling the types and lithium content ranges of lithium-deficient and lithium-rich active materials, while sacrificing some lithium-deficient capacity. The electrolysis equipment in this invention can efficiently extract lithium resources from salt lake brine, with advantages of high lithium recovery rate and current efficiency. Furthermore, the equipment is open-type (semi-open), facilitating installation, maintenance, and monitoring of the lithium extraction process. The extracted solution has a high lithium-ion concentration and a low ratio of impurity ions to lithium ions. Attached Figure Description

[0023] Figure 1 A schematic diagram of the electrolytic cell in Embodiment 1 of the present invention;

[0024] Figure 2 A top view of the electrolytic cell in Embodiment 1 of the present invention;

[0025] Figure 3 Enlarged view of a partial structure of the electrolytic cell in Embodiment 1 of the present invention;

[0026] Figure 4 A schematic diagram of the cathode trench in Embodiment 1 of the present invention;

[0027] Figure 5 A schematic diagram of the electrode assembly structure in Embodiment 1 of the present invention;

[0028] Figure 6 A schematic diagram of the electrode assembly structure in Embodiment 1 of the present invention;

[0029] Figure 7 A schematic diagram of the placement of the electrode assembly in the tank in Embodiment 1 of the present invention.

[0030] The reference numerals in the figure are as follows: 1-side plate; 101-first side plate; 102-second side plate; 2-tank body; 3-connecting plate; 301-first connecting plate; 302-second connecting plate; 303-third connecting plate; 201-anode tank; 202-cathode tank; 2021-first vertical plate; 2022-second vertical plate; 4-side plate gasket; 5-anion exchange membrane; 6-first tank gasket; 7-second tank gasket; 8-bolt; 9-outlet; 10-main inlet channel; 11-branch inlet channel; 12-current collector; 13-granulation active material; 14-carrier frame; 15-fixing frame; 16-elastic porous pad; 17-inlet. Detailed Implementation

[0031] Example 1

[0032] The electrolysis equipment in this embodiment includes an electrolytic cell and an electrode assembly. For example... Figure 1 and Figure 2As shown, the electrolytic cell includes two side plates 1 (first side plate 101 and second side plate 102) and 10 tank bodies 2 sandwiched between the two side plates 1. Each side plate 1 and its adjacent tank body 2 are sandwiched with a side plate gasket 4. Between two adjacent tank bodies 2, a first tank body gasket 6, an anion exchange membrane 5, and a second tank body gasket 7 are arranged in sequence. Figure 3 As shown.

[0033] The thickness of the first side plate 101 and the second side plate 102 is 3mm. The thickness of the side plate rubber pad 4, the first tank rubber pad 6, and the second tank rubber pad 7 is 2mm, and the thickness of the anion exchange membrane 5 is 0.2mm. The side plate rubber pad 4, the first tank rubber pad 6, and the second tank rubber pad 7 are all U-shaped nitrile rubber sheets. The shape of the first tank rubber pad 6 matches the shape of the U-shaped surface of the tank 2, and the shape of the second tank rubber pad 7 is the same as the shape of the first tank rubber pad 6.

[0034] The tank body 2 is divided into an anode tank and a cathode tank. In this embodiment, the electrolytic cell includes 5 anode tanks 201 and 5 cathode tanks 202. With the direction from the first side plate 101 to the second side plate 202 as the X direction, the anode tanks and the cathode tanks are arranged alternately in the X direction.

[0035] The trough 2 is a U-shaped trough made of PVC. For example... Figure 4 As shown, the inner cavity of tank 2 is formed by two parallel and opposing vertical plates and a bottom plate sandwiched between the two vertical plates and perpendicular to them, with an opening at the top. An anion exchange membrane 5 separates the inner cavities of two adjacent tanks 2. In this embodiment, the anion exchange membrane is a Seter anion exchange membrane with a resistance of 7.5 Ω / cm. 2 .

[0036] The two parallel, opposing vertical plates forming the inner cavity of the tank 2 are a first vertical plate 2021 and a second vertical plate 2022. Both the first vertical plate 2021 and the second vertical plate 2022 have a width of 15mm in the X direction (equal to the width of the inner cavity of the tank 2 in the X direction), a height of 200mm, and a thickness of 5mm. Each of the first vertical plate 2021 and the second vertical plate 2022 has one surface that forms the sidewall of the inner cavity of the tank 2, and the vertical distance between these two surfaces is 190mm. That is, with the direction from the first vertical plate 2021 to the second vertical plate 2022 as the Y direction, the width of the inner cavity of the tank 2 in the Y direction is 190mm; and the width of the tank 2 in the Y direction is 200mm, which is equal to the sum of the width of the inner cavity of the tank 2 in the Y direction and the thickness of the two vertical plates. The inner cavity of the tank 2 is 160mm deep.

[0037] The lower surfaces of the base plate, the first vertical plate 2021, and the second vertical plate 2022 are coplanar, and the upper surface of the base plate is the bottom wall of the inner cavity of the tank 2. A cylindrical main inlet channel 10 and a cylindrical branch inlet channel 11 are embedded in the base plate. The main inlet channel 10 extends parallel to the Y direction and is a horizontal, single-end open pipe. The opening of the main inlet channel 10 is the inlet 17 of the tank 2, which is located on the first vertical plate 2021. The main inlet channel 10 is 180mm long and 8mm in diameter, and the thickness of the base plate below the main inlet channel 10 is 25mm. The branch inlet channel 11 is connected between the main inlet channel 10 and the inner cavity of the tank 2, and the opening of the branch inlet channel 11 connecting to the inner cavity of the tank 2 is located on the bottom wall of the inner cavity of the tank 2. In this embodiment, there are five inlet branch channels 11, arranged along the Y direction, and the axis of each inlet branch channel 11 is perpendicular to the axis of the main inlet channel 10. The distance between two adjacent inlet branch channels 11 is 25mm, and the vertical distance between the inlet branch channel 11 closest to the inlet 17 and the plane where the inlet 17 of the tank 2 is located is 25mm. Each inlet branch channel 11 has a diameter of 5mm and a height of 7mm.

[0038] A through-hole 9 is provided on the upper part of the second vertical plate 2022. The outlet 9 is in fluid communication with the inner cavity of the tank 2, and the liquid in the inner cavity of the tank 2 flows out of the inner cavity of the tank 2 through the outlet 9. In this embodiment, the diameter of the outlet 9 is 8mm, and the distance between the outlet 9 and the upper edge of the second vertical plate 2022 is 5mm.

[0039] An elastic porous pad 16 is placed on the bottom wall of the inner cavity of the tank 2. In this embodiment, the elastic porous pad 16 is made of foam, which is 190mm long, 15mm wide, and 5mm thick, meaning that the dimensions of the foam match the dimensions of the bottom wall of the inner cavity of the tank 2. In this embodiment, the pore size of the foam is 0.1mm, and the porosity is 80%.

[0040] Adjacent side plates 1 and tank bodies 2, as well as adjacent tank bodies 2, are connected by connecting plates 3. The connecting plates 3 protrude from the outer edges of the two U-shaped end faces of the tank body 2. The connecting plates 3 include a first connecting plate 301, a second connecting plate 302, and a third connecting plate 303. The first connecting plate 301 is fixedly mounted on the first upright plate 2021, and its lower end extends 5mm above the main inlet channel 10 to avoid obstructing it. The second connecting plate 302 is fixedly mounted on the bottom plate of the tank body 2, and the third connecting plate 303 is fixedly mounted on the second upright plate 2022. One end of the second connecting plate 302 is connected to the lower end of the third connecting plate 303, and the upper end of the third connecting plate 303 extends 5mm below the outlet 9 to avoid obstructing it. Both the first side plate 101 and the second side plate 102 are provided with connecting plates 3 along their edges, and the connecting plates 3 are in contact with the connecting plates 3 of the adjacent tanks, and their shapes are the same as those of the connecting plates 3 of the tanks. In this embodiment, the connecting plates 3 are made of PVC.

[0041] In this embodiment, the thickness of the connecting plate 3 is 3mm. The lengths of the connecting plate 3 protruding from the outer edge of the U-shaped end face of the groove 2, the lengths of the connecting plate 3 protruding from the edge of the first side plate 101, and the lengths of the connecting plate 3 protruding from the edge of the second side plate 102 are all 15mm. The connecting plate 3 has threaded holes with a diameter of 5mm, and the distance between any two adjacent threaded holes is 40mm. The threaded holes of adjacent connecting plates 3 are opposite each other and connected to each other by bolts 8. In this embodiment, the bolts 8 used are M5 type bolts with a thread length of 12mm and a diameter of 5mm.

[0042] In this embodiment, the electrode assembly is placed in tank 2. For example... Figure 5 and Figure 6 As shown, the electrode assembly includes a current collector 12, a carrier frame 14, a fixing frame 15, and a granulating active material 13. The current collector 12 and the carrier frame 14 are fixed together by the fixing frame 15. The current collector 12 has a plate-like structure, and the carrier frame 14 is attached to one side of the current collector 12. The granulating active material 13 is filled inside the carrier frame 14. The electrode assembly is placed on an elastic porous pad, with the bottom of the carrier frame 14 higher than the liquid inlet 17 of the tank 2 and the top lower than the liquid outlet 9 of the tank 2.

[0043] In this embodiment, the current collector 12 is a graphite plate. The current collector 12 has a width of 190mm in the Y direction, a thickness of 2mm, and a height of 180mm. The height of the current collector 12 is 20mm greater than the depth (160mm) of the inner cavity of the tank 2, meaning the upper end of the current collector 12 extends outside the tank body to facilitate secure clamping of the current collector 12 during electrolysis. The carrier frame 14 has a width of 190mm in the Y direction, a width of 12mm in the X direction, and a height of 142mm. It is composed of four PVC plates connected end-to-end, with multiple 0.5mm diameter perforations arranged in a matrix on the PVC plates. When used as a positive electrode assembly, the granulating active material 13 filled in the carrier frame 14 is LiFePO4; when used as a negative electrode assembly, the granulating active material 13 filled in the carrier frame 14 is Li 0.4 FePO4. The loading amount of granulated active material in the carrier frame 14 of both the positive and negative electrode components is 275g, i.e., the filler density is 0.85g / cm³. 3 Granulation active substance 13 consists of short cylindrical particles with a diameter of 1–3 mm and a column length of 3–5 mm.

[0044] In use, the positive electrode assembly and the negative electrode assembly are placed into the anode tank 201 and the cathode tank 202, respectively. For example... Figure 7 As shown, in this embodiment, the electrode assemblies on both sides of the anion exchange membrane 5 are arranged in a mirror-symmetrical manner, and the carrier frame 14 of the electrode assembly (the electrode assembly on the left in the figure) placed in the anode tank 201 adjacent to the first side plate 101 is adjacent to the anion exchange membrane 5. The inlet 17 and outlet 9 of the anode tank are respectively connected to a lithium-rich liquid tank with a volume of 20L. Under the action of the liquid pump, the liquid in the lithium-rich liquid tank flows sequentially through the inlet, main inlet channel, branch inlet channel, inner cavity of the tank, and outlet 9 of the anode tank, and then returns to the lithium-rich liquid tank. The inlet 17 and outlet 9 of the cathode tank are respectively connected to the same brine storage tank with a volume of 40L. Under the action of another liquid pump, the liquid in the brine storage tank flows sequentially through the inlet, main inlet channel, branch inlet channel, inner cavity of the tank, and outlet 9 of the cathode tank, and then returns to the brine storage tank.

[0045] Based on the electrolysis equipment in this embodiment, an electrochemical deintercalation method was used to treat brine from a salt lake. The brine volume was 30L, and the lithium-rich liquid volume was 15L. Both the lithium-rich liquid and the brine flowed through the electrolysis cell in a "bottom-in, top-out" manner. Initial brine and lithium-rich liquid samples were taken for testing, and the power consumption and lithium extraction capacity per unit of granulated active material were calculated. The composition of the brine and lithium-rich liquid before and after lithium extraction is shown in Table 1. It can be seen that after lithium extraction by electrolysis equipment, the lithium ion concentration in the lithium-rich liquid reached 1.25g / L, which is 11 times the initial concentration. The sodium-lithium ratio decreased from 76:1 in the brine to 2.6:1 in the lithium-rich liquid. The calculated electrochemical power consumption per unit of lithium extraction by this electrolysis equipment was 0.78Wh, and the lithium extraction capacity per gram of granulated active material was 13.8mg.

[0046] Table 1. Composition of brine and lithium-rich solution before and after electrochemical deintercalation.

[0047]

[0048] Example 2

[0049] The electrolysis equipment in this embodiment includes an electrolytic cell and an electrode assembly. The electrolytic cell includes two side plates 1 (first side plate 101 and second side plate 102) and a plurality of tank bodies 2 sandwiched between the two side plates 1. A side plate gasket 4 is sandwiched between each side plate 1 and the adjacent tank body 2. A first tank body gasket 6, an anion exchange membrane 5, and a second tank body gasket 7 are arranged sequentially between two adjacent tank bodies 2.

[0050] The tank 2 is divided into an anode tank and a cathode tank. In this embodiment, the electrolytic cell includes 10 anode tanks 201 and 10 cathode tanks 202. With the direction from the first side plate 101 to the second side plate 202 as the X direction, the anode tanks and the cathode tanks are arranged alternately in the X direction. The tank 2 is a U-shaped tank made of PP. The side plate rubber pad 4, the first tank rubber pad 6, and the second tank rubber pad 7 are all U-shaped nitrile rubber sheets. The shape of the first tank rubber pad 6 matches the shape of the U-shaped surface of the tank 2, and the shape of the second tank rubber pad 7 is the same as the shape of the first tank rubber pad 6.

[0051] The thickness of the first side plate 101 is 3.5 mm, and the thickness of the second side plate 102 is 3 mm. The thickness of the side plate pad 4, the first tank pad 6, and the second tank pad 7 is 2 mm, and the thickness of the anion exchange membrane 5 is 0.2 mm.

[0052] The inner cavity of tank 2 is formed by two parallel and opposing vertical plates and a bottom plate sandwiched between the two vertical plates and perpendicular to them, with an opening at the top. An anion exchange membrane 5 separates the inner cavities of two adjacent tanks 2. In this embodiment, the anion exchange membrane is a Zhejiang Lanran anion exchange membrane with a resistivity of 6.6 Ω / cm. 2 .

[0053] The two parallel, opposing vertical plates forming the inner cavity of the tank 2 are a first vertical plate 2021 and a second vertical plate 2022. Both the first vertical plate 2021 and the second vertical plate 2022 have a width of 15mm in the X direction (equal to the width of the inner cavity of the tank 2 in the X direction), a height of 200mm, and a thickness of 5mm. Each of the first vertical plate 2021 and the second vertical plate 2022 has one surface that forms the sidewall of the inner cavity of the tank 2, and the vertical distance between these two surfaces is 190mm. That is, with the direction from the first vertical plate 2021 to the second vertical plate 2022 as the Y direction, the width of the inner cavity of the tank 2 in the Y direction is 190mm; the width of the tank 2 in the Y direction is 200mm, which is equal to the sum of the width of the inner cavity of the tank 2 in the Y direction and the thickness of the two vertical plates. The inner cavity of the tank 2 is 160mm deep.

[0054] The lower surfaces of the base plate, the first vertical plate 2021, and the second vertical plate 2022 are coplanar, and the upper surface of the base plate is the bottom wall of the inner cavity. A cylindrical main inlet channel 10 and a cylindrical branch inlet channel 11 are embedded in the base plate. The main inlet channel 10 extends parallel to the Y direction and is a horizontal, single-end open pipe. The opening of the main inlet channel 10 is the inlet 17 of the tank 2, which is located on the first vertical plate 2021. The main inlet channel 10 is 180mm long and 8mm in diameter, and the thickness of the base plate below the main inlet channel 10 is 25mm. The branch inlet channel 11 is connected between the main inlet channel 10 and the inner cavity of the tank 2, and the opening of the branch inlet channel 11 connecting to the inner cavity of the tank 2 is located on the bottom wall of the inner cavity of the tank 2. In this embodiment, there are five inlet branch channels 11, arranged along the Y direction, and the axis of each inlet branch channel 11 is perpendicular to the axis of the main inlet channel 10. The distance between two adjacent inlet branch channels 11 is 25mm, and the vertical distance between the inlet branch channel 11 closest to the inlet 17 and the plane where the inlet 17 of the tank 2 is located is 25mm. Each inlet branch channel 11 has a diameter of 5mm and a height of 7mm.

[0055] A through-hole 9 is provided on the upper part of the second vertical plate 2022. The outlet 9 is in fluid communication with the inner cavity of the tank 2, and the liquid in the inner cavity of the tank 2 flows out of the inner cavity of the tank 2 through the outlet 9. In this embodiment, the diameter of the outlet 9 is 8mm, and the distance between the outlet 9 and the upper edge of the second vertical plate 2022 is 5mm.

[0056] An elastic porous pad 16 is placed on the bottom wall of the inner cavity of the tank 2. In this embodiment, the elastic porous pad 16 is recycled foam, which is 190mm long, 15mm wide, and 5mm thick. That is, the size of the recycled foam matches the size of the bottom wall of the inner cavity of the tank 2. In this embodiment, the pore size of the foam is 0.1mm, and the porosity is 70%.

[0057] Adjacent side plates 1 and tank bodies 2, as well as adjacent tank bodies 2, are connected by connecting plates 3. The connecting plates 3 protrude from the outer edges of the two U-shaped end faces of the tank body 2. The connecting plates 3 include a first connecting plate 301, a second connecting plate 302, and a third connecting plate 303. The first connecting plate 301 is fixedly mounted on the first upright plate 2021, with its lower end extending 10mm above the main inlet channel 10 to avoid obstructing it. The second connecting plate 302 is fixedly mounted on the bottom plate of the tank body 2, and the third connecting plate 303 is fixedly mounted on the second upright plate 2022. One end of the second connecting plate 302 is connected to the lower end of the third connecting plate 303, and the upper end of the third connecting plate 303 extends 10mm below the outlet 9 to avoid obstructing it. Both the first side plate 101 and the second side plate 102 have connecting plates 3 along their edges, and the connecting plates 3 are in contact with the connecting plates 3 of the adjacent tanks, and their shapes are the same as those of the connecting plates 3 of the tanks. In this embodiment, the connecting plates 3 are made of PP.

[0058] In this embodiment, the thickness of the connecting plate 3 is 4mm. The lengths of the connecting plate 3 protruding from the outer edge of the U-shaped end face of the groove 2, the lengths of the connecting plate 3 protruding from the edge of the first side plate 101, and the lengths of the connecting plate 3 protruding from the edge of the second side plate 102 are all 16mm. The connecting plate 3 has threaded holes with a diameter of 6mm, and the distance between any two adjacent threaded holes is 40mm. The threaded holes of adjacent connecting plates 3 are opposite each other and connected to each other by bolts 8. In this embodiment, the bolts 8 used are M6 type bolts with a thread length of 10mm and a diameter of 6mm.

[0059] In this embodiment, the electrode assembly is placed in the tank 2. The electrode assembly includes a current collector 12, a carrier frame 14, a fixing frame 15, and a granulating active material 13. The current collector 12 and the carrier frame 14 are fixed together by the fixing frame 15. The current collector 12 has a plate-like structure, and the carrier frame 14 is attached to one side of the current collector 12. The granulating active material 13 is filled inside the carrier frame 14. The electrode assembly is placed on an elastic porous pad, with the bottom of the carrier frame 14 higher than the liquid inlet 17 of the tank 2 and the top lower than the liquid outlet 9 of the tank 2.

[0060] In this embodiment, the current collector 12 is a graphite plate. The current collector 12 has a width of 190mm in the Y direction, a thickness of 2mm, and a height of 180mm. The height of the current collector 12 is 20mm greater than the depth (160mm) of the inner cavity of the tank 2, meaning the upper end of the current collector 12 extends outside the tank body to facilitate secure clamping of the current collector 12 during electrolysis. The carrier frame 14 has a width of 190mm in the Y direction, a width of 12mm in the X direction, and a height of 142mm. It is composed of four PVC plates connected end-to-end, with multiple 0.5mm diameter perforations arranged in a matrix on the PVC plates. When used as a positive electrode assembly, the granulating active material 13 filled in the carrier frame 14 is LiFePO4; when used as a negative electrode assembly, the granulating active material 13 filled in the carrier frame 14 is Li 0.4 FePO4. The loading amount of granulated active material 13 in the carrier frame 14 of both the positive and negative electrode components is 275g, i.e., the filler density is 0.85g / cm³. 3 Granulation active substance 13 consists of short cylindrical particles with a diameter of 1–3 mm and a column length of 3–5 mm.

[0061] In use, positive electrode assemblies and negative electrode assemblies are placed into the anode and cathode tanks, respectively. The electrode assemblies on both sides of the anion exchange membrane 5 are arranged symmetrically in mirror image, and the carrier frame 14 of the electrode assembly placed in the tank body 2 adjacent to the first side plate 101 is close to the anion exchange membrane 5. The inlet 17 and outlet 9 of the anode tank are connected to the lithium-rich liquid tank, respectively. Under the action of the liquid pump, the liquid in the lithium-rich liquid tank flows sequentially through the inlet, main inlet channel, branch inlet channel, inner cavity of the tank, and outlet 9 of the anode tank, and then returns to the lithium-rich liquid tank. The inlet 17 and outlet 9 of the cathode tank are connected to the brine storage tank, respectively. Under the action of another liquid pump, the liquid in the brine storage tank flows sequentially through the inlet, main inlet channel, branch inlet channel, inner cavity of the tank, and outlet 9 of the cathode tank, and then returns to the brine storage tank.

[0062] Based on the electrolysis equipment in this embodiment, an electrochemical deintercalation method was used to treat brine from a salt lake. The volume of the brine was 145L, and the volume of the lithium-rich liquid was 75L. Both the lithium-rich liquid and the brine flowed through the electrolysis cell in a "bottom-in, top-out" manner. Initial brine and lithium-rich liquid samples were taken for testing, and the power consumption and lithium extraction capacity per unit of granulated active material were calculated. The composition of the brine and lithium-rich liquid before and after lithium extraction is shown in Table 2. It can be seen that after electrolytic lithium extraction, the lithium ion concentration in the lithium-rich liquid reached 1.15 g / L, which is 8.8 times the initial concentration. The sodium-lithium ratio decreased from 83:1 in the brine to 2.8:1. Calculations showed that the electrochemical power consumption per unit of lithium extraction in this embodiment was 0.76 Wh, and the lithium extraction capacity of the granulated active material 13 in this embodiment was 14.1 mg / g.

[0063] Table 2 Composition of brine and lithium-rich solution before and after electrochemical deintercalation.

[0064]

[0065] Example 3

[0066] The electrolysis equipment in this embodiment includes an electrolytic cell and an electrode assembly. The electrolytic cell includes two side plates 1 (first side plate 101 and second side plate 102) and 160 tank bodies 2 sandwiched between the two side plates 1. Each side plate 1 and its adjacent tank body 2 are sandwiched with a side plate gasket 4. A first tank body gasket 6, an anion exchange membrane 5, and a second tank body gasket 7 are arranged sequentially between two adjacent tank bodies 2. The tank body 2 consists of 80 anode tanks 201 and 80 cathode tanks 202. With the direction from the first side plate 101 to the second side plate 202 as the X direction, the anode tanks and cathode tanks are arranged alternately in the X direction. The tank body 2 is a U-shaped tank, and all are made of PE.

[0067] In this embodiment, the structure, dimensions, and arrangement of the first side plate 101, the second side plate 102, the tank 2, the anion exchange membrane 5, the side plate pad 4, the first tank pad 6, the second tank pad 7, and the elastic porous pad 16 are the same as in embodiment 1. In this embodiment, the connecting plate 3 is made of PE.

[0068] In this embodiment, the electrode assembly is placed in the tank 2. The structure of the electrode assembly is the same as in Embodiment 1. In this embodiment, the current collector 12 is a graphite carbon felt with a width of 190 mm, a thickness of 2 mm, and a height of 185 mm in the Y direction. The height of the current collector 12 is 25 mm greater than the depth (160 mm) of the inner cavity of the tank 2, meaning that the upper end of the current collector 12 extends out of the tank to facilitate the clamping of the current collector 12 during electrolysis. The structure and dimensions of the carrier frame 14 are the same as in Embodiment 1, and the material is PP. When used as a positive electrode assembly, the granulating active material 13 filled in the carrier frame 14 is LiFePO4; when used as a negative electrode assembly, the granulating active material 13 filled in the carrier frame 14 is Li 0.4 FePO4. The loading amount of granulated active material in the carrier frame 14 of both the positive and negative electrode components is 240g, i.e., the filler density is 0.74g / cm³. 3 .

[0069] The method of using the electrolysis equipment in this embodiment is the same as in Embodiment 1.

[0070] Based on the electrolysis equipment in this embodiment, an electrochemical deintercalation method was used to treat brine from a salt lake. The brine volume was 400L, and the lithium-rich solution volume was 200L. Both the lithium-rich solution and the brine flowed through the electrolysis cell in a "bottom-in, top-out" manner. Initial brine and lithium-rich solution samples were taken for testing before operation, and samples were taken again after electrochemical deintercalation. Finally, the energy consumption and lithium extraction capacity per unit of granulated active material were calculated. The main lithium extraction indicators of the electrolysis equipment in this embodiment are listed in Table 3. After lithium extraction by this electrolysis equipment, the lithium concentration (Li) in the lithium-rich solution reached 1.08 g / L, the sodium-lithium ratio decreased to 2.5:1, and the lithium yield reached 88.7%. The electrochemical energy consumption per unit of lithium extraction by this electrolysis equipment was 0.72 Wh, and the lithium extraction capacity per unit of granulated active material was 12.3 mg / g.

[0071] Table 3. Key Indicators for Lithium Extraction in Example 3

[0072]

[0073] Example 4

[0074] The electrolysis equipment in this embodiment includes an electrolytic cell and an electrode assembly. The structure of the electrolytic cell is basically the same as that in Embodiment 3, but it contains 130 anode cells 201 and 130 cathode cells 202, which are arranged alternately. The cell body 2 and the connecting plate 3 are both made of PVC, and the current collector 12 in the electrode assembly is made of graphite plate.

[0075] Based on the electrolysis equipment in this embodiment, an electrochemical deintercalation method is used to treat brine from a salt lake. The loading amount of granulated active material in the carrier frame 14 of both the positive and negative electrode components is 275g, and the filler density is 0.85g / cm³. 3 The brine volume used was 730L, and the lithium-rich liquid volume was 380L. Both the lithium-rich liquid and the brine flowed through the electrolytic cell in a "bottom-in, top-out" manner. Initial brine and lithium-rich liquid samples were taken for testing, and energy consumption and current density were calculated. The main lithium extraction indicators of the electrolytic equipment in this embodiment are shown in Table 4. It can be seen that after lithium extraction by the electrolytic equipment in this embodiment, the lithium yield reached 87.6%, the Li concentration of the lithium-rich liquid reached 1.21g / L, and the sodium-lithium ratio decreased to 2.6:1. The calculated electrochemical energy consumption per unit of lithium extraction by this electrolytic equipment was 0.71Wh, and the lithium extraction capacity of the granulated active material was 12.0mg / g.

[0076] Table 4. Main indicators of lithium extraction in Example 4

[0077]

[0078] Table 5 shows the main indicators of lithium extraction in each embodiment. As can be seen from the table, the electrochemical granulation and deintercalation lithium extraction equipment has the advantages of low power consumption, high lithium extraction efficiency, and removal of impurities.

[0079] Table 5. Main indicators of lithium extraction in different embodiments

[0080]

[0081] In other embodiments, the material of the tank 2 and the connecting plate 3 can also be acrylic. Furthermore, the width and height of the tank 2 in the Y direction can be adjusted according to actual needs. When the width of the tank 2 in the Y direction is within the range of 200-300mm, the height is within the range of 200-300mm, the width of the inner cavity of the tank 2 in the Y direction is within the range of 150-200mm, and the width in the X direction is within the range of 10-30mm, a better lithium extraction effect can be obtained.

[0082] In practical use, the diameter of the outlet 9, the diameter of the main inlet channel 10, and the diameter of the inlet branch channel 11 can also be adjusted as needed. When the diameter of the outlet 9 is in the range of 0.5 to 20 mm, the diameter of the main inlet channel is in the range of 5 to 10 mm, the diameter of the inlet branch channel is in the range of 2 to 6 mm, and the diameter of the main inlet channel 10 is larger than the diameter of the inlet branch channel 11, the inlet and outlet rates are more uniform, and the lithium extraction effect is better.

[0083] In some other embodiments, the distance between the connecting plate 3 and the liquid inlet 17 and the distance between the connecting plate 3 and the liquid outlet 9 can be adjusted, but both should be within the range of 5 to 10 mm.

[0084] The granulation active material in the carrier frame can be adjusted according to the size of the tank cavity and the carrier frame, but the overall filling amount is 230-280g, and the filler density is 0.7-0.86g / cm³. 3 It is preferable to place them inside the tank. Alternatively, the carrier frames of the electrode assembly in tank 2 can also be arranged in the same direction, but the lithium extraction efficiency will decrease accordingly.

[0085] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of the claims of this patent application.

Claims

1. An electrochemical granulation electrode lithium extraction and deintercalation membrane stack electrolysis device, characterized in that, The electrolytic cell includes an electrolytic cell and an electrode assembly; the electrolytic cell includes a first side plate (101), a side plate pad (4), multiple tank bodies (2), another side plate pad (4), a second side plate (102), and a first tank body pad (6), an anion exchange membrane (5), and a second tank body pad (7) arranged sequentially between two adjacent tank bodies (2); the tank body (2) is divided into an anode tank (201) and a cathode tank (202), and is located between the first side plate and the electrode assembly. In the X direction from plate (101) to the second side plate (102), the anode groove (201) and the cathode groove (202) are arranged alternately, and the number of anode grooves (201) and cathode grooves (202) is equal; an elastic porous pad (16) is laid on the bottom wall of the inner cavity of the tank body (2); the liquid inlet (17) of the tank body (2) is located below the elastic porous pad (16), and the liquid outlet (9) is opened on the side wall of the tank body (2); The electrode assembly includes a current collector (12), a carrier frame (14) fixedly mounted on one side of the current collector (12), a fixing frame (15) that fixes the current collector (12) and the carrier frame (14) together, and a granulating active material (13) filled in the carrier frame (14); the granulating active material (13) in the anode tank (201) is Li x FePO4 or Li x Mn2O4, x greater than 0.4 and less than or equal to 1, the granulation active material (13) in the cathode cell (202) is Li y FePO4 or Li y For Mn2O4, y is greater than or equal to 0.4 and less than 1, and x is greater than y; The carrier frame (14) has a plurality of seepage holes arranged in a matrix; the electrode assembly is placed in the anode tank (201) and the cathode tank (202) respectively, and the top of the carrier frame (14) is lower than the liquid outlet (9), and the bottom of the carrier frame (14) is higher than the liquid inlet (17).

2. The electrochemical granulation electrode lithium extraction and deintercalation membrane stack electrolysis equipment according to claim 1, characterized in that, The number of the tanks (2) is an even number greater than or equal to 2 and less than or equal to 260; the side plate pads (4), the tanks (2), the first tank pads (6) and the second tank pads (7) are all U-shaped; the anion membrane (5) separates the inner cavities of two adjacent tanks (2).

3. The electrochemical granulation electrode lithium extraction and deintercalation membrane stack electrolysis equipment according to claim 2, characterized in that, The groove (2) is a U-shaped groove with an open top. The inner cavity of the groove (2) is formed by two parallel and opposite vertical plates and a bottom plate sandwiched between the vertical plates and perpendicular to the vertical plates. The two vertical plates are the first vertical plate (2021) and the second vertical plate (2022). The lower surface of the bottom plate, the lower surface of the first vertical plate (2021) and the lower surface of the second vertical plate (2022) are located in the same plane.

4. The electrochemical granulation electrode lithium extraction and deintercalation membrane stack electrolysis equipment according to claim 3, characterized in that, The adjacent grooves (2), the first side plate (101) and the groove (2) adjacent to the first side plate (101), and the second side plate (102) and the groove (2) adjacent to the second side plate (102) are all connected by connecting plates (3). The connecting plates (3) are respectively protruding along the outer edge of the U-shaped end face of the groove (2), the outer edge of the first side plate (101) and the outer edge of the second side plate (102); the connecting plates (3) are machined with a plurality of threaded holes for bolts (8) to pass through.

5. The electrochemical granulation electrode lithium extraction and deintercalation membrane stack electrolysis equipment according to claim 4, characterized in that, The length of the connecting plate (3) protruding from the edge of the groove (2), the length of the connecting plate (3) protruding from the edge of the first side plate (101), and the length of the connecting plate (3) protruding from the edge of the second side plate (102) are all 10-30 mm. The thickness of the connecting plate (3) is 3 mm-10 mm. The diameter of the threaded hole is 4-7 mm. The material of the connecting plate (3) is one of acrylic, PVC, PP, and PE. The material of the bolt (8) is one of carbon steel, stainless steel, and alloy steel, and the model is one of M4, M5, and M6.

6. The electrochemical granulation electrode lithium extraction and deintercalation membrane stack electrolysis equipment according to claim 3, characterized in that, The outlet (9) is located on the upper part of the second vertical plate (2022); the bottom plate of the tank (2) contains a main inlet channel (10) and a branch inlet channel (11); the main inlet channel (10) is perpendicular to the first vertical plate (2021) and extends toward the second vertical plate (2022), and is a horizontal pipe with a single-end opening; the opening of the main inlet channel (10) is the inlet (17). The inlet branch channel (11) is connected between the main inlet channel (10) and the inner wall of the tank (2). There are multiple inlet branch channels (11) and they are evenly arranged along the extension direction of the main inlet channel (10). The axis of the inlet branch channel (11) is perpendicular to the axis of the main inlet channel (10). The diameter of the main inlet channel (10) is larger than the diameter of the branch inlet channel (11).

7. The electrochemical granulation electrode lithium extraction and deintercalation membrane stack electrolysis equipment according to claim 3, characterized in that, The height of the trough (2) is 200-330 mm, and the width of the trough (2) in the X direction is 10-30 mm; with the first vertical plate (2021) to the second vertical plate (2022) as the Y direction, the width of the trough (2) in the Y direction is 200-300 mm, and the width of the inner cavity of the trough (2) in the Y direction is 150-200 mm.

8. The electrochemical granulation electrode lithium extraction and deintercalation membrane stack electrolysis equipment according to claim 2, characterized in that, The thickness of the side plate pad (4) is 2-5 mm, and the thickness of the anion exchange membrane (5) is 0.1-0.5 mm with a resistance of less than 50 Ω / cm. 2 The thickness of the first tank pad (6) and the second tank pad (7) is 2-5 mm; the thickness of the elastic porous pad (16) is 3-5 mm, the pore size of the elastic porous pad (16) is 0.05-2 mm, and the porosity is 70%-80%; the anion membrane (5) is Zhejiang Lanran anion membrane or Sait anion membrane; the side plate pad (4), the first tank pad (6) and the second tank pad (7) are made of one of silicone rubber, nitrile rubber and neoprene rubber; the elastic porous pad (16) is foamed cotton or recycled cotton.

9. The electrochemical granulation electrode lithium extraction and deintercalation membrane stack electrolysis equipment according to claim 1, characterized in that, The granulating active material (13) is a short cylindrical particle with a diameter of 1-3 mm and a column length of 3-5 mm; the filler density of the granulating active material (13) in the carrier frame (14) is 0.7-0.86 g / cm³. 3 The diameter of the seepage hole is 0.5 to 1.5 mm.

10. The electrochemical granulation electrode lithium extraction and deintercalation membrane stack electrolysis equipment according to claim 1, characterized in that, The current collector (12) is a graphite plate or graphite carbon felt, and the thickness of the current collector (12) is 2-3 mm; the material of the carrier frame (14) is one of PVC, PE and PP; the electrode assemblies located on both sides of the anion membrane (5) are arranged in a mirror symmetrical manner, and the carrier frame (14) in the tank (2) adjacent to the first side plate (101) is adjacent to the anion membrane (5).

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