Electrically-assisted membrane distillation crystallizer for synchronously recovering multiple components of lithium battery leachate

Abstract

The invention provides an electric auxiliary membrane distillation crystallizer for synchronously recovering multiple components of a lithium battery leachate, which comprises a raw material liquid pool, an ammonia recovery pool, a water recovery pool, a low-temperature thermostat, a high-temperature thermostat, a crystallization device, a water recovery cavity, a first conductive distillation membrane, a raw material liquid cavity, a second conductive distillation membrane and an ammonia recovery cavity, the first conductive distillation film is externally connected with a first power supply, the second conductive distillation film is externally connected with a second power supply, and the first power supply is higher than the second power supply; the water recovery cavity, the water recovery pool and the low-temperature thermostat form a circulation path, the ammonia recovery cavity, the ammonia recovery pool and the high-temperature thermostat form a circulation path, and the raw material liquid cavity, the raw material liquid pool and the crystallization device form a circulation path. According to the method, the membrane surface temperature is increased through the Joule heating effect to promote vapor permeation, the vertical electric field is utilized to induce electrochemical reaction to form pH gradient to drive selective migration of NH3, the concentrated leachate is subjected to gradient temperature crystallization treatment, CoCl2 crystals are separated out in a low-temperature area, and Li2CO3 precipitates are formed in a high-temperature area.

Description

Technical Field

[0001] The present invention belongs to the technical field of resource recovery of lithium batteries, and relates to a multi-component synchronous recovery device based on the coupling of electric field regulation and membrane distillation crystallization, specifically an electro-assisted membrane distillation crystallizer for the multi-component synchronous recovery of lithium battery leachate. Background Art

[0002] The ammonia leachate of retired lithium battery cathode materials contains multi-component resources such as lithium, cobalt, ammonia, etc. Traditional recovery processes need to achieve step-by-step recovery of components through multiple steps of separation (such as precipitation, extraction, evaporation, etc.), which have problems such as complex processes, high energy consumption, and low efficiency. Although membrane distillation technology can achieve concentration by selectively permeating water vapor through a hydrophobic membrane, its single mass transfer characteristic is difficult to simultaneously separate volatile components (such as ammonia / water) and non-volatile metal ions (such as Li + / Co 2+ ). In addition, existing membrane distillation devices are prone to membrane fouling and scaling for high-concentration leachate, and lack the ability to directionally recover volatile components such as ammonia, resulting in low resource recovery rate and poor process economy. Therefore, developing a highly efficient integrated device that can simultaneously separate and recover water, ammonia, lithium, and cobalt is of great significance for promoting the development of green recycling technology for lithium batteries. Summary of the Invention

[0003] In order to overcome the problems existing in the prior art, the present invention provides an electro-assisted membrane distillation crystallizer for the multi-component synchronous recovery of lithium battery leachate, which can solve the problems of complex processes, high energy consumption, and the difficulty of membrane distillation technology in simultaneously separating volatile / non-volatile components in the multi-component step-by-step recovery process of existing lithium battery ammonia leachate.

[0004] To achieve the above object, the present invention adopts the following technical solutions:

[0005] The present invention provides an electro-assisted membrane distillation crystallizer for synchronous recovery of multiple components from lithium battery leachate, which includes a directional mass transfer membrane module, a raw material liquid pool, an ammonia recovery pool, a water recovery pool, a low-temperature thermostat, a high-temperature thermostat and a crystallization device; the directional mass transfer membrane module includes a water recovery cavity, a first conductive distillation membrane, a raw material liquid cavity, a second conductive distillation membrane and an ammonia recovery cavity which are distributed in sequence; the first conductive distillation membrane is externally connected to a first power supply, the second conductive distillation membrane is externally connected to a second power supply, and the voltage of the first power supply is higher than that of the second power supply; the outlet of the water recovery cavity is sequentially connected to the water recovery pool and the low-temperature thermostat, and the outlet of the low-temperature thermostat is connected to the inlet of the water recovery cavity; the outlet of the ammonia recovery cavity is sequentially connected to the ammonia recovery pool and the high-temperature thermostat, and the outlet of the high-temperature thermostat is connected to the inlet of the ammonia recovery cavity; the outlet of the raw material liquid cavity is connected to the inlet of the raw material liquid pool, the outlet of the raw material liquid pool is connected to the liquid inlet of the crystallization device, and the liquid outlet of the crystallization device is connected to the inlet of the raw material liquid cavity. The water recovery cavity, the water recovery pool and the low-temperature thermostat are sequentially connected to form a first circulation path; the ammonia recovery cavity, the ammonia recovery pool and the high-temperature thermostat are sequentially connected to form a second circulation path; the raw material liquid cavity, the raw material liquid pool and the crystallization device are sequentially connected to form a third circulation path.

[0006] Further, a voltage-dividing resistor is provided in this structure, and the voltage-dividing resistor is arranged on the connection circuit between the first conductive distillation membrane and the first power supply; the voltage of the voltage-dividing resistor is equal to the voltage difference between the first power supply and the second power supply.

[0007] Further, the voltage of the second power supply is not less than 20V; the voltage difference between the first power supply and the second power supply is 1V - 5V, that is, the voltage-dividing resistor divides a voltage of 1V - 5V.

[0008] Further, the crystallization device includes a low-temperature crystallizer and a high-temperature crystallizer; the liquid inlet of the low-temperature crystallizer is connected to the outlet of the raw material liquid pool, the liquid outlet of the low-temperature crystallizer is connected to the liquid inlet of the high-temperature crystallizer, and the liquid outlet of the high-temperature crystallizer is connected to the inlet of the raw material liquid cavity; the temperature of the low-temperature crystallizer is 20 - 35°C, which is used for the crystallization of cobalt elements; the temperature of the high-temperature crystallizer is 60 - 85°C, which is used for the crystallization of lithium elements.

[0009] Further, deionized water is contained in the water recovery pool, and an acid solution is contained in the ammonia recovery pool.

[0010] Further, a dilute sulfuric acid solution with a concentration of 0.5 - 2.0 mol / L is contained in the ammonia recovery pool.

[0011] Further, the solution in the raw material liquid pool is the ammonia leachate of the cathode material of a retired lithium battery, and its components mainly include LiCl, CoCl2, NH4HCO3 and NH3·H2O.

[0012] Further, the temperature of the high-temperature thermostat is set to 50-80 °C, and the temperature of the low-temperature thermostat is set to 5-15 °C.

[0013] Further, the first conductive distillation membrane and the second conductive distillation membrane are made of the same material. The preparation method is as follows: dissolve carbon nanotubes and polyvinyl alcohol in dimethyl sulfoxide to obtain a conductive modifier; spray the conductive modifier on the surface of a polytetrafluoroethylene membrane and dry it. Repeat this process 10-50 times to obtain the conductive distillation membrane.

[0014] Further, the mass ratio of carbon nanotubes to polyvinyl alcohol is 50:1.

[0015] Further, water pumps are provided on the connection paths between the water recovery cavity, the water recovery pool and the low-temperature thermostat; water pumps are provided on the connection paths between the ammonia recovery cavity, the ammonia recovery pool and the high-temperature thermostat; and water pumps are provided on the connection paths between the raw material liquid cavity, the raw material liquid pool and the crystallization device.

[0016] Further, a raw material liquid outer shell, a water recovery outer shell and an ammonia recovery outer shell are also provided. The water recovery outer shell and the ammonia recovery outer shell are respectively arranged on both sides of the raw material liquid outer shell; the first conductive distillation membrane is arranged between the raw material liquid outer shell and the water recovery outer shell, and the second conductive distillation membrane is arranged between the raw material liquid outer shell and the ammonia recovery outer shell; a through groove is provided at the center of the raw material liquid outer shell, and the first conductive distillation membrane and the second conductive distillation membrane are respectively arranged on both sides of the through groove, enclosing the through groove to form a raw material liquid cavity; the liquid in the raw material liquid cavity contacts the first conductive distillation membrane and the second conductive distillation membrane; a first groove is provided on the side of the water recovery outer shell facing the first conductive distillation membrane, and the first conductive distillation membrane encloses the first groove to form a water recovery cavity; a second groove is provided on the side of the ammonia recovery outer shell facing the second conductive distillation membrane, and the second conductive distillation membrane encloses the second groove to form an ammonia recovery cavity; the raw material liquid outer shell, the water recovery outer shell and the ammonia recovery outer shell are fixedly connected by bolts.

[0017] Further, a liquid inlet and a liquid outlet communicating with the through groove are provided on the raw material liquid outer shell, a liquid inlet and a liquid outlet communicating with the first groove are provided on the water recovery outer shell, and a liquid inlet and a liquid outlet communicating with the second groove are provided on the ammonia recovery outer shell.

[0018] Further, the upper and lower end interfaces of the first conductive distillation membrane are respectively connected to the positive and negative electrodes of a first power supply, and the upper and lower end interfaces of the second conductive distillation membrane are respectively connected to the positive and negative electrodes of a second power supply.

[0019] The beneficial effects of the present invention are:

[0020] (1) The present invention provides an electro-assisted membrane distillation crystallizer and an operation method. By integrating a conductive distillation membrane into a two-way mass transfer membrane module and applying an orthogonal electric field, the Joule heat effect parallel to the membrane surface is utilized to increase the membrane temperature to drive the permeation of water vapor, and the electrochemical reaction is induced by the electric field perpendicular to the membrane surface to form a pH gradient for the directional migration of NH3, so as to efficiently recover water and ammonia synchronously;

[0021] (2) By setting a low-temperature crystallizer and a high-temperature crystallizer, the concentrated solution is crystallized step by step to precipitate cobalt and lithium compounds at gradient temperatures, and the voltage difference between the two power supplies is optimized by a voltage-dividing resistor to control the energy consumption. Finally, the synchronous separation and crystallization of ammonia, water, lithium, and cobalt multi-components are completed in a single device, solving the problems of long traditional process flow, serious membrane fouling, and low resource recovery rate, significantly improving the recovery efficiency and product purity, reducing the system energy consumption, and having the potential for high-efficiency integration and industrial application. Brief Description of the Drawings

[0022] Figure 1 is the system structure diagram of the electro-assisted membrane distillation crystallizer provided by the present invention;

[0023] Figure 2 is the schematic structural diagram of the directional mass transfer membrane module;

[0024] Figure 3 is the schematic diagram of the membrane surface potential distribution under the action of the voltage-dividing resistor;

[0025] The reference numerals in the drawings are:

[0026] 1, mass transfer membrane module; 2, water pump; 3, raw material liquid pool; 4, low-temperature crystallizer; 5, high-temperature crystallizer; 6, ammonia recovery pool; 7, high-temperature thermostat; 8, water recovery pool; 9, low-temperature thermostat; 10, second power supply; 11, first power supply; 12, voltage-dividing resistor; 1-1, raw material liquid cavity; 1-2, second conductive distillation membrane; 1-; 3, ammonia recovery cavity; 1-4, first conductive distillation membrane; 1-5, water recovery cavity; 13, cobalt element crystal; 14, lithium element crystal; 15, raw material liquid outer shell; 16, water recovery outer shell; 17, ammonia recovery outer shell. Detailed Embodiments

[0027] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below with reference to the drawings. Apparently, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art without creative efforts based on the embodiments of the present invention belong to the scope of protection of the present invention.

[0028] Embodiment 1

[0029] As Figure 1As shown in the figure, an electro-assisted membrane distillation crystallizer for the synchronous recovery of multiple components from lithium battery leachate provided by an embodiment of the present invention includes a directional mass transfer membrane module 1, a raw material liquid pool 3, an ammonia recovery pool 6, a water recovery pool 8, a low-temperature thermostat 9, a high-temperature thermostat 7, and a crystallization device. Deionized water is contained in the water recovery pool 8, and a 2.0 mol / L dilute sulfuric acid solution is contained in the ammonia recovery pool 6. The solution in the raw material liquid pool 3 is the ammonia leachate of the cathode material of retired lithium batteries, and the ammonia leachate contains LiCl (1.2 mol / L), CoCl2 (0.8 mol / L), NH4HCO3 (2.0 mol / L), and NH3·H2O (4.0 mol / L). The high-temperature thermostat 7 is set at a temperature of 70 °C, and the low-temperature thermostat 9 is set at a temperature of 10 °C.

[0030] Among them, the directional mass transfer membrane module 1 includes a water recovery cavity 1-5, a first conductive distillation membrane 1-4, a raw material liquid cavity 1-1, a second conductive distillation membrane 1-2, and an ammonia recovery cavity 1-3 that are distributed in sequence.

[0031] The first conductive distillation membrane 1-4 is externally connected to a first power supply 11 and a voltage-dividing resistor 12. The upper and lower end interfaces of the first conductive distillation membrane 1-4 are respectively connected to the positive and negative electrodes of the first power supply 11. The first conductive distillation membrane 1-4, the first power supply 11, and the voltage-dividing resistor 12 form a first circuit. The second conductive distillation membrane 1-2 is externally connected to a second power supply 10. The upper and lower end interfaces of the second conductive distillation membrane 1-2 are respectively connected to the positive and negative electrodes of the second power supply 10. The second conductive distillation membrane 1-2 and the second power supply 10 form a second circuit. The voltage of the first power supply 11 is higher than the voltage of the second power supply 10, and the voltage of the voltage-dividing resistor 12 is equal to the voltage difference between the first power supply 11 and the second power supply 10. Specifically, in this embodiment, the voltage of the second power supply 10 is 25 V, the voltage of the first power supply 11 is 28 V, and the voltage divided by the voltage-dividing resistor is 3 V.

[0032] As Figure 1 shown, the outlet of the water recovery cavity 1-5 is sequentially connected to the water recovery pool 8 and the low-temperature thermostat 9, and the outlet of the low-temperature thermostat 9 is connected to the inlet of the water recovery cavity 1-5. The outlet of the ammonia recovery cavity 1-3 is sequentially connected to the ammonia recovery pool 6 and the high-temperature thermostat 7, and the outlet of the high-temperature thermostat 7 is connected to the inlet of the ammonia recovery cavity 1-3. The outlet of the raw material liquid cavity 1-1 is connected to the inlet of the raw material liquid pool 3, the outlet of the raw material liquid pool 3 is connected to the liquid inlet of the crystallization device, and the liquid outlet of the crystallization device is connected to the inlet of the raw material liquid cavity 1-1. Pumps are provided on the connection paths of the water recovery cavity 1-5, the water recovery pool 8, and the low-temperature thermostat 9, on the connection paths of the ammonia recovery cavity 1-3, the ammonia recovery pool 6, and the high-temperature thermostat 7, and on the connection paths of the raw material liquid cavity 1-1, the raw material liquid pool 3, and the crystallization device. The three pumps respectively provide the power source for the circulation of the three liquid paths.

[0033] As a further preference of the present invention, as Figure 1 shown, the crystallization device includes a low-temperature crystallizer 4 and a high-temperature crystallizer 5. The liquid inlet of the low-temperature crystallizer 4 is connected to the outlet of the raw material liquid pool 3. The liquid outlet of the low-temperature crystallizer 4 is connected to the liquid inlet of the high-temperature crystallizer 5. The liquid outlet of the high-temperature crystallizer 5 is connected to the inlet of the raw material liquid cavity 1-1. The temperature of the low-temperature crystallizer 4 is 25°C and is used for the crystallization of cobalt elements. The temperature of the high-temperature crystallizer 5 is 70°C and is used for the crystallization of lithium elements.

[0034] In the present invention, the first conductive distillation membrane 1-4 and the second conductive distillation membrane 1-2 are made of the same material. The preparation method is as follows: Carbon nanotubes and polyvinyl alcohol (the mass ratio of carbon nanotubes to polyvinyl alcohol is 50:1) are dissolved in dimethyl sulfoxide to obtain a conductive modifier; the conductive modifier is sprayed on the surface of a polytetrafluoroethylene membrane and dried. This process is repeated 30 times to obtain a conductive distillation membrane with a membrane area of 100 cm 2 , and a thickness of 200 μm. The prepared conductive distillation membrane can allow gases (water vapor and ammonia) to pass through, while solids and liquids cannot pass through.

[0035] As a further preference of the present invention, as Figure 2 shown, the present invention also includes a raw material liquid outer shell 15, a water recovery outer shell 16, and an ammonia recovery outer shell 17. The water recovery outer shell 16 and the ammonia recovery outer shell 17 are respectively arranged on both sides of the raw material liquid outer shell 15. The first conductive distillation membrane 1-4 is arranged between the raw material liquid outer shell 15 and the water recovery outer shell 16, and the second conductive distillation membrane 1-2 is arranged between the raw material liquid outer shell 15 and the ammonia recovery outer shell 17. Among them, a through groove is provided in the center of the raw material liquid outer shell 15. The first conductive distillation membrane 1-4 and the second conductive distillation membrane 1-2 are respectively arranged on both sides of the through groove, enclosing the through groove to form a raw material liquid cavity 1-1. The liquid in the raw material liquid cavity 1-1 comes into contact with the first conductive distillation membrane 1-4 and the second conductive distillation membrane 1-2. On the side of the water recovery outer shell 16 facing the first conductive distillation membrane 1-4, a first groove is provided, and the first conductive distillation membrane 1-4 encloses the first groove to form a water recovery cavity 1-5. On the side of the ammonia recovery outer shell 17 facing the second conductive distillation membrane 1-2, a second groove is provided, and the second conductive distillation membrane 1-2 encloses the second groove to form an ammonia recovery cavity 1-3. The raw material liquid outer shell 15, the water recovery outer shell 16, and the ammonia recovery outer shell 17 are fixedly connected by bolts.

[0036] As [[ID=!6]] Figure 2 shown, the raw material liquid outer shell 15 is provided with a liquid inlet and a liquid outlet communicated with the through groove. The water recovery outer shell 16 is provided with a liquid inlet and a liquid outlet communicated with the first groove. The ammonia recovery outer shell 17 is provided with a liquid inlet and a liquid outlet communicated with the second groove. The liquids in the raw material liquid pool 3, the ammonia recovery pool 6, and the water recovery pool 8 respectively enter the raw material liquid cavity 1-1, the ammonia recovery cavity 1-3, and the water recovery cavity 1-5 through the liquid inlets and flow out from the liquid outlets, forming three liquid circulation paths.

[0037] Principle and operation process of the present invention:

[0038] The liquids in the raw material liquid pool 3, ammonia recovery pool 6, and water recovery pool 8 are respectively driven by water pumps to enter the raw material liquid cavity 1-1, ammonia recovery cavity 1-3, and water recovery cavity 1-5 and circulate.

[0039] Connect the connection circuit of the first conductive distillation membrane 1-4, the first power supply 11, and the voltage dividing resistor 12, and connect the connection circuit of the second conductive distillation membrane 1-2 and the second power supply 10 to form a parallel electric field parallel to the first conductive distillation membrane 1-4 and the second conductive distillation membrane 1-2, and form a vertical electric field perpendicular to the first conductive distillation membrane 1-4 and the second conductive distillation membrane 1-2. Among them, the parallel electric field forms a Joule heat effect and increases the surface temperature of the conductive distillation membrane, and the vertical electric field promotes the electrochemical reaction and forms an alkaline microenvironment and an acidic microenvironment on the surfaces of the second conductive distillation membrane 1-2 on the ammonia recovery side and the first conductive distillation membrane 1-4 on the water recovery side respectively. Specifically, the electrochemical reactions include:

[0040] Ammonia recovery side (interface is alkaline):

[0041] 2H2O + 2e → OH - + H2

[0042]

[0043] Water recovery side (interface is acidic):

[0044] 2Cl - -2e → Cl2

[0045] Cl2 + H2O → HCl + HClO

[0046] Under the action of the low-temperature thermostat 9, the temperature of the liquid entering the water recovery cavity 1-5 is relatively low, while the surface temperature of the first conductive distillation membrane 1-4 is relatively high due to the Joule heat effect. Therefore, there is a temperature difference in this circulation path. Under the action of the high-temperature thermostat 7, the temperature of the acidic liquid entering the ammonia recovery cavity 1-3 is not too low (the temperature difference is not too large), and there is a chemical potential in this circulation path.

[0047] Driven by the temperature difference, the water vapor in the raw material liquid cavity 1-1 will pass through the first conductive distillation membrane 1-4 and enter the water recovery cavity 1-5 for recovery. Driven by the chemical potential, NH4 in the raw material liquid cavity 1-1 + will be converted into NH3 and pass through the second conductive distillation membrane 1-2 and enter the ammonia recovery cavity 1-3 for recovery.

[0048] As water molecules and NH4 +They are separately recycled, and the remaining components will be gradually concentrated in the feed liquid cavity 1-1 and the feed liquid pool 3, and then successively enter the low-temperature crystallizer 4 and the high-temperature crystallizer 5, respectively recovering CoCl2 and Li2CO3.

[0049] Operating effect:

[0050] The parallel membrane surface electric field raises the surface temperature of the first conductive distillation membrane 1-4 on the water recovery side to 65 °C, and the vertical membrane surface electric field raises the pH of the microenvironment at the interface of the second conductive distillation membrane 1-2 on the ammonia recovery side to 11.5, and the pH of the microenvironment at the interface of the first conductive distillation membrane 1-4 is reduced to 3.7. After 5 hours of operation, 2.4 L of deionized water is recovered on the water recovery side, and the concentration of NH4 + is lower than 0.02 mol / L. On the ammonia recovery side, the concentration of NH4 + is 2.48 mol / L, and a total of 138.45 g of Li2CO3 and 41.32 g of CoCl2 are recovered.

[0051] As a comparison, under the premise of not applying voltage to the membrane surface and keeping other parameters the same for the experiment, the obtained results are compared in Table 1. It can be seen from Table 1 that compared with the scheme without applying voltage, the present invention has more excellent synchronous recovery effect.

[0052] Table 1

[0053] Electricity is applied to the membrane surface Electricity is not applied to the membrane surface Deionized water recovery volume on the water recovery side 2.4 L 1.7L <![CDATA[NH4 on the water recovery side + concentration]]> 0.02 mol / L 0.66 mol / L <![CDATA[Ammonia recovery side NH4 + Concentration]]> 2.48 mol / L 1.35 mol / L <![CDATA[Recovery amount of Li2CO3]]> 138.45g 88.47g <![CDATA[Recovery amount of CoCl2]]> 41.32g 32.56g

[0054] The present invention promotes the permeation of water vapor by raising the membrane surface temperature through the Joule heat effect, uses the vertical electric field to induce an electrochemical reaction to form a pH gradient to drive the selective migration of NH3, and synchronously realizes the efficient recovery of water and ammonia. The concentrated leaching solution is subjected to gradient temperature crystallization treatment, and CoCl2 crystals are precipitated in the low-temperature zone, and Li2CO3 precipitates are formed in the high-temperature zone. The present invention innovatively combines electric field regulation and membrane distillation crystallization technology, breaks through the technical bottleneck of low separation efficiency of multi-components by traditional methods, and has the advantages of high process integration, complete resource recovery, and controllable energy consumption, and has important application value in the field of resource recovery of lithium batteries.

[0055] The above is only the preferred embodiment of the present invention, and the protection scope of the present invention is not limited to the above embodiments. All technical solutions falling within the idea of the present invention belong to the protection scope of the present invention. It should be noted that for those of ordinary skill in the art, several improvements and refinements made without departing from the principle of the present invention should be regarded as the protection scope of the present invention.

Claims

1. An electro-assisted membrane distillation crystallizer for synchronous recovery of multiple components from lithium battery leaching solution, characterized in that it includes a directional mass transfer membrane module (1), a raw material liquid pool (3), an ammonia recovery pool (6), a water recovery pool (8), a low-temperature thermostat (9), a high-temperature thermostat (7) and a crystallization device; The directional mass transfer membrane module (1) includes a water recovery cavity (1-5), a first conductive distillation membrane (1-4), a raw material liquid cavity (1-1), a second conductive distillation membrane (1-2) and an ammonia recovery cavity (1-3) distributed in sequence; the first conductive distillation membrane (1-4) is externally connected to a first power supply (11), the second conductive distillation membrane (1-2) is externally connected to a second power supply (10), and the voltage of the first power supply (11) is higher than the voltage of the second power supply (10); The water recovery cavity (1-5), the water recovery pool (8), and the low-temperature thermostat (9) are connected in sequence to form a first circulation path; the ammonia recovery cavity (1-3), the ammonia recovery pool (6), and the high-temperature thermostat (7) are connected in sequence to form a second circulation path; the raw material liquid cavity (1-1), the raw material liquid pool (3), and the crystallization device are connected in sequence to form a third circulation path.

2. The electro-assisted membrane distillation crystallizer for synchronous recovery of multiple components from lithium battery leaching solution according to claim 1, characterized in that a voltage dividing resistor (12) is further provided, and the voltage dividing resistor (12) is arranged on the connection loop between the first conductive distillation membrane (1-4) and the first power supply (11); the voltage of the voltage dividing resistor (12) is equal to the voltage difference between the first power supply (11) and the second power supply (10).

3. The electro-assisted membrane distillation crystallizer for synchronous recovery of multiple components from lithium battery leaching solution according to claim 2, characterized in that the voltage of the second power supply (10) is not less than 20V; the voltage difference between the first power supply (11) and the second power supply (10) is 1V to 5V.

4. The electro-assisted membrane distillation crystallizer for synchronous recovery of multiple components from lithium battery leaching solution according to claim 1, characterized in that the crystallization device includes a low-temperature crystallizer (4) and a high-temperature crystallizer (5); the liquid inlet of the low-temperature crystallizer (4) is connected to the outlet of the raw material liquid pool (3), the liquid outlet of the low-temperature crystallizer (4) is connected to the liquid inlet of the high-temperature crystallizer (5), and the liquid outlet of the high-temperature crystallizer (5) is connected to the inlet of the raw material liquid cavity (1-1); the temperature of the low-temperature crystallizer (4) is 20 to 35°C, which is used for the crystallization of cobalt elements; the temperature of the high-temperature crystallizer (5) is 60 to 85°C, which is used for the crystallization of lithium elements.

5. The electro-assisted membrane distillation crystallizer for synchronous recovery of multiple components from lithium battery leaching solution according to claim 1, characterized in that deionized water is contained in the water recovery pool (8), and acid solution is contained in the ammonia recovery pool (6).

6. The electro-assisted membrane distillation crystallizer for synchronous recovery of multiple components from lithium battery leaching solution according to claim 1, characterized in that the high-temperature thermostat (7) is set at a temperature of 50 to 80°C, and the low-temperature thermostat (9) is set at a temperature of 5 to 15°C.

7. The electro-assisted membrane distillation crystallizer for synchronous recovery of multiple components from lithium battery leaching solution according to claim 1, wherein the first conductive distillation membrane (1-4) and the second conductive distillation membrane (1-2) are made of the same material, and the preparation method is as follows: Dissolve carbon nanotubes and polyvinyl alcohol in dimethyl sulfoxide to obtain a conductive modifier; Spray the conductive modifier on the surface of the polytetrafluoroethylene membrane and dry it, repeating the process 10 to 50 times to obtain the conductive distillation membrane.

8. The electro-assisted membrane distillation crystallizer for synchronous recovery of multiple components from lithium battery leaching solution according to claim 1, wherein a water pump is provided on the connection path of the water recovery cavity (1-5), the water recovery pool (8) and the low-temperature thermostat (9); a water pump is provided on the connection path of the ammonia recovery cavity (1-3), the ammonia recovery pool (6) and the high-temperature thermostat (7); a water pump is provided on the connection path of the raw material liquid cavity (1-1), the raw material liquid pool (3) and the crystallization device.

9. The electro-assisted membrane distillation crystallizer for synchronous recovery of multiple components from lithium battery leaching solution according to claim 1, wherein a raw material liquid outer shell (15), a water recovery outer shell (16) and an ammonia recovery outer shell (17) are further provided, and the water recovery outer shell (16) and the ammonia recovery outer shell (17) are respectively arranged on both sides of the raw material liquid outer shell (15); the first conductive distillation membrane (1-4) is arranged between the raw material liquid outer shell (15) and the water recovery outer shell (16), and the second conductive distillation membrane (1-2) is arranged between the raw material liquid outer shell (15) and the ammonia recovery outer shell (17); a through groove is provided in the center of the raw material liquid outer shell (15), and the first conductive distillation membrane (1-4) and the second conductive distillation membrane (1-2) are respectively arranged on both sides of the through groove, surrounding the through groove to form the raw material liquid cavity (1-1); the liquid in the raw material liquid cavity (1-1) is in contact with the first conductive distillation membrane (1-4) and the second conductive distillation membrane (1-2); a first groove is provided on the side of the water recovery outer shell (16) facing the first conductive distillation membrane (1-4), and the first conductive distillation membrane (1-4) surrounds the first groove to form the water recovery cavity (1-5); a second groove is provided on the side of the ammonia recovery outer shell (17) facing the second conductive distillation membrane (1-2), and the second conductive distillation membrane (1-2) surrounds the second groove to form the ammonia recovery cavity (1-3); the raw material liquid outer shell (15), the water recovery outer shell (16) and the ammonia recovery outer shell (17) are fixedly connected by bolts.

10. The electro-assisted membrane distillation crystallizer for synchronous recovery of multiple components from lithium battery leaching solution according to claim 9, wherein a liquid inlet and a liquid outlet communicating with the through groove are provided on the raw material liquid outer shell (15), a liquid inlet and a liquid outlet communicating with the first groove are provided on the water recovery outer shell (16), and a liquid inlet and a liquid outlet communicating with the second groove are provided on the ammonia recovery outer shell (17); the upper and lower end interfaces of the first conductive distillation membrane (1-4) are respectively connected to the positive and negative electrodes of the first power supply (11), and the upper and lower end interfaces of the second conductive distillation membrane (1-2) are respectively connected to the positive and negative electrodes of the second power supply (10).

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