Preparation apparatus and method for lithium metal material

Abstract

A preparation apparatus for a lithium metal material, comprising a lithium storage tank (1), an extrusion barrel (2), an extrusion mechanism (3), and a frame (5). The lithium storage tank, the extrusion barrel, and the extrusion mechanism are all mounted on the frame. The extrusion barrel is arranged vertically and has an opening facing upwards, the extrusion mechanism is provided with a vertically arranged push rod, the push rod extends into an inner cavity of the extrusion barrel through the opening on the upper end of the extrusion barrel, and a lower end of the push rod is connected to an extrusion plate (301) matched with the inner cavity of the extrusion barrel. An openable and closable lithium material outlet (801) is provided on a bottom plate (8) of the extrusion barrel. A first lithium conveying pipe (16) is mounted at a feeding port of the lithium storage tank, and a discharging port of the lithium storage tank is communicated with a feeding port of the extrusion barrel by means of a second lithium conveying pipe (17). An initial position of the extrusion plate is located above the feeding port of the extrusion barrel. A first gate valve (14) is mounted on the second lithium conveying pipe. Further provided is a preparation method for a lithium metal material using the preparation apparatus. According to the apparatus and the method, an ingot casting process of a metal lithium can be reduced, so that the metal lithium can be effectively prevented from being oxidized or nitrided, the resources are saved, and the efficiency is improved.

Description

Device and method for preparing metallic lithium material

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of and priority to Chinese patent application No. CN 2023111325237, filed on September 4, 2023, and is incorporated herein by reference in its entirety for all other purposes. Technical Field

[0003] The present invention belongs to the technical field of production of metallic lithium materials, and in particular relates to a device and method for preparing metallic lithium materials. Background Art

[0004] Lithium metal anodes are a hot topic of research in the energy industry, with various types of power batteries utilizing lithium metal as anode material to varying degrees. To use lithium metal as an anode material, it must be prepared into the appropriate shape and size. Traditionally, the lithium metal is cast into an ingot, which is then placed into an extrusion barrel. A pressing mechanism applies force to the ingot, forcing it through a die opening to form lithium ribbons, rods, and bars. Currently, lithium ribbons are the most widely used and in the highest demand.

[0005] For example, Chinese patent document No. 202223421363.1 discloses a lithium ribbon extrusion device, wherein a vacuum box is used to accommodate lithium ingots and has a heating portion capable of heating the lithium ingots. The heated lithium ingots can enter an extrusion chamber through a connecting port. The extrusion portion is provided at the other end of the extrusion chamber and has an extrusion end extending into the extrusion chamber. The extrusion end can extrude the lithium ingot toward a lithium outlet, thereby obtaining a lithium ribbon. Another example is Chinese patent document No. 202310200606.9, which discloses a lithium ribbon forming device and method. The device includes an extrusion barrel with an inner cavity, the extrusion barrel being open at both ends, a push rod inserted into the extrusion barrel and slidably connected to the extrusion barrel, a drive mechanism being provided at the end of the push rod away from the outlet, and an extrusion die being provided at the end of the extrusion barrel away from the push rod. The push rod extrudes the lithium ingot in the extrusion barrel, causing the metallic lithium to extrude through the extrusion port on the extrusion die and form a lithium ribbon.

[0006] The preparation of existing battery-grade lithium ribbons mainly has the following technical problems:

[0007] First, battery-grade lithium metal obtained through distillation is cast into a mold, and then the lithium ingot is demolded and encapsulated. Due to the reactive nature of lithium metal, casting and demolding must be performed in an argon-filled glove box to prevent contact with air, which could cause oxidation and nitridation of the lithium metal. This process not only carries significant safety risks but also has high environmental requirements and high production costs.

[0008] Second, after the lithium metal ingots are cast, they need to be packaged and stored before being transported to the lithium ribbon production equipment. Due to the unique properties of lithium metal, its transportation and packaging require special requirements, resulting in high costs. After the lithium ingots are transported to the lithium material preparation area, they must be unpacked and the oxide and nitride coating on the surface scraped off before they can be placed in the extrusion barrel. This not only increases time and costs, but also results in unnecessary waste.

[0009] Third, metallic lithium has a high viscosity. After the extrusion mechanism squeezes the metallic lithium out of the extrusion barrel, metallic lithium will remain on the inner wall of the extrusion barrel, which is extremely inconvenient to clean, resulting in increased production costs.

[0010] Summary of the Invention

[0011] The technical problem to be solved by the present invention is to provide a device and method for preparing metallic lithium material, so as to make the production of lithium material continuous.

[0012] The technical solution adopted by the present invention to solve the technical problem is: a preparation device for lithium metal material, comprising a lithium storage tank, an extrusion barrel, an extrusion mechanism and a frame, wherein the lithium storage tank, the extrusion barrel and the extrusion mechanism are all installed on the frame;

[0013] The extrusion barrel is vertically arranged with its opening facing upwards, and the extrusion mechanism has a vertically arranged push rod, which extends into the inner cavity of the extrusion barrel through the upper end opening of the extrusion barrel, and the lower end of the push rod is connected to an extrusion plate adapted to the inner cavity of the extrusion barrel; an openable and closable lithium material outlet is provided on the bottom plate of the extrusion barrel;

[0014] A first lithium delivery pipeline is installed at the feed port of the lithium storage tank, and the discharge port of the lithium storage tank is connected to the feed port of the extrusion barrel through a second lithium delivery pipeline; the initial position of the extrusion plate is located above the feed port of the extrusion barrel; and a first gate valve is installed on the second lithium delivery pipeline.

[0015] Furthermore, it also includes a sealing ring installed at the opening of the upper end of the extrusion barrel, and the sealing ring is located between the push rod of the extrusion mechanism and the inner side wall of the extrusion barrel;

[0016] It also includes a first vacuum pump installed on the frame, the air inlet of the first vacuum pump is connected to the inner cavity of the extrusion barrel through a first exhaust pipe; the connection between the first exhaust pipe and the extrusion barrel is located between the initial position of the extrusion plate and the sealing ring.

[0017] Furthermore, it also includes a flange plate arranged along the circumference of the barrel body of the extrusion barrel, and the flange plate is connected to the upper end opening of the extrusion barrel;

[0018] The flange plate (201) is provided with an exhaust channel connected to the inner cavity of the extrusion barrel, and the flange plate is connected to a gas nozzle joint connected to the exhaust channel, the gas nozzle joint is located on the outer side of the flange plate, and the end of the first exhaust pipe away from the air inlet of the first vacuum pump is installed on the gas nozzle joint.

[0019] Furthermore, it also includes a second vacuum pump installed on the frame, and a second exhaust pipe connected to the air inlet of the second vacuum pump is installed on the top of the lithium storage tank;

[0020] A second gate valve is installed on the first lithium transport pipeline.

[0021] Furthermore, an inert gas inlet pipe communicating with the inner cavity of the lithium storage tank is installed on the top of the lithium storage tank, and a third gate valve is installed on the inert gas inlet pipe.

[0022] Furthermore, a driving mechanism for driving the sealing ring to rise or fall is installed on the frame, and the driving mechanism is connected to the sealing ring.

[0023] Furthermore, the bottom plate of the extrusion barrel and the lower end of the barrel body of the extrusion barrel are detachably mounted; and a heating mechanism is provided on the barrel body of the extrusion barrel.

[0024] Furthermore, the bottom plate opens or closes the lower end opening of the extrusion barrel body through a lifting mechanism; the lifting mechanism is located below the bottom plate and is connected to the bottom plate.

[0025] Furthermore, the base plate is detachably connected to the lifting mechanism.

[0026] Furthermore, it also includes a bottom cover, which is detachably connected to the bottom plate through a connecting piece and is located above the bottom plate;

[0027] The bottom cover is detachably mounted on the lower opening of the extrusion barrel body.

[0028] Furthermore, it also includes a sealing ring arranged along the circumference of the barrel body of the extrusion barrel, the sealing ring is installed on the outer side wall of the barrel body of the extrusion barrel and close to the lower end opening of the extrusion barrel;

[0029] When the bottom cover closes the lower end opening of the extrusion barrel body, the bottom cover and the extrusion barrel body are sealed by the sealing ring.

[0030] Furthermore, a cooling mechanism is provided on the barrel body of the extrusion barrel.

[0031] Furthermore, the first gate valve is a metering valve.

[0032] Furthermore, electric heating wires are installed around the first lithium delivery pipeline and the second lithium delivery pipeline.

[0033] Furthermore, the volume of the lithium storage tank is 50-400 L, and the effective volume of the lithium storage tank is ≥80%.

[0034] Furthermore, the inner diameter of the extrusion barrel is 200-500 mm.

[0035] A method for preparing a metallic lithium material, using a metallic lithium material preparation device, comprises the following steps:

[0036] S1, closing the first gate valve, and allowing the molten metallic lithium obtained by the preparation to flow into the lithium storage tank through the first lithium delivery pipeline;

[0037] S2, close the lithium material outlet located on the bottom plate of the extrusion barrel, make the extrusion plate be in the initial position, open the first gate valve, and allow the molten metallic lithium in the lithium storage tank to flow into the extrusion barrel through the second lithium delivery pipeline;

[0038] S3, after the molten metallic lithium in the extrusion barrel cools and solidifies, the lithium material outlet is opened, and the extrusion mechanism drives the extrusion plate downward to extrude the cooled and solidified metallic lithium, and the lithium material is discharged from the lithium material outlet.

[0039] Furthermore, before step S1, step S01 is also included: a second gate valve is installed on the first lithium delivery pipeline, and after closing the second gate valve and the first gate valve, the inner cavity of the lithium storage tank is evacuated to a vacuum state by a second vacuum pump; and then inert gas is introduced into the lithium storage tank through an inert gas inlet pipe installed on the top of the lithium storage tank.

[0040] Furthermore, the step S2 includes the following steps:

[0041] S21, closing the lithium material outlet located on the bottom plate of the extrusion barrel, placing the extrusion plate in the initial position, and installing a sealing ring at the upper end opening of the extrusion barrel so that the sealing ring seals the gap between the push rod of the extrusion mechanism and the inner wall of the extrusion barrel;

[0042] S22, pumping the inner cavity of the extrusion barrel to a vacuum state by a first vacuum pump;

[0043] S23, opening the first gate valve to allow the molten metallic lithium in the lithium storage tank to flow into the extrusion barrel through the second lithium delivery pipeline.

[0044] Furthermore, closing the lithium material outlet located on the bottom plate of the extrusion barrel in step S2 includes the following steps: the bottom plate is detachably mounted on the lower end of the barrel body of the extrusion barrel, and a bottom cover for closing the lithium material outlet is connected above the bottom plate; a lifting mechanism is connected to the bottom plate and is located below the bottom plate, and the lifting mechanism lifts the bottom plate and the bottom cover to close the lower end opening of the barrel body of the extrusion barrel through the bottom cover.

[0045] Furthermore, when the bottom cover closes the lower end opening of the extrusion barrel body, the bottom cover and the extrusion barrel body are sealed by a sealing ring installed on the outer side wall of the extrusion barrel body.

[0046] Furthermore, opening the lithium material outlet in step S3 includes the following steps: after the molten metallic lithium in the extrusion barrel is cooled and solidified, the bottom cover and the bottom plate are lowered by a lifting mechanism, the bottom cover is removed from the bottom plate, and the lithium material outlet is opened, and the lifting mechanism lifts the bottom plate to close the lower end opening of the extrusion barrel body through the bottom plate.

[0047] Furthermore, in step S3, the molten metallic lithium in the extrusion barrel is cooled and solidified by a cooling mechanism.

[0048] Furthermore, after step S3, step S4 is also included, wherein the bottom plate is lowered by a lifting mechanism, the bottom cover is installed on the bottom plate, the lifting mechanism lifts the bottom plate and the bottom cover, and the lower end opening of the barrel body of the extrusion barrel is closed by the bottom cover, and the lithium material outlet is closed; the extrusion barrel is heated by a heating mechanism, so that the metallic lithium adhering to the inner wall of the extrusion barrel becomes a molten state and converges to the bottom of the extrusion barrel, and then the metallic lithium converged to the bottom of the extrusion barrel is cooled and solidified by a cooling mechanism, the bottom cover and the bottom plate are lowered by the lifting mechanism, and the cooled and solidified metallic lithium is cleaned from the bottom of the extrusion barrel.

[0049] Furthermore, the heating temperature of the heating mechanism is ≥200°C.

[0050] Furthermore, the cooling temperature of the cooling mechanism is ≤10°C.

[0051] Compared with existing technologies, the present invention provides a lithium metal production device and method, enabling continuous lithium material production. This reduces the number of lithium metal casting steps, effectively preventing oxidation and nitridation of lithium metal, and conserving resources. It also facilitates the removal of lithium metal adhered to the inner wall of the extrusion barrel, resulting in convenient operation, labor savings, and improved efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] FIG1 is a schematic structural diagram of the present invention;

[0053] Figure numerals: 1-lithium storage tank; 2-extrusion barrel; 201-flange plate; 202-sealing ring; 3-extrusion mechanism; 301-extrusion plate; 4-lifting mechanism; 5-frame; 6-heating mechanism; 7-cooling mechanism; 8-bottom plate; 801-lithium material outlet; 9-bottom cover; 10-sealing ring; 11-driving mechanism; 12-first vacuum pump; 1201-first exhaust pipe; 13-second gate valve; 14-first gate valve; 15-high-temperature liquid level gauge; 16-first lithium delivery pipeline; 17-second lithium delivery pipeline; 18-second vacuum pump; 1801-second exhaust pipe; 19-inert gas inlet pipe; 20-third gate valve. DETAILED DESCRIPTION

[0054] The present invention will be further described below with reference to the accompanying drawings and examples.

[0055] A device for preparing metallic lithium material comprises a lithium storage tank 1, an extrusion barrel 2, an extrusion mechanism 3 and a frame 5, wherein the lithium storage tank 1, the extrusion barrel 2 and the extrusion mechanism 3 are all mounted on the frame 5; the extrusion barrel 2 is vertically arranged with its opening facing upward, the extrusion mechanism 3 has a vertically arranged push rod, which extends into the inner cavity of the extrusion barrel 2 through the upper end opening of the extrusion barrel 2, and the lower end of the push rod is connected to an extrusion plate 301 adapted to the inner cavity of the extrusion barrel 2; an openable and closable lithium material outlet 801 is provided on the bottom plate 8 of the extrusion barrel 2; a first lithium supply pipeline 16 is installed at the feed port of the lithium storage tank 1, and the discharge port of the lithium storage tank 1 is connected to the feed port of the extrusion barrel 2 via a second lithium supply pipeline 17; the initial position of the extrusion plate 301 is located above the feed port of the extrusion barrel 2; and a first gate valve 14 is installed on the second lithium supply pipeline 17.

[0056] The frame 5 provides mounting support for the lithium storage tank 1, extrusion barrel 2, and extrusion mechanism 3. The lithium storage tank 1 has a capacity of 50 to 400 liters, with an effective capacity of ≥80%. The extrusion barrel 2 comprises a barrel body with openings at both ends and a bottom plate 8 located at the lower end. The inner diameter of the extrusion barrel 2 is 200 to 500 mm. The lithium material outlet 801 and the first gate valve 14 are closed, and the extrusion plate 301 is in its initial position. Molten lithium metal is obtained by electrolyzing molten lithium chloride to obtain crude lithium ingots, which are then distilled. This meets the requirements for battery-grade lithium metal. The molten lithium metal flows into the lithium storage tank 1 through the first lithium supply pipe 16 for enrichment. When the molten lithium metal in the lithium storage tank 1 is high, the first gate valve 14 is opened, and the molten lithium metal flows into the extrusion barrel 2 through the second lithium supply pipe 17. The molten lithium metal flowing into the extrusion barrel 2 is located below the extrusion plate 301. After the lithium metal in the extrusion barrel 2 cools and solidifies, the lithium material outlet 801 is opened, and the push rod of the extrusion mechanism 3 extends downward, driving the extrusion plate 301 to squeeze the lithium metal downward, and the lithium material is discharged from the lithium material outlet 801. This enables continuous lithium material production. During actual operation, the entire device is placed in a drying room with a dew point of -50°C or below.

[0057] The extrusion mechanism 3 is a hydraulic cylinder or a pneumatic cylinder. When the extrusion mechanism 3 is a hydraulic cylinder, the piston rod of the hydraulic cylinder serves as a push rod; when the extrusion mechanism 3 is a pneumatic cylinder, the piston rod of the pneumatic cylinder serves as a push rod.

[0058] Preferably, the extrusion barrel 2 further includes a sealing ring 10 mounted at the upper opening of the extrusion barrel 2, positioned between the push rod of the extrusion mechanism 3 and the inner sidewall of the extrusion barrel 2. A first vacuum pump 12 is also mounted on the frame 5, with the air inlet of the first vacuum pump 12 communicating with the inner cavity of the extrusion barrel 2 via a first exhaust pipe 1201. The connection between the first exhaust pipe 1201 and the extrusion barrel 2 is located between the initial position of the extrusion plate 301 and the sealing ring 10. The first gate valve 14 and the lithium material outlet 801 are closed, and the sealing ring 10 is installed at the upper opening of the extrusion barrel 2, sealing the gap between the inner sidewall of the extrusion barrel 2 and the push rod. After the inner cavity of the extrusion barrel 2 is evacuated to a vacuum state by the first vacuum pump 12, the first gate valve 14 is opened, allowing the molten lithium metal in the lithium storage tank 1 to flow into the extrusion barrel 2, preventing the lithium metal in the inner cavity of the extrusion barrel 2 from coming into contact with air. The sealing ring 10 is made of high-temperature resistant rubber, preferably silicone rubber, fluororubber, or the like. Silicone rubber products and fluororubber products can still maintain good performance in environments with temperatures above 200°C.

[0059] The first exhaust pipe 1201 can be connected to the barrel of the extrusion barrel 2. Preferably, it also includes a flange plate 201 arranged along the circumference of the barrel of the extrusion barrel 2. The flange plate 201 is connected to the upper opening of the extrusion barrel 2. The flange plate 201 is provided with an exhaust channel connected to the inner cavity of the extrusion barrel 2. The flange plate 201 is connected to a gas nozzle joint connected to the exhaust channel. The gas nozzle joint is located on the outer side of the flange plate 201. The end of the first exhaust pipe 1201 away from the air inlet of the first vacuum pump 12 is installed on the gas nozzle joint. The flange plate 201 is welded to the extrusion barrel 2. The connection between the gas nozzle joint and the flange plate 201 is conventional technology, and the gas nozzle joint provides connection and installation support for the first exhaust pipe 1201. After the sealing ring 10 is installed, it contacts the flange plate 201.

[0060] Preferably, the system further comprises a second vacuum pump 18 mounted on the frame 5, a second exhaust pipe 1801 connected to the air inlet of the second vacuum pump 18 mounted on the top of the lithium storage tank 1, and a second gate valve 13 mounted on the first lithium delivery pipeline 16. The frame 5 provides mounting support for the second vacuum pump 18. After closing the second gate valve 13 and the first gate valve 14, the inner cavity of the lithium storage tank 1 is evacuated to a vacuum state by the second vacuum pump 18, and then the second gate valve 13 is opened to allow the molten metallic lithium to flow into the lithium storage tank 1 through the first lithium delivery pipeline 16 for enrichment. This prevents the metallic lithium in the lithium storage tank 1 from coming into contact with air.

[0061] Preferably, an inert gas inlet pipe 19 is installed at the top of the lithium storage tank 1, communicating with the inner cavity of the lithium storage tank 1. A third gate valve 20 is installed on the inert gas inlet pipe 19. When the second vacuum pump 18 is operating, the third gate valve 20 is closed. After the second vacuum pump 18 evacuates the inner cavity of the lithium storage tank 1 to a vacuum state, the third gate valve 20 is opened, and an inert gas is introduced into the lithium storage tank 1, bringing the pressure inside the lithium storage tank to the same level as atmospheric pressure, thereby protecting the metallic lithium in the lithium storage tank 1. Inert gases include argon, neon, helium, etc.

[0062] Preferably, a driving mechanism 11 for driving the sealing ring 10 to rise or fall is installed on the frame 5, and the driving mechanism 11 is connected to the sealing ring 10. The frame 5 provides mounting support for the driving mechanism 11, and the driving mechanism 11 drives the sealing ring 10 to move downward and is clamped between the inner wall of the extrusion barrel 2 and the push rod of the extrusion mechanism 3. When the push rod needs to be removed from the extrusion barrel 2, the driving mechanism 11 drives the sealing ring 10 to move upward, so that the sealing ring 10 is disengaged from the upper end opening of the extrusion barrel 2, and the extrusion mechanism 3 drives the push rod to rise, thereby removing the push rod from the upper end opening of the extrusion barrel 2. Specifically, the driving mechanism 11 is a hydraulic cylinder or a pneumatic cylinder, and the piston rod of the hydraulic cylinder or the piston rod of the pneumatic cylinder is connected to the sealing ring 10.

[0063] The bottom plate 8 of the extrusion barrel 2 and the barrel body of the extrusion barrel 2 can be a connected integral structure. After the lithium material production is completed, the staff can first remove the sealing ring 10 and remove the extrusion plate 301 from the upper end opening of the extrusion barrel 2 through the extrusion mechanism 3. The staff can then use a scraper to scrape off and remove the metallic lithium on the inner wall of the extrusion barrel 2. However, the above method has the disadvantage of being inconvenient to operate. In order to facilitate the staff to clean the metallic lithium stuck on the inner wall of the extrusion barrel 2, the bottom plate 8 of the extrusion barrel 2 and the lower end of the barrel body of the extrusion barrel 2 are preferably detachably mounted, and the barrel body of the extrusion barrel 2 is provided with a heating mechanism 6. The heating temperature of the heating mechanism 6 is ≥200°C. After the lithium material production is completed, the bottom plate 8 of the extrusion barrel 2 is kept closed to the lower end opening of the barrel body of the extrusion barrel 2, the lithium material outlet 801 is closed, and the heating mechanism 6 is heated to heat the metallic lithium in the extrusion barrel 2 to above 200°C, so that the metallic lithium stuck on the inner wall of the extrusion barrel 2 becomes molten, and the molten metallic lithium flows to the bottom of the extrusion barrel 2. After the metallic lithium collected at the bottom of the extrusion barrel 2 cools and solidifies, the bottom plate 8 is opened to recover the solid metallic lithium. This has the advantages of convenient operation, labor saving, and improved work efficiency. The heating mechanism 6 is preferably an electric heating block mounted on the outer wall of the extrusion barrel 2, and the electric heating block is conventional.

[0064] The bottom plate 8 can be connected to the barrel body of the extrusion barrel 2 through a slider and slot structure to open or close the lower end opening of the barrel body of the extrusion barrel 2. Preferably, the bottom plate 8 opens or closes the lower end opening of the barrel body of the extrusion barrel 2 through a lifting mechanism 4; the lifting mechanism 4 is located below the bottom plate 8 and is connected to the bottom plate 8.

[0065] Preferably, the base plate 8 is detachably connected to the lifting mechanism 4. This can be achieved by replacing the base plate 8 when different types of lithium materials are required. The lithium material outlets 801 on different base plates 8 have different shapes. Specifically, the lifting mechanism 4 is preferably a hydraulic cylinder or a pneumatic cylinder. If the lifting mechanism 4 is a hydraulic cylinder, the piston rod of the hydraulic cylinder is detachably connected to the base plate 8 via bolts or a snap-fit ​​slot structure. If the lifting mechanism 4 is a pneumatic cylinder, the piston rod of the pneumatic cylinder is detachably connected to the base plate 8 via bolts or a snap-fit ​​slot structure.

[0066] Preferably, it also includes a bottom cover 9, which is detachably connected to the bottom plate 8 via a connector and is located above the bottom plate 8; the bottom cover 9 is detachably mounted on the lower end opening of the barrel body of the extrusion barrel 2. The bottom cover 9 is a cover structure with an opening facing upward. The bottom cover 9 not only opens or closes the lithium material outlet 801 on the bottom plate 8, but also opens or closes the lower end opening of the barrel body of the extrusion barrel 2. By covering the lower end opening of the barrel body of the extrusion barrel 2 with the bottom cover 9, it can also effectively prevent the molten metallic lithium from leaking from the lower end of the barrel body. Before the molten metallic lithium is passed into the extrusion barrel 2, the bottom cover 9 is connected to the bottom plate 8 via a connector, and then the bottom cover 9 is lifted by the lifting mechanism 4 to close the lower end opening of the barrel body of the extrusion barrel 2. After the lithium metal in the extrusion barrel 2 cools and solidifies, and lithium material is produced, the bottom cover 9 and bottom plate 8 are lowered by the lifting mechanism 4. After the bottom cover 9 is removed from the bottom plate 8, the lifting mechanism 4 is used to lift the bottom plate 8 to close the lower end opening of the extrusion barrel 2. When the lithium metal adhering to the inner wall of the extrusion barrel 2 needs to be recovered, the lifting mechanism 4 first lowers the bottom plate 8, and the bottom cover 9 is installed on the bottom plate 8 via the connector. The lifting mechanism 4 is then used to lift the bottom cover 9 to close the lower end opening of the extrusion barrel 2. The heating mechanism 6 heats the lithium metal adhering to the inner wall of the extrusion barrel 2 into a molten state and flows to the bottom of the extrusion barrel 2. After the lithium metal at the bottom of the extrusion barrel 2 cools and solidifies, the lifting mechanism 4 lowers the bottom cover 9 and bottom plate 8 to recover the lithium metal. The connector can be implemented in various ways. Specifically, the bottom plate 8 and bottom cover 9 are removably connected by bolts or a snap-on slot structure.

[0067] Preferably, the extrusion barrel 2 further comprises a sealing ring 202 arranged circumferentially along the barrel body of the extrusion barrel 2. The sealing ring 202 is mounted on the outer wall of the barrel body of the extrusion barrel 2 and is close to the lower opening of the extrusion barrel 2. When the bottom cover 9 closes the lower opening of the barrel body of the extrusion barrel 2, the bottom cover 9 and the barrel body of the extrusion barrel 2 are sealed by the sealing ring 202. When the bottom cover 9 closes the lower opening of the barrel body of the extrusion barrel 2, the gap between the bottom cover 9 and the barrel body of the extrusion barrel 2 is sealed by the sealing ring 202, which facilitates the first vacuum pump 12 to evacuate the inner cavity of the extrusion barrel 2 to a vacuum state. The sealing ring 202 is a high-temperature resistant rubber product, preferably a silicone rubber product, a fluororubber product, or the like. Silicone rubber products and fluororubber products can still maintain good performance in an environment with a temperature above 200°C.

[0068] The sealing ring 202 can be installed in a variety of ways. In the first embodiment, the sealing ring 202 can be connected to the outer wall of the barrel 2 by screws. In the second embodiment, a mounting ring arranged along the circumference of the outer wall of the barrel 2 is welded to the outer wall of the barrel 2. The sealing ring 202 is connected to the mounting ring by bolts or a block and slot structure and is located below the mounting ring.

[0069] Preferably, the upper surface of the bottom cover 9 is coated with oil to prevent the metallic lithium from adhering to the baffle 9 .

[0070] To accelerate the cooling of the molten lithium metal in the extrusion barrel 2, the extrusion barrel 2 is preferably provided with a cooling mechanism 7. When the molten lithium metal in the extrusion barrel 2 needs to be cooled, the cooling mechanism 7 accelerates the cooling of the molten lithium metal in the extrusion barrel 2. The cooling mechanism 7 is preferably a cooling water pipe installed around the outer circumference of the extrusion barrel 2, which is conventional technology. The cooling temperature of the cooling mechanism 7 is ≤10°C.

[0071] Preferably, a high temperature level gauge 15 is installed on the lithium storage tank 1, the probe of the high temperature level gauge 15 is located in the lithium storage tank 1, and the head of the high temperature level gauge 15 is located outside the lithium storage tank 1. The high temperature level gauge 15 is an existing technology, model: HCUS-500.

[0072] Preferably, the first gate valve 14 is a metering valve. The metering valve measures the amount of molten lithium metal flowing through it and closes when a set threshold is reached, achieving automatic control. The metering valve is a conventional 381LSB-30 model with a flow rate of ≥5 L / min.

[0073] To prevent the molten lithium metal from sticking to the inner walls of the first and second lithium supply pipes 16, 17 when it cools, electric heating wires are preferably installed around each of the first and second lithium supply pipes 16, 17. The heating wires keep the lithium metal flowing through the first and second lithium supply pipes 16, 17 molten. The heating wires are heated to a temperature of 200-250°C.

[0074] The method for preparing a metallic lithium material uses a metallic lithium material preparation device, comprising the steps of:

[0075] S1, close the first gate valve 14, and the prepared molten lithium metal flows into the lithium storage tank 1 through the first lithium delivery pipeline 16.

[0076] Preferably, the step S1 further includes step S01: a second gate valve 13 is installed on the first lithium delivery pipeline 16, and after closing the second gate valve 13 and the first gate valve 14, the inner cavity of the lithium storage tank 1 is evacuated to a vacuum state by a second vacuum pump 18; and then an inert gas is introduced into the lithium storage tank 1 through an inert gas inlet pipe 19 installed on the top of the lithium storage tank 1. The inert gas includes argon, neon, helium, etc.

[0077] S2, close the lithium material outlet 801 located on the bottom plate 8 of the extrusion barrel 2, make the extrusion plate 301 located in the initial position, open the first gate valve 14, and allow the molten metallic lithium in the lithium storage tank 1 to flow into the extrusion barrel 2 through the second lithium delivery pipeline 17.

[0078] Specifically, step S2 includes the following steps:

[0079] S21, closing the lithium material outlet 801 on the bottom plate 8 of the extrusion barrel 2, placing the extrusion plate 301 in the initial position, and installing the sealing ring 10 at the upper end opening of the extrusion barrel 2 so that the sealing ring 10 seals the gap between the push rod of the extrusion mechanism 3 and the inner wall of the extrusion barrel 2;

[0080] S22, pumping the inner cavity of the extrusion barrel 2 to a vacuum state by the first vacuum pump 12;

[0081] S23, opening the first gate valve 14, so that the molten metallic lithium in the lithium storage tank 1 flows into the extrusion barrel 2 through the second lithium delivery pipeline 17.

[0082] Specifically, closing the lithium material outlet 801 located on the bottom plate 8 of the extrusion barrel 2 in step S2 includes the following steps: the bottom plate 8 is detachably mounted on the lower end of the barrel body of the extrusion barrel 2, a bottom cover 9 for closing the lithium material outlet 801 is connected above the bottom plate 8, a lifting mechanism 4 is connected to the bottom plate 8 and is located below the bottom plate 8, the lifting mechanism 4 lifts the bottom plate 8 and the bottom cover 9, and closes the lower end opening of the barrel body of the extrusion barrel 2 through the bottom cover 9.

[0083] S3 , after the molten lithium metal in the extrusion barrel 2 cools and solidifies, the lithium material outlet 801 is opened, and the extrusion mechanism 3 drives the extrusion plate 301 downward to extrude the cooled and solidified lithium metal, and the lithium material is discharged from the lithium material outlet 801 .

[0084] Specifically, opening the lithium material outlet 801 in step S3 includes the following steps: after the molten metallic lithium in the extrusion barrel 2 is cooled and solidified, the bottom cover 9 and the bottom plate 8 are lowered by the lifting mechanism 4, and the lithium material outlet 801 is opened after the bottom cover 9 is removed from the bottom plate 8. The lifting mechanism 4 lifts the bottom plate 8 to close the lower end opening of the barrel body of the extrusion barrel 2 through the bottom plate 8.

[0085] Preferably, when the bottom cover 9 closes the lower end opening of the barrel body of the extrusion barrel 2, the bottom cover 9 and the barrel body of the extrusion barrel 2 are sealed by a sealing ring 202 installed on the outer wall of the barrel body of the extrusion barrel 2. This is conducive to the first vacuum pump 12 pumping the inner cavity of the extrusion barrel 2 to a vacuum state.

[0086] Specifically, in step S3 , the molten metallic lithium in the extrusion barrel 2 is cooled and solidified by the cooling mechanism 7 .

[0087] After step S3, the method further includes step S4, wherein the bottom plate 8 is lowered by the lifting mechanism 4, and the bottom cover 9 is installed on the bottom plate 8. The lifting mechanism 4 lifts the bottom plate 8 and the bottom cover 9, and closes the lower end opening of the barrel body of the extrusion barrel 2 and the lithium material outlet 801 by the bottom cover 9; the extrusion barrel 2 is heated by the heating mechanism 6, so that the metallic lithium adhering to the inner wall of the extrusion barrel 2 becomes a molten state and converges to the bottom of the extrusion barrel 2, and then the metallic lithium converged to the bottom of the extrusion barrel 2 is cooled and solidified by the cooling mechanism 7, and the bottom cover 9 and the bottom plate 8 are lowered by the lifting mechanism 4, and then the cooled and solidified metallic lithium is cleaned from the bottom of the extrusion barrel 2.

[0088] The above is a detailed description of the present invention. As can be seen from the implementation process, the present invention provides an apparatus and method for preparing lithium metal, enabling continuous lithium material production. This reduces the number of lithium metal casting steps, effectively preventing oxidation and nitridation of lithium metal, and conserving resources. It also facilitates the removal of lithium metal adhering to the inner wall of the extrusion barrel, resulting in convenient operation, labor savings, and improved efficiency.

Claims

1. A device for preparing lithium metal material, characterized in that: It comprises a lithium storage tank (1), an extrusion barrel (2), an extrusion mechanism (3) and a frame (5), wherein the lithium storage tank (1), the extrusion barrel (2) and the extrusion mechanism (3) are all mounted on the frame (5); The extrusion barrel (2) is arranged vertically and its opening faces upwards; the extrusion mechanism (3) has a vertically arranged push rod, the push rod extends into the inner cavity of the extrusion barrel (2) through the upper opening of the extrusion barrel (2); the lower end of the push rod is connected to an extrusion plate (301) adapted to the inner cavity of the extrusion barrel (2); an openable and closable lithium material outlet (801) is arranged on the bottom plate (8) of the extrusion barrel (2); A first lithium delivery pipeline (16) is installed at the feed inlet of the lithium storage tank (1); the discharge port of the lithium storage tank (1) is connected to the feed inlet of the extrusion barrel (2) via a second lithium delivery pipeline (17); the initial position of the extrusion plate (301) is located above the feed inlet of the extrusion barrel (2); and a first gate valve (14) is installed on the second lithium delivery pipeline (17).

2. The device for preparing the metallic lithium material according to claim 1, characterized in that: It also includes a sealing ring (10) installed at the upper opening of the extrusion barrel (2), wherein the sealing ring (10) is located between the push rod of the extrusion mechanism (3) and the inner side wall of the extrusion barrel (2); It also includes a first vacuum pump (12) installed on the frame (5), the air inlet of the first vacuum pump (12) is connected to the inner cavity of the extrusion barrel (2) through a first exhaust pipe (1201); the connection between the first exhaust pipe (1201) and the extrusion barrel (2) is located between the initial position of the extrusion plate (301) and the sealing ring (10).

3. The device for preparing the metallic lithium material according to claim 2, characterized in that: It also includes a flange plate (201) arranged along the circumference of the barrel body of the extrusion barrel (2), and the flange plate (201) is connected to the upper end opening of the extrusion barrel (2); The flange plate (201) is provided with an exhaust channel connected to the inner cavity of the extrusion barrel (2), and the flange plate (201) is connected with a gas nozzle joint connected to the exhaust channel. The gas nozzle joint is located on the outer side of the flange plate (201), and the end of the first exhaust pipe (1201) away from the air inlet of the first vacuum pump (12) is installed on the gas nozzle joint.

4. The device for preparing the metallic lithium material according to claim 1, characterized in that: It also includes a second vacuum pump (18) installed on the frame (5), and a second exhaust pipe (1801) connected to the air inlet of the second vacuum pump (18) is installed on the top of the lithium storage tank (1); A second gate valve (13) is installed on the first lithium transport pipeline (16).

5. The device for preparing the metallic lithium material according to claim 4, characterized in that: An inert gas inlet pipe (19) communicating with the inner cavity of the lithium storage tank (1) is installed on the top of the lithium storage tank (1), and a third gate valve (20) is installed on the inert gas inlet pipe (19).

6. The device for preparing the metallic lithium material according to claim 2, characterized in that: A driving mechanism (11) for driving the sealing ring (10) to rise or fall is installed on the frame (5); the driving mechanism (11) is connected to the sealing ring (10).

7. The device for preparing the metallic lithium material according to claim 2, characterized in that: The bottom plate (8) of the extrusion barrel (2) and the lower end of the barrel body of the extrusion barrel (2) are detachably mounted; and a heating mechanism (6) is provided on the barrel body of the extrusion barrel (2).

8. The device for preparing the metallic lithium material according to claim 7, characterized in that: The bottom plate (8) opens or closes the lower end opening of the barrel body of the extrusion barrel (2) through a lifting mechanism (4); the lifting mechanism (4) is located below the bottom plate (8) and is connected to the bottom plate (8).

9. The device for preparing the metallic lithium material according to claim 8, characterized in that: The bottom plate (8) is detachably connected to the lifting mechanism (4).

10. The device for preparing metallic lithium material according to claim 7, characterized in that: It also includes a bottom cover (9), which is detachably connected to the bottom plate (8) via a connecting piece and is located above the bottom plate (8); The bottom cover (9) is detachably mounted on the lower end opening of the barrel body of the extrusion barrel (2).

11. The device for preparing metallic lithium material according to claim 10, characterized in that: It also includes a sealing ring (202) arranged along the circumference of the barrel body of the extrusion barrel (2), wherein the sealing ring (202) is installed on the outer side wall of the barrel body of the extrusion barrel (2) and is close to the lower end opening of the extrusion barrel (2); When the bottom cover (9) closes the lower end opening of the barrel body of the extrusion barrel (2), the bottom cover (9) and the barrel body of the extrusion barrel (2) are sealed via the sealing ring (202).

12. The device for preparing metallic lithium material according to claim 1, characterized in that: A cooling mechanism (7) is provided on the barrel body of the extrusion barrel (2).

13. The device for preparing metallic lithium material according to claim 1, characterized in that: The first gate valve (14) is a metering valve.

14. The device for preparing metallic lithium material according to claim 1, characterized in that: Electric heating wires are installed around the first lithium transport pipeline (16) and the second lithium transport pipeline (17).

15. The device for preparing metallic lithium material according to claim 1, characterized in that: The volume of the lithium storage tank (1) is 50-400L, and the effective volume of the lithium storage tank (1) is ≥80%.

16. The device for preparing metallic lithium material according to claim 1, characterized in that: The inner diameter of the extrusion barrel (2) is 200 to 500 mm.

17. A method for preparing a metallic lithium material, characterized in that: The device for preparing the metallic lithium material according to any one of claims 1 to 16 comprises the steps of: S1, closing the first gate valve (14), allowing the prepared molten metal lithium to flow into the lithium storage tank (1) through the first lithium delivery pipeline (16); S2, closing the lithium material outlet (801) located on the bottom plate (8) of the extrusion barrel (2), placing the extrusion plate (301) in the initial position, opening the first gate valve (14), and allowing the molten metal lithium in the lithium storage tank (1) to flow into the extrusion barrel (2) through the second lithium delivery pipeline (17); S3, after the molten lithium metal in the extrusion barrel (2) cools and solidifies, the lithium material outlet (801) is opened, and the extrusion mechanism (3) drives the extrusion plate (301) to extrude the cooled and solidified lithium metal downward, and the lithium material is discharged from the lithium material outlet (801).

18. The method for preparing a metallic lithium material according to claim 17, characterized in that: The method also includes step S01 before step S1: a second gate valve (13) is installed on the first lithium transport pipeline (16); after closing the second gate valve (13) and the first gate valve (14), the inner cavity of the lithium storage tank (1) is evacuated to a vacuum state by a second vacuum pump (18); and an inert gas is introduced into the lithium storage tank (1) through an inert gas inlet pipe (19) installed on the top of the lithium storage tank (1).

19. The method for preparing a metallic lithium material according to claim 17, wherein: The step S2 comprises the following steps: S21, closing the lithium material outlet (801) located on the bottom plate (8) of the extrusion barrel (2), placing the extrusion plate (301) in the initial position, installing the sealing ring (10) at the upper opening of the extrusion barrel (2), so that the sealing ring (10) seals the gap between the push rod of the extrusion mechanism (3) and the inner wall of the extrusion barrel (2); S22, evacuating the inner cavity of the extrusion barrel (2) to a vacuum state by using a first vacuum pump (12); S23, opening the first gate valve (14), allowing the molten metal lithium in the lithium storage tank (1) to flow into the extrusion barrel (2) through the second lithium delivery pipeline (17).

20. The method for preparing a metallic lithium material according to claim 17, wherein: The step S2 of closing the lithium material outlet (801) located on the bottom plate (8) of the extrusion barrel (2) comprises the following steps: the bottom plate (8) is detachably mounted on the lower end of the barrel body of the extrusion barrel (2); a bottom cover (9) for closing the lithium material outlet (801) is connected above the bottom plate (8); a lifting mechanism (4) is connected to the bottom plate (8) and is located below the bottom plate (8); the lifting mechanism (4) lifts the bottom plate (8) and the bottom cover (9), and closes the lower end opening of the barrel body of the extrusion barrel (2) through the bottom cover (9).

21. The method for preparing a metallic lithium material according to claim 20, characterized in that: When the bottom cover (9) closes the lower end opening of the barrel body of the extrusion barrel (2), the bottom cover (9) and the barrel body of the extrusion barrel (2) are sealed by a sealing ring (202) installed on the outer side wall of the barrel body of the extrusion barrel (2).

22. The method for preparing a metallic lithium material according to claim 17, wherein: The step S3 of opening the lithium material outlet (801) comprises the following steps: after the molten lithium metal in the extrusion barrel (2) is cooled and solidified, the bottom cover (9) and the bottom plate (8) are lowered by the lifting mechanism (4), the bottom cover (9) is removed from the bottom plate (8), and the lithium material outlet (801) is opened; the lifting mechanism (4) lifts the bottom plate (8), and the lower end opening of the barrel body of the extrusion barrel (2) is closed by the bottom plate (8).

23. The method for preparing a metallic lithium material according to claim 17, wherein: In the step S3, the molten metal lithium in the extrusion barrel (2) is cooled and solidified by a cooling mechanism (7).

24. The method for preparing a metallic lithium material according to claim 22, characterized in that: After step S3, the method further comprises step S4, wherein the bottom plate (8) is lowered by the lifting mechanism (4), the bottom cover (9) is installed on the bottom plate (8), the lifting mechanism (4) lifts the bottom plate (8) and the bottom cover (9), the lower end opening of the barrel body of the extrusion barrel (2) is closed by the bottom cover (9), and the lithium material outlet (801) is closed; the extrusion barrel (2) is heated by the heating mechanism (6), so that the metallic lithium adhering to the inner wall of the extrusion barrel (2) becomes molten and converges to the bottom of the extrusion barrel (2); the metallic lithium converged to the bottom of the extrusion barrel (2) is cooled and solidified by the cooling mechanism (7); the bottom cover (9) and the bottom plate (8) are lowered by the lifting mechanism (4), and the cooled and solidified metallic lithium is cleaned from the bottom of the extrusion barrel (2).

25. The method for preparing a metallic lithium material according to claim 24, characterized in that: The heating temperature of the heating mechanism (6) is ≥200°C.

26. The method for preparing a metallic lithium material according to claim 23 or 24, characterized in that: The cooling temperature of the cooling mechanism (7) is ≤10°C.

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