Preparation device and method of high-purity ultrafine lithium sulfide electrolyte

Abstract

The application belongs to the technical field of lithium-sulfur battery manufacturing, and particularly relates to a preparation device and a preparation method of high-purity ultrafine lithium sulfide electrolyte. The preparation device of high-purity ultrafine lithium sulfide electrolyte comprises a reaction furnace, a lithium microflow mechanism and a sulfur gasification mechanism are throughly arranged on the reaction furnace, and an ultrasonic generator is further arranged on the reaction furnace, and a tray is slidably arranged in the reaction furnace. The lithium microflow mechanism comprises a glove box and a smelting furnace which are throughly connected, a first mechanical valve is arranged at the communication part of the glove box and the smelting furnace, and a feeding pipe is further throughly arranged between the glove box and the smelting furnace. The smelting furnace is throughly connected with the reaction furnace through a microflow pipeline, and a microflow meter is arranged on the microflow pipeline. The sulfur gasification mechanism comprises a sulfur raw material bin and a tubular furnace which are throughly connected through a raw material pipeline, and the tubular furnace is throughly connected with the reaction furnace through an airflow pipeline. The application can continuously prepare lithium-sulfur electrolyte with high purity and low particle size without interruption, has the advantages of low cost and no other sulfide production, and is suitable for industrial production.

Description

Technical Field

[0001] This invention belongs to the field of lithium-sulfur battery manufacturing technology, specifically relating to a preparation apparatus and method for high-purity ultrafine lithium sulfide electrolyte. Background Technology

[0002] Traditional lithium-ion batteries still have significant drawbacks. Currently, commercially available lithium-ion batteries use carbon anodes and flammable liquid electrolytes. Their energy density and safety are gradually failing to meet people's needs, and there is an urgent need to develop batteries with high specific energy and high specific capacity.

[0003] Lithium-sulfur (Li-S) batteries have a high theoretical specific capacity (1672 mAh g). -1 ) and specific energy (2600Wh Kg) -1 Currently, lithium-ion batteries based on liquid electrolytes still have some practical problems. Compared with Li-ion batteries based on liquid electrolytes, Li-S batteries based on lithium sulfide solid electrolytes have significant advantages, specifically: ① avoiding the dissolution and shuttle effect of long-chain polysulfides in liquid electrolytes; ② eliminating the side reactions between lithium and organic electrolytes, avoiding the continuous consumption of electrolyte by lithium metal, and improving battery life; ③ solid electrolytes have high thermal stability, which can largely avoid high-temperature gas expansion and leakage, thereby improving safety.

[0004] Currently, the mainstream methods for preparing lithium sulfide can be broadly categorized into ball milling synthesis, solvent reaction, and high-temperature sintering. Ball milling synthesis involves drying elemental sulfur and elements such as lithium or lithium hydride, then milling them in a ball mill to produce elemental lithium sulfide. While this method is simple and does not generate organic waste, the raw material costs are too high, the reaction time is too long, and the conversion rate is low. Furthermore, the resulting powder is difficult to purify into lithium sulfide. Solvent reaction involves dissolving lithium and sulfur compounds in an organic solvent and reacting them to prepare lithium sulfide. This method offers advantages such as high yield, nanoscale product size, and low cost. However, it suffers from lower product purity, requires organic solvents that are flammable, explosive, and volatile, and are difficult to recover after the reaction, leading to severe environmental pollution. High-temperature sintering is a method for preparing lithium sulfide by reacting lithium and sulfur compounds under a reducing atmosphere. Its advantages include obtaining high-purity, high-crystal-quality lithium sulfide. However, its disadvantages include high production costs due to the high temperature conditions, low yield, inability to produce continuously, large particle size of the sintered product, expensive high-temperature equipment, and complex treatment of reaction exhaust gases. In summary, the current lack of high-purity, low-cost, and continuous production processes for lithium sulfide significantly hinders its commercial application, and further breakthroughs are needed to develop a continuous high-temperature sintering process. Summary of the Invention

[0005] To address the shortcomings of the existing technology, the purpose of this invention is to provide a device and method for preparing high-purity ultrafine lithium sulfide electrolyte. This invention not only enables the uninterrupted and continuous preparation of high-purity lithium sulfide electrolyte with low particle size, but also has the advantages of low cost and no other sulfides generated, making it suitable for industrial production.

[0006] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0007] A device for preparing high-purity ultrafine lithium sulfide electrolyte includes a reactor, on which a lithium microfluidic mechanism and a sulfur gasification mechanism are arranged in a continuous manner, and an ultrasonic generator is also provided on the reactor. A tray is slidably arranged inside the reactor.

[0008] The lithium microfluidic mechanism includes: a glove box and a smelting furnace that are connected through each other, with a first mechanical valve provided at the connection between the two, and a feeding pipe that is also connected through between the glove box and the smelting furnace. The feeding pipe is inclined, and a smelting tray is provided inside the smelting furnace and below the inclined bottom end of the feeding pipe. The smelting tray is detachably connected to the smelting furnace.

[0009] The smelting furnace and the reaction furnace are connected through a microfluidic pipe, and a microfluidic meter is installed on the microfluidic pipe;

[0010] The sulfur gasification mechanism includes a sulfur feedstock silo and a tubular furnace connected by a feedstock pipeline, wherein the tubular furnace and the reaction furnace are connected by a gas flow pipeline.

[0011] Preferably, a second mechanical valve is detachably connected to the reactor, which divides the reactor into a reaction chamber and a transition chamber from top to bottom. The microfluidic pipe and the gas flow pipe are respectively connected to the reaction chamber, and the ultrasonic generator is disposed on the reaction chamber.

[0012] Preferably, an electric telescopic rod is provided on the inner wall of the reaction chamber, and a frame is fixed to the telescopic end of the electric telescopic rod, with the tray located on the frame;

[0013] The free ends of the microfluidic pipes and the free ends of the airflow pipes, which extend into the reaction chamber, are both located above the tray.

[0014] Preferably, an observation window is provided on the side wall of the reaction chamber, and a material inlet is provided on the bottom wall of the transition chamber, with a cover detachably and sealingly connected to the material inlet.

[0015] Preferably, the smelting furnace is equipped with a first vacuum pump and a first gas charging pump; the reaction chamber is equipped with a second vacuum pump and a second gas charging pump; and the tubular furnace is also provided with a gas exhaust pipe, on which a third vacuum pump is installed.

[0016] Preferably, a first switch is provided on the feeding pipe, a second switch is provided on the microfluidic pipe, a third switch is provided on the airflow pipe, a fourth switch is provided on the raw material pipe, and a fifth switch is provided on the exhaust pipe.

[0017] This invention also protects the method for preparing high-purity ultrafine lithium sulfide electrolyte using the above-mentioned preparation apparatus, comprising the following steps:

[0018] S1. Open the first switch, the second switch, the third switch, the fourth switch and the fifth switch. After evacuating the high-purity ultrafine lithium sulfide electrolyte preparation device using the first vacuum pump, the second vacuum pump and the third vacuum pump, argon gas is introduced through the first gas pump and the second gas pump. Then, close the first switch, the second switch, the third switch, the fourth switch and the fifth switch.

[0019] S2. Take out elemental lithium from the glove box, open the first mechanical valve and bring the smelting tray into the glove box. After putting in the elemental lithium, put the smelting tray containing the elemental lithium into the slot of the smelting furnace and reset the first mechanical valve.

[0020] S3. Open the fourth switch to allow elemental sulfur in the sulfur raw material silo to be discharged into the tubular furnace through the raw material pipeline. Close the fourth switch and open the fifth switch. Use the third vacuum pump to evacuate the tubular furnace and then close the fifth switch and the third vacuum pump. The tubular furnace will run and heat the solid sulfur until the elemental sulfur is vaporized to obtain sulfur vapor.

[0021] S4. Heat elemental lithium in a melting furnace until all lithium is melted into liquid. Simultaneously turn on the second switch, the third switch, and the ultrasonic generator. Inject the liquid lithium into the reaction chamber through a microfluidic pipe. The microfluidic meter on the microfluidic pipe causes the elemental lithium to flow in the form of droplets. At the same time, the ultrasonic generator atomizes the lithium droplets in the reaction chamber. The atomized lithium droplets fall naturally. Meanwhile, the vaporized elemental sulfur is discharged into the reaction chamber through the gas flow pipe. After the lithium droplets come into contact with the sulfur vapor, they react on the tray to generate high-purity ultrafine lithium sulfide electrolyte.

[0022] S5. After observing through the observation window that no lithium sulfide is generated, simultaneously turn on the first and fourth switches, add elemental lithium through the feeding pipe, and replenish elemental sulfur through the raw material pipe to continue the preparation of high-purity ultrafine lithium sulfide electrolyte.

[0023] After the reaction is complete, open the second mechanical valve and start the electric telescopic rod. The electric telescopic rod drives the frame, and the frame drives the tray into the transition chamber for cooling. Once cooled to room temperature, open the material dispensing port and remove the tray from the transition chamber through the material dispensing port.

[0024] Preferably, the melting furnace is in an argon atmosphere, and the melting temperature of elemental lithium in the melting furnace is 250℃~400℃; the tube furnace is in a vacuum environment, and the heating temperature of elemental sulfur in the tube furnace is 500℃~700℃.

[0025] Preferably, the ultrasonic generator produces sound waves with a frequency of 20KHz to 50KHz, and the flow rate adjustment range of the microfluidic meter is 0.2g / min to 20g / min.

[0026] Preferably, the temperature inside the reaction chamber is 750℃~900℃.

[0027] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0028] 1. This invention effectively solves the technical problems of continuous production and large particle size caused by high-temperature sintering by coupling high-temperature solid-state sintering, microfluidic technology and ultrasonic pulverization technology. The prepared lithium sulfide has high purity, nano-sized particle size, no need for purification treatment and the ability to be produced continuously for 24 hours.

[0029] 2. In this invention, lithium and sulfur are reacted using a coupled high-temperature solid-state sintering method to prepare lithium sulfide. The raw materials are simple, the resulting lithium sulfide has high purity, and the raw material cost is low. Liquid lithium is injected using microfluidic technology; adjusting the microfluidic valve allows for control of the flow rate and droplet size, thus controlling the production rate. Simultaneously, ultrasonic pulverization technology further disperses and pulverizes the droplets using ultrasound, ensuring a complete reaction while limiting the particle size to the nanometer scale. In industrial production, lithium can be added via a feeding pipeline, and then the sulfur feedstock can be opened to replenish elemental sulfur, enabling continuous production without frequent on / off cycles and maximizing cost reduction. Attached Figure Description

[0030] Figure 1 This is an observation image under a light microscope of the sample prepared in Example 1 of the present invention;

[0031] Figure 2 These are diagrams of the apparatus used in Examples 1-5 of the present invention;

[0032] Figure 3 This is the XRD pattern of the high-purity ultrafine lithium sulfide electrolyte sample prepared in Example 1 of the present invention.

[0033] Explanation of reference numerals in the attached figures:

[0034] 1. Glove box; 2. First mechanical valve; 3. Smelting furnace; 4. Feed pipe; 5. First switch; 6. First vacuum pump; 7. First air pump; 8. Smelting tray; 9. Second switch; 10. Microfluidometer; 11. Second vacuum pump; 12. Third switch; 13. Fourth switch; 14. Sulfur raw material silo; 15. Fifth switch; 16. Third vacuum pump; 17. Tube furnace; 18. Second air pump; 19. Ultrasonic generator; 20. Observation window; 21. Reactor; 22. Tray; 23. Second mechanical valve; 24. Transition chamber; 25. Feed port; 26. Microfluidic pipe; 27. Gas flow pipe; 28. Electric telescopic rod; 29. ​​Frame; 30. Raw material pipe; 31. Reactor; 32. Gas exhaust pipe. Detailed Implementation

[0035] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention. Parameters not specifically specified can be performed using conventional techniques. These all fall within the scope of protection of this invention, but are not limited to it.

[0036] It should be noted that: the smelting furnace 3 of the present invention is selected from Baofeng high vacuum furnace BF-GB4, the tube furnace 17 is selected from OTL1200 stainless steel tube furnace, and the inner wall of the reaction chamber 31 of the reaction furnace 21 is provided with a high temperature resistance wire, and the high temperature resistance wire is used to heat the lithium droplets and sulfur vapor on the tray 22.

[0037] The preparation of the high-purity ultrafine lithium sulfide electrolyte in this invention is based on a high-purity ultrafine lithium sulfide electrolyte preparation device, such as... Figure 2 As shown, the apparatus for preparing high-purity ultrafine lithium sulfide electrolyte includes a reactor 21, in which the high-purity ultrafine lithium sulfide electrolyte is prepared. A lithium microfluidic mechanism and a sulfur vaporization mechanism are arranged in a continuous manner on the reactor 21. The lithium microfluidic mechanism is used to obtain lithium droplets, and the sulfur vaporization mechanism is used to obtain sulfur vapor. An ultrasonic generator 19 is also provided on the reactor 21. The ultrasonic generator 19 atomizes the lithium droplets and further disperses and pulverizes the droplets. While ensuring sufficient reaction, it can also limit the particle size of the prepared lithium sulfide electrolyte, so that the particle size of the obtained lithium sulfide electrolyte is in the nanometer scale. A tray 22 is slidably arranged in the reactor 21, and the high-purity ultrafine lithium sulfide electrolyte is prepared in the tray 22.

[0038] The lithium microfluidic mechanism includes a glove box 1 and a smelting furnace 3 connected in a continuous manner. Elemental lithium is oxidized in air, so it is stored in the glove box 1. The smelting furnace 3 liquefies solid elemental lithium. A first mechanical valve 2 is provided at the connection between the two. When the first mechanical valve 2 is opened, the glove box 1 and the smelting furnace 3 are connected. A feeding pipe 4 is also provided between the glove box 1 and the smelting furnace 3. The feeding pipe 4 is used to supplement the feed during the preparation of lithium sulfide electrolyte. The feeding pipe 4 is inclined. A smelting tray 8 is provided in the smelting furnace 3, below the inclined bottom end of the feeding pipe 4. Elemental lithium in the glove box 1 is transported to the smelting tray 8 in the smelting furnace 3 through the feeding pipe 4, and liquefaction of solid elemental lithium is achieved on the smelting tray 8. The smelting tray 8 is detachably connected to the smelting furnace 3. A slot is provided on the side wall of the smelting furnace 3, and the smelting tray 8 can be placed in the slot.

[0039] The smelting furnace 3 and the reactor 21 are connected through a microfluidic pipe 26. The connection between the microfluidic pipe 26 and the smelting furnace 3 is flush with the smelting tray 8, which facilitates the flow of liquefied lithium on the smelting tray 8. The liquefied lithium on the smelting tray 8 is discharged into the reactor 21 through the microfluidic pipe 26. A microfluidic meter 10 is installed on the microfluidic pipe 26. The microfluidic meter 10 regulates the flow rate and droplet size of the liquefied lithium to control the production rate.

[0040] The sulfur gasification mechanism includes a sulfur raw material silo 14 and a tubular furnace 17 connected through a raw material pipeline 30. Elemental sulfur is stored in the sulfur raw material silo 14 and discharged into the tubular furnace 17 through the raw material pipeline 30, where it is gasified. The tubular furnace 17 is connected to the reactor 21 through a gas flow pipeline 27, and the gasified sulfur in the tubular furnace 17 is discharged into the reactor 21 through the gas flow pipeline 27.

[0041] A second mechanical valve 23 is detachably connected to the reactor 21. The opening of the first mechanical valve 2 and the second mechanical valve 23 does not affect the argon environment inside the device. The second mechanical valve 23 divides the reactor 21 from top to bottom into a reaction chamber 31 and a transition chamber 24. After the second mechanical valve 23 is opened, the reaction chamber 31 and the transition chamber 24 are connected. High-purity ultrafine lithium sulfide electrolyte is prepared in the reaction chamber 31, and the prepared lithium sulfide electrolyte is cooled in the transition chamber 24. The microfluidic pipe 26 and the gas flow pipe 27 are respectively connected to the reaction chamber 31, and the ultrasonic generator 19 is set on the reaction chamber 31.

[0042] An electric telescopic rod 28 is installed on the inner wall of the reaction chamber 31. A frame 29 is fixed to the telescopic end of the electric telescopic rod 28. The tray 22 is located on the frame 29. The electric telescopic rod 28 drives the frame 29, and the frame 29 drives the tray 22 to move up and down, so as to facilitate the adjustment of the position of the tray 22.

[0043] The free ends of the microfluidic pipe 26 and the gas flow pipe 27, which extend into the reaction chamber 31, are both located above the tray 22, facilitating the atomized lithium droplets and the vaporized elemental sulfur to fall into the tray 22.

[0044] An observation window 20 is provided on the side wall of the reaction chamber 31. The observation window 20 facilitates the observation of the reaction between lithium droplets and sulfur vapor in the reaction chamber 31. A material outlet 25 is provided on the bottom wall of the transition chamber 24. A cover is detachably and sealed to the material outlet 25. After the reaction is completed, the tray 22 can be taken out through the material outlet 25 for use.

[0045] The smelting furnace 3 is equipped with a first vacuum pump 6 and a first gas charging pump 7; the reaction chamber 31 is equipped with a second vacuum pump 11 and a second gas charging pump 18; the tube furnace 17 is also connected by a gas exhaust pipe 32, and a third vacuum pump 16 is installed on the gas exhaust pipe 32; the first vacuum pump 6, the second vacuum pump 11, and the third vacuum pump 16 work together to evacuate the device, and the first gas charging pump 7 and the second gas charging pump 18 work together to replenish argon gas into the device; the tube furnace 17, which is filled with argon gas, continues to be evacuated under the action of the third vacuum pump 16;

[0046] A first switch 5 is installed on the feeding pipe 4, a second switch 9 is installed on the microflow pipe 26, a third switch 12 is installed on the airflow pipe 27, a fourth switch 13 is installed on the raw material pipe 30, and a fifth switch 15 is installed on the exhaust pipe 32. The first switch 5, the second switch 9, the third switch 12, the fourth switch 13, and the fifth switch 15 work together to regulate the flow of lithium droplets and sulfur vapor.

[0047] Based on the above-mentioned apparatus, the present invention prepares lithium sulfide electrolyte, and the specific preparation method includes the following steps:

[0048] a. Open the valves on the first switch 5, the second switch 9, the third switch 12, the fourth switch 13, and the fifth switch 15. After evacuating the device using the first vacuum pump 6, the second vacuum pump 11, and the third vacuum pump 16, fill the device with argon gas through the first gas filling pump 7 and the second gas filling pump 18. Then close the valves on the first switch 5, the second switch 9, the third switch 12, the fourth switch 13, and the fifth switch 15 to fill the device with argon gas.

[0049] b. Take out the elemental lithium from the glove box 1, then open the first mechanical valve 2 between the glove box 1 and the smelting furnace 3, and bring the smelting tray 8 into the glove box 1. After putting in the elemental lithium, put the smelting tray 8 containing the elemental lithium into the smelting furnace 3. Note that it needs to be placed in the designated slot position so that the lithium can flow into the microfluidic pipe 26 after melting. Then reset the first mechanical valve 2.

[0050] c. Open the fourth switch 13, take elemental sulfur and transport it to the tubular furnace 17 through the sulfur raw material silo 14. Close the fourth switch 13 and open the fifth switch 15. Use the third vacuum pump 16 to evacuate the tubular furnace 17 again. Then close the fifth switch 15 and the third vacuum pump 16 to make the tubular furnace 17 run and heat it to 500-700°C. Wait for 10-15 minutes.

[0051] d. Heat elemental lithium in the melting furnace 3 to bring the temperature of the melting tray 8 in the melting furnace 3 to 250℃~400℃, and wait for 10min~15min to melt all the solid lithium into liquid state.

[0052] e. Simultaneously turn on the second switch 9, the third switch 12, and the ultrasonic generator 19, and make the ultrasonic generator 19 generate sound waves with a frequency of 20KHz to 50KHz, while heating the reaction chamber 31 to 750℃ to 900℃, and keeping the temperature inside the melting furnace 3 and the reaction chamber 31 constant.

[0053] f. Liquid lithium is injected into the reaction chamber 31 along the microfluidic channel 26. The microfluidic meter 10 on the microfluidic channel 26 causes the lithium element to flow in the form of droplets. At the same time, the ultrasonic generator 19 atomizes the lithium droplets in the reaction chamber 31. The atomized lithium droplets fall naturally. Meanwhile, the vaporized sulfur element is discharged into the reaction chamber 31 through the airflow channel 27. After the lithium droplets come into contact with the sulfur vapor, they react on the tray 22 to generate high-purity ultrafine lithium sulfide electrolyte.

[0054] g. After observing through the observation window 20 that no lithium sulfide is generated, simultaneously open the first switch 5 on the feeding pipe 4 and the fourth switch 13 on the raw material pipe 30. Add the elemental lithium in the glove box 1 to the smelting tray 8 through the feeding pipe 4. The elemental sulfur is discharged into the tube furnace 17 through the sulfur raw material silo 14 to replenish the elemental sulfur. Continue to perform the above operations.

[0055] After the reaction is completed, the second mechanical valve 23 is opened and the electric telescopic rod 28 is started. The electric telescopic rod 28 drives the frame 29, and the frame 29 drives the tray 22 into the transition chamber 24 for cooling. After cooling to room temperature, the material outlet 25 is opened, and the tray 22 is taken out from the transition chamber 24 through the material outlet 25 to obtain high-purity ultrafine lithium sulfide electrolyte.

[0056] The molar ratio of sulfur added in step c to lithium added in step b is 1:4, 1:2 or 1:1, and the specific temperatures are 500℃, 550℃, 600℃, 650℃ or 700℃.

[0057] The specific temperatures in step d are 250℃, 300℃, 350℃, and 400℃;

[0058] The specific sound wave frequencies in step e are 20KHz, 30KHz, 35KHz, 40KHz, and 50KHz, and the specific temperatures are 750℃, 800℃, 850℃, and 900℃.

[0059] In step f, the flow rate of the microfluidic meter is in the range of 0.2 g / min to 20 g / min, specifically 0.2 g / min, 1 g / min, 2 g / min, 5 g / min, 10 g / min, 15 g / min, and 20 g / min.

[0060] The present invention will be further described in detail below with reference to examples, but this does not limit the present invention in any way. The equipment and reagents used in the examples are all conventional equipment and reagents in this technical field.

[0061] Example 1

[0062] The high-purity ultrafine lithium sulfide electrolyte was prepared according to steps a to g above. In step c, 8 kg of sulfur and 3.5 kg of lithium were added, the temperature was set at 550℃, and the time was 15 min. In step d, the temperature was 250℃ and the time was 15 min. In step e, the ultrasonic frequency was 40 kHz and the temperature was 750℃. In step f, the microfluidic flow rate was 0.2 g / min.

[0063] Example 2

[0064] The high-purity ultrafine lithium sulfide electrolyte was prepared according to steps a to g above. In step c, 8 kg of sulfur and 1.75 kg of lithium were added, the temperature was set to 500℃, and the time was 15 min. In step d, the temperature was set to 300℃ and the time was 13 min. In step e, the ultrasonic frequency was 20 kHz and the temperature was set to 800℃. In step f, the microfluidic flow rate was 2 g / min.

[0065] Example 3

[0066] The high-purity ultrafine lithium sulfide electrolyte was prepared according to steps a to g above. In step c, 16 kg of sulfur and 14 kg of lithium were added, the temperature was set to 600℃, and the time was 12 min. In step d, the temperature was set to 350℃ and the time was 12 min. In step e, the ultrasonic frequency was 30 kHz and the temperature was set to 850℃. In step f, the microfluidic flow rate was 10 g / min.

[0067] Example 4

[0068] The high-purity ultrafine lithium sulfide electrolyte was prepared according to steps a to g above. In step c, 16 kg of sulfur and 7 kg of lithium were added, the temperature was set to 650℃, and the time was 11 min. In step d, the temperature was set to 350℃ and the time was 11 min. In step e, the ultrasonic frequency was 35 kHz and the temperature was set to 850℃. In step f, the microfluidic flow rate was 15 g / min.

[0069] Example 5

[0070] The high-purity ultrafine lithium sulfide electrolyte was prepared according to steps a to g above. In step c, 8 kg of sulfur and 3.5 kg of lithium were added at a temperature of 700℃ for 10 min. In step d, the temperature was 400℃ for 10 min. In step e, the ultrasonic frequency was 50 kHz and the temperature was 900℃. In step f, the microfluidic flow rate was 10 g / min. After no more lithium sulfide was generated in step f, 3 kg of lithium and 8 kg of sulfur were added again, and the process was repeated 3 times.

[0071] Figure 1 The results showed that the prepared lithium sulfide particles had a small particle size, which was measured to be approximately 16.8 μm.

[0072] Figure 3 The XRD results showed that the prepared lithium sulfide had high purity and no other impurities were generated.

[0073] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims and their equivalents, this invention also intends to include these modifications and variations. The above-described embodiments are merely preferred embodiments for fully illustrating the invention, and their scope of protection is not limited thereto. Equivalent substitutions or modifications made by those skilled in the art based on this invention are all within the scope of protection of this invention, which is defined by the claims.

Claims

1. An apparatus for preparing high-purity ultrafine lithium sulfide electrolyte, characterized in that, The reactor includes a reactor (21), on which a lithium microfluidic mechanism and a sulfur gasification mechanism are provided, and an ultrasonic generator (19) is also provided on the reactor (21). A tray (22) is slidably arranged inside the reactor (21). The lithium microfluidic mechanism includes: a glove box (1) and a smelting furnace (3) that are connected through each other, a first mechanical valve (2) is provided at the connection between the two, a feeding pipe (4) is also provided through between the glove box (1) and the smelting furnace (3), the feeding pipe (4) is inclined, a smelting tray (8) is provided inside the smelting furnace (3) below the inclined bottom end of the feeding pipe (4), and the smelting tray (8) is detachably connected to the smelting furnace (3); The smelting furnace (3) and the reaction furnace (21) are connected through a microfluidic pipe (26), and a microfluidic meter (10) is installed on the microfluidic pipe (26); The sulfur gasification mechanism includes a sulfur raw material silo (14) and a tubular furnace (17) connected through a raw material pipeline (30), and the tubular furnace (17) and the reaction furnace (21) are connected through a gas flow pipeline (27).

2. The apparatus for preparing high-purity ultrafine lithium sulfide electrolyte as described in claim 1, characterized in that, A second mechanical valve (23) is detachably connected to the reactor (21). The second mechanical valve (23) divides the reactor (21) from top to bottom into a reaction chamber (31) and a transition chamber (24). The microfluidic pipe (26) and the gas flow pipe (27) are respectively connected to the reaction chamber (31), and the ultrasonic generator (19) is installed on the reaction chamber (31).

3. The apparatus for preparing high-purity ultrafine lithium sulfide electrolyte as described in claim 2, characterized in that, An electric telescopic rod (28) is provided on the inner wall of the reaction chamber (31), and a frame (29) is fixedly connected to the telescopic end of the electric telescopic rod (28). The tray (22) is located on the frame (29). The free ends of the microfluidic pipe (26) and the airflow pipe (27) extending into the reaction chamber (31) are both located above the tray (22).

4. The apparatus for preparing high-purity ultrafine lithium sulfide electrolyte as described in claim 3, characterized in that, An observation window (20) is provided on the side wall of the reaction chamber (31), and a material inlet (25) is provided on the bottom wall of the transition chamber (24). A cover is detachably and sealed to the material inlet (25).

5. The apparatus for preparing high-purity ultrafine lithium sulfide electrolyte as described in claim 4, characterized in that, The smelting furnace (3) is equipped with a first vacuum pump (6) and a first gas pump (7); the reaction chamber (31) is equipped with a second vacuum pump (11) and a second gas pump (18); the tubular furnace (17) is also equipped with a gas exhaust pipe (32), and a third vacuum pump (16) is installed on the gas exhaust pipe (32).

6. The apparatus for preparing high-purity ultrafine lithium sulfide electrolyte as described in claim 5, characterized in that, The feeding pipe (4) is equipped with a first switch (5), the microfluidic pipe (26) is equipped with a second switch (9), the airflow pipe (27) is equipped with a third switch (12), the raw material pipe (30) is equipped with a fourth switch (13), and the exhaust pipe (32) is equipped with a fifth switch (15).

7. A method for preparing high-purity ultrafine lithium sulfide electrolyte using the preparation apparatus described in claim 6, characterized in that, Includes the following steps: S1. Open the first switch (5), the second switch (9), the third switch (12), the fourth switch (13) and the fifth switch (15). After evacuating the high-purity ultrafine lithium sulfide electrolyte preparation device using the first vacuum pump (6), the second vacuum pump (11) and the third vacuum pump (16), fill it with argon gas through the first gas pump (7) and the second gas pump (18). Then close the first switch (5), the second switch (9), the third switch (12), the fourth switch (13) and the fifth switch (15). S2. Take out the lithium element from the glove box (1), open the first mechanical valve (2) and bring the smelting tray (8) into the glove box (1), put in the lithium element, put the smelting tray (8) containing the lithium element into the slot of the smelting furnace (3), and reset the first mechanical valve (2). S3. Open the fourth switch (13) so that the elemental sulfur in the sulfur raw material silo (14) is discharged into the tube furnace (17) through the raw material pipeline (30). Close the fourth switch (13) and open the fifth switch (15). Use the third vacuum pump (16) to evacuate the tube furnace (17) and then close the fifth switch (15) and the third vacuum pump (16). The tube furnace (17) runs and heats the solid sulfur until the elemental sulfur is vaporized to obtain sulfur vapor. S4. Heat lithium in the melting furnace (3) until all lithium is melted into liquid. At the same time, turn on the second switch (9), the third switch (12), and the ultrasonic generator (19). Inject the liquid lithium into the reaction chamber (31) along the microfluidic pipe (26). The microfluidic meter (10) on the microfluidic pipe (26) makes the lithium flow in the form of droplets. At the same time, the ultrasonic generator (19) atomizes the lithium droplets in the reaction chamber (31). The atomized lithium droplets fall naturally. At the same time, the vaporized sulfur is discharged into the reaction chamber (31) through the airflow pipe (27). After the lithium droplets come into contact with the sulfur vapor, they react on the tray (22) to generate high-purity ultrafine lithium sulfide electrolyte. S5. After observing through the observation window (20) that no lithium sulfide is generated, the first switch (5) and the fourth switch (13) are opened at the same time. Lithium is added through the feeding pipe (4), and sulfur is replenished through the raw material pipe (30) to continue the preparation of high-purity ultrafine lithium sulfide electrolyte. After the reaction is completed, the second mechanical valve (23) is opened and the electric telescopic rod (28) is started. The electric telescopic rod (28) drives the frame (29), and the frame (29) drives the tray (22) into the transition chamber (24) for cooling. After cooling to room temperature, the material outlet (25) is opened, and the tray (22) is taken out from the transition chamber (24) through the material outlet (25).

8. The method for preparing high-purity ultrafine lithium sulfide electrolyte according to claim 7, characterized in that, The melting furnace (3) is in an argon atmosphere, and the melting temperature of elemental lithium in the melting furnace (3) is 250℃~400℃; the tube furnace (17) is in a vacuum environment, and the heating temperature of elemental sulfur in the tube furnace (17) is 500℃~700℃.

9. The method for preparing high-purity ultrafine lithium sulfide electrolyte according to claim 7, characterized in that, The ultrasonic generator (19) generates sound waves with a frequency of 20KHz to 50KHz, and the flow rate adjustment range of the microfluidic meter (10) is 0.2g / min to 20g / min.

10. The method for preparing high-purity ultrafine lithium sulfide electrolyte according to claim 7, characterized in that, The temperature inside the reaction chamber (31) is 750℃~900℃.

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