Lithium sulfide preparation device

Abstract

The apparatus for producing lithium sulfide according to the present invention comprises a plurality of reaction chambers having a reaction space for generating lithium sulfide by reacting a lithium raw material with hydrogen sulfide and arranged so as to move the supplied lithium raw material in one direction, the lithium raw material being sequentially supplied to the plurality of reaction chambers in one direction, hydrogen sulfide is sequentially supplied to the plurality of reaction chambers from any one of the plurality of reaction chambers other than the reaction chamber to which the lithium raw material is supplied in a direction opposite to the one direction.

Description

Technical Field

[0001] This invention relates to an apparatus for preparing lithium sulfide. Background Technology

[0002] Because of their high energy density and long lifespan, lithium-ion batteries are widely used in electronic devices such as home appliances, laptops, and smartphones. Recently, they have also been used in electric vehicles (EVs) or hybrid electric vehicles (HEVs), significantly expanding their application range.

[0003] Since mass production began in 1991, lithium-ion rechargeable batteries have been widely used as the main power source for mobile phones, laptops, PCs, etc. due to their high energy density and output voltage. However, the organic electrolyte used to ensure the smooth movement of lithium ions poses a risk of explosion under overheating and overcharging conditions, and is prone to ignition in the presence of a fire source. In addition, when side reactions occur inside the battery, the generation of gas can lead to a decrease in battery performance and stability.

[0004] Therefore, in order to overcome the shortcomings of lithium-ion secondary batteries, research and development on all-solid lithium secondary batteries are actively underway. All-solid lithium secondary batteries, by using a solid electrolyte instead of a volatile electrolyte, not only reduce the risk of explosion but also allow the use of lithium metal or lithium alloy as the negative electrode material, thus significantly improving battery energy density.

[0005] Currently, among the candidate solid electrolytes for all-solid-state batteries, sulfide-based solid electrolytes are considered suitable for preparing high-capacity large-scale secondary batteries due to their high ductility and high ionic conductivity. Lithium sulfide (Li₂S) is considered a key material in the preparation of such sulfide-based solid electrolytes. Although various methods for synthesizing lithium sulfide are known, the most common method is to react metallic lithium, such as lithium hydroxide (LiOH) or lithium carbonate (Li₂CO₃), with hydrogen sulfide (H₂S).

[0006] On the other hand, according to existing technology, when lithium metal such as lithium hydroxide is reacted with hydrogen sulfide, the supplied hydrogen sulfide may not react completely and may be discharged, or the reaction rate of hydrogen sulfide may decrease, leading to a decrease in economic efficiency when mass-producing lithium sulfide.

[0007] Furthermore, when metallic lithium, such as lithium hydroxide, reacts with hydrogen sulfide, water vapor is inevitably produced. This water vapor hinders the contact between metallic lithium and hydrogen sulfide, thus reducing the yield of lithium sulfide. Moreover, the water vapor can also undergo a reverse reaction with lithium sulfide, accelerating the reverse formation of lithium hydroxide, thereby reducing the purity of the produced lithium sulfide. In addition, moisture can cause the produced lithium sulfide particles to aggregate, leading to a decrease in quality.

[0008] Therefore, the inventors investigated a method for preparing lithium sulfide by reacting metallic lithium with hydrogen sulfide, but by completely consuming the hydrogen sulfide to increase the reaction rate of hydrogen sulfide and effectively removing water vapor from the reaction products, thereby enabling the preparation of lithium sulfide with high purity and high yield, and finally completed the present invention. Summary of the Invention

[0009] The problem the invention aims to solve

[0010] The present invention is proposed to solve the above-mentioned problems and aims to provide a lithium sulfide preparation apparatus that can improve the hydrogen sulfide reaction rate when preparing lithium sulfide by reacting metallic lithium with hydrogen sulfide, thereby making it suitable for high-purity, high-yield mass production of lithium sulfide.

[0011] means for solving problems

[0012] In one example, the lithium sulfide preparation apparatus includes a plurality of reaction chambers having reaction spaces for generating lithium sulfide by reacting a lithium feedstock with hydrogen sulfide and being configured to move the supplied lithium feedstock in one direction sequentially into the plurality of reaction chambers in one direction, and hydrogen sulfide being sequentially supplied from any of the plurality of reaction chambers other than the one supplying the lithium feedstock into the plurality of reaction chambers in the opposite direction in one direction.

[0013] In another example, a greater amount of lithium feedstock may be present in the reaction chamber initially supplied with lithium than the amount of lithium sulfide produced, and a greater amount of hydrogen sulfide may be present in the reaction chamber initially supplied with hydrogen sulfide than the amount of lithium sulfide produced.

[0014] In another example, in multiple reaction chambers, the more upstream the reaction chamber is in one direction, the higher the hydrogen sulfide reaction rate can be.

[0015] In another example, the plurality of reaction chambers include a first reaction chamber, a second reaction chamber, and a third reaction chamber connected in series. The lithium sulfide preparation apparatus further includes: a lithium raw material supply unit configured to supply lithium raw material to the first reaction chamber; and a hydrogen sulfide supply unit configured to supply hydrogen sulfide to the third reaction chamber.

[0016] In another example, the lithium sulfide preparation apparatus may further include: a lithium raw material supply unit configured to supply lithium raw material to the reaction chamber; a hydrogen sulfide supply unit configured to supply hydrogen sulfide to the reaction chamber; a plurality of heating units respectively disposed in the plurality of reaction chambers to heat the reaction space; and a lithium sulfide recovery unit configured to recover lithium sulfide generated in the reaction chamber.

[0017] In another example, the lithium sulfide preparation apparatus described above may further include: an inert gas supply unit disposed in the reaction chamber at the most downstream side in one direction among a plurality of reaction chambers, and configured to supply inert gas into the reaction chamber; and an inert gas discharge unit disposed in the reaction chamber at the most upstream side in one direction among a plurality of reaction chambers, and configured to discharge the inert gas from the reaction chamber.

[0018] In another example, the plurality of chambers includes an auxiliary chamber located downstream of the chamber supplying hydrogen sulfide in one direction, and the lithium sulfide preparation apparatus further includes an inert gas supply unit for supplying inert gas to the auxiliary chamber.

[0019] In another example, the lithium sulfide preparation apparatus described above may further include: a conveyor line disposed between one reaction chamber located upstream in one direction and another reaction chamber located downstream in one direction in an adjacent pair of reaction chambers, providing a passage for gas in the other reaction chamber to flow into the one reaction chamber; and a dehumidification section disposed on the conveyor line to remove water vapor from the gas flowing within the conveyor line.

[0020] In another example, the reaction chamber can be made of Hastelloy X or SUS 310 stainless steel.

[0021] In another example, the heating element can be installed on the outer surface of the reaction chamber to heat the temperature of the reaction space to above 160°C and below 300°C.

[0022] In another example, the particle size of the lithium feedstock supplied from the lithium feedstock supply unit to the reaction chamber can be less than 1 mm.

[0023] The effects of the invention

[0024] According to the present invention, when lithium sulfide is prepared by reacting metallic lithium with hydrogen sulfide, the reaction rate of hydrogen sulfide is increased, for example, by completely consuming the supplied hydrogen sulfide, so that high-quality lithium sulfide can be produced in large quantities with high purity and high yield. Attached Figure Description

[0025] Figure 1 This is a schematic diagram illustrating a lithium sulfide preparation apparatus according to an embodiment of the present invention.

[0026] Figure 2This is a schematic diagram illustrating the lithium sulfide preparation process according to an embodiment of the present invention.

[0027] Figure 3 A schematic diagram illustrating a lithium sulfide preparation apparatus according to another embodiment of the present invention.

[0028] Figure 4 This is a schematic diagram illustrating a dehumidification section according to an embodiment of the present invention.

[0029] Figure 5 This is a schematic diagram illustrating a sublimation cooling section according to an embodiment of the present invention.

[0030] Figure 6 This is a schematic diagram illustrating a sublimation cooling section according to an embodiment of the present invention.

[0031] Figure 7 This is a schematic diagram illustrating a sublimation cooling section according to an embodiment of the present invention. Detailed Implementation

[0032] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. When adding reference numerals to components in all the drawings, it should be noted that even components shown in different drawings use the same reference numerals to refer to the same component. Furthermore, in the process of describing embodiments of the present invention, detailed descriptions of related well-known structures or functions will be omitted if it is determined that such detailed descriptions would hinder the understanding of the embodiments of the present invention.

[0033] Figure 1 A schematic diagram illustrating a lithium sulfide preparation apparatus according to an embodiment of the present invention is provided. In the following, reference is made to... Figure 1 A lithium sulfide preparation apparatus according to an embodiment of the present invention is described.

[0034] Reference Figure 1 According to an embodiment of the present invention, a lithium sulfide preparation apparatus may include a plurality of reaction chambers 100. Furthermore, the lithium sulfide preparation apparatus according to the present invention may include a lithium raw material supply unit 200, a hydrogen sulfide supply unit 300, a dehumidification unit 450, a lithium sulfide recovery unit 500, an inert gas supply unit 600, and an inert gas discharge unit 800.

[0035] Multiple reaction chambers 100 each have a reaction space for generating lithium sulfide by reacting a lithium feedstock with hydrogen sulfide. For example, the multiple reaction chambers 100 may include a first reaction chamber 110, a second reaction chamber 120, and a third reaction chamber 130 connected in series. There is no particular limitation on the number of reaction chambers 100.

[0036] Each reaction chamber 100 is configured to be aligned in one direction (e.g., Figure 1The supplied lithium feedstock is moved from left to right. There are no particular restrictions on the method or direction of moving the lithium feedstock. For example, as... Figure 1 As shown, the bottom surface of the reaction chamber 100 can be inclined, allowing the lithium material to move by gravity. Alternatively, a conveyor belt (not shown) for moving the lithium material can be provided inside the reaction chamber 100.

[0037] On the other hand, the reaction chamber 100 may further be equipped with a stirring member 350 for promoting reaction and transport. As an example, the stirring member 350 may be a rotating disk, rotor, propeller, etc., but there are no particular limitations on this.

[0038] Furthermore, a heating element 310 may be provided in the reaction chamber 100. The heating element 310 is configured to heat the reaction space and may be provided in multiple reaction chambers 100. There are no particular limitations on the method by which the heating element 310 heats the reaction space. For example, the heating element 310 may be a heater, an electric heating wire, or an infrared heater mounted on the outer surface of the reaction chamber 100.

[0039] Furthermore, the heating unit 310 can heat the temperature of the reaction space to above 160°C and below 300°C. To ensure a smooth reaction between the lithium raw material and hydrogen sulfide, the lithium raw material (lithium hydroxide) needs to be sufficiently heated. Additionally, as mentioned above, water (H₂O) is produced as a byproduct of the reaction between lithium hydroxide and hydrogen sulfide. If the water exists in liquid form, it may seep into the spaces between the lithium hydroxide particles, thereby reducing the surface area of ​​the lithium hydroxide reacting with hydrogen sulfide. Therefore, by heating the temperature of the reaction space to above 160°C to evaporate the water, high-purity lithium sulfide can be obtained.

[0040] On the other hand, the higher the temperature of the reaction space, the more the reaction between lithium hydroxide and hydrogen sulfide is promoted. However, the melting point of lithium hydroxide is 445°C, therefore, the temperature of the reaction space is preferably no higher than 445°C.

[0041] Furthermore, as the temperature of the reaction space increases, the risk of corrosion on the inner surface of the reaction chamber 100 caused by hydrogen sulfide increases. Therefore, the reaction chamber 100 can be made of a material with high heat resistance and corrosion resistance. For example, the reaction chamber 100 can be made of Hastelloy X or stainless steel 310. Moreover, the heating unit 310 can heat the temperature of the reaction space to below 300°C. Therefore, frequent maintenance or replacement of equipment such as pipes, including the reaction chamber 100, can be prevented, while fully promoting the reaction between hydrogen sulfide and lithium feedstock, thereby obtaining high-purity lithium sulfide.

[0042] The lithium feedstock supply unit 200 can be configured to continuously supply lithium feedstock to the reaction chamber 100. Specifically, the lithium feedstock supply unit 200 can be connected to the first reaction chamber 110 located at the upstream side in one direction. There are no particular limitations on the form of the lithium feedstock supply unit 200. For example, the lithium feedstock supply unit 200 can be a hopper.

[0043] Therefore, lithium raw materials are sequentially supplied to multiple reaction chambers 100 in one direction. That is, after the lithium raw materials are supplied to the first reaction chamber 110 and react, the remaining lithium raw materials are transported to the second reaction chamber 120. Similarly, after the lithium raw materials are supplied to the second reaction chamber 120 and react, the remaining lithium raw materials can be transported to the third reaction chamber 130.

[0044] The lithium raw material supply unit 200 can supply lithium hydroxide (LiOH) or lithium carbonate (Li2CO3) as lithium raw materials. Specifically, it can supply lithium hydroxide to the reaction chamber 100. The lithium hydroxide supplied to the reaction chamber 100 can react with hydrogen sulfide as shown in the following formula to produce lithium sulfide. That is, it is known that water is produced as a byproduct when lithium hydroxide reacts with hydrogen sulfide.

[0045] 2LiOH + H₂S → Li₂S + 2H₂O

[0046] Furthermore, the particle size of the supplied lithium raw material can be less than 1 mm. Therefore, by increasing the reaction surface with hydrogen sulfide, high-purity lithium sulfide can be prepared.

[0047] The hydrogen sulfide supply unit 300 can be configured to supply hydrogen sulfide to the reaction chamber 100. Specifically, the hydrogen sulfide supply unit 300 can sequentially supply hydrogen sulfide from any of the multiple reaction chambers 100 except the reaction chamber 100 that supplies lithium feedstock, in the opposite direction to the reaction chambers 100. For example, the hydrogen sulfide supply unit 300 can be connected to the third reaction chamber 130. In addition, the hydrogen sulfide remaining after the reaction occurs in the third reaction chamber 130 can be transported to the second reaction chamber 120, and the hydrogen sulfide remaining after the reaction occurs in the second reaction chamber 120 can be transported to the first reaction chamber 110.

[0048] Therefore, the lithium sulfide preparation apparatus according to the present invention may include a conveyor line 400 disposed between one reaction chamber located upstream in one direction and the other reaction chamber located downstream in one direction in an adjacent pair of reaction chambers. For example, the conveyor line 400 may be disposed between the first reaction chamber 110 and the second reaction chamber 120, and between the second reaction chamber 120 and the third reaction chamber 130. The conveyor line 400 provides a pathway for gas to flow between the two reaction chambers 100. In addition, the conveyor line 400 may be provided with a pump (not shown) for drawing gas from the reaction chambers 100.

[0049] Additionally, a dehumidifier 450 may be provided on the conveyor line 400. The dehumidifier 450 is configured to recover the gas discharged from the reaction chamber 100, remove water vapor from the gas, and then resupply the water vapor-free gas to another reaction chamber 100. As described above, unreacted hydrogen sulfide that has not reacted with lithium hydroxide and water vapor generated by the reaction of hydrogen sulfide with lithium hydroxide may be present in the reaction chamber 100. This unreacted hydrogen sulfide is resupplyed to the reaction chamber 100 located upstream in one direction, while the water vapor generated during the reaction needs to be removed. For this purpose, the dehumidifier 450 can recover the gas in the reaction chamber 100 via the conveyor line 400, remove the water vapor, and then supply it to the reaction chamber 100 located upstream in one direction.

[0050] The lithium sulfide recovery unit 500 is configured to recover lithium sulfide generated in the reaction chamber 100 by the reaction of hydrogen sulfide with lithium feedstock. The lithium sulfide recovery unit 500 can be located in the reaction chamber 100 at its downstream end in one direction. For example, the lithium sulfide recovery unit 500 can be connected to a third reaction chamber 130. There are no particular limitations on the structure of the lithium sulfide recovery unit 500. For example, it can be a chamber for capturing lithium sulfide.

[0051] An inert gas supply unit 600 may be provided in the reaction chamber at the downstream end in one direction to supply inert gas to the reaction chamber 100. Alternatively, the inert gas supply unit 600 may also be provided in the lithium sulfide recovery unit 500. The inert gas supplied by the inert gas supply unit 600 can prevent backflow of gas in the reaction chamber 100 in one direction at the downstream end.

[0052] When the inert gas supply unit 600 is installed in the lithium sulfide recovery unit 500, a conveyor line 400 and a dehumidification unit 450 may also be installed between the third reaction chamber 130 and the lithium sulfide recovery unit 500. Therefore, when hydrogen sulfide is present and flows back from the third reaction chamber to the lithium sulfide recovery unit 500, the hydrogen sulfide can be supplied back to the third reaction chamber 130 via the conveyor line 400.

[0053] Additionally, when the inert gas supply unit 600 is directly connected to the third reaction chamber 130, the inert gas supply unit 600 can also stir the lithium raw material to promote its reaction with hydrogen sulfide. There are no particular restrictions on the type of inert gas supplied. For example, helium, neon, argon, nitrogen, etc., can be used.

[0054] The inert gas discharge section 800 can be configured to discharge inert gas from the reaction chamber 100. Specifically, the inert gas discharge section 800 can be provided in the first reaction chamber 110 located at the upstream side in one direction. Therefore, the inert gas supplied from the downstream side in one direction prevents hydrogen sulfide from flowing back in one direction while passing through the third reaction chamber 130, the second reaction chamber 120 and the first reaction chamber 110, and can then be discharged to the outside through the inert gas discharge section 800.

[0055] Figure 2 This is a schematic diagram illustrating the lithium sulfide preparation process according to an embodiment of the present invention. The following will refer to... Figure 2 The process of generating lithium sulfide using the lithium sulfide preparation apparatus of the present invention is described.

[0056] As mentioned earlier, lithium feedstock is supplied sequentially to multiple reaction chambers 100 in one direction, while hydrogen sulfide is supplied sequentially to multiple reaction chambers 100 in the opposite direction. Therefore, the relative proportions of lithium feedstock and hydrogen sulfide reacting may differ in each reaction chamber 100.

[0057] In other words, a greater amount of lithium feedstock can be present in the reaction chamber initially supplying lithium, compared to the amount of lithium sulfide produced; similarly, a greater amount of hydrogen sulfide can be present in the reaction chamber initially supplying hydrogen sulfide, compared to the amount of lithium sulfide produced. Therefore, in the multiple reaction chambers 100, the more upstream in one direction, the higher the hydrogen sulfide reaction rate within the reaction chamber. Ultimately, in the overall process of lithium sulfide production, the hydrogen sulfide reaction rate is improved, and the hydrogen sulfide can be completely consumed.

[0058] For ease of explanation, assume that the first reaction chamber 110 is continuously supplied with 200 units of lithium feedstock, and the third reaction chamber 130 is continuously supplied with 100 units of hydrogen sulfide. The numbers 200 and 100 here are example values ​​representing the proportions between the components, indicating relative amounts only, not absolute amounts.

[0059] First, the reaction in the third reaction chamber 130 will be explained. Although the third reaction chamber 130 is supplied with 100g of hydrogen sulfide, the lithium feedstock is first reacted in the first reaction chamber 110 and the second reaction chamber 120 before being supplied to the third reaction chamber 130. Therefore, the third reaction chamber 130 can supply 20g of lithium feedstock. In other words, the third reaction chamber 130 can contain a larger amount of hydrogen sulfide than the amount of lithium feedstock, and the hydrogen sulfide supplied in the third reaction chamber 130 is of high purity. Therefore, high-quality lithium sulfide can be prepared with high purity and high yield.

[0060] The lithium sulfide generated in the third reaction chamber 130 is conveyed to the lithium sulfide recovery unit 500 for recovery, while the unreacted hydrogen sulfide is conveyed to the second reaction chamber 120 via the conveyor line 400. The previous 20% lithium feedstock reacted with 10% hydrogen sulfide to generate 10% lithium sulfide, therefore 90% of the hydrogen sulfide was conveyed to the second reaction chamber 120.

[0061] Next, the reaction in the second reaction chamber 120 will be described. As mentioned earlier, 90% hydrogen sulfide is supplied to the second reaction chamber 120, while in the case of lithium feedstock, the remaining 180% of the lithium feedstock after the reaction in the first reaction chamber 110 can be supplied. That is, relatively similar amounts of lithium feedstock and hydrogen sulfide can exist in the second reaction chamber 120, so the hydrogen sulfide may not be completely consumed. For example, after 160% of the lithium feedstock reacts with 80% of the hydrogen sulfide to produce 80% of lithium sulfide, the remaining 20% ​​of the lithium feedstock can be sent to the third reaction chamber 130, while the remaining 10% of the hydrogen sulfide can be sent to the first reaction chamber 110.

[0062] Finally, the reaction in the first reaction chamber 110 will be described. As mentioned earlier, 10 units of hydrogen sulfide are supplied to the first reaction chamber 110, while 200 units of lithium feedstock are supplied. That is, there may be a sufficient amount of lithium feedstock in the first reaction chamber 110 to consume all the supplied hydrogen sulfide. Therefore, if one cycle of supplying 100 units of hydrogen sulfide is considered as one lithium sulfide preparation cycle, this means that the hydrogen sulfide supplied for one preparation cycle can be completely consumed. In other words, the hydrogen sulfide reaction rate, which represents the amount of hydrogen sulfide produced relative to the supplied amount of hydrogen sulfide, can be increased, and lithium sulfide can be prepared with high purity and high yield by adjusting the ratio of lithium feedstock to hydrogen sulfide in each reaction chamber 100. On the other hand, the present invention is not limited to the above example. By adjusting the amount of supplied lithium feedstock and hydrogen sulfide, or by adjusting the residence time of each reaction chamber, the process can be controlled according to the desired objective to achieve an increase in the hydrogen sulfide reaction rate and complete consumption of hydrogen sulfide.

[0063] Figure 3 This is a schematic diagram illustrating a lithium sulfide preparation apparatus according to another embodiment of the present invention. The lithium sulfide preparation apparatus according to another embodiment of the present invention may further include an auxiliary chamber 140. For configurations identical or corresponding to those in the foregoing embodiments of the lithium sulfide preparation apparatus, identical or corresponding reference numerals are used, and detailed descriptions are omitted.

[0064] The auxiliary chamber 140 is connected in series with multiple reaction chambers 100 and can be located downstream in one direction relative to the reaction chamber supplying hydrogen sulfide. That is, the auxiliary chamber 140 can be connected in series downstream of the third reaction chamber 130. Therefore, the generated lithium sulfide can be supplied to the auxiliary chamber 140. Furthermore, a lithium sulfide recovery unit 500 can be connected to the auxiliary chamber 140, so that the generated lithium sulfide is recovered to the lithium sulfide recovery unit 500 after passing through the auxiliary chamber 140.

[0065] Additionally, a conveyor line 400 and a dehumidification unit 450 can be provided between the third reaction chamber 130 and the auxiliary chamber 140. Therefore, when unreacted lithium raw materials are present, or when hydrogen sulfide flows counter-currently to the auxiliary chamber 140 in one direction, a reaction can occur in the auxiliary chamber 140 to generate lithium sulfide. Furthermore, if unreacted hydrogen sulfide remains, it can be supplied back to the third reaction chamber 130 via the conveyor line 400. In other words, the auxiliary chamber 140 can play a supporting role when reactions in the multiple reaction chambers 100 fail to proceed smoothly.

[0066] On the other hand, in order to more effectively prevent hydrogen sulfide from flowing back in one direction, the inert gas supply unit 600 can be connected to the auxiliary chamber 140. In addition, if necessary, the auxiliary chamber 140 can also be equipped with a stirring member and a heating unit.

[0067] Figure 4 The configuration of a dehumidifier 450 according to another embodiment of the present invention is shown. Specifically, the dehumidifier is configured to recover the gas discharged from the reaction chamber 100, and after removing water vapor from the gas, supply the water vapor-free gas to the upstream reaction chamber 100. As described above, unreacted hydrogen sulfide that has not reacted with lithium hydroxide in the supplied hydrogen sulfide and water vapor generated by the reaction of hydrogen sulfide with lithium hydroxide may be present in the reaction chamber 100. This unreacted hydrogen sulfide is supplied to the upstream reaction chamber 100, while the water vapor generated during the reaction needs to be removed. For this purpose, the dehumidifier 450 can recover the gas in the reaction chamber 100 from the upstream side of the reaction chamber 100 via a conveyor line 400, remove the water vapor, and supply it to the downstream side of the upstream reaction chamber 100. On the other hand, in order to supply the hydrogen sulfide gas with the aforementioned water vapor removed to the reaction chamber, a supply unit such as a circulation pump (not shown) can be used.

[0068] Reference Figure 4The dehumidification unit 450 may include a liquefaction cooling unit 460 and a sublimation cooling unit 470. The liquefaction cooling unit 460 performs a primary cooling of the gas recovered from the reaction chamber 100, thereby selectively removing only moisture from the recovered gas. For example, the liquefaction cooling unit 460 may be configured to liquefy water vapor by cooling the gas recovered through the conveyor line 400a to approximately 40°C, and the liquefied water may be removed via the discharge unit 465. There are no particular limitations on the cooling structure of the liquefaction cooling unit 460; for example, it may be a chamber equipped with a cooling unit (not shown in the figure).

[0069] On the other hand, the sublimation cooling section 470 can be configured to perform secondary cooling on the gas recovered from the reaction chamber 100 to remove moisture. For example, water vapor can be cooled to approximately -30°C and removed by sublimation. The sublimation cooling section 470 can recover the gas passing through the liquefaction cooling section 460 via the conveyor line 400b to further remove water vapor that could not be removed in the liquefaction cooling section 460. Furthermore, the terms "primary" and "secondary" as used in this specification and claims should be understood as an arbitrary order assigned for distinction.

[0070] On the other hand, primary cooling and secondary cooling do not refer to the order of cooling. The dehumidification unit 450 may include only the liquefaction cooling unit 460, or only the sublimation cooling unit 470, or both the liquefaction cooling unit 460 and the sublimation cooling unit 470.

[0071] Figure 5 This is a perspective view illustrating a sublimation cooling section according to an embodiment of the present invention. The sublimation cooling section 470 may include a cooling chamber 471, a cooling unit 475 disposed in the cooling chamber 471, and a control unit (not shown) for controlling the sublimation cooling section 470. The control unit may be a control unit for controlling a lithium sulfide preparation apparatus.

[0072] The water vapor supplied to cooling chamber 471 sublimates and freezes on the inner surface of cooling chamber 471 through cooling unit 475, and since hydrogen sulfide has a boiling point of -59.6°C, it can pass directly through cooling chamber 471. Therefore, cooling chamber 471 can remove water vapor only from the recovered gas and supply hydrogen sulfide back to reaction chamber 100.

[0073] However, since the sublimation cooling section 470 sublimates water vapor and causes it to change phase to an ice state, it freezes on the inner surface of the cooling chamber. Therefore, in order to remove the frozen water on the inner surface of the cooling chamber 471, it is necessary to reheat the cooling chamber 471 to liquefy it. That is, if only one cooling chamber 471 is provided, the operation of the lithium sulfide preparation apparatus must be stopped in order to heat the cooling chamber 471, making it difficult to carry out the process continuously.

[0074] Therefore, the sublimation cooling unit 470 according to an embodiment of the present invention may include a plurality of cooling chambers 471a, 471b, a plurality of branch lines 401 for conveying recovered gas to each of the cooling chambers 471a, 471b, and a plurality of second branch lines 403 for conveying gas from the plurality of cooling chambers 471 to a resupply line 400c. The resupply line 400c refers to a conveying line that resupplyes the recovered gas to another reaction chamber 100. Furthermore, the control unit controls the cooling process such that when the recovered gas is conveyed to a predetermined cooling chamber among the plurality of cooling chambers 471, cooling occurs in the cooling chamber to which the recovered gas is conveyed.

[0075] The first branch valve 402a, the second branch valve 402b, the third branch valve 404a, and the fourth branch valve 404b can be provided in each of the branch lines 401a, 401b and the second branch lines 403a, 403b. The control unit can be configured to determine the destination of the recovered gas in the cooling chambers 471a, 471b by controlling the branch valves 402a, 402b, 404a, 404b provided on the branch lines 401a, 401b and the second branch lines 403a, 403b. For example, to deliver the recovered gas to the cooling chambers 471a, 471b located at... Figure 3 The upper cooling chamber 471a can open the first branch valve 402a and the third branch valve 404a, and close the second branch valve 402b and the fourth branch valve 404b.

[0076] After a predetermined cooling period, the upper cooling chamber 471a, where the recovered gas is transported, needs to be heated to remove the ice that has sublimated and frozen on the inner wall of the cooling chamber 471a. In this case, the control unit can activate the cooling unit (not shown in the figure) located in the lower cooling chamber 471b to perform a cooling operation in the lower cooling chamber 471b, and then transport the recovered gas to the lower cooling chamber 471b. That is, the first branch valve 402a and the third branch valve 404a can be closed, and the second branch valve 402b and the fourth branch valve 404b can be opened, so that the recovered gas is transported to the lower cooling chamber 471b. Therefore, not only can lithium sulfide be continuously produced without stopping the lithium sulfide preparation apparatus, but the production efficiency of lithium sulfide can also be improved by further removing moisture from the recovered gas, and high-purity lithium sulfide can be obtained.

[0077] On the other hand, the control unit can switch to heating the upper cooling chamber 471a, which has undergone a predetermined cooling operation, to liquefy and remove the ice that has sublimated through cooling. A separate heating unit can be provided in the cooling chamber 471, or moisture can be removed simply by stopping the operation of the cooling unit 475 and allowing the cooling chamber 471 to return to room temperature. The removed moisture can be conveyed to the discharge unit 465 and removed.

[0078] Alternatively, instead of installing branch valves 402a, 402b, 404a, and 404b in each of the branch lines 401a, 401b, 403a, and 403b, three-way valves (not shown in the figure) can be installed at the branch points of conveying line 400b and branch line 401, and at the branch points of branch line 403 and resupply line 400c. The control unit can control the three-way valves to determine the chamber for conveying the recovered gas.

[0079] Furthermore, there is no particular limitation on the number of cooling chambers 471. When three or more cooling chambers 471 are provided, cooling can be carried out simultaneously in multiple cooling chambers 471. The number of cooling chambers 471 can be appropriately set according to the amount of water vapor generated based on the size of the reaction chamber 100 and the temperature of the heating unit 310 heating the reaction space.

[0080] Figure 6 This is a perspective view illustrating a sublimation cooling section according to another embodiment of the present invention. The sublimation cooling section 470' according to another embodiment of the present invention differs from the sublimation cooling section 470 described above according to one embodiment in that the sublimation cooling section 470' includes a main body 473 rotatable about an axis C parallel to the direction of recovery gas delivery. Furthermore, a plurality of cooling chambers 471 are formed along the axis C parallel to the direction of recovery gas delivery through the main body 473. Also, the sublimation cooling section 470' according to this embodiment does not have branch lines 401, but at least one of the plurality of cooling chambers 471 communicates with the delivery line 400b and the resupply line 400c.

[0081] That is, the control unit controls a portion of the multiple cooling chambers 471 to be cooled, and by rotating the main body 473 around the axis C, it can control the cooling chamber 471 to be connected to the transmission line 400b and the resupply line 400c.

[0082] More specifically, when located Figure 6 When the upper cooling chamber 471a is cooled by a cooling unit (not shown) in connection with the conveying line 400b and the resupply line 400c, water vapor sublimates and freezes inside the cooling chamber as the recovered gas passes through it, thus being removed from the recovered gas. However, after a predetermined cooling period, the space inside the upper cooling chamber 471a, which carries the recovered gas, narrows, and it becomes necessary to remove the frozen ice. In this case, the control unit can control the lower cooling chamber 471b to perform a cooling operation, and then rotate the main body 473 around axis C to switch the cooling chamber 471a carrying the recovered gas to the lower cooling chamber 471b. Alternatively, for the cooling chamber 471a, which has undergone a predetermined cooling period, heating can be applied by switching to liquefy and remove the sublimated ice.

[0083] In the sublimation cooling section 470' according to this embodiment, the cooling chamber 471 for conveying the recovered gas can be changed simply by rotating the main body 473 about the axis C. This allows for the continuous production of lithium sulfide without stopping the lithium sulfide preparation apparatus, improving efficiency and obtaining high-purity lithium sulfide by more thoroughly removing moisture.

[0084] Figure 7 This is a front view of a sublimation cooling section according to another embodiment of the present invention. The difference between the sublimation cooling section 470” of this embodiment and the sublimation cooling section 470’ described above is that the sublimation cooling section 470” is provided with three or more cooling chambers 471. There is no particular limitation on the number of cooling chambers 471.

[0085] For example, when Figure 7 When the four cooling chambers 471a, 471b, 471c, and 471d are formed through the main body 473, at least one cooling chamber can be connected to the conveyor line 400b and the resupply line 400c. Furthermore, the control unit can control the multiple cooling chambers 471a, 471b, 471c, and 471d to sequentially perform cooling operations, and simultaneously control the main body 473 to rotate around axis C to deliver the recovered gas to the cooling chambers currently being cooled. Similarly, for cooling chambers that have undergone a predetermined cooling operation, heating can be applied to liquefy and remove the ice that has sublimated through cooling.

[0086] Alternatively, according to this embodiment, the sublimation cooling unit 470 can be controlled to perform cooling in multiple cooling chambers 471a, 471b. In this case, multiple branch lines branching from the conveyor line 400b can be connected to the multiple cooling chambers 471a, 471b respectively. The number of cooling chambers 471 can be appropriately set according to the amount of water vapor generated based on the size of the reaction chamber 100 and the temperature of the heating unit 310 heating the reaction space.

[0087] As described above, the gas recovered and dehydrated from reaction chamber 100 can be resupplyed to upstream reaction chamber 100 via resupply line 400c (see reference). Figure 1 The resupply line 400c can be connected to the downstream end of the reaction chamber 100. Since the lithium feedstock supplied to the reaction chamber 100 will fall to the lower side of the reaction chamber 100 by gravity and then move, the hydrogen sulfide supplied through the resupply line 400c can ensure sufficient reaction time with the lithium feedstock.

[0088] The above description is merely an exemplary illustration of the technical concept of the present invention, and those skilled in the art can make various modifications and variations without departing from the essential characteristics of the present invention. Therefore, the embodiments described herein are not intended to be limiting, but rather to explain the spirit of this disclosure, and the spirit of this disclosure is not limited to these embodiments. The scope of protection of the present invention should be determined by the claims, and all technical spirit within the equivalent scope should be interpreted as being included in the patent rights of the present invention.

[0089] Explanation of reference numerals in the attached figures

[0090] 100: Reaction Chamber

[0091] 110: First Reaction Chamber

[0092] 120: Second Reaction Chamber

[0093] 130: Third Reaction Chamber

[0094] 140: Auxiliary Room

[0095] 200: Lithium Raw Material Supply Department

[0096] 300: Hydrogen Sulfide Supply Department

[0097] 310: Heating section

[0098] 350: Mixing component

[0099] 400, 400a, 400b, 400c: Conveyor lines

[0100] 401: Branch Line

[0101] 403: Second branch line

[0102] 402a: First branch valve

[0103] 402b: Second branch valve

[0104] 404a: Third branch valve

[0105] 404b: Fourth branch valve

[0106] 450: Dehumidification section

[0107] 460: Liquefaction Cooling Section

[0108] 465: Discharge section

[0109] 470: Sublimation Cooling Section

[0110] 471: Cooling Chamber

[0111] 475: Cooling Unit

[0112] 473: Main Body

[0113] C: Axis

[0114] 500: Lithium Sulfide Recycling Department

[0115] 600: Inert Gas Supply Department

[0116] 800: Inert gas discharge section

Claims

1. A lithium sulfide preparation apparatus, characterized in that, The reactor comprises multiple reaction chambers, each having a reaction space for generating lithium sulfide by reacting a lithium feedstock with hydrogen sulfide, and configured to move the supplied lithium feedstock in one direction. The lithium raw materials mentioned above are sequentially supplied to the plurality of reaction chambers along the aforementioned one direction. The hydrogen sulfide is supplied sequentially from any of the plurality of reaction chambers except the one supplying the lithium raw material, in the opposite direction to the aforementioned one direction to the plurality of reaction chambers.

2. The lithium sulfide preparation apparatus according to claim 1, characterized in that, The reaction chamber initially supplied with the aforementioned lithium raw materials contained a greater amount of lithium raw materials than the amount of lithium sulfide produced. The amount of hydrogen sulfide present in the reaction chamber initially supplied with the aforementioned hydrogen sulfide is greater than the amount of lithium sulfide produced.

3. The lithium sulfide preparation apparatus according to claim 1, characterized in that, In the aforementioned reaction chambers, the more upstream the reaction chamber is in one of the aforementioned directions, the higher the hydrogen sulfide reaction rate within that chamber.

4. The lithium sulfide preparation apparatus according to claim 1, characterized in that, The aforementioned reaction chambers include a first reaction chamber, a second reaction chamber, and a third reaction chamber connected in series. The lithium sulfide preparation apparatus further includes: a lithium raw material supply unit configured to supply the lithium raw material to the first reaction chamber; and a hydrogen sulfide supply unit configured to supply the hydrogen sulfide to the third reaction chamber.

5. The lithium sulfide preparation apparatus according to claim 1, characterized in that, Also includes: The lithium raw material supply department is configured to supply the lithium raw material to the aforementioned reaction chamber; The hydrogen sulfide supply unit is configured to supply the aforementioned hydrogen sulfide to the aforementioned reaction chamber; Multiple heating elements are respectively disposed in the aforementioned multiple reaction chambers to heat the aforementioned reaction space; and The lithium sulfide recovery unit is configured to recover the lithium sulfide generated in the above-mentioned reaction chamber.

6. The lithium sulfide preparation apparatus according to claim 1, characterized in that, Also includes: An inert gas supply unit is provided in the reaction chamber located at the most downstream side of the plurality of reaction chambers along one of the aforementioned directions, and is configured to supply inert gas into the reaction chamber; and An inert gas discharge section is provided in the upstream reaction chamber along one of the plurality of reaction chambers and is configured to discharge the inert gas inside the reaction chamber.

7. The lithium sulfide preparation apparatus according to claim 1, characterized in that, The aforementioned multiple chambers include an auxiliary chamber located downstream of the chamber supplying the aforementioned hydrogen sulfide along one of the aforementioned directions. The lithium sulfide preparation apparatus also includes an inert gas supply unit that supplies inert gas to the auxiliary chamber.

8. The lithium sulfide preparation apparatus according to claim 1, characterized in that, Also includes: A conveyor line is provided between one of the reaction chambers located upstream in one of the aforementioned directions and the other reaction chamber located downstream in the aforementioned direction, providing a pathway for gas to flow from the other reaction chamber to the first of the aforementioned reaction chambers; and A dehumidification unit is installed on the above-mentioned conveyor line to remove water vapor from the gas flowing within the conveyor line.

9. The lithium sulfide preparation apparatus according to claim 1, characterized in that, The reaction chamber is made of Hastelloy X or stainless steel 310.

10. The lithium sulfide preparation apparatus according to claim 1, characterized in that, It also includes multiple heating elements, which are respectively arranged in the multiple reaction chambers to heat the reaction space. The heating element is installed on the outer surface of the reaction chamber to heat the temperature of the reaction space to 160°C or higher and less than 300°C.

11. The lithium sulfide preparation apparatus according to claim 1, characterized in that, It also includes a lithium raw material supply department, which is configured to supply the lithium raw material to the reaction chamber. The lithium raw materials supplied from the lithium raw material supply department to the reaction chamber have a particle size of less than 1 mm.

Images