Solid-state battery lithium sulfide synthesis apparatus

Abstract

This application relates to the field of solid-state battery material production technology, specifically to a synthesis apparatus for lithium sulfide in solid-state batteries. The synthesis apparatus comprises a reaction unit connected to a solvent delivery unit, a lithium source delivery unit, and a sulfur source delivery unit, forming a closed space to accommodate a composite solvent, lithium source, and sulfur source to form a reaction system. A dehydration module removes the azeotropic mixture formed by the dehydrating agent and byproduct water in the reaction system. A separation and purification unit receives the reaction products from the reaction unit and performs solid-liquid separation and washing treatments to obtain lithium sulfide. This application achieves integrated closed-loop production of lithium sulfide synthesis. The dehydration module can promptly remove the water generated in the reaction, breaking the reaction equilibrium limitation and thus improving the reaction yield and product purity. Simultaneously, the closed-loop design connecting each unit ensures the flow of materials in a closed environment, reducing the risk of toxic gas leakage and meeting the needs of continuous and large-scale production.

Description

Technical Field

[0001] This application relates to the field of solid-state battery material production technology, and specifically to an apparatus for synthesizing lithium sulfide for solid-state batteries. Background Technology

[0002] Lithium sulfide is a key precursor material for the preparation of sulfide solid electrolytes, and its purity and consistency directly affect the electrochemical performance and safety of solid-state batteries. Currently, lithium sulfide is mainly prepared using the liquid-phase method, which has mild reaction conditions and is suitable for large-scale production. In existing lithium sulfide synthesis processes, a reaction vessel is typically used as the core equipment. The lithium source and solvent are mixed and then sulfur source gas is introduced to carry out the reaction. After the reaction is completed, the solid product is separated by centrifugation or filtration, and the solvent is recovered by distillation.

[0003] However, existing technologies face several technical challenges in practical applications. First, water is generated as a byproduct during the synthesis reaction. If water remains in the reaction system, it can reverse the reaction equilibrium, reduce product yield, and cause subsequent products to deteriorate due to hydrolysis. Second, lithium sulfide and intermediate products are extremely sensitive to water and oxygen. Existing equipment often suffers from insufficient airtightness in material conveying and solid-liquid separation, making it prone to air intrusion. This not only introduces impurities affecting purity but may also lead to the leakage of toxic gases, posing safety hazards. Furthermore, existing production equipment typically operates independently between units, lacking systematic linkage control. Material ratios and reaction conditions rely on manual adjustment, making it difficult to ensure the stability of process parameters and limiting the continuous and large-scale production of the product. Summary of the Invention

[0004] To address the technical problems mentioned in the background art, this application provides an apparatus for synthesizing lithium sulfide for solid-state batteries, comprising: A solvent delivery unit for delivering a composite solvent, wherein the composite solvent includes at least a water-carrying agent; Lithium source delivery unit, used to deliver lithium source; Sulfur source conveying unit, used to convey sulfur source; The reaction unit is connected to the solvent delivery unit, lithium source delivery unit and sulfur source delivery unit to form a closed space, which is used to contain the composite solvent, lithium source and sulfur source to form a reaction system and to provide a reaction environment for the reaction system; the reaction unit has a dehydration module, which is configured to remove the azeotropic mixture formed by the water-carrying agent and the by-product water in the reaction system. The separation and purification unit is connected to the reaction unit to form a closed space, which is used to receive the reaction products in the reaction unit and to perform solid-liquid separation and washing treatment on the reaction products to obtain lithium sulfide.

[0005] This application achieves integrated, closed-loop production of lithium sulfide synthesis by systematically integrating solvent delivery units, lithium source delivery units, sulfur source delivery units, reaction units, and separation and purification units, and by configuring a dehydration module in the reaction unit. The dehydration module can promptly remove water generated in the reaction, breaking the reaction equilibrium limitation, thereby improving the reaction yield and product purity. At the same time, the interconnected and closed design between the units ensures the flow of materials in a closed environment, reduces the risk of toxic gas leakage, and meets the needs of continuous and large-scale production.

[0006] As a preferred embodiment, the dehydration module includes: The exhaust pipe is connected at one end to the gas phase outlet of the reaction unit, and at the other end extends from the condenser to the water separator. A condenser, fitted outside the exhaust pipe, is used to condense the solvent gas inside the exhaust pipe. The water separator is connected to the exhaust pipe and has a reflux port and a water phase discharge port. The reflux port is connected to the reaction unit through a reflux pipeline, and the water phase discharge port is used to discharge the separated water phase from the reaction system.

[0007] By incorporating a dehydration module consisting of an exhaust pipe, a condenser, and a water separator, the azeotropic mixture gas evaporated in the reaction system is condensed and enters the water separator. The separated solvent is returned to the reaction unit through the reflux port to continue participating in the reaction, while the water is discharged through the aqueous phase outlet. This structure achieves solvent recycling and targeted water removal, reducing solvent consumption, effectively promoting the forward reaction, and avoiding the impact of residual moisture on product stability.

[0008] As a preferred embodiment, the reaction unit includes: A heating module, located on the outer wall or inside the reaction unit, is configured to raise the temperature of the reaction system to the boiling point range of the azeotropic mixture; The pressure control module, connected to the inner cavity of the reaction unit, is configured to maintain the pressure state within the reaction unit in order to control the vaporization rate of the azeotropic mixture.

[0009] By configuring a heating module and a pressure control module, the reaction unit can precisely regulate the thermodynamic environment of the reaction system. The heating module provides the heat required for dehydration, while the pressure control module maintains a suitable pressure state to match the vaporization rate of the azeotropic mixture. The two work together to ensure the synchronization of dehydration efficiency and reaction rate, preventing reaction runaway or poor dehydration due to temperature or pressure fluctuations.

[0010] As a preferred embodiment, the heating module includes at least one of a jacket, a coil, or an electric heating element; The heating module also includes a temperature sensor and an automatic control valve. The temperature sensor is used to monitor the real-time temperature in the reaction unit, and the automatic control valve is used to regulate the flow rate of the heating medium to the jacket or coil, or to regulate the power of the electric heating element, so that the temperature of the reaction system is maintained between 100°C and 200°C. The pressure control module includes a pressure transmitter, an inlet valve, and an outlet valve. The pressure transmitter is used to monitor the real-time pressure in the reaction unit. The inlet valve and outlet valve are adjusted in conjunction with the real-time pressure: when the real-time pressure is lower than the preset lower limit, the inlet valve is opened to allow inert gas to enter; when the real-time pressure is higher than the preset upper limit, the outlet valve is opened to discharge the gas.

[0011] By employing specific heating elements in conjunction with temperature sensors and automatic control valves, as well as the coordinated regulation of pressure transmitters and valves, closed-loop automatic control of reaction temperature and pressure is achieved. Maintaining the temperature between 100℃ and 200℃ ensures effective azeotropic dehydration, while the coordinated pressure regulation maintains a slightly positive pressure state in the system, preventing backflow of external air and avoiding system overpressure, thus ensuring the stability of process parameters and the safety of equipment operation.

[0012] As a preferred embodiment, the sulfur source transport unit includes: The hydrogen sulfide gas storage tank is connected to the reaction unit via a sulfur source pipeline and is used to supply hydrogen sulfide gas into the reaction unit. A mass flow controller, installed on the sulfur source pipeline, is used to control the flow rate of hydrogen sulfide gas.

[0013] By installing a hydrogen sulfide gas storage tank and a mass flow controller, the sulfur source delivery unit can accurately measure and stably deliver gaseous reactants. The mass flow controller ensures the accuracy of the hydrogen sulfide gas flow rate, guarantees precise control of the reaction stoichiometry, and avoids increased product impurities or raw material waste due to gas ratio imbalances.

[0014] As a preferred embodiment, the lithium source delivery unit includes: A silo is used to store lithium sources or to connect to a lithium source supply point. The feeder connects the outlet of the silo to the inlet of the reaction unit and is configured to meter and output the lithium source.

[0015] By incorporating a silo and a feeding machine, the lithium source conveying unit achieves sealed storage and precise metering of solid raw materials. The silo reduces the time the lithium source is exposed to air, lowering the risk of moisture absorption, while the feeding machine's metering output function reduces manual intervention, improving feeding accuracy and the degree of automation in the production process.

[0016] As a preferred embodiment, the solvent delivery unit includes: The main solvent storage tank contains the main solvent and is connected to the reaction unit through a delivery pipeline. The output pipeline of the main solvent storage tank is equipped with a first metering delivery pump. A water-containing agent storage tank is used to store water-containing agent and is connected to the reaction unit through a delivery pipeline. A second metering delivery pump is installed on the output pipeline of the water-containing agent storage tank. The first and second metering pumps are configured to deliver the main solvent and the dehydrating agent to the reaction unit at a preset volume ratio.

[0017] By setting up a main solvent storage tank, a water-carrying agent storage tank, and corresponding metering pumps, the solvent delivery unit achieves automated proportioning and delivery of various solvents. The metering pumps precisely deliver solvents according to preset volume ratios, ensuring the stability of the reaction solvent composition and providing the foundation for establishing an azeotropic dehydration system, thereby guaranteeing the consistency of each batch of products.

[0018] As a preferred embodiment, the solvent delivery unit further includes: The impurity removal agent storage tank contains impurity removal agent and is connected to the reaction unit via an output pipeline. It is used to inject the impurity removal agent into the reaction unit after the reaction is completed. Alternatively, the impurity removal agent storage tank is connected to the separation and purification unit via an output pipeline. It is used to inject the impurity removal agent into the reaction product in the separation and purification unit. The cleaning agent storage tank contains cleaning agent and is connected to the reaction unit via an output pipeline. It is used to inject cleaning agent into the reaction unit after the reaction is completed. Alternatively, the cleaning agent storage tank is connected to the separation and purification unit via an output pipeline. It is used to inject cleaning agent into the reaction products in the separation and purification unit. The third metering pump is connected to the output pipeline of the impurity removal agent storage tank. The third metering pump is configured to deliver the impurity removal agent to the reaction unit according to a preset volume ratio of the reaction system. The fourth metering pump is connected to the output pipeline of the cleaning agent storage tank. The fourth metering pump is configured to deliver the cleaning agent to the reaction unit according to a preset volume ratio of the cleaning agent to the reaction system.

[0019] By adding impurity remover storage tanks, cleaning agent storage tanks, and corresponding metering pumps, the solvent delivery unit expands the automated addition function of post-treatment reagents. Impurity removers and cleaning agents can be precisely injected into the reaction unit or separation and purification unit according to preset ratios, improving product purity and washing efficiency, and avoiding the errors and contamination risks caused by manual addition.

[0020] As a preferred embodiment, the separation and purification unit includes: The pressure filter has a sealed filter chamber, inside which is a solid-liquid separation medium; the solid-liquid separation medium is used to separate the reaction products into solid and liquid components. The built-in stirring module includes a drive motor and a stirring paddle extending into the filter chamber. The drive motor is configured to drive the stirring paddle to rotate during solid-liquid separation or washing processes to dynamically agitate the material in the filter chamber.

[0021] By incorporating a pressure filter with a sealed filtration chamber and a built-in stirring module, the separation and purification unit achieves dynamic filtration and washing under sealed conditions. The rotation of the stirring paddle dynamically agitates the material, breaking up the filter cake caking and improving the penetration and separation efficiency of the washing liquid. At the same time, the sealed chamber prevents the product from oxidizing in the air, ensuring the purity of the final product.

[0022] As a preferred option, it also includes: A heat exchanger is connected in series in the connecting pipeline between the reaction unit and the separation and purification unit. The heat exchanger is configured to reduce the temperature of the reaction product from the reaction temperature to a preset crystallization temperature or filtration temperature. The drying module is integrated into the separation and purification unit or located at the material outlet of the separation and purification unit; the drying module is configured to dry the material after it has been washed by the separation and purification unit.

[0023] By connecting a heat exchanger in series with a drying module, the device achieves temperature-controlled crystallization and final drying of the material. The heat exchanger cools the high-temperature reaction products to a suitable temperature range for crystallization or filtration, which is beneficial for solid-liquid separation; the drying module removes residual solvents from the washed material, ensuring the product's form and purity, and meeting the requirements for subsequent packaging or use.

[0024] As a preferred embodiment, the heat exchanger includes at least one of a plate heat exchanger, a shell-and-tube heat exchanger, or a jacketed cooler. The heat exchanger also includes a cooling medium flow control valve and an outlet temperature sensor. The outlet temperature sensor is used to monitor the real-time temperature of the cooled reaction products. The cooling medium flow control valve adjusts the flow rate of the cooling medium according to the real-time temperature to maintain the preset crystallization temperature or filtration temperature between 20°C and 80°C.

[0025] By specifically defining the type of heat exchanger and the temperature control strategy, the heat exchanger can precisely control the material cooling process. The combination of the outlet temperature sensor and the flow control valve maintains the crystallization temperature or filtration temperature between 20℃ and 80℃, ensuring optimized crystallization effect and filtration performance, and avoiding solvent evaporation due to excessively high temperature or increased material viscosity due to excessively low temperature, which would affect filtration.

[0026] As a preferred option, it also includes: The solvent recovery unit is connected to the separation and purification unit and is used to recover the solvent filtered by the separation and purification unit.

[0027] By incorporating a solvent recovery unit, the device achieves solvent recycling. The filtered solvent is collected, processed, and reused, reducing solvent consumption costs in the production process, while also minimizing wastewater discharge and alleviating environmental burden.

[0028] As a preferred option, it also includes: The exhaust gas treatment unit is connected to the gas phase outlets of the reaction unit and the separation and purification unit, respectively, and is used to treat the reaction exhaust gas.

[0029] By installing a tail gas treatment unit, the device eliminates the emission of toxic and harmful gases. The sulfur-containing tail gas generated during the reaction and separation process is centrally treated to meet emission standards, satisfying environmental regulations and improving the safety and environmental compliance of the production site.

[0030] As a preferred option, it also includes: The inert atmosphere protection unit includes an inert gas source, a main gas supply line, and multiple branch lines. One end of the main gas supply pipeline is connected to an inert gas source, and the other end is connected to the reaction unit, solvent delivery unit, lithium source delivery unit, sulfur source delivery unit, and separation and purification unit through multiple branch pipelines.

[0031] By incorporating an inert atmosphere protection unit, the device achieves inert gas protection throughout the entire process. Inert gas is distributed to each critical unit via branch pipelines, eliminating the intrusion paths of water and oxygen, preventing material oxidation and explosion risks, and ensuring product purity and operational safety.

[0032] As a preferred option, it also includes: The control system is connected to the solvent delivery unit, lithium source delivery unit, sulfur source delivery unit, and reaction unit via signals. The control system is configured to calculate and output control commands in real time according to the preset reaction stoichiometry, so as to coordinate the flow rates of the solvent delivery unit, lithium source delivery unit and sulfur source delivery unit, maintain the flow ratio of each material entering the reaction unit within the target range, and control the reaction unit to reach the temperature and pressure required for the reaction.

[0033] By setting up a control system, the plant achieves automated and coordinated control across the entire facility. The control system collaboratively adjusts the flow rate, temperature, and pressure of each unit according to preset parameters, reducing human error, improving production stability and product consistency, and making large-scale continuous production possible.

[0034] In summary, this application, through the system integration of solvent delivery, lithium source delivery, sulfur source delivery, reaction, and separation purification units, along with a dehydration module, inert atmosphere protection, and control system, effectively solves the problems of difficult water removal, insufficient airtightness, and lack of linkage control in existing technologies. This device as a whole achieves safe, continuous, and large-scale production of high-purity lithium sulfide, improving product consistency and production efficiency, while reducing production costs and environmental risks. Attached Figure Description

[0035] To more clearly illustrate the embodiments of this application, the relevant drawings will be briefly described below. It is understood that the drawings described below are only for illustrating some embodiments of this application, and those skilled in the art can obtain many other technical features and connections not mentioned herein based on these drawings.

[0036] Figure 1 This is a schematic diagram of the structure of the lithium sulfide synthesis apparatus for solid-state batteries according to this application; Figure 2 This is a partial structural schematic diagram of the apparatus for synthesizing lithium sulfide for solid-state batteries according to this application; Explanation of reference numerals in the attached figures: 1. Sulfur source conveying unit; 11. Hydrogen sulfide gas storage tank; 12. Mass flow controller; 2. Inert atmosphere protection unit; 21. Inert gas storage tank; 3. Solvent delivery unit; 31. Main solvent storage tank; 311. First metering delivery pump; 32. Water-containing agent storage tank; 321. Second metering delivery pump; 33. Impurity removal agent storage tank; 331. Third metering delivery pump; 34. Cleaning agent storage tank; 341. Fourth metering delivery pump; 4. Lithium source conveying unit; 41. Hopper; 42. Feeder; 5. Reaction unit; 51. Heating module; 52. Pressure control module; 53. Dehydration module; 531. Exhaust pipe; 532. Condenser; 533. Water separator; 5331. Water outlet; 534. Reflux pipe; 54. Solvent inlet; 55. Sulfur source inlet; 56. Lithium source inlet; 57. Discharge outlet; 6. Separation and purification unit; 61. Heat exchanger; 611. Temperature control module; 62. Drying module; 63. Vacuum module; 7. Solvent recovery unit; 8. Recycling unit; 81. Recycling pump; 9. Exhaust gas treatment unit. Detailed Implementation

[0037] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings.

[0038] The present application will now be described in detail with reference to the accompanying drawings.

[0039] In the field of solid-state battery material production technology, sulfide solid electrolytes are considered key materials for next-generation high-energy storage systems due to their high ionic conductivity. Lithium sulfide, as the core precursor of sulfide solid electrolytes, directly determines the electrochemical performance and battery safety of the final electrolyte product through its purity and consistency. With the expansion of applications such as low-altitude drone flight and energy storage in AI data centers, the market demand for high-purity lithium sulfide is increasing, and sensitivity to production costs is gradually rising. Therefore, developing a lithium sulfide synthesis device capable of achieving high purity, high safety, and large-scale production has become a crucial issue that urgently needs to be addressed in this technological field.

[0040] In a widely used existing technology, lithium sulfide is typically prepared using a liquid-phase synthesis method. For example, existing technology discloses a method using lithium hydroxide and an organic solvent as raw materials, reacting them with hydrogen sulfide gas. In this method, the reaction is usually carried out in a glass container. After the raw materials are mixed, the gas is introduced and the reaction proceeds for several hours. Excess gas is then removed by heating, and the resulting slurry undergoes separate processing steps such as centrifugation, thermal dissolution, filtration, and vacuum distillation to finally obtain the solid product. The equipment typically includes a round-bottom flask, a centrifuge, and a separate vacuum distillation unit.

[0041] However, this existing technical solution has significant limitations in principle. First, the water and gas generated during the reaction cannot be effectively and synchronously removed during the reaction. Since the reaction is reversible, the accumulation of water will inhibit the shift of the reaction equilibrium towards the formation of lithium sulfide, thus directly affecting the product yield and purity. Second, this solution typically relies on glass containers as the reaction carrier. The transport of sulfur-containing media in such an insufficiently sealed environment poses a risk of hydrogen sulfide leakage, which not only affects the control of oxygen content in the product but also brings significant safety and environmental hazards.

[0042] Further analysis reveals that due to the delayed removal of moisture, a separate distillation step is often required. This results in the separated wastewater containing a large amount of valuable solvents, and the lack of an effective solvent recovery system leads to resource waste and environmental burden. Furthermore, the lack of coordinated control between processing units means that material transport and reaction processes rely heavily on manual intervention or semi-automation. This discrete equipment layout limits the solution to laboratory validation only, hindering continuous and large-scale production. This results in high equipment depreciation and labor costs, restricting the commercial application of lithium sulfide.

[0043] Those skilled in the art might attempt to improve the aforementioned problems by simply enhancing the sealing of the container or adding a separate drying step. However, simply enhancing the sealing cannot solve the problem of continuous removal of azeotropic water during the reaction, while adding a separate drying step would lengthen the process chain, introduce new contamination risks, and fail to address the inefficiency caused by the lack of coordinated control between units. Therefore, the existing technology lacks a synthesis apparatus that can systematically integrate feeding, reaction, separation and purification, effectively remove reaction water, and achieve closed-loop control, which constitutes a major obstacle to current technological development.

[0044] In view of this, the embodiments of this application aim to provide an apparatus for synthesizing lithium sulfide for solid-state batteries, in order to solve or at least partially alleviate the above-mentioned technical problems.

[0045] First Implementation Method This embodiment provides an apparatus for synthesizing lithium sulfide for solid-state batteries. This apparatus can be applied to the preparation of sulfide solid electrolytes, and is particularly suitable for scenarios requiring high purity, high safety, and large-scale production of lithium sulfide.

[0046] Please see Figure 1 The synthesis apparatus mainly includes a solvent delivery unit 3, a lithium source delivery unit 4, a sulfur source delivery unit 1, a reaction unit 5, and a separation and purification unit 6. These units are interconnected through pipelines and control interfaces to form a closed material flow and reaction system.

[0047] Solvent delivery unit 3 is used to deliver the composite solvent to reaction unit 5. In one specific embodiment, solvent delivery unit 3 may include at least one main solvent storage tank 31 and a dehydrating agent storage tank 32. The main solvent storage tank 31 may store a main solvent capable of dissolving the lithium source and sulfur source, such as acetonitrile, tetrahydrofuran, or other organic solvents. The dehydrating agent storage tank 32 may store a dehydrating agent capable of forming an azeotropic system with water. Solvent delivery unit 3 may also include a delivery pipeline and a metering pump. One end of the delivery pipeline is connected to the main solvent storage tank 31 and the dehydrating agent storage tank 32, respectively, and the other end is connected to reaction unit 5. The metering pump is located on the delivery pipeline and is configured to quantitatively deliver the main solvent and the dehydrating agent to the reaction unit according to a preset volume ratio. For example, the metering pump may be a gear pump, a diaphragm pump, or a peristaltic pump, and its flow rate can be adjusted according to process requirements.

[0048] The lithium source delivery unit 4 is used to deliver lithium source to the reaction unit 5. In one specific embodiment, the lithium source delivery unit 4 may include a hopper 41 and a feeder 42. The hopper 41 is used to store solid lithium source, such as lithium hydroxide powder, or is connected to the lithium source replenishment end, such as to a packaging unpacking machine. The feeder 42 connects the outlet of the hopper 41 to the inlet of the reaction unit 5. The feeder 42 is used to meter and output the lithium source, for example, by means of a screw feeder, a vibrating feeder, or a gravity discharge valve. To maintain airtightness, the hopper 41 and the feeder 42 may be installed in an inert gas protected environment.

[0049] The sulfur source delivery unit 1 is used to deliver sulfur to the reaction unit 5. In one specific embodiment, the sulfur source delivery unit 1 may include a hydrogen sulfide gas storage tank 11 and a sulfur source pipeline. The hydrogen sulfide gas storage tank 11 is connected to the reaction unit 5 via the sulfur source pipeline and is used to deliver hydrogen sulfide gas into the reaction unit 5. A flow control valve or a mass flow controller 12 may also be installed on the sulfur source pipeline to control the flow rate of hydrogen sulfide gas to ensure the accuracy of the stoichiometry of the reactants.

[0050] The reaction unit 5 is connected to the solvent delivery unit 3, the lithium source delivery unit 4, and the sulfur source delivery unit 1, forming a closed reaction space. The reaction unit 5 is used to contain the composite solvent, lithium source, and sulfur source to form a reaction system and to provide a reaction environment for the system. In one specific embodiment, the reaction unit 5 may include a reaction vessel. The reaction vessel has a closed inner cavity containing a stirrer configured to agitate the reaction system to promote material mixing. A heating module 51, such as a heating jacket, coil, or electric heating element, may be installed on the outer wall or inside the reaction vessel to raise the temperature of the reaction system. The reaction vessel is also equipped with a pressure control module 52 to maintain the pressure state within the reaction unit 5 to control the vaporization rate of the azeotropic mixture.

[0051] The reaction unit 5 also includes a dehydration module 53. The dehydration module 53 is configured to remove the azeotropic mixture formed by the water-carrying agent and the byproduct water in the reaction system. In one specific embodiment, the dehydration module 53 may include a gas phase outlet located at the top of the reactor. This gas phase outlet may be connected to an external pipeline, allowing the azeotropic vapors generated during the reaction to escape from the reaction system. By continuously removing the water generated in the reaction, the reaction equilibrium can be shifted towards the formation of lithium sulfide.

[0052] The separation and purification unit 6 is connected to the reaction unit 5, forming a closed reaction space. The separation and purification unit 6 receives the reaction products from the reaction unit 5 and performs solid-liquid separation and washing on the products to obtain lithium sulfide. In one specific embodiment, the separation and purification unit 6 may include a filtration device. The filtration device has a closed filtration chamber containing a solid-liquid separation medium, such as filter cloth or a sintered filter element. The filtration device may also include a washing liquid inlet for injecting a cleaning agent into the filtration chamber. The separation and purification unit 6 may also include a drive motor for rotating a stirring paddle within the filtration chamber to dynamically agitate the material, thereby improving washing efficiency.

[0053] During operation, solvent delivery unit 3 first delivers the composite solvent into reaction unit 5. Subsequently, lithium source delivery unit 4 and sulfur source delivery unit 1 deliver solid lithium source and hydrogen sulfide gas into reaction unit 5, respectively. The reaction unit undergoes reaction under heating and stirring conditions, while dehydration module 53 removes the generated water. After the reaction is completed, the reaction product is transported to separation and purification unit 6, where solid-liquid separation and washing yield lithium sulfide product.

[0054] This embodiment integrates five major units: solvent delivery, lithium source delivery, sulfur source delivery, reaction, and separation and purification, to realize a synthesis device for solid-state battery lithium sulfide. The device, by incorporating a dehydration module 53, can continuously remove the azeotropic mixture formed by the water-carrying agent and byproduct water during the reaction process, effectively solving the problem of reaction equilibrium reversal caused by the difficulty in removing the generated water. Simultaneously, the fully enclosed design reduces the risk of toxic gas leakage, improving production safety. The coordinated configuration of each unit makes material delivery and the reaction process more stable, facilitating large-scale continuous production and thus improving product consistency and purity.

[0055] Second Implementation Method Based on the first embodiment, this embodiment further improves the specific structure of the reaction unit 5, focusing on providing a more comprehensive reaction environment control scheme. This scheme mainly involves the specific configuration of the dehydration module 53, the heating module 51, and the pressure control module 52, aiming to more precisely control the thermodynamic conditions during the reaction process to ensure efficient azeotropic dehydration and the safe and stable reaction system.

[0056] like Figure 2As shown, in a specific embodiment, the dehydration module 53 may include an exhaust pipe 531, a condenser 532, and a water separator 533. One end of the exhaust pipe 531 may be connected to the gas phase outlet of the reaction unit 5, and the other end may extend through the condenser 532 to the water separator 533. The condenser 532 may be fitted outside the exhaust pipe 531, or other heat exchange structures may be used to condense the gas mixture inside the exhaust pipe 531. For example, the condenser 532 may be a jacket or coil wrapped around the exhaust pipe 531. The water separator 533 is connected to the exhaust pipe 531 and has a reflux port and a water distribution port 5331. The reflux port may be connected to the reaction unit 5 through a reflux pipe 534, while the water distribution port 5331 is used to discharge the separated aqueous phase. For example, the water separator 533 may be an oil-water separator or a gravity settling tank, and its internal structure is configured to separate the condensed liquid phase mixture into an organic solvent phase and an aqueous phase. The organic solvent phase, including the aqueous phase, can be returned to reaction unit 5 through the reflux port to continue participating in the reaction cycle, while the aqueous phase is removed from the system through the aqueous phase discharge port.

[0057] like Figure 2 As shown, the part of the exhaust pipe 531 that passes through the condenser 532 is also connected to the exhaust gas treatment unit 9. The exhaust gas treatment unit 9 treats the reaction gas in the exhaust pipe 531 to ensure that the gas meets the safety emission standards.

[0058] The top of reaction unit 5 has a solvent inlet 54, a sulfur source inlet 55, and a lithium source inlet 56. Solvent inlet 54 is connected to the pipeline outlet of solvent delivery unit 3, sulfur source inlet 55 is connected to the pipeline outlet of sulfur source delivery unit 1, and lithium source inlet 56 is connected to the pipeline outlet of lithium source delivery unit 4. The bottom of reaction unit 5 has a discharge outlet 57, which is connected to a separation and purification unit via a pipeline. Alternatively, reaction unit 5 may also have an inert gas inlet to allow the introduction of an inert protective gas to protect the reaction environment.

[0059] To provide the heat energy required for the reaction, the reaction unit 5 in this embodiment is equipped with a heating module 51. In one specific embodiment, the heating module can be located on the outer wall or inside the reaction unit 5. For example, the heating module 51 may include at least one of a jacket, a coil, or an electric heating element. If a jacket or coil is used, the heating medium may be heat transfer oil, molten salt, or high-temperature steam. The heating module 51 may also include a temperature sensor and a self-regulating valve. The temperature sensor is used to monitor the real-time temperature within the reaction unit, and the self-regulating valve is used to regulate the flow rate of the heating medium to the jacket or coil, or to regulate the power of the electric heating element. With this configuration, the temperature of the reaction system can be maintained within a specific range, for example, between 100°C and 200°C. Preferably, the temperature sensor may be a thermocouple or a resistance temperature detector (RTD), and the self-regulating valve may be a pneumatic or electric regulating valve, which are connected to the control system signal or manually controlled to achieve closed-loop control.

[0060] Furthermore, the reaction unit 5 in this embodiment is also equipped with a pressure control module 52 for maintaining the pressure state within the reaction unit. In a specific embodiment, the pressure control module 52 can communicate with the inner cavity of the reaction unit 5. The pressure control module 52 may include a pressure transmitter, an inlet valve, and an outlet valve. The pressure transmitter is used to monitor the real-time pressure within the reaction unit 5. The inlet valve and outlet valve can be adjusted in conjunction with the real-time pressure. For example, when the real-time pressure is lower than a preset lower limit, the control system can open the inlet valve to introduce an inert gas, such as argon or nitrogen, to increase the pressure; when the real-time pressure is higher than a preset upper limit, the outlet valve can be opened manually or through the control system to discharge some gas to reduce the pressure. Through this coordinated adjustment, the pressure within the reaction unit 5 can be maintained at a slightly positive pressure state, for example, between 30 Pa and 3 kPa. This pressure control strategy helps control the vaporization rate of the azeotropic mixture, prevents backflow of external air, and avoids the risk of system overpressure.

[0061] This embodiment, through the aforementioned improvements, provides a lithium sulfide synthesis apparatus with refined environmental control capabilities. The specific structure of the exhaust pipe 531, condenser 532, and water separator 533 achieves effective condensation and separation of the azeotropic mixture, allowing the solvent to be recycled and reused, while the aqueous phase generated in the reaction is discharged separately, thereby reducing solvent consumption and promoting the forward reaction. Simultaneously, the specific configuration of the heating module 51 and pressure control module 52 enables closed-loop automatic control of the reaction temperature and pressure. This precise thermodynamic condition control ensures a match between dehydration efficiency and reaction rate, avoiding side reactions caused by temperature fluctuations or safety risks caused by pressure instability. Overall, this solution improves the stability of process parameters, creating a reliable reaction environment for the continuous production of high-purity lithium sulfide.

[0062] Third Implementation Method Based on the above embodiments, this embodiment further improves the material conveying system, providing a more precise and automated material conveying solution. This solution mainly involves the specific configuration of the sulfur source conveying unit 1, the lithium source conveying unit 4, and the solvent conveying unit 3, aiming to achieve closed storage, precise metering, and coordinated conveying of multiple reaction raw materials to ensure the accuracy of the stoichiometry of the reaction system and production safety.

[0063] like Figure 1As shown, in a specific embodiment, the sulfur source delivery unit 1 may include a hydrogen sulfide gas storage tank 11 and a sulfur source pipeline. The hydrogen sulfide gas storage tank 11 is connected to the reaction unit 5 via the sulfur source pipeline for supplying hydrogen sulfide gas into the reaction unit 5. A flow control device, such as a mass flow controller 12, may also be installed on the sulfur source pipeline. The mass flow controller 12 is used to monitor and adjust the flow rate of the hydrogen sulfide gas in real time to ensure that the amount of sulfur source entering the reaction unit 5 conforms to the preset reaction stoichiometry. For example, the mass flow controller 12 can be manually operated or connected to a control system signal to dynamically adjust the gas flow rate according to the reaction progress. This configuration helps prevent reaction ratio imbalances caused by gas flow fluctuations and reduces errors caused by manual intervention.

[0064] The lithium source delivery unit 4 is configured to deliver solid lithium source to the reaction unit 5. In one specific embodiment, the lithium source delivery unit 4 may include a hopper 41 and a feeder 42. The hopper 41 is used to store lithium source, such as lithium hydroxide powder, or is connected to the lithium source replenishment end. The feeder 42 connects the discharge port of the hopper 41 to the inlet of the reaction unit 5. The feeder 42 is configured to meter the lithium source output, for example, it may be a screw feeder, a vibrating feeder, or a gravity discharge valve. To reduce the risk of lithium source moisture absorption, the hopper 41 and the feeder 42 may be placed in an inert gas protected environment, or their internal space may be connected to an inert atmosphere. For example, an inert gas inlet may be provided at the top of the hopper to maintain a slightly positive pressure state. This closed storage and delivery structure effectively reduces the opportunity for solid raw materials to come into contact with outside air, reducing the risk of oxygen content impurities in the product.

[0065] Solvent delivery unit 3 is used to deliver the composite solvent to reaction unit 5. For example... Figure 1 As shown, in a specific embodiment, the solvent delivery unit 3 may include a main solvent storage tank 31 and a dehydrating agent storage tank 32. The main solvent storage tank 31 stores the main solvent and is connected to the reaction unit 5 via a delivery pipeline. A first metering pump 311 is installed on the output pipeline of the main solvent storage tank 31. The dehydrating agent storage tank 32 stores the dehydrating agent and is connected to the reaction unit 5 via a delivery pipeline. A second metering pump 321 is installed on the output pipeline of the dehydrating agent storage tank 32. The first metering pump 311 and the second metering pump 321 are used to deliver the main solvent and the dehydrating agent to the reaction unit 5 at a preset volume ratio. For example, the first metering pump 311 and the second metering pump 321 may be gear pumps, diaphragm pumps, or peristaltic pumps, and their speed or stroke frequency can be adjusted according to control commands. Through the coordinated control of the two pumps, the automated proportioning of the solvent composition can be achieved, ensuring the consistency of the reaction solvent system.

[0066] In addition, the solvent delivery unit 3 may also include a purifying agent storage tank 33 and a cleaning agent storage tank 34. The purifying agent storage tank 33 stores purifying agent and is connected to the reaction unit 5 via an output pipeline for injecting purifying agent into the reaction unit after the reaction is completed; alternatively, the purifying agent storage tank 33 is connected to the separation and purification unit 6 via an output pipeline for injecting purifying agent into the reaction product within the separation and purification unit 6. The cleaning agent storage tank 34 stores cleaning agent and is connected to the reaction unit 5 via an output pipeline for injecting cleaning agent into the reaction unit 5 after the reaction is completed; alternatively, the cleaning agent storage tank 34 is connected to the separation and purification unit 6 via an output pipeline for injecting cleaning agent into the reaction product within the separation and purification unit 6. A third metering pump 331 may be connected to the output pipeline of the purifying agent storage tank 33 for delivering the purifying agent to the reaction unit 5 according to a preset volume ratio of its proportion in the reaction system. The fourth metering pump 341 can be connected to the output pipeline of the cleaning agent to deliver the cleaning agent to the reaction unit 5 according to a preset volume ratio of the cleaning agent to the reaction system. For example, the impurity remover can be an alkaline solution used to neutralize residual acidic substances, and the cleaning agent can be an organic solvent used to remove surface-adhered solvents.

[0067] This embodiment, through the aforementioned improvements, provides a lithium sulfide synthesis apparatus with precise multi-material conveying capabilities. The improvements lie in the automated conveying of various raw materials—gaseous, solid, and liquid—through specific configurations of storage tanks, pipelines, and metering pumps. Mass flow control of the sulfur source ensures the accuracy of the stoichiometric ratio in the gas-liquid reaction; the sealed silo and feeder structure of the lithium source reduces the risk of moisture absorption and contamination from solid raw materials; and the multi-tank and multi-pump configuration of the solvent unit enables flexible proportioning and addition of composite solvents and auxiliary reagents. This integrated material conveying system not only improves feeding accuracy and production efficiency but also reduces the possibility of leakage of toxic and harmful media through its sealed design, providing a reliable material foundation for the stable operation of subsequent reaction units.

[0068] Fourth Implementation Method Based on the above embodiments, this embodiment further improves the post-processing system, providing a more efficient and closed product processing solution. This solution mainly involves the specific configuration of the heat exchanger, separation and purification unit, and drying module, aiming to achieve a smooth transition of the reaction product from a high-temperature reaction state to a solid finished product, ensuring that the product is not affected by the external environment during separation, washing, and drying, while optimizing the crystal morphology and filtration performance.

[0069] like Figure 1As shown, in this embodiment of the solid-state battery lithium sulfide synthesis apparatus, a heat exchanger 61 is connected in series on the connecting pipeline between the reaction unit 5 and the separation and purification unit 6. In a specific embodiment, the heat exchanger 61 is configured to reduce the temperature of the reaction product from the reaction temperature to a preset crystallization temperature or filtration temperature. For example, the temperature of the slurry after the reaction may be between 160°C and 200°C, and the heat exchanger 61 can cool it down to between 20°C and 80°C. The heat exchanger 61 can be at least one of a plate heat exchanger, a shell-and-tube heat exchanger, or a jacketed cooler. To precisely control the cooling process, the heat exchanger 61 may also include a temperature control module 611, which can be a cooling medium flow control valve and an outlet temperature sensor. The outlet temperature sensor is used to monitor the real-time temperature of the cooled reaction product, and the cooling medium flow control valve adjusts the flow rate of the cooling medium according to the real-time temperature to maintain a preset temperature range. This configuration helps control the crystallization process of lithium sulfide, avoiding crystal refinement that is difficult to filter due to excessively rapid cooling, or increased energy consumption due to excessively slow cooling, while ensuring that the material is at a safe operating temperature when entering the separation unit.

[0070] The separation and purification unit 6 is connected to the outlet of the heat exchanger 61 to receive the cooled reaction products. In one specific embodiment, the separation and purification unit 6 may include a pressure filter. The pressure filter has a sealed filter chamber containing a solid-liquid separation medium, such as filter cloth, sintered metal filter element, or ceramic membrane. The sealed filter chamber prevents outside air from entering, avoiding deterioration of the lithium sulfide product in a water-oxygen environment. The separation and purification unit 6 may also include a built-in stirring module. The built-in stirring module may include a drive motor and a stirring paddle extending into the filter chamber. The drive motor is configured to rotate the stirring paddle during the solid-liquid separation process or the washing process to dynamically agitate the material in the filter chamber. For example, during the washing stage, the rotation of the stirring paddle allows the cleaning agent to fully contact the filter cake, removing residual solvents and impurities, thereby improving washing efficiency and product purity.

[0071] The separation and purification unit 6 is also connected to a vacuum module 63, which is used to evacuate the separation and purification unit 6 and remove excess gas; and the vacuum module 63 is connected to a tail gas treatment unit 9, which is used to safely treat the tail gas in the separation and purification unit 6.

[0072] Furthermore, the apparatus of this embodiment also includes a drying module 62. In one specific embodiment, the drying module 62 may be integrated inside the separation and purification unit 6, or disposed at the material outlet end of the separation and purification unit 6. The drying module 62 is configured to dry the material after washing in the separation and purification unit 6. For example, the drying module 62 may be a vacuum drying chamber, a fluidized bed dryer, or a drying filter with a heating jacket. The drying module 62 can operate under inert gas protection, removing residual solvents and moisture from the material by heating and vacuuming, ultimately obtaining dry lithium sulfide powder.

[0073] This embodiment, through the aforementioned improvements, provides a lithium sulfide synthesis apparatus with temperature-controlled crystallization and closed-loop drying capabilities. The improvement lies in the introduction of a heat exchanger 61, which enables precise and controllable cooling of the reaction product from high temperature to filtration temperature, optimizing the crystal morphology and ensuring the safety of subsequent operations. The combination of a pressure filter and a built-in stirring module achieves dynamic filtration and washing in a closed environment, effectively preventing product oxidation and improving impurity removal rates. Further configuration of the drying module 62 ensures that the final product's moisture content and solvent residue meet high purity requirements. Overall, this solution improves the post-processing chain from reaction slurry to solid finished product, enhancing the final product quality and the continuity of the production process.

[0074] Fifth Implementation Method Based on the above embodiments, this embodiment further improves the auxiliary and control systems, providing a more complete and intelligent device operation scheme. This scheme mainly involves a solvent recovery unit, a tail gas treatment unit, an inert atmosphere protection unit, and a central control system, aiming to achieve resource recycling, safe waste gas treatment, full-process oxygen-free protection, and automated linkage between units, thereby reducing production costs, eliminating safety hazards, and ensuring product consistency.

[0075] The solid-state battery lithium sulfide synthesis apparatus in this embodiment further includes a solvent recovery unit 7. In one specific embodiment, the solvent recovery unit 7 can be a recovery tank connected to the liquid phase outlet of the separation and purification unit 6. The outlet end of the recovery tank is connected to a recovery processing unit 8, and a recovery pump 81 is installed on the pipeline. The recovery pump 81 is used to send the solvent in the recovery tank to the recovery processing unit 8. The recovery processing unit 8 is used to recover the solvent filtered by the separation and purification unit 6. For example, the recovery processing unit 8 may include a distillation column, a thin-film evaporator, or a molecular sieve dehydration device. When the filtrate after filtration contains a large amount of reusable organic solvent, the recovery processing unit 8 can separate the solvent from the impurities by distillation or adsorption, and the purified solvent can be returned to the storage tank of the solvent delivery unit. This configuration helps to reduce solvent consumption and waste discharge, thereby reducing production costs and environmental burden.

[0076] like Figure 1 As shown, the device also includes a tail gas treatment unit 9. In one specific embodiment, the tail gas treatment unit 9 can be connected to the gas phase outlets of the reaction unit 5 and the separation and purification unit 6, respectively. The tail gas treatment unit 9 is used to treat the tail gas generated during the reaction process. For example, the tail gas treatment unit 9 may include an alkaline spray tower, an activated carbon adsorption box, or a combustion device. Since unreacted hydrogen sulfide gas or other volatile organic compounds may be generated during the reaction process, the tail gas treatment unit 9 can remove harmful substances through chemical neutralization or physical adsorption, ensuring that the final emitted gas meets environmental protection standards. This configuration eliminates the risk of direct emission of toxic and harmful gases and meets the safety and environmental protection requirements of the production site.

[0077] To further prevent water and oxygen intrusion, the apparatus of this embodiment also includes an inert atmosphere protection unit 2. In a specific embodiment, the inert atmosphere protection unit 2 may include an inert gas source, a main gas supply pipeline, and multiple branch pipelines. The inert gas source may be an inert gas storage tank 21, such as an argon storage tank or a nitrogen generator. One end of the main gas supply pipeline is connected to the inert gas source, and the other end is connected to the reaction unit 5, solvent delivery unit 3, lithium source delivery unit 4, sulfur source delivery unit 1, and separation and purification unit 6 respectively through multiple branch pipelines. For example, inert gas branch pipelines can be introduced into the top space of each storage tank, inside the silo, and in the filter chamber to maintain a slightly positive pressure inert atmosphere. This end-to-end inert gas protection eliminates the possibility of material contact with air during storage, transportation, and reaction, effectively ensuring product purity and reducing the risk of explosion.

[0078] Furthermore, the apparatus of this embodiment also includes a control system. In one specific embodiment, the control system can be signal-connected to the solvent delivery unit 3, the lithium source delivery unit 4, the sulfur source delivery unit 1, and the reaction unit 5, respectively. The control system is configured to calculate and output control commands in real time according to a preset reaction stoichiometry. For example, the control system can be an automation platform based on a programmable logic controller (PLC) or a distributed control system (DCS). The control system can coordinately adjust the delivery flow rates of the solvent delivery unit 3, the lithium source delivery unit 4, and the sulfur source delivery unit 1 to maintain the flow rate ratio of each material entering the reaction unit within a target range.

[0079] Specifically, the control system is signal-connected to the first metering pump 311, the second metering pump 321, the third metering pump 331, and the fourth metering pump 341 mentioned in the above embodiments, and also signal-connected to the mass flow controller 12 and the feeder 42, thereby automatically controlling the proportion of each component in the reaction system. Simultaneously, the control system can also control the reaction unit 5 to reach the required temperature and pressure based on feedback signals from the temperature sensor and pressure transmitter. For example, the control system is also signal-connected to the heating module 51, the pressure control module 52, the heat exchanger 61, and the drying module 62 mentioned in the above embodiments, realizing automated regulation of the reaction environment. This automated, interconnected control reduces errors caused by human intervention and improves production stability and product consistency.

[0080] This embodiment, through the aforementioned improvements, provides a lithium sulfide synthesis apparatus with resource recovery, environmentally friendly treatment, and automated control capabilities. The apparatus achieves the recycling of valuable solvents through solvent recovery unit 7, reducing material costs; eliminates the risk of toxic gas emissions through tail gas treatment unit 9; constructs an oxygen-free environment throughout the process through inert atmosphere protection unit 2, ensuring high product purity; and achieves coordinated operation between various units through a central control system. Overall, this solution makes the apparatus more suitable for continuous industrial production, improving system reliability, safety, and economic efficiency.

[0081] Sixth Implementation Method Based on the solid-state battery lithium sulfide synthesis apparatus described in the foregoing embodiments, this embodiment provides an exemplary operation process for lithium sulfide synthesis using this apparatus. This operation process demonstrates how the various units of the apparatus work collaboratively to achieve continuous material transport, reaction, and post-processing. The following process is only an example of a preferred combination of process parameters; those skilled in the art can adjust the specific parameters according to actual production needs.

[0082] Please see Figure 1 In the initial stage of operation, inert gas purging and system protection are performed first. Before feeding materials, the entire internal space of the system can be purged with high-purity argon using the inert atmosphere protection unit 2. For example, the purging can be performed 2 to 4 times to ensure that the oxygen and water content in the system is reduced to below a preset threshold. During the preparation process, argon can be maintained in the inert gas atmosphere of the system through a constant pressure control system. This step helps to create an oxygen-free and water-free environment, preventing oxidation or hydrolysis reactions of raw materials and products in subsequent steps, thereby ensuring the chemical purity of the product.

[0083] Following this, liquid and powder feeding operations are performed. Solvent delivery unit 3 can quantitatively deliver the solvent stored in the solvent tank into reaction unit 5 via a metering pump according to a preset ratio. For example, the main solvent, dehydrating agent, cleaning agent, and impurity remover can be selectively delivered according to the process formulation. Simultaneously, solid raw materials such as lithium sources can be added via lithium source delivery unit 4. The lithium source is fed into silo 41 after passing through an unpacking machine, and then quantitatively metered and fed into reaction unit 5 by the feeding control system of feeder 42. This automated proportioning and feeding method reduces human error and ensures the accuracy of the initial composition of the reaction system.

[0084] Next, the dehydration and reaction stages are carried out. The stirring device of reaction unit 5 is turned on, with the stirring speed controlled, for example, between 100 and 300 revolutions per minute. The temperature of reaction unit 5 is raised to 100 to 160 degrees Celsius via the temperature control system of heating module 51, for example, 0.5 to 12 hours, to remove free water or water of crystallization from the reaction system. After dehydration, a reaction gas, such as hydrogen sulfide gas, is metered into reaction unit 5 via hydrogen sulfide gas storage tank 11 and mass flow controller 12. Heating continues for 2 to 30 hours to allow hydrogen sulfide and the lithium source to fully contact and react in the solvent system.

[0085] During this period, the system pressure is adjusted by the pressure control module 52 to maintain the pressure of the reaction unit 5 at a slightly positive pressure, for example, between 30 Pa and 3 kPa. The generated exhaust gas can be discharged into the exhaust gas treatment unit 9 in a closed manner for solvent recovery. Maintaining a slightly positive pressure helps prevent backflow of outside air and promotes the smooth discharge of the azeotropic water vapor generated in the reaction, thus shifting the reaction equilibrium towards the formation of lithium sulfide.

[0086] After the synthesis reaction is completed, the post-processing stage begins. First, the reaction gas inlet is cut off, and the reaction temperature is raised to 160-200 degrees Celsius via heating module 51. Degassing is then performed for 1-6 hours to obtain lithium sulfide slurry. Subsequently, the lithium sulfide slurry is pumped into heat exchanger 61 to cool to 20-80 degrees Celsius. The outlet temperature can be precisely controlled by the temperature control module 611 of heat exchanger 61. The cooled material is then sent to separation and purification unit 6, where it is vacuum filtered by vacuum module 63 to obtain crude lithium sulfide. During filtration, the material can be repeatedly washed 3-6 times with a cleaning agent, with stirring maintained at, for example, 10-100 rpm. The cleaned filter cake is then sent to drying module 62 to obtain high-purity lithium sulfide. The washed filtrate can be sent to solvent recovery unit 7, and then via recovery pump 81 to recycling treatment unit 8 for further processing.

[0087] This embodiment demonstrates how to achieve efficient synthesis of lithium sulfide using the aforementioned apparatus through the above-described operating procedure. This process effectively solves the problems of difficult moisture removal, easy product oxidation, and solvent waste in traditional processes through strict inert gas protection, precise temperature and pressure control, and continuous separation and washing steps. Specific parameter range examples provide a reference for the optimal operating range of the apparatus, helping to obtain high-purity, highly consistent lithium sulfide products in actual production. Simultaneously, it achieves solvent recycling and safe treatment of exhaust gases, improving overall production efficiency and environmental safety.

[0088] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. An apparatus for synthesizing lithium sulfide for solid-state batteries, characterized in that, include: A solvent delivery unit for delivering a composite solvent, wherein the composite solvent includes at least a water-carrying agent; Lithium source delivery unit, used to deliver lithium source; Sulfur source conveying unit, used to convey sulfur source; The reaction unit is connected to the solvent delivery unit, the lithium source delivery unit, and the sulfur source delivery unit to form a closed space for containing the composite solvent, the lithium source, and the sulfur source to form a reaction system and providing a reaction environment for the reaction system; the reaction unit has a dehydration module configured to remove the azeotropic mixture formed by the water-carrying agent and the by-product water in the reaction system. The separation and purification unit is connected to the reaction unit to form a closed space, used to receive the reaction products in the reaction unit, and to perform solid-liquid separation and washing treatment on the reaction products to obtain lithium sulfide.

2. The apparatus for synthesizing lithium sulfide for solid-state batteries according to claim 1, characterized in that, The dehydration module includes: The exhaust pipe is connected at one end to the gas phase outlet of the reaction unit, and at the other end extends through the condenser to the water separator. A condenser, fitted outside the exhaust pipe, is used to condense the gas inside the exhaust pipe; A water separator is connected to the exhaust pipe and has a reflux port and a water phase discharge port. The reflux port is connected to the reaction unit through a reflux pipeline, and the water phase discharge port is used to discharge the separated water phase from the reaction system.

3. The apparatus for synthesizing lithium sulfide for solid-state batteries according to claim 1, characterized in that, The reaction unit includes: A heating module, disposed on the outer wall or inside the reaction unit, is configured to raise the temperature of the reaction system to the boiling point range of the azeotropic mixture; A pressure control module, connected to the inner cavity of the reaction unit, is configured to maintain the pressure state within the reaction unit in order to control the vaporization rate of the azeotropic mixture.

4. The apparatus for synthesizing lithium sulfide for solid-state batteries according to claim 3, characterized in that, The heating module includes at least one of a jacket, a coil, or an electric heating element; The heating module also includes a temperature sensor and a self-regulating valve. The temperature sensor is used to monitor the real-time temperature in the reaction unit, and the self-regulating valve is used to adjust the flow rate of the heating medium to the jacket or coil, or to adjust the power of the electric heating element, so that the temperature of the reaction system is maintained between 100°C and 200°C. The pressure control module includes a pressure transmitter, an inlet valve, and an outlet valve. The pressure transmitter is used to monitor the real-time pressure in the reaction unit. The inlet valve and the outlet valve are adjusted in conjunction with each other according to the real-time pressure: when the real-time pressure is lower than a preset lower limit, the inlet valve is opened to allow inert gas to enter; when the real-time pressure is higher than a preset upper limit, the outlet valve is opened to discharge gas.

5. The apparatus for synthesizing lithium sulfide for solid-state batteries according to claim 1, characterized in that, The sulfur source transport unit includes: A hydrogen sulfide gas storage tank is connected to the reaction unit via a sulfur source pipeline for supplying hydrogen sulfide gas into the reaction unit. A mass flow controller is installed on the sulfur source pipeline to control the flow rate of hydrogen sulfide gas.

6. The apparatus for synthesizing lithium sulfide for solid-state batteries according to claim 1, characterized in that, The lithium source delivery unit includes: A silo is used to store lithium sources or to connect to a lithium source supply point. A feeder connects the outlet of the silo to the inlet of the reaction unit, and the feeder is configured to meter and output the lithium source.

7. The apparatus for synthesizing lithium sulfide for solid-state batteries according to claim 1, characterized in that, The solvent delivery unit includes: A main solvent storage tank, which stores the main solvent, is connected to the reaction unit through a delivery pipeline. A first metering delivery pump is installed on the output pipeline of the main solvent storage tank. A water-containing agent storage tank is provided, which stores water-containing agent and is connected to the reaction unit through a delivery pipeline. A second metering delivery pump is installed on the output pipeline of the water-containing agent storage tank. The first metering pump and the second metering pump are configured to deliver the main solvent and the dehydrating agent to the reaction unit at a preset volume ratio.

8. The apparatus for synthesizing lithium sulfide for solid-state batteries according to claim 7, characterized in that, The solvent delivery unit further includes: A purification agent storage tank, which stores purification agent inside, is connected to the reaction unit through an output pipeline for injecting purification agent into the reaction unit after the reaction is completed; or, the purification agent storage tank is connected to the separation and purification unit through an output pipeline for injecting purification agent into the reaction product in the separation and purification unit. A cleaning agent storage tank, which stores cleaning agent inside, is connected to the reaction unit through an output pipeline for injecting cleaning agent into the reaction unit after the reaction is completed; or, the cleaning agent storage tank is connected to the separation and purification unit through an output pipeline for injecting cleaning agent into the reaction product in the separation and purification unit. A third metering pump is connected to the output pipeline of the impurity removal agent storage tank. The third metering pump is configured to deliver the impurity removal agent to the reaction unit according to a preset volume ratio of the impurity removal agent to the reaction system. A fourth metering pump is connected to the output pipeline of the cleaning agent storage tank. The fourth metering pump is configured to deliver the cleaning agent to the reaction unit according to a preset volume ratio of the cleaning agent to the reaction system.

9. The apparatus for synthesizing lithium sulfide for solid-state batteries according to claim 1, characterized in that, The separation and purification unit includes: A pressure filter has a sealed filter chamber, inside which a solid-liquid separation medium is provided; the solid-liquid separation medium is used to separate the reaction products into solid and liquid components. The built-in stirring module includes a drive motor and a stirring paddle extending into the filter chamber. The drive motor is configured to drive the stirring paddle to rotate during solid-liquid separation or washing processes to dynamically agitate the material within the filter chamber.

10. The apparatus for synthesizing lithium sulfide for solid-state batteries according to claim 1, characterized in that, Also includes: A heat exchanger is connected in series in the connecting pipeline between the reaction unit and the separation and purification unit. The heat exchanger is configured to reduce the temperature of the reaction product from the reaction temperature to a preset crystallization temperature or filtration temperature. A drying module is integrated into the separation and purification unit or disposed at the material outlet end of the separation and purification unit; the drying module is configured to dry the material after it has been washed by the separation and purification unit.

11. The apparatus for synthesizing lithium sulfide for solid-state batteries according to claim 10, characterized in that, The heat exchanger includes at least one of a plate heat exchanger, a shell-and-tube heat exchanger, or a jacketed cooler. The heat exchanger also includes a cooling medium flow control valve and an outlet temperature sensor. The outlet temperature sensor is used to monitor the real-time temperature of the cooled reaction products. The cooling medium flow control valve adjusts the flow rate of the cooling medium according to the real-time temperature to maintain a preset crystallization temperature or filtration temperature between 20°C and 80°C.

12. The apparatus for synthesizing lithium sulfide for solid-state batteries according to any one of claims 1 to 11, characterized in that, Also includes: A solvent recovery unit is connected to the separation and purification unit and is used to recover the solvent filtered by the separation and purification unit.

13. The apparatus for synthesizing lithium sulfide for solid-state batteries according to any one of claims 1 to 11, characterized in that, Also includes: The exhaust gas treatment unit is connected to the gas phase outlet of the separation and purification unit and is used to treat the reaction exhaust gas.

14. The apparatus for synthesizing lithium sulfide for solid-state batteries according to any one of claims 1 to 11, characterized in that, Also includes: An inert atmosphere protection unit, comprising an inert gas source, a main gas supply pipeline, and multiple branch pipelines; One end of the main gas supply pipeline is connected to the inert gas source, and the other end is connected to the reaction unit, the solvent delivery unit, the lithium source delivery unit, the sulfur source delivery unit, and the separation and purification unit through multiple branch pipelines.

15. The apparatus for synthesizing lithium sulfide for solid-state batteries according to any one of claims 1 to 11, characterized in that, Also includes: The control system is connected to the solvent delivery unit, the lithium source delivery unit, the sulfur source delivery unit, and the reaction unit via signals. The control system is configured to calculate and output control commands in real time according to a preset reaction stoichiometry, so as to coordinately adjust the flow rates of the solvent delivery unit, the lithium source delivery unit and the sulfur source delivery unit, so that the flow rate ratio of each material entering the reaction unit is maintained within the target range, and the reaction unit is controlled to reach the temperature and pressure required for the reaction.

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