A system for producing lithium sulfide

Abstract

The utility model discloses a preparation system of lithium sulfide, include: hydrogen sulfide generating device for generating hydrogen sulfide gas, gas drying device for drying hydrogen sulfide gas that hydrogen sulfide generating device generates, reaction device, including the stirring reaction cavity of being equipped with lithium source and organic solvent, for hydrogen sulfide gas and lithium source reaction of gas drying device after drying lithium sulfide generation, condensing device for the tail gas condensation of reaction device exhaust, tail gas absorption device for absorbing the tail gas of condensing treatment through the condensing device and generating sulfur source. The utility model not only can effectively improve the utilization rate of sulfur element, prevent sulfur in the form of hydrogen sulfide or sodium sulfide becomes gas or solid waste and influences the environment, and can effectively improve the contact efficiency of hydrogen sulfide and anhydrous lithium hydroxide, reduce the proportion of water vapor in the system, improve lithium sulfide product conversion efficiency, reaction efficiency is high, and the product quality is good.

Description

Technical Field

[0001] This utility model belongs to the field of battery materials, and in particular relates to an apparatus for preparing lithium sulfide. Background Technology

[0002] Lithium-ion batteries are currently widely used in digital products, electric vehicles, and energy storage power stations. However, the safety concerns associated with liquid electrolytes and their approaching theoretical energy limits necessitate the search for new solutions for next-generation power batteries. All-solid-state batteries using non-flammable solid electrolytes can effectively address these issues. Lithium sulfide (Li2S) is an important inorganic lithium salt, attracting considerable attention from researchers as a precursor for high-performance lithium-sulfur batteries' cathode materials and a core raw material for sulfide solid electrolytes.

[0003] The solid-state synthesis of hydrogen sulfide was once considered a promising method due to its relatively low reaction temperature and high conversion rate. However, the traditional solid-state synthesis of hydrogen sulfide has the following drawbacks: 1. Low utilization rate of hydrogen sulfide gas, with unreacted gas being directly emitted, resulting in resource waste and environmental pollution; 2. Insufficient contact between hydrogen sulfide and the solid lithium source due to solid-phase accumulation, which easily affects the reaction process; 3. Water vapor generated during the reaction also affects the reaction process and the purity of the product.

[0004] Therefore, it is of great significance to develop a lithium sulfide preparation system that has high hydrogen sulfide gas utilization, high reaction efficiency, and is environmentally friendly. Utility Model Content

[0005] The technical problem to be solved by this utility model is to overcome the deficiencies and defects mentioned in the background art above and provide a lithium sulfide preparation system to solve the problems of insufficient utilization of hydrogen sulfide, low reaction efficiency and low product quality in the preparation of lithium sulfide by gas-solid synthesis.

[0006] To solve the above-mentioned technical problems, the technical solution proposed by this utility model is as follows: A lithium sulfide preparation system, comprising: A hydrogen sulfide generating device used to generate hydrogen sulfide gas; A gas drying device is used to dry the hydrogen sulfide gas generated by the hydrogen sulfide generating device; the hydrogen sulfide generating device and the gas drying device are connected by a first pipeline; The reaction apparatus includes a stirred reaction chamber containing a lithium source and an organic solvent, for reacting hydrogen sulfide gas dried by the gas drying device with the lithium source to generate lithium sulfide; the gas drying device and the reaction apparatus are connected by a second pipeline; A condensing device is used to condense the exhaust gas discharged from the reaction device; the reaction device and the condensing device are connected by a third pipeline. The exhaust gas absorption device is used to absorb the exhaust gas that has been condensed by the condensation device and generate a sulfur source. The condensation device and the exhaust gas absorption device are connected by a fourth pipeline. The sulfur source generated by the exhaust gas absorption device is returned to the hydrogen sulfide generating device through a fifth pipeline.

[0007] In the above preparation system, preferably, the hydrogen sulfide generating device is connected to a sulfuric acid pipeline, and the hydrogen sulfide generating device is equipped with a stirring component.

[0008] In the above preparation system, preferably, a first moisture detector is provided on the second pipeline, and a sixth pipeline is provided downstream of the first moisture detector for returning incompletely dried hydrogen sulfide gas to the gas drying device.

[0009] In the above preparation system, preferably, the outer wall of the stirring reaction chamber is provided with a heating component, the bottom of the stirring reaction chamber is provided with a discharge port, and a detachable filter membrane is provided at the discharge port.

[0010] In the above preparation system, preferably, the third pipeline is equipped with a second moisture detector for monitoring the reaction endpoint.

[0011] In the above preparation system, preferably, the tail gas absorption device is an alkaline absorption tower.

[0012] In the above preparation system, preferably, the bottom of the alkaline absorption tower is provided with an absorbent circulation pump, and the outlet of the absorbent circulation pump is provided with a first branch and a second branch. The first branch is connected to the absorbent inlet at the upper end of the alkaline absorption tower, and the second branch is connected to the fifth pipeline. The outlet of the absorbent circulation pump is also provided with a concentration monitoring component for monitoring the concentration of sulfur source in the absorbent.

[0013] In the above preparation system, preferably, the top of the alkaline absorption tower is provided with a tail gas discharge pipe, and an induced draft fan is provided on the tail gas discharge pipe.

[0014] Compared with the prior art, the beneficial effects of this utility model are as follows: This invention discloses a lithium sulfide preparation system, comprising a hydrogen sulfide gas generating device, a gas drying device, a reaction device, a condensation device, and a tail gas absorption device. The hydrogen sulfide gas generated by the hydrogen sulfide gas generating device, after passing through the gas drying device, enters the reaction device to react with a "liquid phase" lithium source. Unreacted hydrogen sulfide is condensed by the condensation device and then enters the tail gas absorption device to absorb unreacted hydrogen sulfide, obtaining a sulfur source, which is then returned to the hydrogen sulfide gas generating device for reuse. During this process, anhydrous lithium hydroxide is effectively dispersed by organic solvents and stirring conditions, ensuring sufficient contact between the anhydrous lithium hydroxide and hydrogen sulfide gas, thus advancing the reaction. The reaction raw materials and products are primarily in the organic solvent, minimizing the impact of moisture on the reaction process and products. Furthermore, the generated moisture can be volatilized and collected by the condensation device, promoting forward reaction and increasing the reaction conversion rate. The unreacted hydrogen sulfide is absorbed by the tail gas absorption device to obtain a sulfur source, which is then returned to the hydrogen sulfide gas generating device for reuse. This effectively improves the utilization rate of sulfur and prevents sulfur from becoming gaseous or solid waste in the form of hydrogen sulfide or sodium sulfide, thus protecting the environment. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 This is a schematic diagram of the lithium sulfide preparation system in the example.

[0017] Legend 1. Hydrogen sulfide generating device; 2. Gas drying device; 3. Reaction device; 31. Stirred reaction chamber; 32. Heating component; 33. Discharge port; 4. Condensation device; 5. Tail gas absorption device; 6. Absorbent liquid circulation pump; 7. Exhaust fan; 101. First pipeline; 102. Second pipeline; 103. Third pipeline; 104. Fourth pipeline; 105. Fifth pipeline; 106. Sixth pipeline; 107. First branch; 108. Second branch; 109. Tail gas discharge pipeline; 110. Sulfuric acid pipeline; 201. First moisture detector; 202. Second moisture detector. Detailed Implementation

[0018] To facilitate understanding of this utility model, it will be described more comprehensively and in detail below with reference to the accompanying drawings and preferred embodiments. However, the scope of protection of this utility model is not limited to the following specific embodiments.

[0019] It should be noted that when a component is described as being "fixed to, attached to, connected to or connected to" another component, it can be directly fixed to, attached to, connected to or connected to the other component, or it can be indirectly fixed to, attached to, connected to or connected to the other component through other intermediate connectors.

[0020] Unless otherwise defined, all technical terms used herein have the same meaning as commonly understood by those skilled in the art. The technical terms used herein are for the purpose of describing particular embodiments only and are not intended to limit the scope of protection of this invention.

[0021] Unless otherwise specified, all raw materials, reagents, instruments and equipment used in this invention can be purchased from the market or prepared by existing methods.

[0022] Example: like Figure 1 As shown, the lithium sulfide preparation system of this embodiment includes: Hydrogen sulfide generating device 1, used to generate hydrogen sulfide gas; Gas drying device 2 is used to dry hydrogen sulfide gas generated by hydrogen sulfide generating device 1; hydrogen sulfide generating device 1 and gas drying device 2 are connected through first pipeline 101; The reaction apparatus 3 includes a stirred reaction chamber 31 containing a lithium source and an organic solvent, used for reacting hydrogen sulfide gas dried by the gas drying device 2 with the lithium source to generate lithium sulfide; the gas drying device 2 and the reaction apparatus 3 are connected by a second pipeline 102. Condensation device 4 is used to condense the exhaust gas discharged from reaction device 3; reaction device 3 and condensation device 4 are connected by a third pipeline 103; the exhaust gas after the reaction in reaction device 3 contains water (and may also contain a very small amount of organic solvent), which is collected after condensation. The exhaust gas absorption device 5 is used to absorb the exhaust gas that has been condensed by the condenser 4 and generate a sulfur source. The condenser 4 and the exhaust gas absorption device 5 are connected through the fourth pipeline 104. The sulfur source generated by the exhaust gas absorption device 5 is returned to the hydrogen sulfide generating device 1 through the fifth pipeline 105.

[0023] In this embodiment, the hydrogen sulfide generating device 1 is connected to a sulfuric acid pipeline 110, and a stirring assembly is provided inside the hydrogen sulfide generating device 1. The hydrogen sulfide generating device 1 may include a glass reactor, to which the sulfuric acid pipeline 110, the stirring assembly, the fifth pipeline 105, and the gas outlet pipe are connected. The glass reactor is the main site for the reaction of dilute sulfuric acid with sodium sulfide solution to generate hydrogen sulfide gas. The sulfuric acid pipeline 110 can adjust the flow rate of dilute sulfuric acid according to experimental requirements to control the hydrogen sulfide generation rate. A valve or flow meter may be installed in the pipeline. The gas outlet pipe introduces the hydrogen sulfide gas into the first pipeline 101.

[0024] In this embodiment, a first moisture detector 201 is installed on the second pipeline 102, and a sixth pipeline 106 is installed downstream of the first moisture detector 201 to return incompletely dried hydrogen sulfide gas to the gas drying device 2. Due to the high sensitivity of lithium sulfide products to water, the moisture content of the entire reaction system needs to be strictly monitored. The generated hydrogen sulfide gas must be dried by the gas drying device 2 and the first moisture detector 201 must determine that the water content is below a certain value before it can enter the reaction system. The first moisture detector 201 is used to detect the degree of dryness of the hydrogen sulfide gas after drying by the gas drying device 2. If it is qualified, it is transported for use. If the drying is not qualified, the hydrogen sulfide gas is returned to the first pipeline 101 through the sixth pipeline 106 and dried again by the gas drying device 2 to ensure that the water content of the hydrogen sulfide gas transported to the reaction device 3 is qualified.

[0025] In this embodiment, a heating assembly 32 is provided on the outer wall of the stirred reaction chamber 31, and a discharge port 33 is provided at the bottom of the stirred reaction chamber 31. A removable filter membrane is provided at the discharge port 33. The reaction device 3 includes a stirred reaction chamber 31, a heating assembly 32, and a discharge port 33. A certain amount of anhydrous lithium hydroxide is added to the stirred reaction chamber 31, along with a specific organic solvent. The anhydrous lithium hydroxide is uniformly dispersed in the organic solvent by the stirring assembly. Dry hydrogen sulfide gas is added through the second pipeline 102 to react with the anhydrous lithium hydroxide. The heating assembly 32 increases the temperature of the reaction system, accelerates the reaction rate, and discharges the reaction product water in the form of steam, promoting the forward reaction. A filter membrane is placed at the discharge port 33. During discharge, lithium sulfide is first filtered and remains in the reaction chamber, while the organic solvent is received in a storage tank and recycled. The organic solvent should be a substance with a boiling point significantly higher than that of water and immiscible with water (such as n-decane).

[0026] In this embodiment, a second moisture detector 202 for monitoring the reaction endpoint is installed on the third pipeline 103. When anhydrous lithium hydroxide is completely converted into lithium sulfide, the tail gas will no longer contain water. The second moisture detector 202 is used to detect the reaction tail gas. When the water content is zero, it is determined that the reaction is complete. The hydrogen sulfide generating device 1 can be stopped, and the hydrogen sulfide in the system can be led to the alkali absorption tower by the induced draft fan 7 for complete treatment, thus avoiding hydrogen sulfide leakage during discharge.

[0027] In this embodiment, the tail gas absorption device 5 is an alkaline absorption tower. To ensure that the hydrogen sulfide-containing tail gas does not affect the environment, the tail gas is absorbed by the alkaline solution in the alkaline absorption tower, and the following reaction occurs: 2NaOH + H2S = Na2S + 2H2O. After passing through the alkaline absorption tower, the tail gas is completely absorbed.

[0028] In this embodiment, an absorbent circulation pump 6 is installed at the bottom of the alkaline absorption tower. The outlet of the absorbent circulation pump 6 has a first branch 107 and a second branch 108. The first branch 107 is connected to the absorbent inlet at the top of the alkaline absorption tower, and the second branch 108 is connected to the fifth pipeline 105. The outlet of the absorbent circulation pump 6 is also equipped with a concentration monitoring component for monitoring the sulfur source concentration in the absorbent. The reaction product Na2S is the raw material for generating hydrogen sulfide. When the Na2S concentration reaches a certain level, the Na2S solution is transported to the hydrogen sulfide generating device 1 via the absorbent circulation pump 6 to generate hydrogen sulfide gas. This device allows for 100% utilization of sulfur. However, to ensure the concentration of sodium sulfide delivered to the hydrogen sulfide generating device 1, the absorbent liquid needs to be reused to increase its concentration. This can be achieved by real-time monitoring of the sodium sulfide concentration in the absorbent liquid using a concentration monitoring component. If the concentration is too low, it is recycled through the first branch 107. If the concentration is within acceptable limits, it can be returned to the hydrogen sulfide generating device 1 through the second branch 108, or concentrated and then returned to the device. This process requires ensuring the absorption rate of the absorbent liquid for hydrogen sulfide gas.

[0029] In this embodiment, the top of the alkaline absorption tower is equipped with a tail gas discharge pipe 109, and an induced draft fan 7 is installed on the tail gas discharge pipe 109. The induced draft fan 7 can drive the gas flow in the entire system and discharge the generated water vapor in a timely manner.

[0030] In this embodiment, when the second moisture detector 202 detects zero moisture content, the reaction is stopped, the gas in the system is replaced, and the outlet 33 is opened. After passing through a filter membrane, the organic solvent is received by the storage tank for use in the next experiment, while the lithium sulfide product remains in the stirring reaction chamber 31. After filtration, the lithium sulfide product will carry a small amount of organic solvent. After evaporating the solvent in a vacuum oven, high-purity lithium sulfide product can be obtained.

[0031] In this embodiment, gas flow meters, valves, pressure transmitters, etc., can be installed on each pipeline to control the reaction process. Two absorbent circulation pumps 6 can also be installed to prevent malfunctions from affecting the reaction process. Components such as level gauges and overflow pipes can also be installed to ensure the normal operation of the reaction. For details, please refer to [link to relevant documentation]. Figure 1 .

[0032] In this embodiment, the lithium sulfide preparation system generates hydrogen sulfide by adding dilute sulfuric acid dropwise to a hydrogen sulfide generator 1 and reacting it with sodium sulfide. A hydrogen sulfide gas detection device can be installed near the hydrogen sulfide generator 1. If any leakage is detected, the addition of dilute sulfuric acid will be stopped immediately, effectively reducing the danger of using hydrogen sulfide. After drying, the hydrogen sulfide gas reacts with anhydrous lithium hydroxide in a stirred reaction chamber 31 through a bottom inlet pipe. The anhydrous lithium hydroxide is effectively dispersed by the organic solvent and the stirring assembly, ensuring sufficient contact between the anhydrous lithium hydroxide and the hydrogen sulfide gas. The heating assembly 32 provides heat to accelerate the reaction rate and evaporates the water produced in the reaction. The water is then discharged from the reaction system through a condenser 4, promoting the forward movement of the reaction and improving the reaction conversion rate. A second moisture detector 202 measures the moisture content in the exhaust gas to determine the intensity of the reaction. When the reading is zero, it indicates that the reaction is complete, significantly reducing the loss of hydrogen sulfide. The alkaline solution in the alkaline absorption tower can effectively absorb unreacted hydrogen sulfide gas, reducing its environmental harm. Meanwhile, the alkali solution absorbs hydrogen sulfide and becomes sodium sulfide solution. When the sodium sulfide reaches a certain concentration, it can be returned to the hydrogen sulfide generating device 1 through the fifth pipeline 105 as a raw material for generating hydrogen sulfide, thus achieving 100% utilization of sulfur.

[0033] In summary, this embodiment can not only effectively improve the utilization rate of sulfur and prevent sulfur from becoming gaseous or solid waste in the form of hydrogen sulfide or sodium sulfide, thus affecting the environment, but also effectively improve the contact efficiency between hydrogen sulfide and anhydrous lithium hydroxide, reduce the proportion of water vapor in the system, improve the conversion efficiency of lithium sulfide products, and achieve high reaction efficiency and good product quality.

Claims

1. A lithium sulfide preparation system, characterized in that, include: Hydrogen sulfide generating device (1), used to generate hydrogen sulfide gas; A gas drying device (2) is used to dry the hydrogen sulfide gas generated by the hydrogen sulfide generating device (1); the hydrogen sulfide generating device (1) and the gas drying device (2) are connected by a first pipeline (101); The reaction apparatus (3) includes a stirred reaction chamber (31) containing a lithium source and an organic solvent, for reacting hydrogen sulfide gas dried by the gas drying device (2) with the lithium source to generate lithium sulfide; the gas drying device (2) and the reaction apparatus (3) are connected by a second pipeline (102); A condenser (4) is used to condense the exhaust gas discharged from the reaction device (3); the reaction device (3) and the condenser (4) are connected by a third pipeline (103); The tail gas absorption device (5) is used to absorb the tail gas that has been condensed by the condenser (4) and generate a sulfur source. The condenser (4) and the tail gas absorption device (5) are connected through a fourth pipeline (104). The sulfur source generated by the tail gas absorption device (5) is returned to the hydrogen sulfide generating device (1) through a fifth pipeline (105).

2. The preparation system according to claim 1, characterized in that, The hydrogen sulfide generating device (1) is connected to a sulfuric acid pipeline (110), and the hydrogen sulfide generating device (1) is equipped with a stirring assembly.

3. The preparation system according to claim 1, characterized in that, The second pipeline (102) is equipped with a first moisture detector (201), and downstream of the first moisture detector (201) is a sixth pipeline (106) for returning incompletely dried hydrogen sulfide gas to the gas drying device (2).

4. The preparation system according to claim 1, characterized in that, The outer wall of the stirring reaction chamber (31) is provided with a heating component (32), and the bottom of the stirring reaction chamber (31) is provided with a discharge port (33), and a detachable filter membrane is provided at the discharge port (33).

5. The preparation system according to claim 1, characterized in that, The third pipeline (103) is equipped with a second moisture detector (202) for monitoring the reaction endpoint.

6. The preparation system according to claim 1, characterized in that, The tail gas absorption device (5) is an alkaline absorption tower.

7. The preparation system according to claim 6, characterized in that, The bottom of the alkali absorption tower is equipped with an absorbent circulation pump (6). The outlet of the absorbent circulation pump (6) is provided with a first branch (107) and a second branch (108). The first branch (107) is connected to the absorbent inlet at the top of the alkali absorption tower, and the second branch (108) is connected to the fifth pipeline (105). The outlet of the absorbent circulation pump (6) is also equipped with a concentration monitoring component for monitoring the concentration of sulfur source in the absorbent.

8. The preparation system according to claim 6, characterized in that, The top of the alkaline absorption tower is provided with a tail gas discharge pipe (109), and an induced draft fan (7) is provided on the tail gas discharge pipe (109).

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