Lithium battery organic electrolyte recovery and extraction device

Abstract

The utility model discloses a lithium battery organic electrolyte recycling and extracting device and relates to the technical field of waste lithium battery recycling. The utility model aims to solve the problems that an existing waste lithium battery electrolyte recovery device is complex in recovery step and high in recovery cost, and hydrogen fluoride, especially fluorinated acid, released in the recovery process is harmful to the environment and human bodies. The utility model relates to a lithium battery organic electrolyte recovery and extraction device, which is favorable for reducing the complexity of electrolyte recovery of waste lithium batteries and paves a way for comprehensive recovery and subsequent treatment of the waste lithium batteries. The device not only can effectively recover the electrolyte, but also is small in occupied area, does not cause environmental pollution and personnel poisoning, and is easy for large-scale production. The device is suitable for recycling and extracting the organic electrolyte of the lithium battery.

Description

Technical Field

[0001] The utility model relates to the technical field of waste lithium battery recycling, in particular to a lithium battery organic electrolyte recycling and extraction device. Background Art

[0002] Lithium-ion batteries (LIBs) are widely used as electrochemical power sources in modern appliances, including consumer electronics and electric vehicles. At the end of their useful life, LIBs may be sent to recycling centers for use in energy storage batteries. It is well known that spent LIBs still contain valuable chemicals; in addition to the cathode active material, they also include copper foil, aluminum foil, and electrolyte. Besides the expensive cathode material, the electrolyte is also the most valuable component of spent LIBs. Currently, there are many recycling programs for the positive and negative electrode materials, as well as valuable metals, of spent LIBs. However, recycling of spent electrolytes is less common. This is because most electrolytes in these solutions are toxic and easily hydrolyze, leading to water pollution and significant recycling challenges. Currently, the electrolyte left after disassembly of spent LIBs is a mixture containing common conductive salts as well as some aprotic solvents. The most commonly used conductive salt is LiPF6, which readily hydrolyzes and produces toxic hydrogen fluoride gas when exposed to water or humid air. When hydrogen fluoride gas comes into contact with moist air, it immediately converts into fluorinated acid, which is highly corrosive to battery recycling facilities and toxic to recycling operators. Commonly used solvents are propylene carbonate, ethyl carbonate, diethyl carbonate, and dimethyl carbonate. Therefore, when recycling other materials from used lithium batteries, these electrolytes must be safely separated or removed to prevent accidents.

[0003] Several electrolyte separation and extraction techniques have been applied to the recycling of spent lithium batteries. For example, reduced pressure evaporation is used to recover the solvent, ultimately yielding pure electrolyte. However, this process is limited by the fact that the boiling point of the solvent under reduced pressure must be below the decomposition temperature of the lithium salt (800°C). Similarly, other researchers have developed suitable solvents for extracting organic electrolyte solvents, such as 1,2-dimethoxyethane, dimethyl carbonate, ethyl acetate, and acetone. Meanwhile, a pyrolysis process using a vacuum pyrolysis system has been used to separate the electrolyte from spent lithium batteries: a temperature of 600°C, a vacuum evaporation time of 30 minutes, and a residual gas pressure of 1.0 kPa. This method has the advantage of allowing the enrichment and recovery of most fluorinated compounds, preventing environmental pollution and resource waste. These extraction methods using organic solvents introduce solvent impurities, which not only complicates the process but also introduces new contaminants during the separation process. During vacuum pyrolysis, the electrolyte may be completely decomposed during the process, or the decomposition products may be too complex to be reused. Utility Model Content

[0004] The purpose of the utility model is to provide a lithium battery organic electrolyte recovery and extraction device to solve the problems of complex recovery steps, high recovery costs, and the release of hydrogen fluoride, especially fluorinated acid, which is harmful to the environment and human body during the recovery process of existing waste lithium battery electrolyte recovery devices.

[0005] A lithium battery organic electrolyte recovery and extraction device, comprising a carbon dioxide cylinder 1, a cooling cylinder 2, a gas booster pump 3, an air compression pump 4, an air conditioner 5, an extraction container 8, a heating device a9, a throttle valve 13, a heating device b15, a collection device 16 and a filter 17;

[0006] The air outlet of the air compression pump 4 is connected to the feed port of the extraction container 8 through a pipeline, and an air conditioner 5 is provided on the pipeline; the air outlet of the carbon dioxide cylinder 1 is connected to the air inlet of the cooling cylinder 2 through a pipeline, and the air outlet of the cooling cylinder 2 is connected to the feed port of the extraction container 8 through a pipeline, and a gas booster pump 3 is provided on the pipeline. The outer surface of the extraction container 8 is provided with a heating device a9;

[0007] The discharge port of the extraction container 8 is connected to the feed port of the throttle valve 13 through a pipeline, and a heating device b15 is provided on the outer surface of the throttle valve 13; the discharge port of the throttle valve 13 is connected to the feed port of the collecting device 16 through a pipeline, and the discharge port of the collecting device 16 is connected to the feed port of the filter 17 through a pipeline.

[0008] Beneficial effects of the utility model:

[0009] (1) The utility model provides a lithium battery organic electrolyte recovery and extraction device, which helps reduce the complexity of electrolyte recovery from waste lithium batteries and paves the way for comprehensive recovery and subsequent treatment of waste lithium batteries. The utility model not only effectively recovers electrolytes, but also occupies a small area, does not cause environmental pollution and human poisoning, and is easy to scale up.

[0010] (2) The use of the lithium battery organic electrolyte recovery and extraction device of the utility model can reduce costs and increase efficiency for recycling companies, improve the overall recovery efficiency of waste lithium batteries, and reduce the cost of electrolyte treatment.

[0011] The utility model can obtain a lithium battery organic electrolyte recovery and extraction device. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1A schematic structural diagram of a lithium battery organic electrolyte recovery and extraction device according to the present invention is shown, wherein 1 represents a carbon dioxide cylinder, 2 represents a cooling cylinder, 3 represents a gas booster pump, 4 represents an air compression pump, 5 represents an air conditioner, 6 represents a carbon dioxide pressure gauge, 7 represents an inlet valve, 8 represents an extraction container, 9 represents a heating jacket, 10 represents a container thermometer, 11 represents an exhaust valve, 12 represents an outlet valve, 13 represents a throttle valve, 14 represents a throttle valve thermometer, 15 represents a heating cylinder, 16 represents a collecting bottle, 17 represents an alumina filter, and 18 represents a gas low pressure gauge. DETAILED DESCRIPTION

[0013] Specific embodiment 1: This embodiment is a lithium battery organic electrolyte recovery and extraction device, including a carbon dioxide cylinder 1, a cooling cylinder 2, a gas booster pump 3, an air compression pump 4, an air conditioner 5, an extraction container 8, a heating device a9, a throttle valve 13, a heating device b15, a collection device 16 and a filter 17;

[0014] The air outlet of the air compression pump 4 is connected to the feed port of the extraction container 8 through a pipeline, and an air conditioner 5 is provided on the pipeline; the air outlet of the carbon dioxide cylinder 1 is connected to the air inlet of the cooling cylinder 2 through a pipeline, and the air outlet of the cooling cylinder 2 is connected to the feed port of the extraction container 8 through a pipeline, and a gas booster pump 3 is provided on the pipeline. The outer surface of the extraction container 8 is provided with a heating device a9;

[0015] The discharge port of the extraction container 8 is connected to the feed port of the throttle valve 13 through a pipeline, and a heating device b15 is provided on the outer surface of the throttle valve 13; the discharge port of the throttle valve 13 is connected to the feed port of the collecting device 16 through a pipeline, and the discharge port of the collecting device 16 is connected to the feed port of the filter 17 through a pipeline.

[0016] Specific embodiment 2: The difference between this embodiment and specific embodiment 1 is that an inlet valve 7 is provided on the pipeline between the air compression pump 4 and the air outlet of the cooling cylinder 2 and the feed port of the extraction container 8.

[0017] Other components and connection methods are the same as those in the first embodiment.

[0018] Specific embodiment three: The difference between this embodiment and specific embodiment one or two is that a carbon dioxide pressure gauge 6 is provided on the pipeline between the gas booster pump 3 and the inlet valve 7.

[0019] Other components and connection methods are the same as those in the first or second embodiment.

[0020] Specific embodiment 4: This embodiment differs from specific embodiments 1 to 3 in that: the heating device a9 is a heating jacket, and the extraction container 8 is provided with a container thermometer 10.

[0021] Other components and connection methods are the same as those in specific embodiments one to three.

[0022] Specific embodiment 5: The difference between this embodiment and specific embodiments 1 to 4 is that the discharge port of the extraction container 8 is also connected to the air inlet of the exhaust pipeline, and the pipeline is provided with an exhaust valve 11.

[0023] Other components and connection methods are the same as those in specific embodiments one to four.

[0024] Specific embodiment 6: The difference between this embodiment and specific embodiments 1 to 5 is that an outlet valve 12 is provided on the pipeline between the discharge port of the extraction container 8 and the feed port of the throttle valve 13.

[0025] Other components and connection methods are the same as those in specific embodiments one to five.

[0026] Specific embodiment seven: This embodiment differs from specific embodiments one to six in that a throttle valve thermometer 14 is provided on the throttle valve 13 .

[0027] Other components and connection methods are the same as those in specific embodiments one to six.

[0028] Specific embodiment eight: This embodiment differs from specific embodiments one to seven in that the heating device b15 is a heating cylinder.

[0029] Other components and connection methods are the same as those in specific embodiments one to seven.

[0030] Specific embodiment 9: This embodiment differs from specific embodiments 1 to 8 in that the collecting device 16 is a collecting bottle.

[0031] Other components and connection methods are the same as those in specific embodiments one to eight.

[0032] Specific embodiment 10: This embodiment differs from specific embodiments 1 to 9 in that the filter 17 is an alumina filter, and a gas low pressure gauge 18 is provided on the pipe of the outlet of the alumina filter.

[0033] Other components and connection methods are the same as those in specific embodiments one to nine.

[0034] The following examples are used to verify the beneficial effects of the present invention:

[0035] Example 1: A lithium battery organic electrolyte recovery and extraction device, comprising a carbon dioxide cylinder 1, a cooling cylinder 2, a gas booster pump 3, an air compression pump 4, an air conditioner 5, an extraction container 8, a heating jacket, a throttle valve 13, a heating cylinder, a collection bottle, and an alumina filter;

[0036] The air outlet of the air compression pump 4 is connected to the feed port of the extraction container 8 through a pipeline, and an air conditioner 5 is provided on the pipeline; the air outlet of the carbon dioxide cylinder 1 is connected to the air inlet of the cooling cylinder 2 through a pipeline, and the air outlet of the cooling cylinder 2 is connected to the feed port of the extraction container 8 through a pipeline, and a gas booster pump 3 is provided on the pipeline. The air compression pump 4 and the air outlet of the cooling cylinder 2 and the feed port of the extraction container 8 are all provided with an inlet valve 7. A carbon dioxide pressure gauge 6 is provided on the pipeline between the gas booster pump 3 and the inlet valve 7. The outer surface of the extraction container 8 is provided with a heating jacket, and the extraction container 8 is provided with a container thermometer 10;

[0037] The discharge port of the extraction container 8 is connected to the feed port of the throttle valve 13 through a pipeline, and an outlet valve 12 is provided on the pipeline. A heating cylinder is provided on the outer surface of the throttle valve 13, and a throttle valve thermometer 14 is provided on the throttle valve 13; the discharge port of the throttle valve 13 is connected to the feed port of the collection bottle through a pipeline, and the discharge port of the collection bottle is connected to the feed port of the alumina filter through a pipeline. A gas low pressure gauge 18 is provided on the pipeline of the discharge port of the alumina filter;

[0038] The discharge port of the extraction container 8 is also connected to the air inlet of the exhaust pipeline, and the exhaust valve 11 is provided on the pipeline.

[0039] The operating method of the above-mentioned lithium battery organic electrolyte recovery and extraction device is carried out according to the following steps:

[0040] Step S1: Open the air compression pump 4, the air regulator 5, the inlet valve 7 and the exhaust valve 11, and close the outlet valve 12 at the same time. The air compressor continuously compresses a certain amount of air to pump the collected electrolyte through the air compression pump 4 to the extraction container 8 extraction device until the electrolyte occupies two-thirds of the volume of the entire extraction container 8. Then, stop the air compression pump 4 from pumping the electrolyte.

[0041] Step S2: Subsequently, the air compression pump 4 and the air conditioner 5 are turned off, and the carbon dioxide cylinder 1, the cooling cylinder 2, and the gas booster pump (air-driven fluid pump) 3 are turned on. The carbon dioxide passes through the cooling cylinder 2 and is compressed to a supercritical state by the gas booster pump 3. The carbon dioxide is pumped into the extraction container 8 at a flow rate of 1 to 15 L / min. After all the impurity air in the extraction container 8 is discharged, the exhaust valve 11 is closed. At the same time, supercritical carbon dioxide is continuously introduced until the pressure in the carbon dioxide pressure gauge 6 is maintained between 15 and 35 MPa. The optimal processing pressure is 30 MPa, which is subject to the actual on-site process.

[0042] Step S3: When the pressure in the extraction container 8 reaches the processing pressure, the heating jacket on the outside of the extraction container 8 is turned on for continuous heating. The final temperature is maintained between 40 and 70°C. The optimal extraction temperature is 45.5°C. The overall extraction time is 3 to 5 hours, depending on the actual process on site.

[0043] The temperature is set at ≤70℃ because LiPF6 will undergo thermal degradation at higher temperatures, resulting in thermal degradation of the electrolyte, thereby reducing the electrolyte extraction yield; and it is higher than 40℃ because the boiling point of carbon dioxide is 31℃, in order to maintain the supercritical state of carbon dioxide.

[0044] Step S4: After the extraction is completed, the outlet valve 12 is opened, and the high-pressure gas containing the electrolyte LiPF6 leaves the top of the extraction container 8 and reaches the throttle valve 13 through the outlet valve 12 for throttling and pressure reduction. At the same time, the high-pressure air is heated to gasify the carbon dioxide in the supercritical state, and finally the electrolyte LiPF6 is precipitated in the collection bottle at a constant low rate of 10.0L / min; the carbon dioxide gas containing some toxic gases or electrolytes is absorbed by the alumina filter to prevent environmental pollution and personal poisoning.

[0045] After the waste lithium batteries in a factory are disassembled, the electrolytes are collected and transferred to a dedicated storage cell. They are then transported to an extraction container 8, where the electrolyte is recovered and extracted using the recovery process described in Example 1. The main electrolyte in the electrolyte is LiPF6, and the volume ratio of the solvents ethylene carbonate EC / dimethyl carbonate DMC / ethyl methyl carbonate EMC in the electrolyte is 1:1:1. The purity of the CO2 in the CO2 cylinder is above 99.95%.

[0046] Principle of this embodiment:

[0047] This embodiment provides a lithium battery organic electrolyte recovery and extraction device that utilizes the relationship between density and the solubility of supercritical fluid carbon dioxide to use supercritical carbon dioxide as a highly efficient extraction solvent to extract electrolytes from waste battery electrolytes. This device has a higher extraction rate than traditional organic solvent extraction methods and does not leave any toxic or harmful organic solvents. CO2 in a supercritical state not only has a moderate critical pressure and a low critical temperature, but also has a greater solubility for low-polar and non-polar substances. At the same time, CO2 is highly volatile and easy to separate from the extract, allowing it to be completely recycled and reused without discharging hazardous solvent waste.

Claims

1. A lithium battery organic electrolyte recovery and extraction device, characterized in that The lithium battery organic electrolyte recovery and extraction device comprises a carbon dioxide cylinder (1), a cooling cylinder (2), a gas booster pump (3), an air compression pump (4), an air conditioner (5), an extraction container (8), a heating device a (9), a throttle valve (13), a heating device b (15), a collecting device (16) and a filter (17); The air outlet of the air compression pump (4) is connected to the feed port of the extraction container (8) through a pipeline, and an air conditioner (5) is provided on the pipeline; the air outlet of the carbon dioxide cylinder (1) is connected to the air inlet of the cooling cylinder (2) through a pipeline, and the air outlet of the cooling cylinder (2) is connected to the feed port of the extraction container (8) through a pipeline, and a gas booster pump (3) is provided on the pipeline, and a heating device a (9) is provided on the outer surface of the extraction container (8); The discharge port of the extraction container (8) is connected to the feed port of the throttle valve (13) through a pipeline, and a heating device b (15) is provided on the outer surface of the throttle valve (13); the discharge port of the throttle valve (13) is connected to the feed port of the collecting device (16) through a pipeline, and the discharge port of the collecting device (16) is connected to the feed port of the filter (17) through a pipeline.

2. A lithium battery organic electrolyte recovery and extraction device according to claim 1, characterized in that Inlet valves (7) are provided on the pipelines between the air compression pump (4), the air outlet of the cooling cylinder (2) and the feed port of the extraction container (8).

3. A lithium battery organic electrolyte recovery and extraction device according to claim 1, characterized in that A carbon dioxide pressure gauge (6) is provided on the pipeline between the gas booster pump (3) and the inlet valve (7).

4. A lithium battery organic electrolyte recovery and extraction device according to claim 1, characterized in that The heating device a (9) is a heating jacket, and the extraction container (8) is provided with a container thermometer (10).

5. The lithium battery organic electrolyte recovery and extraction device according to claim 1, characterized in that The discharge port of the extraction container (8) is also connected to the air inlet of the exhaust pipeline, and the pipeline is provided with an exhaust valve (11).

6. The lithium battery organic electrolyte recovery and extraction device according to claim 1, characterized in that An outlet valve (12) is provided on the pipeline of the feed port between the discharge port of the extraction container (8) and the throttle valve (13).

7. The lithium battery organic electrolyte recovery and extraction device according to claim 1, characterized in that The throttle valve (13) is provided with a throttle valve thermometer (14).

8. The lithium battery organic electrolyte recovery and extraction device according to claim 1, characterized in that The heating device b (15) is a heating cylinder.

9. The lithium battery organic electrolyte recovery and extraction device according to claim 1, characterized in that The collecting device (16) is a collecting bottle.

10. The lithium battery organic electrolyte recovery and extraction device according to claim 1, characterized in that The filter (17) is an alumina filter, and a gas low pressure gauge (18) is provided on the pipeline of the discharge port of the alumina filter.

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