Lithium battery cleaning system
By using supercritical carbon dioxide to dissolve and separate the electrolyte on the surface of lithium batteries, the problem of electrolyte contaminant generation in existing technologies is solved, achieving low-pollution and high-efficiency battery cleaning and electrolyte recycling.
Patent Information
- Application Number
- CN202520444252.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-03-14
- Publication Date
- 2026-02-24
- Estimated Expiration
- 2035-03-14
AI Technical Summary
In existing lithium battery cleaning processes, laser cleaning, pure water cleaning, and non-woven fabric wiping generate waste gas, wastewater, and waste containing electrolyte. It is necessary to solve how to reduce the generation of electrolyte contaminants while ensuring the cleaning effect.
Supercritical carbon dioxide is used to dissolve the electrolyte on the battery surface, and the critical conditions are broken by a cooling cabinet to separate the electrolyte from the carbon dioxide, thereby cleaning the battery and recovering the electrolyte to reduce waste disposal costs.
It achieves low-pollution battery cleaning, reduces the generation of electrolyte waste, lowers processing costs, and recycles carbon dioxide.
Smart Images
Figure CN223932110U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to lithium battery production and is mainly used in the battery cleaning process after the liquid injection process, specifically a lithium battery cleaning system. Background Technology
[0002] In the lithium battery production process, the electrolyte injection step results in a small amount of electrolyte residue remaining on the battery surface. Typically, a battery cleaning step follows the electrolyte injection process. Conventional battery cleaning methods include laser cleaning, pure water cleaning, and non-woven fabric wiping. Laser cleaning generates waste gas containing electrolyte, pure water cleaning generates wastewater containing electrolyte, and non-woven fabric wiping generates waste containing electrolyte. All three methods require special treatment of the resulting waste. The problem this invention aims to solve is how to reduce the generation of electrolyte contaminants while ensuring effective battery cleaning. Utility Model Content
[0003] This invention proposes a cleaning system that utilizes the unique solubility of supercritical carbon dioxide to dissolve the electrolyte on the battery surface in the supercritical carbon dioxide fluid, which then carries it out. The electrolyte is then separated from the carbon dioxide by disrupting the critical conditions, thus achieving the purpose of battery cleaning. Simultaneously, disrupting the critical conditions at low temperatures also facilitates electrolyte recovery, reducing the cost of electrolyte waste disposal.
[0004] The present invention provides a solution using the following technical solution:
[0005] In a first aspect, this utility model provides a lithium battery cleaning system, comprising:
[0006] Gas compressor, used to connect to a carbon dioxide gas source;
[0007] A cleaning cabinet is used to hold lithium batteries to be cleaned. The fluid inlet of the cleaning cabinet is connected to the outlet of the gas compressor through a first flow channel. A fan and a heater are sequentially arranged on the first flow channel along the flow direction. The carbon dioxide output by the gas compressor can flow into the cleaning cabinet in a supercritical state after passing through the first flow channel.
[0008] The cooling cabinet has a fluid inlet at the bottom connected to the fluid outlet of the cleaning cabinet, and a cooling mechanism inside the cooling cabinet for disrupting the supercritical state of carbon dioxide. The top of the cooling cabinet has a gas outlet for discharging gaseous carbon dioxide, which is connected to the first flow channel upstream of the fan. The bottom of the cooling cabinet also has a liquid outlet for discharging electrolyte.
[0009] This invention uses supercritical carbon dioxide to clean batteries. The supercritical carbon dioxide carries the electrolyte out and separates it within the cooling cabinet, thus recovering the electrolyte. A fan maintains gas flow within the system to continuously flush the lithium batteries with supercritical carbon dioxide, and a heater heats the airflow to convert the carbon dioxide from a gaseous state to a supercritical state. After cooling in the cooling cabinet, the gaseous carbon dioxide flows out through the gas outlet at the top of the cooling cabinet and returns to the first flow channel for recycling.
[0010] Optionally, the heater is an electric heater, a steam heater, or a heat medium heater.
[0011] The heater of this invention can be specifically selected by electric heating, steam heating or heat medium heating to ensure that the temperature of the oxide is greater than or equal to the critical temperature of 31.26℃.
[0012] Optionally, a gas supply valve is provided at the outlet of the gas compressor.
[0013] The gas replenishment valve of this invention is used to disconnect the gas flow between the cleaning cabinet and the gas compressor. When the pressure in the cleaning system exceeds the critical pressure, shutting off the gas compressor and the gas replenishment valve can reduce the compressor's energy consumption and prevent gas backflow.
[0014] Optionally, the cleaning cabinet is provided with a first sealing valve and a second sealing valve at the fluid inlet and fluid outlet, respectively.
[0015] The first and second sealing valves of this invention are used to shut off the fluid inlet of the cleaning cabinet when batteries are being removed or placed inside the cleaning cabinet, and to maintain the pressure of the rest of the system to reduce the amount of carbon dioxide used.
[0016] Optionally, the cleaning cabinet is also equipped with a pressure relief valve.
[0017] The pressure relief valve of this invention is used to release the pressure inside the cleaning cabinet when the battery is removed after cleaning, and can also be used for emergency pressure relief in case of system failure and overpressure.
[0018] Optionally, the cooling mechanism includes a chilled water coil.
[0019] This invention uses a cold water coil to cool the fluid in order to break the critical state.
[0020] Optionally, the cold water coil is installed at an angle, and the relative angle between the cold water coil and the horizontal plane of the cooling cabinet is greater than or equal to 45° and less than or equal to 90°.
[0021] This invention, through the design of the cold water coil, allows the separated electrolyte to drip down the surface of the cold water coil to the bottom of the cooling cabinet; the cold water inside the cold water coil flows from top to bottom, and the fluid can fully contact the cold water coil to ensure the cooling effect.
[0022] Optionally, the bottom of the cooling cabinet is also equipped with an electrolyte discharge valve.
[0023] The electrolyte discharge valve of this invention is used to control the discharge of the separated electrolyte.
[0024] Compared with the prior art, the present invention has the following beneficial effects:
[0025] This invention utilizes the unique solubility of supercritical carbon dioxide to allow the electrolyte on the surface of a lithium battery to dissolve in the supercritical carbon dioxide fluid and be carried out with the fluid. Subsequently, by breaking the critical conditions in a cooling cabinet, the electrolyte and carbon dioxide can be separated. The separated gaseous carbon dioxide can be recycled, and the separated electrolyte can be discharged from the liquid outlet at the bottom of the cooling cabinet, thereby effectively cleaning the lithium battery with low pollution. Attached Figure Description
[0026] Figure 1 This is a schematic diagram of a lithium battery cleaning system in one embodiment;
[0027] The following are the labels in the diagram: 101, cleaning cabinet; 102, first sealing valve; 103, second sealing valve; 104, pressure relief valve; 2, heater; 3, fan; 401, gas compressor; 402, gas supply valve; 501, cooling cabinet; 502, cold water coil; 503, electrolyte discharge valve. Detailed Implementation
[0028] In the description of this utility model, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings and are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, features defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this utility model, unless otherwise stated, "a plurality of" means two or more. In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.
[0029] The present invention will be further described below with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and should not be construed as limiting the scope of protection of the present invention. Example 1
[0030] like Figure 1 As shown, this embodiment discloses a lithium battery cleaning system. The entire system is a pressurized system, and all valves, pipes, and equipment must ensure good airtightness. Specifically, the cleaning system includes a gas compressor 401, a cleaning cabinet 101, and a cooling cabinet 501. The gas compressor 401 is used to connect to a carbon dioxide gas source and increase the gas pressure within the system, playing a role in pressurization and pressure stabilization, ensuring that the gas pressure within the system is greater than or equal to the critical pressure of 7.29 MPa, while considering a margin of 0.1 to 1 MPa to maintain the gas pressure between 7.39 and 8.29 MPa. Furthermore, since some components in the electrolyte react with water, the carbon dioxide input into the system should be a dry gas.
[0031] In one specific embodiment, a gas supply valve 402 is provided at the outlet of the gas compressor 401. The gas supply valve 402 is located between the gas compressor 401 and the cleaning cabinet 101, and is used to disconnect the gas flow between the system and the gas compressor 401. When the pressure in the system exceeds the critical pressure, shutting off the gas compressor 401 and the gas supply valve 402 can reduce compressor energy consumption and prevent gas backflow.
[0032] The cleaning cabinet 101 is used to hold lithium batteries to be cleaned. The fluid inlet of the cleaning cabinet 101 is connected to the fluid outlet of the gas compressor 401 through a first flow channel. Carbon dioxide can flow into the cleaning cabinet 101 in a supercritical state after passing through the first flow channel. In a specific embodiment, a first sealing valve 102 and a second sealing valve 103 are respectively provided at the fluid inlet and fluid outlet of the cleaning cabinet 101. The first sealing valve 102 and the second sealing valve 103 are used to shut off the fluid inlet of the cleaning cabinet 101 and maintain the pressure in the rest of the system to reduce the amount of carbon dioxide used when the battery is removed or taken out. The cleaning cabinet 101 is provided with a pressure relief valve 104. The pressure relief valve 104 is used to release the pressure in the cleaning cabinet 101 when the battery is removed after cleaning. It can also be used for emergency pressure relief in case of system failure and overpressure.
[0033] In one specific embodiment, a fan 3 and a heater 2 are sequentially arranged along the flow direction on the first flow channel. The fan 3 is used to maintain the gas flow within the system, allowing the fluid to continuously rinse the battery surface. The fluid velocity within the system is controlled between 5 and 40 m / s. The heater 2 is located at one end of the fluid inlet of the cleaning cabinet 101 and is used to heat the airflow. The heater 2 is used to ensure that the high-pressure gas entering the cleaning cabinet 101 has a temperature greater than or equal to the critical temperature of 31.26°C. In actual operation, a margin temperature of 1 to 5°C needs to be considered simultaneously, and the gas temperature needs to be maintained between 32.26 and 36.26°C. The heating method of the heater 2 can be electric heating, steam heating, heat transfer medium heating, or other existing heating methods with the same function. This embodiment does not impose specific limitations.
[0034] In one specific embodiment, the cleaning cabinet 101 further includes a sealing system, a temperature and pressure detection system, and an online VOCs (volatile organic compounds) concentration detection system. After electrolyte filling, the batteries are grouped into the cleaning cabinet 101 using trays, with gaps between the batteries. A support frame can also be installed inside the cleaning cabinet 101 for tray stacking. The temperature and pressure detection system monitors the temperature and pressure data within the cleaning cabinet 101 to determine if the carbon dioxide is in a supercritical state, and feeds back the temperature and pressure data signals to the gas compressor 401 and heater 2 to maintain the carbon dioxide in a supercritical state. The online VOCs concentration detection system determines whether the cleaning of the lithium batteries is complete and feeds back the data signal indicating whether the cleaning of the lithium batteries is complete to the fan 3, gas compressor 401, and heater 2 to indicate subsequent operations.
[0035] Furthermore, the fluid inlet of the cooling cabinet 501 is connected to the fluid outlet of the cleaning cabinet 101. The cooling cabinet 501 is equipped with a cooling mechanism, which includes a cold water coil 502. The fluid inlet at the bottom of the cooling cabinet 501 is connected to the fluid outlet of the cleaning cabinet 101, and the gas outlet at the top of the cooling cabinet 501 is connected to the first flow channel. The bottom of the cooling cabinet 501 also has a liquid outlet. The cooling cabinet 501 is used to reduce the fluid pressure within the system, disrupting the critical conditions to convert supercritical carbon dioxide into gaseous carbon dioxide, and simultaneously separating the mixed electrolyte. The electrolyte, under the influence of gravity, collects at the bottom of the cooling cabinet 501 and flows out through the liquid outlet at the bottom of the cooling cabinet 501, while the gaseous carbon dioxide is discharged through the gas outlet at the top of the cooling cabinet 501 and returns to the first flow channel for circulation. Typically, the temperature inside the cooling cabinet 501 needs to be less than 31.26°C. An electrolyte discharge valve 503 is also provided at the liquid outlet to discharge the separated electrolyte.
[0036] Specifically, in this embodiment, supercritical carbon dioxide is used to clean the lithium battery. The supercritical carbon dioxide fluid carrying the electrolyte is cooled in the cooling cabinet 501, which breaks the critical conditions. The carbon dioxide flows out from the gas outlet at the top of the cooling cabinet 501 in a gaseous state and returns to the first flow channel to form a cycle, while the electrolyte can flow out from the liquid outlet at the bottom of the cooling cabinet 501 in a liquid state, thereby reducing the treatment cost of electrolyte waste.
[0037] The actual working process of the cleaning system is as follows: Batteries that have completed electrolyte filling are placed on a tray and grouped into cleaning cabinet 101, which is then closed and sealed. Initially, the pressure relief valve 104 and electrolyte discharge valve 503 of cleaning cabinet 101 are closed, while all other valves are open. Gas compressor 401 starts working, compressing carbon dioxide gas to raise the pressure within the entire system to 8 MPa. After the pressure stabilizes, fan 3 is started, allowing the high-pressure carbon dioxide to flow within the system at a speed of 10 m / s. The high-pressure carbon dioxide fluid passes through heater 2 and is heated to 33°C. The carbon dioxide fluid pressure is ≥7.29 MPa, and the temperature is ≥31.26°C. The carbon dioxide enters a supercritical state, and its overall properties change to an organic liquid fluid. The supercritical carbon dioxide enters cleaning cabinet 101 and rinses the surface of the lithium batteries. Residual electrolyte on the lithium battery surface dissolves in the supercritical carbon dioxide fluid and is discharged with the fluid. Supercritical carbon dioxide fluid containing electrolyte enters the cooling cabinet 501. The supercritical carbon dioxide fluid comes into contact with the surface of the cooling water coil 502, and its temperature drops to 30°C, breaking the critical temperature. The overall properties of the supercritical carbon dioxide change to an inorganic gaseous fluid, and the electrolyte separates from the carbon dioxide fluid. The electrolyte is discharged from the liquid outlet at the bottom of the cooling cabinet 501, while the carbon dioxide is discharged from the gas outlet at the top of the cooling cabinet 501 and returns to the first flow channel. The carbon dioxide is reheated by heater 2 and reaches the critical temperature again, repeating the above rinsing-separation process. After the battery cleaning is completed, the pressure relief valve 104 on the cleaning cabinet 101 is opened, and the remaining valves and equipment are closed. At the same time, the electrolyte discharge valve 503 is opened to discharge the recovered electrolyte. Because the system is pressurized, the electrolyte discharge valve 503 only needs to be opened briefly for the electrolyte to be discharged with the high-pressure gas flow. The opening degree of the electrolyte discharge valve 503 must be controlled to avoid a sudden pressure drop affecting system stability. After the carbon dioxide in the cleaning cabinet 101 is released, the cleaned battery is removed, and a new battery with liquid filling is inserted. The cleaning cabinet 101 is then sealed and closed. The pressure relief valve 104 of the cleaning cabinet 101 is closed, and other valves and equipment are opened. The gas compressor 401 starts working to pressurize the system and repeat the flushing process. Example 2
[0038] Similar to Embodiment 1, the difference between this embodiment and Embodiment 1 is that the pipe of the cold water coil 502 is installed at an angle, and the relative inclination angle between the pipe of the cold water coil 502 and the horizontal plane of the cooling cabinet 501 is 45~90°. The inclined installation of the cold water coil 502 allows the electrolyte separated after the critical state is broken to drip down the pipe surface to the bottom of the cooling cabinet 501; the cold water in the cold water coil 502 flows from top to bottom, so that the fluid can fully contact the cold water coil 502 to ensure the cooling effect; the cold water coil 502 is made of stainless steel to prevent electrolyte corrosion.
[0039] The present invention has been described in detail above. The above description is only one of the preferred embodiments of the present invention and should not be construed as limiting the scope of the present invention. Various simple modifications to the technical solutions of the embodiments of the present invention should still be included within the scope of the present invention.
Claims
1. A lithium battery cleaning system, characterized in that, include: Gas compressor (401) is used to connect to a carbon dioxide gas source; A cleaning cabinet (101) is used to hold lithium batteries to be cleaned. The fluid inlet of the cleaning cabinet (101) is connected to the outlet of the gas compressor (401) through a first flow channel. A fan (3) and a heater (2) are arranged sequentially along the flow direction on the first flow channel. The carbon dioxide output by the gas compressor (401) can flow into the cleaning cabinet (101) in a supercritical state after passing through the first flow channel. The cooling cabinet (501) has a fluid inlet at the bottom connected to the fluid outlet of the cleaning cabinet (101). The cooling cabinet (501) is equipped with a cooling mechanism for breaking the supercritical state of carbon dioxide. The top of the cooling cabinet (501) is equipped with a gas outlet for discharging gaseous carbon dioxide. The gas outlet is connected to the first flow channel upstream of the fan (3). The bottom of the cooling cabinet (501) is also equipped with a liquid outlet for discharging electrolyte.
2. The lithium battery cleaning system according to claim 1, characterized in that, The heater (2) is heated by electricity, steam, or heat medium.
3. The lithium battery cleaning system according to claim 1, characterized in that, The gas compressor (401) is provided with a gas supply valve (402) at its outlet.
4. The lithium battery cleaning system according to claim 1, characterized in that, The cleaning cabinet (101) is equipped with a first sealing valve (102) and a second sealing valve (103) at the fluid inlet and fluid outlet, respectively.
5. The lithium battery cleaning system according to claim 1, characterized in that, The cleaning cabinet (101) is also equipped with a pressure relief valve (104).
6. The lithium battery cleaning system according to claim 1, characterized in that, The cooling mechanism includes a cold water coil (502).
7. The lithium battery cleaning system according to claim 6, characterized in that, The pipe of the cold water coil (502) is installed at an angle, and the relative angle between the pipe of the cold water coil (502) and the horizontal plane of the cooling cabinet (501) is greater than or equal to 45° and less than or equal to 90°.
8. The lithium battery cleaning system according to claim 7, characterized in that, The bottom of the cooling cabinet (501) is also equipped with an electrolyte discharge valve (503).