CN113357878B - Battery cell dewatering method - Google Patents
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- CN113357878B CN113357878B CN202110602358.1A CN202110602358A CN113357878B CN 113357878 B CN113357878 B CN 113357878B CN 202110602358 A CN202110602358 A CN 202110602358A CN 113357878 B CN113357878 B CN 113357878B
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F26—DRYING
- F26B—DRYING SOLID MATERIALS OR OBJECTS BY REMOVING LIQUID THEREFROM
- F26B5/00—Drying solid materials or objects by processes not involving the application of heat
- F26B5/04—Drying solid materials or objects by processes not involving the application of heat by evaporation or sublimation of moisture under reduced pressure, e.g. in a vacuum
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F26—DRYING
- F26B—DRYING SOLID MATERIALS OR OBJECTS BY REMOVING LIQUID THEREFROM
- F26B23/00—Heating arrangements
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M10/00—Secondary cells; Manufacture thereof
- H01M10/05—Accumulators with non-aqueous electrolyte
- H01M10/052—Li-accumulators
- H01M10/0525—Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M10/00—Secondary cells; Manufacture thereof
- H01M10/05—Accumulators with non-aqueous electrolyte
- H01M10/058—Construction or manufacture
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
- Y02E60/10—Energy storage using batteries
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P70/00—Climate change mitigation technologies in the production process for final industrial or consumer products
- Y02P70/50—Manufacturing or production processes characterised by the final manufactured product
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Abstract
The invention discloses a cell dewatering method, which comprises the following steps: s1, taking the sheet-type drying material and the polar roll to be dried, superposing and winding to form a mixed roll; s2, putting the mixed roll into a vacuum oven for heating and baking; the baking step comprises: s2-1, heating to 60-79 ℃, keeping the vacuum degree less than or equal to 200Pa, and keeping for 10-60 min; s2-2, keeping the temperature stable, putting dry inert gas into the vacuum oven, keeping the vacuum degree of 50000 Pa-less than or equal to 80000Pa, and keeping the duration for 5-30 min; s2-3, continuously keeping the temperature stable, slowly increasing the vacuum degree to be less than or equal to 50Pa, and keeping the time for 120-240 min; s2-4, cooling to normal temperature; s3, the sheet-type dried material is peeled off, leaving a polar roll. The invention has the beneficial effects that: because the sheet-type drying material and the polar roll to be dried are superposed and wound in a pre-treatment way, the temperature can be lower in the drying process, and the energy consumption is obviously superior. The battery cell does not need to be baked again before liquid injection, so that the production efficiency can be improved, and the energy consumption is further reduced.
Description
Technical Field
The invention relates to the field of lithium battery manufacturing, in particular to a battery core dewatering method.
Background
For lithium ion batteries using organic solvents as electrolytes, strict control of moisture during production is required. The moisture not only can generate side reaction with the organic electrolyte, but also can generate gas when the battery is formed, and the overall performance of the battery is influenced. In order to solve the problem, each manufacturer generally performs vacuum baking on the battery cell after the battery cell is assembled and before liquid injection in the actual production process.
Chinese patent document CN109755655A discloses "a baking method of lithium ion battery cell" in 2019, 5 months and 14 days, which includes the following steps: the bottom of the vacuum oven is provided with a nitrogen inlet, a ventilating baffle plate and a heating device, and the top of the vacuum oven is provided with a nitrogen outlet; putting a lithium ion battery cell into the vacuum oven, vacuumizing to less than or equal to-0.085 MPa, and heating the temperature in the vacuum oven to 80-90 ℃ through the heating device; introducing nitrogen into the vacuum oven through the nitrogen inlet, maintaining the vacuum degree in the vacuum oven to be less than or equal to-0.085 MPa, keeping the temperature in the vacuum oven to be 80-90 ℃, and lasting for 3-6 hours; stopping heating, and continuously introducing nitrogen to cool the battery cell in the vacuum oven to room temperature. The invention can realize the synchronous implementation of the baking process and the taking-away process of the lithium ion battery cell moisture, so that the whole baking process only needs 3-6h, and compared with the existing baking process of more than 20h, the invention saves the baking time and the energy consumption.
In the traditional method, the pole pieces are wound or stacked in a close packing manner and are blocked by the diaphragm and the shell, so that the baking effect is not ideal, the baking time is long, and the production and processing period of the battery cell is influenced. Other manufacturers bake the pole pieces or pole rolls in vacuum, but the pole rolls or pole pieces are also in a close-packed state, and the moisture removal effect is not ideal.
Disclosure of Invention
Based on the problems, the invention provides the cell dewatering method which can rapidly, efficiently and thoroughly improve the dewatering effect, reduce the production period, improve the production efficiency and reduce the energy consumption.
In order to realize the purpose of the invention, the invention adopts the following technical scheme: a cell dewatering method comprises the following steps:
s1, taking the sheet-type drying material and the polar roll to be dried, superposing and winding to form a mixed roll;
s2, putting the mixed coil into a vacuum oven for heating and baking; the baking step comprises:
s2-1, heating to 60-79 ℃, keeping the vacuum degree less than or equal to 200Pa, and keeping for 10-60 min;
s2-2, keeping the temperature stable, putting dry inert gas into the vacuum oven, keeping the vacuum degree of 50000 Pa-less than or equal to 80000Pa, and keeping the duration for 5-30 min;
s2-3, continuously keeping the temperature stable, slowly raising the vacuum degree to be less than or equal to 50Pa, and keeping the time for 120-240 min;
s2-4, cooling to normal temperature;
s3, peeling off the sheet-type dried material to leave a polar roll.
Preferably, the flake-type dry material is: mixing a drying agent into an organic solution to prepare slurry, coating the slurry on two sides of a base film, and drying for later use; the desiccant is one or more of aluminum oxide, activated carbon, silica gel or other desiccant powder with moisture adsorption function; the organic solvent is ketone or alcohol; the base film is made of PP, PE, PVC or PET.
Preferably, the mass ratio of the drying agent to the organic solvent is 1: 20-1: 100.
Preferably, the organic solvent is N-methyl pyrrolidone.
Preferably, the sheet-type desiccant material is a fibrous desiccant film.
Preferably, the sheet-type drying material is laminated with the polar roll to be dried, and then rolled and rewound.
Preferably, step S3 is followed by step S4: carrying out die cutting, laminating, spot welding and packaging operations on the pole coil in sequence; the environmental dew point of each operation link is less than or equal to minus 45 ℃.
Preferably, the thickness of the pole roll to be dried is 1, the thickness of the base film is 0.05-0.2, and the total thickness of the base film after the two sides of the base film are coated with the desiccant slurry is 0.06-0.25.
Preferably, the thickness of the pole roll to be dried is 1, and the thickness of the fiber drying agent film is 0.05-0.3.
The battery core dewatering method designed by the scheme needs to prepare a sheet type drying material. Sheet-type dry materials generally have two options: either by self-made or by using existing fibrous desiccant films. The self-made method comprises the following steps: selecting PP, PE, PVC or PET as a base film, selecting proper desiccant powder and proper organic solution, mixing the desiccant powder into the organic solution to prepare slurry, uniformly coating the slurry on two side surfaces of the base film, and drying to prepare the base film. The desiccant can be one or more of aluminum oxide, activated carbon, silica gel or other desiccant powder with moisture adsorption function; the organic solvent is ketone or alcohol; n-methyl-pyrrolidone is preferred. When the drying device is used, the sheet-type drying material and the pole roll to be dried are overlapped, preferably rolled, so that the sheet-type drying material and the pole roll to be dried are in full and close contact to form a double-layer structure, then the double-layer structure is tightly wound by a winding device to form a mixed roll, and at the moment, both sides of the pole roll to be dried are in close contact with the sheet-type drying material. The thickness of the self-made sheet type drying material or the existing fiber drying agent film has certain parameter range requirements, the sheet type drying material can be kept to be tightly attached to the pole roll to be dried, local separation and tilting cannot occur, and therefore a good water absorption effect is kept.
When baking, the mixed roll is put into a vacuum oven for heating and baking. The baking process comprises four steps:
s2-1, heating to 60-79 ℃, keeping the vacuum degree less than or equal to 200Pa, and keeping for 10-60 min;
s2-2, keeping the temperature stable, putting dry inert gas into the vacuum oven, keeping the vacuum degree of 50000 Pa-less than or equal to 80000Pa, and keeping the duration for 5-30 min;
s2-3, continuously keeping the temperature stable, slowly increasing the vacuum degree to be less than or equal to 50Pa, and keeping the time for 120-240 min;
and S2-4, cooling to the normal temperature.
The baking temperature is obviously reduced compared with the prior art, and the baking device has the advantages of: firstly, the boiling point of water in a high-vacuum environment can be obviously reduced, so that the water can be fully gasified only by heating to a proper temperature, and the energy-saving environment-friendly energy-saving system has an advantage in energy conservation; and secondly, the pole piece is baked at a lower temperature, so that the pole piece can keep better flexibility, and better shaping capacity can be obtained in subsequent assembly. A dry inert gas is used to fill the vacuum oven in order to displace the evaporated air containing water vapor. When cooling, the product can be kept stand for natural cooling, and normal-temperature or even low-temperature dry inert gas can be continuously filled into the vacuum oven for forced cooling. The cooled mixed coil can be unfolded, the stripped sheet-type dry material can be recycled and reused after treatment, the left polar coil can be subjected to die cutting, lamination, spot welding and packaging, and the polar coil can be used for liquid injection after passing a moisture test. After leaving the vacuum oven, the environment of the subsequent process steps requires that the dew point is less than or equal to minus 45 ℃ so as to avoid over-moist in the ambient air and moisture absorption and moisture regain of the pole piece.
In conclusion, the beneficial effects of the invention are as follows: because the sheet-type drying material and the polar roll to be dried are superposed and wound in a pre-treatment way, the temperature can be lower in the drying process, and the energy consumption is obviously superior. The battery cell does not need to be baked again before liquid injection, so that the production efficiency can be improved, and the energy consumption is further reduced.
Drawings
Fig. 1 is a schematic view of a sheet-type drying material wound in superposition with a polar web to be dried.
Fig. 2 is a schematic view of the sheet-type dry material and the pole roll being peeled from each other.
Wherein: 1, drying a polar roll to be dried, 2, sheet-type drying materials, 3, a rolling device, 4, a mixed roll, 5, drying the polar roll and 6, die cutting equipment; the arrow indicates the direction of advance of the material or the direction of rolling of the drum.
Detailed Description
The invention is further described with reference to the following detailed description and accompanying drawings.
Example 1
Embodiment 1 is a method for removing water from a battery cell, including the steps of:
s1, taking the sheet-type drying material and the polar roll to be dried, superposing and winding to form a mixed roll;
s2, putting the mixed roll into a vacuum oven for heating and baking; the baking step comprises:
s2-1, heating to 60 ℃, keeping the vacuum degree at 195Pa, and keeping the time for 60 min;
s2-2, keeping the temperature stable, putting dry inert gas, in this case nitrogen, into the vacuum oven, keeping the vacuum degree =80000Pa, and keeping the duration for 25 min;
s2-3, continuously keeping the temperature stable, slowly increasing the vacuum degree to 45Pa, and keeping the time for 240 min;
s2-4, naturally cooling to normal temperature;
s3, peeling off the thin sheet type drying material to leave a polar roll;
and S4, sequentially carrying out die cutting, laminating, spot welding and packaging on the pole roll.
Wherein, the flake type dry material is self-made, and the simple step of self-making is: and mixing the drying agent into the organic solution to prepare slurry, coating the slurry on the two sides of the base film, and drying for later use. The drying agent in the embodiment is alumina powder; the organic solvent is N-methyl pyridine alkyl ketone; the base film is made of PP. The mass ratio of the alumina powder to the N-methyl pyridine-ketone is 1: 20. The thickness of the pole roll to be dried is 1, the thickness of the base film is 0.1, and the total thickness of the base film coated with the desiccant slurry on the two sides is 0.22. As shown in fig. 1, after the sheet-type drying material 2 is laminated with the pole roll 1 to be dried, it is rolled by a rolling device 3 and then wound to form a mixed roll 4.
After leaving the vacuum oven, the hybrid roll 4 needs to be subjected to a subsequent treatment as shown in fig. 2: stripping the sheet type drying material 2, feeding the remained dried polar roll 5 into a die cutting device 6 for die cutting, and then carrying out operations such as lamination, spot welding, packaging and the like, wherein the environmental dew point of each operation link after leaving the vacuum oven is required to be less than or equal to minus 45 ℃.
The pole piece obtained by the method of the embodiment is processed, and the moisture test shows that the moisture of the positive pole piece is 110ppm, the moisture of the negative pole piece is 260ppm, and the water is qualified, so that the pole piece can be injected.
Example 2
s1, taking the sheet-type drying material and the polar roll to be dried, superposing and winding to form a mixed roll;
s2, putting the mixed roll into a vacuum oven for heating and baking; the baking step comprises:
s2-1, heating to 70 ℃, keeping the vacuum degree at 165Pa, and keeping the time for 40 min;
s2-2, keeping the temperature stable, putting dry inert gas, in this case nitrogen, into the vacuum oven, keeping the vacuum degree =70000Pa, and keeping the duration for 20 min;
s2-3, continuously keeping the temperature stable, slowly increasing the vacuum degree to 40Pa, and keeping the vacuum degree for 180 min;
s2-4, naturally cooling to normal temperature;
s3, peeling off the thin sheet type drying material to leave a polar roll;
and S4, performing die cutting, laminating, spot welding and packaging on the pole coil in sequence.
Wherein, the flake type dry material is self-made, and the simple step of self-making is: and mixing the drying agent into the organic solution to prepare slurry, coating the slurry on the two sides of the base film, and drying for later use. The drying agent in the embodiment is active carbon powder; the organic solvent is N-methyl pyridine alkyl ketone; the base film is made of PE. The mass ratio of the activated carbon powder to the N-methyl pyridine alkyl ketone is 1: 45. The thickness of the pole roll to be dried is 1, the thickness of the base film is 0.12, and the total thickness of the base film coated with the desiccant slurry on the two sides is 0.2. As shown in fig. 1, after the sheet-type drying material 2 is laminated with the pole roll 1 to be dried, it is rolled by a rolling device 3 and then wound to form a mixed roll 4.
After leaving the vacuum oven, the hybrid roll 4 needs to be subjected to a subsequent treatment as shown in fig. 2: stripping the sheet type drying material 2, feeding the remained dried polar roll 5 into a die cutting device 6 for die cutting, and then carrying out operations such as lamination, spot welding, packaging and the like, wherein the environmental dew point of each operation link after leaving the vacuum oven is required to be less than or equal to minus 45 ℃.
The pole piece obtained by the method of the embodiment is processed, and the moisture test shows that the moisture of the positive pole piece is 130ppm, the moisture of the negative pole piece is 272ppm, and the moisture is qualified, so that the pole piece can be injected.
Example 3
s1, taking the sheet-type drying material and the polar roll to be dried, superposing and winding to form a mixed roll;
s2, putting the mixed roll into a vacuum oven for heating and baking; the baking step comprises:
s2-1, heating to 60 ℃, keeping the vacuum degree at 180Pa, and keeping the time for 35 min;
s2-2, keeping the temperature stable, putting dry inert gas, in this case nitrogen, into the vacuum oven, keeping the vacuum degree =65000Pa, and keeping the duration for 25 min;
s2-3, continuously keeping the temperature stable, slowly increasing the vacuum degree to 38Pa, and keeping the vacuum degree for 165 min;
s2-4, naturally cooling to normal temperature;
s3, peeling off the thin sheet type drying material to leave a polar roll;
and S4, performing die cutting, laminating, spot welding and packaging on the pole coil in sequence.
Wherein, the flake type drying material is self-made, and the simple steps of the self-made are: and mixing the drying agent into the organic solution to prepare slurry, coating the slurry on the two sides of the base film, and drying for later use. The drying agent in the embodiment is silica gel powder; the organic solvent is N-methyl pyridine alkyl ketone; the base film material is PVC. The mass ratio of the silica gel powder to the N-methyl pyridine alkyl ketone is 1: 75. The thickness of the pole roll to be dried is 1, the thickness of the base film is 0.05, and the total thickness of the base film coated with the desiccant slurry on the two sides is 0.17. As shown in fig. 1, after the sheet-type drying material 2 is laminated with the pole roll 1 to be dried, it is rolled by a rolling device 3 and then wound to form a mixed roll 4.
After leaving the vacuum oven, the hybrid roll 4 needs to be subjected to a subsequent treatment as shown in fig. 2: stripping the sheet type drying material 2, feeding the remained dried polar roll 5 into a die cutting device 6 for die cutting, and then carrying out operations such as lamination, spot welding, packaging and the like, wherein the environmental dew point of each operation link after leaving the vacuum oven is required to be less than or equal to minus 45 ℃.
The pole piece obtained by the method of the embodiment is processed, and the moisture test shows that the moisture of the positive pole piece is 116ppm, the moisture of the negative pole piece is 255ppm, and the moisture is qualified, so that the pole piece can be injected with liquid.
Example 4
s1, taking the sheet-type drying material and the polar roll to be dried, superposing and winding to form a mixed roll;
s2, putting the mixed roll into a vacuum oven for heating and baking; the baking step comprises:
s2-1, heating to 65 ℃, keeping the vacuum degree at 185Pa, and keeping the time for 15 min;
s2-2, keeping the temperature stable, putting dry inert gas, in this case nitrogen, into the vacuum oven, keeping the vacuum degree =55000Pa, and keeping the duration for 30 min;
s2-3, continuously keeping the temperature stable, slowly increasing the vacuum degree to 50Pa, and keeping the vacuum degree for 190 min;
s2-4, naturally cooling to normal temperature;
s3, peeling off the thin sheet type drying material to leave a polar roll;
and S4, performing die cutting, laminating, spot welding and packaging on the pole coil in sequence.
Wherein, the flake type drying material is self-made, and the simple steps of the self-made are: and mixing the drying agent into the organic solution to prepare slurry, coating the slurry on the two sides of the base film, and drying for later use. The drying agent in the embodiment is silica gel powder; the organic solvent is N-methyl pyridine alkyl ketone; the base film material is PET. The mass ratio of the silica gel powder to the N-methyl pyridine alkyl ketone is 1: 100. The thickness of the pole roll to be dried is 1, the thickness of the base film is 0.15, and the total thickness of the base film coated with the desiccant slurry on the two sides is 0.25. As shown in fig. 1, a sheet-type drying material 2 is laminated on a pole roll 1 to be dried, and then rolled and rewound by a rolling device 3 to form a mixed roll 4.
After leaving the vacuum oven, the hybrid roll 4 needs to be subjected to a subsequent treatment as shown in fig. 2: stripping the sheet type drying material 2, feeding the remained dried polar roll 5 into a die cutting device 6 for die cutting, and then carrying out operations such as lamination, spot welding, packaging and the like, wherein the environmental dew point of each operation link after leaving the vacuum oven is required to be less than or equal to minus 45 ℃.
The obtained pole piece is processed by the method of the embodiment, and the moisture of the positive pole piece is 119ppm, the moisture of the negative pole piece is 269ppm and the water is qualified after a moisture test, so that the pole piece can be injected.
Example 5
Embodiment 5 is a cell dewatering method, including the following steps:
s1, taking the sheet-type drying material and the polar roll to be dried, superposing and winding to form a mixed roll;
s2, putting the mixed roll into a vacuum oven for heating and baking; the baking step comprises:
s2-1, heating to 79 ℃, keeping the vacuum degree at 150Pa, and keeping the time for 10 min;
s2-2, keeping the temperature stable, putting dry inert gas, in this case nitrogen, into the vacuum oven, keeping the vacuum degree =50000Pa, and keeping the duration for 5 min;
s2-3, continuously keeping the temperature stable, slowly increasing the vacuum degree to 50Pa, and keeping the vacuum degree for 240 min;
s2-4, naturally cooling to normal temperature;
s3, peeling off the thin sheet type drying material to leave a polar roll;
and S4, performing die cutting, laminating, spot welding and packaging on the pole coil in sequence.
Wherein the flake type drying material is a commercially available fiber desiccant film. The thickness of the pole roll to be dried is 1, and the thickness of the fiber desiccant film is 0.27. As shown in fig. 1, after the sheet-type drying material 2 is laminated with the pole roll 1 to be dried, it is rolled by a rolling device 3 and then wound to form a mixed roll 4.
After leaving the vacuum oven, the hybrid roll 4 needs to be subjected to a subsequent treatment as shown in fig. 2: stripping the sheet type drying material 2, feeding the remained dried polar roll 5 into a die cutting device 6 for die cutting, and then carrying out operations such as lamination, spot welding, packaging and the like, wherein the environmental dew point of each operation link after leaving the vacuum oven is required to be less than or equal to minus 45 ℃.
The pole piece obtained by the method of the embodiment is processed, and the moisture test shows that the moisture of the positive pole piece is 126ppm, the moisture of the negative pole piece is 276ppm, and the water is qualified, so that the pole piece can be injected.
Comparative example
S1, putting the rolled lithium manganate positive electrode roll and the rolled graphite negative electrode roll into a vacuum oven for baking, wherein the baking process is as follows: the first step is as follows: preheating at 90 deg.C and vacuum degree of less than or equal to 100Pa for 30 min; the second step is that: heating, replacing with nitrogen, wherein the vacuum degree is more than or equal to 50000Pa and less than or equal to 80000Pa, and the time is 30 min; the third step: heating to vacuum degree of less than or equal to 50Pa for 480 min; the fourth step: cooling and baking;
s2, die cutting is carried out on the electrode roll baked in the step S1, the electrode roll and the cathode roll are cut into small pieces through a die cutting machine, and the dew point of a die cutting workshop is less than or equal to minus 45 ℃;
s3, laminating, spot welding and packaging the positive and negative pole pieces cut in the S2, wherein the dew point of a workshop is less than or equal to minus 45 ℃;
and S4, carrying out a pole piece moisture test on the battery cell packaged in the S3 mode, wherein the moisture of the positive pole piece is 380ppm, the moisture of the negative pole piece is 570ppm, the moisture is higher, and the battery cell needs to be baked.
By analyzing each embodiment and each comparative example, the embodiment shortens the baking time of the pole piece, reduces the water content of the pole piece, cancels the baking before liquid injection, and has obvious advantages in energy consumption. The method is simple to operate, can shorten the production period of the battery cell, improves the production efficiency, has strong practicability, and is suitable for application in the mass production process.
Claims (9)
1. A cell dewatering method comprises the following steps:
s1, taking the sheet-type drying material and the polar roll to be dried, superposing and winding to form a mixed roll;
s2, putting the mixed roll into a vacuum oven for heating and baking; the baking step comprises:
s2-1, heating to 60-79 ℃, keeping the vacuum degree less than or equal to 200Pa, and keeping for 10-60 min;
s2-2, keeping the temperature stable, putting dry inert gas into the vacuum oven, keeping the vacuum degree of 50000 Pa-less than or equal to 80000Pa, and keeping the duration for 5-30 min;
s2-3, continuously keeping the temperature stable, slowly reducing the vacuum degree to be less than or equal to 50Pa, and keeping the time for 120-240 min;
s2-4, cooling to normal temperature;
s3, peeling off the sheet-type dried material to leave a polar roll.
2. The method for removing water from a battery cell according to claim 1, wherein the flake-type drying material is: mixing a drying agent into an organic solution to prepare slurry, coating the slurry on two sides of a base film, and drying for later use; the desiccant is one or more of aluminum oxide, activated carbon, silica gel or other desiccant powder with moisture adsorption function; the organic solvent is ketone or alcohol; the base film is made of PP, PE, PVC or PET.
3. The method for removing water from the battery cell according to claim 2, wherein the mass ratio of the drying agent to the organic solvent is 1: 20-1: 100.
4. The method for removing water from a battery cell according to claim 2 or 3, wherein the organic solvent is N-methyl pyrrolidone.
5. The method of claim 1, wherein the sheet-type desiccant material is a fibrous desiccant film.
6. The method of claim 1, wherein the sheet-type drying material is rolled and then wound after being laminated with the polar coil to be dried.
7. The method for removing water from a battery cell of claim 1, wherein step S4 is further performed after step S3: carrying out die cutting, laminating, spot welding and packaging operations on the pole coil in sequence; the environmental dew point of each operation link is less than or equal to minus 45 ℃.
8. The method for removing water from the battery cell of claim 2 or 3, wherein the thickness of the pole roll to be dried is 1, the thickness of the base film is 0.05-0.2, and the total thickness of the base film after the drying agent slurry is coated on the two sides of the base film is 0.06-0.25.
9. The method for removing water from a battery cell according to claim 5, wherein the thickness of the pole roll to be dried is 1, and the thickness of the fiber desiccant film is 0.05-0.3.
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Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103868330A (en) * | 2014-03-27 | 2014-06-18 | 威格高纯气体设备科技（苏州工业园区）有限公司 | Deep drying and dewatering method |
| CN105202882A (en) * | 2014-06-13 | 2015-12-30 | 宁德时代新能源科技有限公司 | Pole piece drying device |
| CN206656567U (en) * | 2017-03-10 | 2017-11-21 | 宁德时代新能源科技股份有限公司 | Pole piece drying device |
| CN107782096A (en) * | 2016-10-09 | 2018-03-09 | 万向二三股份公司 | A kind of lithium ion cell electrode drying device and its drying means |
| CN212339909U (en) * | 2020-05-15 | 2021-01-12 | 昆山聚创新能源科技有限公司 | Winding drum for drying pole roll of lithium ion power battery |
| CN112747565A (en) * | 2021-01-26 | 2021-05-04 | 昆山聚创新能源科技有限公司 | Vacuum baking method of electrode roll |
Family Cites Families (1)
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| US20190081317A1 (en) * | 2017-09-11 | 2019-03-14 | Andreas Keil | Web coating and calendering system and method |
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Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103868330A (en) * | 2014-03-27 | 2014-06-18 | 威格高纯气体设备科技（苏州工业园区）有限公司 | Deep drying and dewatering method |
| CN105202882A (en) * | 2014-06-13 | 2015-12-30 | 宁德时代新能源科技有限公司 | Pole piece drying device |
| CN107782096A (en) * | 2016-10-09 | 2018-03-09 | 万向二三股份公司 | A kind of lithium ion cell electrode drying device and its drying means |
| CN206656567U (en) * | 2017-03-10 | 2017-11-21 | 宁德时代新能源科技股份有限公司 | Pole piece drying device |
| CN212339909U (en) * | 2020-05-15 | 2021-01-12 | 昆山聚创新能源科技有限公司 | Winding drum for drying pole roll of lithium ion power battery |
| CN112747565A (en) * | 2021-01-26 | 2021-05-04 | 昆山聚创新能源科技有限公司 | Vacuum baking method of electrode roll |
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