Environment-friendly fluorine-free lithium-manganese button cell and manufacturing method of positive electrode sheet thereof

Abstract

This invention discloses a method for manufacturing the positive electrode sheet of an environmentally friendly fluorine-free lithium manganese button battery, comprising the following steps: A) Soaking and stirring collagen powder in an appropriate amount of pure water or organic solvent to dissolve the collagen powder into a fluorine-free gel water in a gel state, wherein the collagen powder is a powder combination including at least one of polyethylene glycol, sodium polyacrylate, or polyacrylic acid; B) Dry mixing and stirring the powdered raw materials of the battery positive electrode sheet evenly; C) Stirring the powdered raw materials and the fluorine-free gel water evenly to form a clump, and then drying it; D) Pressing it into a sheet and then granulating it to form the battery positive electrode sheet. Using fluorine-free raw materials as an adhesive, and employing a process of first preparing the gel water and then wet mixing to form the sheet, high-temperature drying will not cause carbonization, resulting in a loose and non-firm positive electrode sheet. This method produces a strong, fluorine-free, and non-loose positive electrode sheet. This invention also discloses an environmentally friendly fluorine-free lithium manganese button battery manufactured using the above-mentioned positive electrode sheet manufacturing method, wherein the positive electrode sheet is fluorine-free and firmly fixed.

Description

Technical Field

[0001] This invention relates to button batteries and their positive electrode manufacturing technology, and more particularly to an environmentally friendly fluorine-free lithium manganese button battery and its positive electrode manufacturing method. Background Technology

[0002] In the manufacturing of existing lithium-manganese button batteries, polytetrafluoroethylene (PTFE) is often added as a binder to the positive electrode powder and stirred evenly during the positive electrode sheet production process. The advantage of using PTFE is that it can withstand the requirement of the positive electrode sheet to be dried at high temperatures of 200-250°C for more than 24 hours to completely remove moisture while maintaining its adhesive strength, ensuring the positive electrode sheet remains intact and does not crack in the button battery manufacturing process. However, fluorinated PTFE is harmful to both humans and the environment. Batteries assembled using positive electrode sheets made with PTFE as a binder pose potential risks of harm to both humans and the environment, leading to consumer resistance to these products.

[0003] Many adhesives on the market carbonize and lose their bonding strength at high temperatures of 200-250℃, causing the positive electrode sheet to loosen and crack. In addition, some adhesives can catch fire at high temperatures of 200-250℃, thus causing a fire. Therefore, it is necessary to develop adhesives that can withstand high temperatures of 200-250℃, maintain their bonding strength, and not catch fire to replace harmful polytetrafluoroethylene.

[0004] Chinese invention patent application CN117199243A describes a method of dry-mixing polyethylene powder, or the addition of polyethylene glycol or polyacrylic acid powder, with battery positive electrode materials. The resulting powder is then mixed with water or electrolyte to produce a fluorine-free positive electrode sheet. However, because polyethylene powder is insoluble in water and has low binding strength, it cannot form a gel and therefore cannot replace harmful polytetrafluoroethylene (PTFE). Even with the addition of combinations of polyethylene glycol, polyacrylic acid, or sodium polyacrylate, the mixing process is still dry-mixing and fails to form a gel. The positive electrode sheet produced by this dry-mixing method has relatively weak adhesion, far less than that produced with harmful PTFE. After drying at 200-250°C to completely remove moisture, this type of positive electrode sheet will loosen and crack, and the current collector will easily detach, making it unsuitable for producing a qualified lithium-manganese button battery. Therefore, there are currently no fluorine-free lithium-manganese button batteries on the market. Summary of the Invention

[0005] To address the shortcomings of existing technologies, the technical problem this invention aims to solve is to provide a method for manufacturing a positive electrode sheet for an environmentally friendly, fluorine-free lithium manganese button battery. This method produces a positive electrode sheet with strong adhesion, which is fluorine-free and does not loosen or crack. This invention also provides an environmentally friendly, fluorine-free lithium manganese button battery manufactured using the above-described positive electrode sheet manufacturing method, whose positive electrode sheet is fluorine-free and firmly bonded.

[0006] To solve the above-mentioned technical problems, the method and technical solution adopted by the present invention is: a method for manufacturing the positive electrode sheet of an environmentally friendly fluorine-free lithium manganese button battery, which includes the following steps: A. Add collagen powder to an appropriate amount of pure water or organic solvent and soak and stir to dissolve the collagen powder in water or organic solvent into a fluoride-free gel water in a gel state. The collagen powder is a powder combination including at least one of polyethylene glycol, sodium polyacrylate, or polyacrylic acid. B. Dry mix and stir the powdered raw materials of the battery positive electrode sheet evenly. The powdered raw materials include manganese powder and conductive agent. C. Gradually add an appropriate amount of fluoride-free gel water to the well-stirred powdered raw materials, stir the mixture evenly to form a ball, and then dry it. D. Press into sheets and then granulate. Use a tablet pressing machine to press into fluorine-free lithium manganese battery positive electrode sheets according to the required size and specifications.

[0007] As an improvement to the technical solution of the positive electrode sheet manufacturing method of the environmentally friendly fluorine-free lithium manganese button battery of the present invention, in step A, the collagen powder is a combination of at least two of the following: polyethylene glycol, sodium polyacrylate, and polyacrylic acid. First, one of the powders is mixed with pure water or organic solvent heated to 85℃-95℃, and then the remaining powders are slowly added while maintaining the temperature by continuous stirring.

[0008] As an improvement to the technical solution of the positive electrode sheet manufacturing method of the environmentally friendly fluorine-free lithium manganese button battery of the present invention, in step A, the collagen powder is a powder combination including polyethylene glycol and at least one of sodium polyacrylate or polyacrylic acid, and the material is heated and kept warm in a container during the soaking and stirring process.

[0009] As an improvement to the technical solution of the positive electrode sheet manufacturing method of the environmentally friendly fluorine-free lithium manganese button battery of the present invention, in step A, the collagen powder is a powder combination including polyethylene glycol and at least one of sodium polyacrylate or polyacrylic acid. Hot water or organic solvent at 85℃-95℃ is injected into the heat-insulated container, polyethylene glycol is added and soaked and stirred evenly, and then the remaining powder is slowly added by continuous stirring.

[0010] As an improvement to the technical solution of the positive electrode sheet manufacturing method of the environmentally friendly fluorine-free lithium manganese button battery of the present invention, in step A, the weight ratio of collagen powder to pure water or organic solvent is 1:(17-18), and the collagen powder is soaked and stirred until it is completely dissolved. The entire cycle includes four stages in sequence: soaking, mixing, melting and infiltration, and remixing. Among them, stirring is required in the mixing and remixing stages.

[0011] As an improvement to the technical solution of the positive electrode sheet manufacturing method of the environmentally friendly fluorine-free lithium manganese button battery of the present invention, the time ratio of the soaking, mixing, melting and remixing stages is (2-3): (5-6): (4-8): (6-8).

[0012] To solve the above-mentioned technical problems, the product technical solution adopted by the present invention is: an environmentally friendly fluorine-free lithium manganese button battery, which includes a positive electrode sheet made by the above-mentioned positive electrode sheet manufacturing method, wherein the positive electrode sheet includes an electrode sheet body and a metal current collector covering the bottom surface of the electrode sheet body.

[0013] As an improvement to the technical solution of the environmentally friendly fluorine-free lithium manganese button battery of the present invention, the lithium manganese button battery includes a negative electrode cover, lithium metal, a separator, a positive electrode sheet and a positive electrode shell arranged in sequence from top to bottom. The positive electrode sheet is filled with electrolyte. The negative electrode cover and the positive electrode shell are interlocked and assembled and sealed by a sealing ring to form a fluorine-free lithium manganese button battery.

[0014] The beneficial effects of this invention are as follows: In the method for manufacturing the positive electrode sheet of a lithium manganese button battery, a powder combination including at least one of polyethylene glycol, sodium polyacrylate, or polyacrylic acid is used as the collagen powder. First, the collagen powder is soaked and stirred with pure water or an organic solvent to obtain an environmentally friendly, fluorine-free gel in a gel state. Then, the gel is wet-mixed with battery powder raw materials in a suitable ratio to obtain a lumpy mixture, which is then dried. Next, the material is pressed and granulated using conventional methods to obtain a fluorine-free lithium manganese battery positive electrode sheet. This manufacturing method uses fluorine-free raw materials as adhesives, avoiding the harmful problems associated with fluorine raw materials. The process of first obtaining the gel and then wet-mixing the sheet avoids the problem of insufficient adhesion caused by insufficient water absorption and gel formation in the adhesive material, which indirectly leads to a loose and unbonded positive electrode sheet. The positive electrode sheet prepared by first producing gel water and then mixing it with other materials avoids the use of fluorinated adhesives. Furthermore, high-temperature drying will not cause carbonization, resulting in a loose and unconsolidated positive electrode sheet. This method produces a strong, fluorine-free, and non-loose positive electrode sheet. Even after drying at 200-250℃ for more than 24 hours to remove moisture, the adhesive strength is maintained, and the positive electrode sheet will not loosen or crack.

[0015] The present invention discloses an environmentally friendly fluorine-free lithium manganese button battery made using the above-mentioned positive electrode manufacturing method. Its positive electrode is fluorine-free and tightly fixed, and can replace batteries containing harmful polytetrafluoroethylene. Attached Figure Description

[0016] Figure 1 This is a longitudinal cross-sectional view of an environmentally friendly, fluorine-free lithium manganese button battery according to the present invention.

[0017] Figure 2 This is a longitudinal cross-sectional view of the positive electrode sheet of an environmentally friendly fluorine-free lithium manganese button battery according to the present invention. Detailed Implementation

[0018] The specific embodiments of the present invention will be further described below with reference to the accompanying drawings.

[0019] A method for manufacturing the positive electrode sheet of an environmentally friendly fluorine-free lithium manganese button battery includes the following steps: A. Add collagen powder to an appropriate amount of pure water or organic solvent and soak and stir to dissolve the collagen powder in water or organic solvent into a fluoride-free gel water in a gel state. The collagen powder is a powder combination including at least one of polyethylene glycol, sodium polyacrylate, or polyacrylic acid. The weight ratio of collagen powder to solvent is usually about 1:(15-20), which varies depending on the type of collagen powder and the difference in solubility with the solvent, and may even exceed this range. B. Dry mix and stir the powdered raw materials of the battery positive electrode sheet evenly. The powdered raw materials include manganese powder and conductive agent. C. Gradually add an appropriate amount of fluoride-free gel water to the well-stirred powdered raw materials, stir the mixture evenly to form a ball, and then dry it; the weight ratio of powdered raw materials to fluoride-free gel water is about 100: (5-9). The ratio may vary depending on the type of powder and the difference in water absorption, and may even exceed this range. D. Press into sheets and then granulate. Use a tablet pressing machine to press into fluorine-free lithium manganese battery positive electrode sheets according to the required size and specifications.

[0020] In the manufacturing method of the positive electrode sheet for lithium-manganese button batteries, a powder combination including at least one of polyethylene glycol, sodium polyacrylate, or polyacrylic acid is used as the collagen powder. First, the collagen powder is soaked and stirred with pure water or an organic solvent to obtain an environmentally friendly, fluorine-free gel in a gel state. Then, the gel is wet-mixed with battery powdered raw materials in an appropriate ratio to obtain a lumpy mixture, which is then dried. Next, the material is pressed and granulated using conventional methods to obtain a fluorine-free lithium-manganese battery positive electrode sheet. This manufacturing method uses fluorine-free raw materials as adhesives, avoiding the harmful problems associated with fluorine-containing materials. The process of first obtaining the gel and then wet-mixing the sheet avoids the problem of insufficient adhesion due to insufficient water absorption and gel formation in the adhesive material, indirectly causing the positive electrode sheet to be loose and not firmly bonded. The positive electrode sheet obtained by first preparing the gel and then mixing the materials avoids fluorine-containing adhesive materials, and high-temperature drying will not cause carbonization, resulting in a loose and non-firm positive electrode sheet with strong adhesion. Even after drying at 200-250℃ for more than 24 hours to remove moisture, the positive electrode sheet can still maintain its adhesion and will not loosen or crack.

[0021] In practice, the following raw materials in the indicated weight ratios are used to mix and stir to prepare the gel water: The method for manufacturing the positive electrode sheet of this invention involves first mixing 1 kg of water-soluble polyethylene glycol, sodium polyacrylate, or polyacrylic acid (or a combination thereof) with 15-20 kg of pure water or an organic solvent, stirring and soaking until completely dissolved to form a fluorine-free positive electrode gel. Then, 100 kg of positive electrode powder (including manganese powder, conductive agent, lithium hydroxide, etc.) is mixed with 5-9 kg of the fluorine-free positive electrode gel, stirred evenly, dried, and fibrousized. The resulting positive electrode sheet is then die-cut using conventional methods. Baking at 200-250°C for more than 24 hours maintains its adhesive strength, preventing it from loosening or cracking. Following conventional processes, the fluorine-free positive electrode sheet is assembled and sealed to produce a fluorine-free lithium-manganese button battery. This fluorine-free button battery has been tested and shows normal electrical performance, and can replace batteries containing harmful polytetrafluoroethylene (PTFE).

[0022] In step A, the collagen powder is a combination of at least two of the following: polyethylene glycol, sodium polyacrylate, and polyacrylic acid. One of the powders is first mixed with pure water or an organic solvent heated to 85℃-95℃. Then, the remaining powders are slowly added while continuously stirring and maintaining the temperature. As shown in the material ratios in groups 4-9 of the table above, first mixing one type of collagen powder with pure water allows for easier blending of the single powder. Then, the remaining powders are added, resulting in a more uniform and thorough mixing of the gel water. Furthermore, the two materials can blend more quickly and evenly under the action of ion separation, resulting in a finer slurry that is more suitable for subsequent use.

[0023] In step A, the collagen powder is a powder combination including polyethylene glycol and at least one of sodium polyacrylate or polyacrylic acid. During the soaking and stirring process, the material is heated and kept warm in a container. As shown in the material ratios of groups 1 and 4-7 in the table above, polyethylene glycol is first stirred and mixed with pure water or organic solvent, and then heated and kept warm to allow it to fuse more quickly and easily. Then, the remaining powder is mixed in, which allows it to fuse together more quickly and evenly, resulting in a finer slurry that is more suitable for subsequent use.

[0024] In step A, the collagen powder is a powder combination including polyethylene glycol and at least one of sodium polyacrylate or polyacrylic acid. Hot water or an organic solvent at 85℃-95℃ is injected into a heat-insulated container, and the polyethylene glycol is added and stirred until homogeneous. Then, the remaining powder is slowly added while continuously stirring. As shown in the material ratios of groups 1 and 4-7 in the table above, the polyethylene glycol is first stirred and mixed with pure water or an organic solvent while being heated and kept at a constant temperature to allow for faster and easier integration. Then, the remaining powder is mixed in, allowing for faster and more uniform integration, resulting in a finer slurry more suitable for subsequent use. This method uses hot water to fully melt the polyethylene glycol initially, and the subsequent addition of other materials does not require continuous heating; only heat preservation is needed. The process is simpler, more convenient, and easier to implement.

[0025] In step A, the weight ratio of collagen powder to pure water or organic solvent is 1:(17-18). If the proportion of polyethylene glycol in the collagen powder is high, more pure water is needed. Soaking and stirring are performed until the collagen powder is completely dissolved. The entire process includes four stages: soaking, mixing, melting, and remixing. In the soaking stage, one or more powders are mixed with pure water and soaked together. Simple stirring can ensure thorough mixing of the powder and water, allowing the powder to absorb and dissolve. In the mixing stage, continuous stirring is required, which can be intermittent, i.e., intermittent continuous stirring in multiple short cycles, allowing the powder and water to fully blend and absorb each other. The melting stage primarily involves static soaking, but short-term stirring or short-term heat supplementation can also be performed, either by heating or heating the water (with a corresponding reduction in the proportion of pure water initially). The remixing stage is similar to the mixing stage, involving intermittent or continuous stirring.

[0026] Furthermore, the time ratio for the soaking, mixing, melting, and remixing stages is (2-3):(5-6):(4-8):(6-8). The time ratio is related to the material composition and proportion. A higher proportion of polyethylene glycol in the collagen powder results in a longer total time and a larger proportion of mixing and remixing time; a higher proportion of sodium polyacrylate results in a shorter total time and a smaller proportion of mixing and remixing time.

[0027] The product obtained by the above-described process is an environmentally friendly fluorine-free lithium manganese button battery, which includes a positive electrode 12 manufactured by the above-described positive electrode manufacturing method. The positive electrode 12 includes an electrode body 21 and a metal current collector 23 covering the bottom surface of the electrode body 21. The electrode body 21 of the positive electrode 12 is manufactured by the above-described process, and it has the characteristics of strong adhesion and non-loosening. With the assistance of the metal current collector 23, it can be used firmly without dispersing and dissolving into the electrolyte, making the battery easy to assemble and ensuring its service life.

[0028] The lithium-manganese button battery comprises a negative electrode cover 16, lithium metal 15, a separator 13, a positive electrode sheet 12, and a positive electrode casing 11 arranged sequentially from top to bottom. The positive electrode sheet is surrounded by electrolyte. The negative electrode cover 16 and the positive electrode casing 11 are interlocked and assembled and sealed using a sealing ring 18 to create a fluorine-free lithium-manganese button battery. The electrode body 21 of the positive electrode sheet 12 is manufactured using the aforementioned process, exhibiting strong adhesion and preventing loosening. With the assistance of the metal current collector 23, it can be used securely without dissolving into the electrolyte, making the battery easy to assemble and ensuring its lifespan. Furthermore, this lithium-manganese button battery exhibits stable discharge performance, continuously and stably outputting power, resulting in more complete total power output and better battery performance.

[0029] The above-disclosed embodiments are merely preferred embodiments of the present invention and should not be construed as limiting the scope of the present invention. Therefore, any equivalent variations made in accordance with the claims of the present invention are still within the scope of the present invention.

Claims

1. A method for manufacturing the positive electrode sheet of an environmentally friendly fluorine-free lithium manganese button battery, characterized in that, Includes the following steps: A. Add collagen powder to an appropriate amount of pure water or organic solvent and soak and stir to dissolve the collagen powder in water or organic solvent into a fluoride-free gel water in a gel state. The collagen powder is a powder combination including at least one of polyethylene glycol, sodium polyacrylate, or polyacrylic acid. B. Dry mix and stir the powdered raw materials of the battery positive electrode sheet evenly. The powdered raw materials include manganese powder and conductive agent. C. Gradually add an appropriate amount of fluoride-free gel water to the well-stirred powdered raw materials, stir the mixture evenly to form a ball, and then dry it. D. Press into sheets and then granulate. Use a tablet pressing machine to press into fluorine-free lithium manganese battery positive electrode sheets according to the required size and specifications.

2. The method for manufacturing the positive electrode sheet of the environmentally friendly fluorine-free lithium manganese button battery according to claim 1, characterized in that: In step A, the collagen powder is a combination of at least two of the following: polyethylene glycol, sodium polyacrylate, and polyacrylic acid. First, one of the powders is mixed with pure water or an organic solvent heated to 85°C-95°C. Then, the remaining powders are slowly added while maintaining the temperature through continuous stirring.

3. The method for manufacturing the positive electrode sheet of the environmentally friendly fluorine-free lithium manganese button battery according to claim 1, characterized in that: In step A, the collagen powder is a powder combination including polyethylene glycol and at least one of sodium polyacrylate or polyacrylic acid, and the material is heated and kept warm in a container during the soaking and stirring process.

4. The method for manufacturing the positive electrode sheet of the environmentally friendly fluorine-free lithium manganese button battery according to claim 1, characterized in that: In step A, the collagen powder is a powder combination including polyethylene glycol and at least one of sodium polyacrylate or polyacrylic acid. Hot water or organic solvent at 85°C-95°C is injected into an insulated container, polyethylene glycol is added and soaked and stirred evenly, and then the remaining powder is slowly added by continuous stirring.

5. The method for manufacturing the positive electrode sheet of the environmentally friendly fluorine-free lithium manganese button battery according to claim 1, characterized in that: In step A, the weight ratio of collagen powder to pure water or organic solvent is 1:(17-18). Soak and stir until the collagen powder is completely dissolved. The entire cycle includes four stages: soaking, mixing, melting and remixing. Among them, stirring is required in the mixing and remixing stages.

6. The method for manufacturing the positive electrode sheet of the environmentally friendly fluorine-free lithium manganese button battery according to claim 5, characterized in that: The time ratio of the infiltration, mixing, melting and remixing stages is (2-3): (5-6): (4-8): (6-8).

7. An environmentally friendly, fluorine-free lithium manganese button battery, characterized in that: The positive electrode includes a positive electrode obtained by the positive electrode manufacturing method according to any one of claims 1 to 6, wherein the positive electrode includes an electrode body and a metal current collector covering the bottom surface of the electrode body.

8. The environmentally friendly fluorine-free lithium manganese button battery according to claim 7, characterized in that: A lithium manganese button battery consists of a negative electrode cover, lithium metal, a separator, a positive electrode sheet, and a positive electrode casing arranged sequentially from top to bottom. The positive electrode sheet is surrounded by electrolyte. The negative electrode cover and the positive electrode casing are interlocked and assembled and sealed with a sealing ring to produce a fluorine-free lithium manganese button battery.

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