Release agent for rolling negative electrode of lithium ion battery as well as preparation method and application of release agent

Abstract

The invention discloses a release agent for rolling a negative electrode of a lithium ion battery as well as a preparation method and application of the release agent, and the release agent comprises the following raw material components in percentage by mass: 2-10% of fatty alcohol-polyoxyethylene ether, 1-5% of sodium carbonate, 20-60% of polydimethylsiloxane and 30-70% of deionized water. The release agent disclosed by the invention has self-cleaning and anti-sticking roller protection effects, and foreign matters on the surface of a steel roller are effectively removed through fatty alcohol-polyoxyethylene ether and sodium carbonate; meanwhile, a thin protective film is formed on the surface of the steel roller through polydimethylsiloxane, so that a roller sticking prevention protection effect can be achieved in the rolling process, and the situation that the product yield is affected and the steel roller is damaged due to the fact that negative electrode slurry sticks to the roller in the rolling process is avoided; the product is low in raw material cost, free of pungent smell and harmless to human bodies; meanwhile, no pollution is caused to the environment, and the material is environment-friendly; and the release agent is a flash-point-free non-combustible material, so that the potential safety hazard of flammable and explosive materials is avoided.

Description

Technical Field

[0001] The invention relates to the technical field of release agents, and in particular to a release agent for roller pressing of a negative electrode of a lithium ion battery, and a preparation method and application thereof. Background Art

[0002] In recent years, with the rapid development of new energy vehicles, the demand for power batteries has soared, directly driving the rapid development of related industries based on lithium-ion batteries. At present, the power battery system is mainly based on aqueous negative electrodes, which are very easy to stick to the roller during the rolling process, thus causing certain effects on production yield and equipment damage.

[0003] At present, the main solution to the problem of sticky rollers on the market is to wipe the surface of the steel roller with anhydrous ethanol or acetone, which mainly plays a cleaning role but has no protective effect on the steel roller. At the same time, anhydrous ethanol or acetone is relatively expensive and has a pungent odor. Long-term contact may even cause cancer. In addition, anhydrous ethanol and acetone are flammable and explosive, which poses a safety problem.

[0004] Therefore, in view of the technical defects of existing products, it is of great significance to develop a release agent that can effectively solve the problem of negative electrode sticking to the roller, is harmless to the human body, and does not pollute the environment. Summary of the invention

[0005] In view of the deficiencies in the prior art, the present invention provides a release agent for negative electrode rolling of lithium ion batteries and a preparation method and application thereof. Fatty alcohol polyoxyethylene ether and sodium carbonate are added to the release agent component to effectively remove foreign matter on the surface of a steel roller. At the same time, polydimethylsiloxane is added to form a thin protective film on the surface of the steel roller during the wiping process, which can play a role in preventing the roller from sticking during the rolling process, thereby preventing the negative electrode slurry from sticking to the roller during the rolling process, affecting the product yield and damaging the steel roller.

[0006] In order to solve the above technical problems, the present invention provides a release agent for lithium ion battery negative electrode rolling, which includes the following raw material components by mass percentage: 2-10% fatty alcohol polyoxyethylene ether, 1-5% sodium carbonate, 20-60% polydimethylsiloxane, and 30-70% deionized water.

[0007] The release agent of the present invention has both self-cleaning and anti-sticking roller protection functions. A certain amount of fatty alcohol polyoxyethylene ether and sodium carbonate are added to the release agent component. The two have good emulsification and softening effects. During the steel roller wiping process, foreign matter on the surface of the steel roller can be effectively wiped and removed, and a good cleaning effect is played. In addition, a certain amount of polydimethylsiloxane is added to the release agent component. During the steel roller wiping process, a thin release film can be formed on the surface of the steel roller to prevent the roller from sticking. At the same time, the release film has good stability to acids and alkalis, oxidants and reducing agents, is not prone to chemical reactions, and can also protect the steel roller, avoiding the problem that the steel roller is easy to stick to the roller due to direct rolling, and the problem that the product yield is low and the surface of the steel roller is damaged due to the sticking of the roller.

[0008] The raw material cost of the invention is low, has no irritating odor, and is harmless to the human body; at the same time, it is pollution-free and is an environmentally friendly material; in addition, the release agent is a non-flash point non-flammable material, avoiding the hidden dangers of safety problems easily caused by flammable and explosive materials.

[0009] Furthermore, the raw material components are included in percentage by mass: 10% fatty alcohol polyoxyethylene ether, 2% sodium carbonate, 58% polydimethylsiloxane, and 30% deionized water.

[0010] Furthermore, the release agent is a non-flammable material with no flash point.

[0011] Furthermore, the release agent is a transparent material.

[0012] The second aspect of the present invention provides a method for preparing the release agent for lithium ion battery negative electrode rolling described in the first aspect, wherein the fatty alcohol polyoxyethylene ether, sodium carbonate, polydimethylsiloxane and deionized water are mixed and dissolved according to the mass percentage of the raw material components to obtain the release agent.

[0013] Furthermore, the mixed dissolution specifically comprises the following steps:

[0014] S1. First, dissolving sodium carbonate in deionized water to obtain a primary mixed solution;

[0015] S2, adding fatty alcohol polyoxyethylene ether to the primary mixed solution, stirring and dissolving, to obtain an intermediate mixed solution;

[0016] S3, adding polydimethylsiloxane to the intermediate mixed solution, stirring and dissolving to obtain the release agent.

[0017] Furthermore, in S2 and S3, the stirring and dissolving time is independently selected from 30-60 min.

[0018] The third aspect of the present invention provides the use of the release agent for lithium ion battery negative electrode rolling according to the first aspect in cleaning and protecting the surface of a steel roller for lithium ion battery negative electrode rolling.

[0019] Furthermore, the release agent is coated on the surface of the steel roller by wiping, which is convenient and quick to operate.

[0020] Furthermore, the polydimethylsiloxane in the release agent forms a protective film on the surface of the steel roller to prevent the roller from sticking and protect the steel roller from damage.

[0021] Beneficial effects of the present invention:

[0022] The release agent of the present invention has both self-cleaning and anti-sticking roller protection functions, and is also a safe and environmentally friendly release agent, specifically:

[0023] A certain amount of fatty alcohol polyoxyethylene ether and sodium carbonate are added to the release agent component. The two have good emulsifying and softening effects. During the steel roller wiping process, they can effectively wipe and remove foreign matter on the surface of the steel roller and play a good cleaning role.

[0024] By adding a certain amount of polydimethylsiloxane to the release agent component, a thin release film can be formed on the surface of the steel roller during the steel roller wiping process, which can prevent the roller from sticking. At the same time, the release film has good stability to acids, alkalis, oxidants and reducing agents, is not prone to chemical reactions, and can also protect the steel roller, avoiding the problem of easy sticking of the steel roller due to direct rolling, as well as the problem of low product yield and damage to the surface of the steel roller caused by sticking.

[0025] The raw material cost of the invention is low, has no irritating odor, and is harmless to the human body; at the same time, it is pollution-free and is an environmentally friendly material; in addition, the release agent is a non-flash point non-flammable material, avoiding the hidden dangers of safety problems easily caused by flammable and explosive materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the technical solution of the present invention, the drawings required for use in the embodiments are briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0027] Figure 1 is a photograph of a steel roller after being wiped with the release agent prepared in Example 4 of the present invention;

[0028] Figure 2 This is a photograph of the release agent-wiped steel roller prepared in Example 4 of the present invention after the negative electrode rolling process of the lithium-ion battery is carried out. DETAILED DESCRIPTION

[0029] The technical solution of the present invention will be described clearly and completely below in conjunction with the specific embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0030] The present embodiment relates to a release agent for negative electrode rolling of lithium ion batteries, which comprises the following raw material components by mass percentage: 2-10% fatty alcohol polyoxyethylene ether, 1-5% sodium carbonate, 20-60% polydimethylsiloxane, and 30-70% deionized water. Preferably, the release agent comprises the following raw material components: 10% fatty alcohol polyoxyethylene ether, 2% sodium carbonate, 58% polydimethylsiloxane, and 30% deionized water.

[0031] Specifically, the release agent is a non-flammable material with no flash point and is also a transparent material.

[0032] Another embodiment relates to a method for preparing a release agent for lithium-ion battery negative electrode roller pressing, wherein the fatty alcohol polyoxyethylene ether, sodium carbonate, polydimethylsiloxane, and deionized water are mixed and dissolved according to the mass percentage of the raw material components to obtain the release agent. Specifically, the mixed dissolution specifically includes the following steps:

[0033] S1. First, dissolving sodium carbonate in deionized water to obtain a primary mixed solution;

[0034] S2, adding fatty alcohol polyoxyethylene ether to the primary mixed solution, stirring and dissolving, to obtain an intermediate mixed solution;

[0035] S3, adding polydimethylsiloxane to the intermediate mixed solution, stirring and dissolving to obtain the release agent.

[0036] As a specific example, in S2 and S3, the stirring and dissolving time is independently selected from 30-60 minutes.

[0037] Another embodiment provides the use of a release agent for lithium-ion battery negative electrode rolling in cleaning and protecting the surface of a steel roller for lithium-ion battery negative electrode rolling. Specifically, the release agent is coated on the surface of the steel roller by wiping, and the operation is convenient and quick; the polydimethylsiloxane in the release agent forms a protective film on the surface of the steel roller to prevent the roller from sticking and protect the steel roller from damage.

[0038] The following are specific embodiments.

[0039] Example 1

[0040] This embodiment relates to a method for preparing a release agent for roller pressing of a negative electrode of a lithium ion battery, comprising the following steps:

[0041] First, 5 parts of sodium carbonate were added to 70 parts of deionized water, and after it was completely dissolved, 2 parts of fatty alcohol polyoxyethylene ether were added, and stirred for 30 minutes until it was completely dissolved, and finally 23 parts of polydimethylsiloxane were added and stirred for 30 minutes. The product of this embodiment has a colorless and transparent appearance, no irritating odor, and does not burn.

[0042] Example 2

[0043] This embodiment relates to a method for preparing a release agent for roller pressing of a negative electrode of a lithium ion battery, comprising the following steps:

[0044] First, 4 parts of sodium carbonate were added to 50 parts of deionized water, and after it was completely dissolved, 5 parts of fatty alcohol polyoxyethylene ether were added, and stirred for 30 minutes until it was completely dissolved, and finally 31 parts of polydimethylsiloxane were added and stirred for 30 minutes. The product of this embodiment has a colorless and transparent appearance, no irritating odor, and does not burn.

[0045] Example 3

[0046] This embodiment relates to a method for preparing a release agent for roller pressing of a negative electrode of a lithium ion battery, comprising the following steps:

[0047] First, 3 parts of sodium carbonate were added to 40 parts of deionized water, and after it was completely dissolved, 8 parts of fatty alcohol polyoxyethylene ether were added, and stirred for 30 minutes to completely dissolve, and finally 49 parts of polydimethylsiloxane were added and stirred for 30 minutes. The product of this embodiment has a colorless and transparent appearance, no irritating odor, and does not burn.

[0048] Example 4

[0049] This embodiment relates to a method for preparing a release agent for roller pressing of a negative electrode of a lithium ion battery, comprising the following steps:

[0050] First, add 2 parts of sodium carbonate to 30 parts of deionized water, and after it is completely dissolved, add 10 parts of fatty alcohol polyoxyethylene ether, stir for 30 minutes to completely dissolve, and finally add 58 parts of polydimethylsiloxane and stir for 30 minutes. The product of this embodiment has a light yellow transparent appearance, no irritating odor, and does not burn.

[0051] Comparative Example 1

[0052] This comparative example relates to a method for preparing a lithium ion battery negative electrode roller-pressing cleaning agent, comprising the following steps:

[0053] First, add 2 parts of sodium carbonate to 58 parts of deionized water, and after it is completely dissolved, add 40 parts of fatty alcohol polyoxyethylene ether, and stir for 30 minutes to completely dissolve. The product of this embodiment is colorless and transparent in appearance, has no irritating odor, and does not burn.

[0054] Comparative Example 2

[0055] This comparative example relates to a method for preparing a lithium ion battery negative electrode roller-pressing cleaning agent, comprising the following steps:

[0056] First, 2 parts of sodium carbonate were added to 40 parts of deionized water, and after it was completely dissolved, 58 parts of polydimethylsiloxane were added and stirred for 30 minutes to completely dissolve. The product of this embodiment has a light yellow transparent appearance, no irritating odor, and does not burn.

[0057] Comparative Example 3

[0058] This comparative example relates to a method for preparing a lithium ion battery negative electrode roller-pressing cleaning agent, comprising the following steps:

[0059] First, 12 parts of fatty alcohol polyoxyethylene ether were added to 30 parts of deionized water, and after it was completely dissolved, 58 parts of polydimethylsiloxane were added, and stirred for 30 minutes before it was completely dissolved. The product of this embodiment has a light yellow transparent appearance, no irritating odor, and does not burn.

[0060] Comparative Example 4

[0061] This comparative example uses commercially available alcohol as a cleaning agent.

[0062] Test Case

[0063] The products of Examples 1-4 and Comparative Examples 1-4 were used to wipe the steel roller in the same manner and to perform the lithium-ion battery negative electrode rolling process. The performance of each group of products and their application in steel rod cleaning and protection are shown in Table 1.

[0064] Table 1

[0065]

[0066]

[0067] As shown in Table 1, the products of Examples 1-4 of the present invention and Comparative Examples 1-3 are non-flammable materials with no irritating odor and no flash point, and are safe and environmentally friendly. The release agents of Examples 1-4 of the present invention have good cleaning and protection effects when applied to the cleaning and protection of steel rods in the negative electrode rolling process of lithium-ion batteries. Among them, the cleaning and protection effects of Example 4 are the best. The release agent of Example 4 is used to wipe the surface of the steel rod. The photos of the steel roller before and after rolling are as follows: Figure 1 and Figure 2 As shown, it can be seen that the surface of the steel roller is smooth after rolling, and there is no sticking phenomenon. The release agent has an excellent protective effect.

[0068] From the comparison between Example 4 and Comparative Example 1, it can be seen that when polydimethylsiloxane is not added, due to the addition of a large amount of fatty alcohol polyoxyethylene ether, it has an excellent cleaning effect, but cannot play a protective effect on the anti-sticking roller; from the comparison between Example 4 and Comparative Example 2, it can be seen that when fatty alcohol polyoxyethylene ether is not added, the cleaning effect is poor; from the comparison between Example 4 and Comparative Example 3, it can be seen that without adding sodium carbonate, even if the content of fatty alcohol polyoxyethylene ether is increased, it still cannot play an excellent cleaning effect, because the synergistic effect of sodium carbonate and fatty alcohol polyoxyethylene ether can play a better cleaning effect. Comparative Example 4 uses alcohol as a cleaning agent. First, it has a pungent smell and is flammable, which has a safety hazard; secondly, it can only play a cleaning effect, but cannot play a protective effect on the anti-sticking roller.

[0069] In summary, the release agent of the present invention has both self-cleaning and anti-sticking roller protection functions. A certain amount of fatty alcohol polyoxyethylene ether and sodium carbonate are added to the release agent component. The two have good emulsification and softening effects. During the steel roller wiping process, they can effectively wipe and remove foreign matter on the steel roller surface, and play a good cleaning role. In addition, a certain amount of polydimethylsiloxane is added to the release agent component. During the steel roller wiping process, a thin release film can be formed on the steel roller surface to prevent the roller from sticking. At the same time, the release film has good stability to acids, alkalis, oxidants and reducing agents, is not easy to react chemically, and can also protect the steel roller, avoiding the problem of easy sticking to the steel roller due to direct rolling, and the problem of low product yield and damage to the surface of the steel roller caused by sticking to the roller. At the same time, the raw material cost is low, there is no irritating odor, and it is harmless to the human body; at the same time, it is pollution-free to the environment and is an environmentally friendly material; in addition, the release agent is a non-flammable material with no flash point, which avoids the hidden dangers of safety problems caused by flammable and explosive materials.

[0070] The present invention has been described in detail above in conjunction with specific implementations and exemplary examples, but these descriptions cannot be understood as limiting the present invention. Those skilled in the art understand that, without departing from the spirit and scope of the present invention, a variety of equivalent substitutions, modifications or improvements may be made to the technical solution of the present invention and its implementation methods, all of which fall within the scope of the present invention. The scope of protection of the present invention shall be subject to the attached claims.

Claims

1. A release agent for roller pressing of negative electrode of lithium ion battery, characterized in that: The raw material components include the following by mass percentage: 2-10% fatty alcohol polyoxyethylene ether, 1-5% sodium carbonate, 20-60% polydimethylsiloxane and 30-70% deionized water.

2. The release agent for negative electrode roller pressing of lithium ion battery according to claim 1, characterized in that: The raw material components are as follows, calculated by mass percentage: 10% fatty alcohol polyoxyethylene ether, 2% sodium carbonate, 58% polydimethylsiloxane and 30% deionized water.

3. The release agent for negative electrode roller pressing of lithium ion battery according to claim 1, characterized in that: The release agent is a non-flammable material with no flash point.

4. The release agent for negative electrode roller pressing of lithium ion battery according to claim 1, characterized in that: The release agent is a transparent material.

5. A method for preparing a release agent for negative electrode roller pressing of a lithium ion battery according to any one of claims 1 to 4, characterized in that: The fatty alcohol polyoxyethylene ether, sodium carbonate, polydimethylsiloxane and deionized water are mixed and dissolved according to the mass percentage of the raw material components to obtain the release agent.

6. The method for preparing a release agent for negative electrode roller pressing of a lithium ion battery according to claim 5, characterized in that: The mixed dissolution specifically comprises the following steps: S1. First, dissolving sodium carbonate in deionized water to obtain a primary mixed solution; S2, adding fatty alcohol polyoxyethylene ether to the primary mixed solution, stirring and dissolving, to obtain an intermediate mixed solution; S3, adding polydimethylsiloxane to the intermediate mixed solution, stirring and dissolving to obtain the release agent.

7. The method for preparing a release agent for negative electrode roller pressing of a lithium ion battery according to claim 6, characterized in that: In S2 and S3, the stirring and dissolving time is independently selected from 30-60 min.

8. Use of the release agent for lithium ion battery negative electrode rolling according to any one of claims 1 to 4 in cleaning and protecting the surface of a steel roller for lithium ion battery negative electrode rolling.

9. The use according to claim 8, characterized in that The release agent is coated on the surface of the steel roller by wiping.

10. The use according to claim 9, characterized in that The polydimethylsiloxane in the release agent forms a protective film on the surface of the steel roller.

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