Lithium battery adhesive and preparation method thereof

Abstract

The present invention discloses a lithium battery adhesive and a preparation method thereof, belonging to the technical field of lithium ion batteries. The lithium battery adhesive comprises modified lithium carboxymethyl cellulose; the modified lithium carboxymethyl cellulose uses free radical polymerization to introduce a monomer structure containing a large π conjugated structure into the lithium carboxymethyl cellulose, thereby improving its compatibility with negative electrode graphite; the use of two molecules with large π conjugated structures, an acceptor and a donor, can form a more efficient lithium ion transmission channel through intermolecular charge transfer, thereby reducing the internal resistance of the battery.

Description

Technical Field

[0001] The present invention belongs to the technical field of lithium ion batteries, and in particular relates to a lithium battery adhesive and a preparation method thereof. Background Art

[0002] Lithium battery binders are crucial auxiliary functional materials in lithium-ion batteries. Their primary function is to bond the active material, conductive agent, and current collector together. This bonding ensures a cohesive connection between the materials and prevents the active material from decomposing due to chemical and mechanical stress during continuous charging and discharging. Furthermore, binders play a key role in forming a continuous electronic network, helping to create efficient electron and ion pathways, reducing the battery's internal resistance, and promoting good electronic and ionic conductivity within the battery. Therefore, binders play a vital role in improving the overall performance of lithium-ion batteries. Lithium carboxymethyl cellulose is a carboxymethylated derivative of cellulose, a water-soluble ionic cellulose ether obtained through chemical modification. Lithium carboxymethyl cellulose is used in lithium batteries because of its thickening, water-retention, emulsification, and dispersion properties in water. As a new auxiliary material for lithium battery negative electrode adhesives, carboxymethyl cellulose lithium plays two main roles: first, as a binder, it tightly bonds the negative electrode active materials such as graphite and silicon carbon to the current collector, maintaining the stability of the battery during the charge and discharge process; second, as an auxiliary lithium supplement material, it provides a lithium ion reservoir, which can improve the charge and discharge specific capacity and rate performance of lithium batteries. Although carboxymethyl cellulose lithium performs well in graphite negative electrodes, it still has the following shortcomings: carboxymethyl cellulose lithium is an insulator and lacks electronic conductivity. It relies on conductive agents (such as carbon black) in the electrode to provide an electronic conduction path. The insulating property of carboxymethyl cellulose lithium may lead to an increase in the internal resistance of the electrode, limiting the rate performance of the battery; and the problem of matching the interface wettability with graphite. The graphite surface has a certain hydrophobicity, while the strong hydrophilicity of carboxymethyl cellulose lithium may lead to insufficient interface wettability, affecting the uniform dispersion of graphite particles in the slurry and the adhesion of the electrode coating to the current collector. Summary of the Invention

[0003] In order to overcome the shortcomings of the above-mentioned prior art, the present invention provides a lithium battery adhesive, which introduces a large π conjugated structure into lithium carboxymethyl cellulose to obtain modified lithium carboxymethyl cellulose, thereby improving its compatibility with negative electrode graphite; the large π conjugated structure is modified with polyethylene glycol to retain the hydrophilicity of lithium carboxymethyl cellulose; and two molecules with large π conjugated structures, acceptor and donor, are used to form a more efficient lithium ion transmission channel.

[0004] The technical solution for achieving the purpose of the present invention is as follows: a lithium battery adhesive, preferably, the lithium battery adhesive comprises modified lithium carboxymethyl cellulose; the preparation method of the modified lithium carboxymethyl cellulose is as follows:

[0005] S1. Under an inert atmosphere, disperse sodium carboxymethyl cellulose, propylene carboxylic acid monomer, acceptor monomer, donor monomer, and peroxide in water, and disperse silver nitrate in acetonitrile. Mix and stir at 60-80°C for at least 4 h, then vacuum filter. Wash sequentially with alcohol, dilute acid, and deionized water at least twice, and filter to obtain a solid.

[0006] S2. The solid obtained in step S1 is sequentially added with a lithium hydroxide aqueous solution and an alcohol for lithiation and stirred for at least 2 h to obtain a crude product, which is then neutralized, washed, dried, and pulverized to obtain modified lithium carboxymethyl cellulose;

[0007] The receptor monomer has one or more of the following molecular structures:

[0008] ; In formula I, R1 is at least one of methyl and hydrogen; a=1~5; b=20~60;

[0009] The donor monomer has one or more of the following molecular structures:

[0010] ; In formula II, R2 is at least one of methyl and hydrogen; c=1~5; d=20~60.

[0011] Preferably, the alcohol in step S1 is at least one of methanol and ethanol.

[0012] It should be noted that the reason for introducing polyethylene glycol structure into the donor monomer and the acceptor monomer is to improve the water solubility and the dispersibility in the negative electrode material.

[0013] Specifically, the synthesis method of the receptor monomer is:

[0014] (1) Perylene-3,4,9,10-tetracarboxylic dianhydride was dissolved in 5 wt.% potassium hydroxide solution at 85-95 °C and stirred until it was completely dissolved. 10 wt.% acetic acid solution was slowly added dropwise over 3-4 h until the pH was in the range of 4.5-5.5. The addition was stopped and the reactant was burgundy. The mixture was stirred at 85-95 °C for 1-2 h, cooled to room temperature, filtered, and the filter cake was repeatedly washed with deionized water. The filter cake was vacuum dried at 70-90 °C overnight to obtain a burgundy powder solid.

[0015] (2) Add deionized water, 4-5 eq of alcohol amine, and 1 eq of the reddish-brown powder solid obtained in step (1) to the reactor, keep stirring at 25-35 °C for 1.5-3 h. After the color changes from green to red, heat the solution to 85-95 °C for 2-3 h, add 1-2 mol / L hydrochloric acid solution, continue stirring at 85-95 °C for 1.5-3 h, cool to room temperature, filter, repeatedly wash the filter cake with deionized water, and vacuum dry at 70-90 °C overnight to obtain a reddish-purple powder solid;

[0016] (3) Under an argon atmosphere, 1.0-3.0 eq of the purple-red powder solid obtained in step (2), 1 eq of aminopolyethylene glycol monomethyl ether, and 15-25 eq of imidazole were dissolved in dimethylacetamide, the temperature was raised to 130-140 °C, and the mixture was stirred for 20-24 h. After the solution was cooled, the solid was filtered out, and the dimethylacetamide was removed by vacuum distillation to obtain a solid. The solid was dissolved in DCM, and the excess imidazole was removed with 1-2 mol / L hydrochloric acid. The organic phase was collected, dried over anhydrous magnesium sulfate, and filtered. The excess solvent was removed by rotary evaporation to obtain a red solid.

[0017] (4) Weigh 1 eq of the red solid obtained in step (3) and add it to a reactor. Add anhydrous dichloromethane and 2-3 eq of triethylamine. Disperse 1.2-2.0 eq of acryloyl chloride in dichloromethane and slowly add it dropwise to the mixture at 0-5 °C under an argon atmosphere. After reacting for 10-12 h, wash the organic phase with 1-2 mol / L hydrochloric acid and 1-2 mol / L sodium hydroxide solution, respectively. Collect the organic phase, dry it with anhydrous magnesium sulfate, filter it, and remove the excess solvent on a rotary evaporator to obtain the receptor monomer.

[0018] Specifically, the synthesis method of the donor monomer is:

[0019] Compared with the preparation method of the above-mentioned receptor monomer, the difference is that (I) in step (1), perylene-3,4,9,10-tetracarboxylic dianhydride is replaced with tetrachloroperylene anhydride; (II) before performing step (4), the product obtained in step (3) is reacted with phenol, and then the reaction in step (4) is performed. The specific operation is as follows:

[0020] 1 eq of the product obtained in step (3), 10-20 eq of phenol and 10-20 eq of potassium carbonate are dispersed in N-methylpyrrolidone at 130-140 °C under argon protection and stirred for 14-18 h. The reaction mixture is then poured into a 1-2 mol / L aqueous hydrochloric acid solution and stirred at room temperature for 1-2 h. The precipitate is collected by vacuum filtration and washed with water. The purple solid is vacuum dried at 130 °C to obtain the target product, and then the reaction in step (4) is carried out to obtain the donor monomer.

[0021] Preferably, the mass ratio of the sodium carboxymethyl cellulose, peroxide and silver nitrate is (1-3): (2-4): (0.05-0.25); the mass ratio of water to acetonitrile is (0.8-1.2): (0.8-1.2).

[0022] Preferably, the mass ratio of the sodium carboxymethyl cellulose, the carboxylic acid monomer, the acceptor monomer and the donor monomer is (250-400): (150-300): (5-10): (0.5-1).

[0023] Preferably, the propylene carboxylic acid monomer has one or more of the following molecular structures:

[0024] , ; In formula III, R3 and R4 are independently at least one of methyl and hydrogen; e=1~5.

[0025] Preferably, in step S1, the alcohol is methanol, and the dilute acid is 1-2 mol / L hydrochloric acid; in step S2, the mass fraction of the lithium hydroxide aqueous solution is 5-12 wt.%, the volume ratio of the alcohol to the lithium hydroxide aqueous solution is (1:1)-(1:3), the alcohol is at least one of methanol, ethanol and isopropanol, and the temperature of the lithiation reaction is 20-50 °C.

[0026] Preferably, the neutralization treatment in step S2 is to add glacial acetic acid to adjust the pH to 7-9, the washing is performed by at least one of water and ethanol; the drying is performed by at least one of drying at 60-70°C under vacuum and drying at 90-110°C under normal pressure; and the particle size of the modified lithium carboxymethyl cellulose obtained after the pulverization treatment is not less than 200 mesh.

[0027] Beneficial effects

[0028] The present invention has the following beneficial effects: the present invention provides a lithium battery adhesive, which introduces a large π conjugated structure into lithium carboxymethyl cellulose to obtain modified lithium carboxymethyl cellulose, and enhances the interfacial bonding between the lithium carboxymethyl cellulose and graphite through π-π interaction, thereby improving its compatibility with negative electrode graphite; the large π conjugated structure is modified with polyethylene glycol, retaining the hydrophilicity of the lithium carboxymethyl cellulose; and the use of two molecules with large π conjugated structures, an acceptor and a donor, can form a more efficient lithium ion transmission channel through intermolecular charge transfer, thereby reducing the internal resistance of the battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 Schematic diagram of the synthetic route of modified lithium carboxymethyl cellulose;

[0030] Figure 2 is the H NMR spectrum of the receptor monomer;

[0031] Figure 3 This is the H NMR spectrum of the donor monomer. DETAILED DESCRIPTION

[0032] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described 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 making any creative efforts are within the scope of protection of the present invention.

[0033] In the examples, the experimental methods used are conventional methods unless otherwise specified, and the materials, reagents, etc. used are all commercially available unless otherwise specified.

[0034] The raw materials and equipment used in the embodiments and comparative examples are described below:

[0035] Sodium carboxymethyl cellulose: homemade or commercially available, MW250,000 (DS=0.9), 1500-3100 mPa.s;

[0036] Propylene carboxylic acid monomer: acrylic acid, purchased from Maclean;

[0037] Silver nitrate: purchased from Sinopharm Reagent;

[0038] Peroxide: potassium persulfate, purchased from Sinopharm Reagent;

[0039] Ethanolamine: purchased from Maclean;

[0040] Acryloyl chloride: purchased from Maclean;

[0041] Lithium hydroxide: purchased from Maclean;

[0042] Polyvinylidene fluoride (PVDF): purchased from MacLean;

[0043] Perylene-3,4,9,10-tetracarboxylic dianhydride: purchased from MacLean;

[0044] Tetrachloroperylene anhydride: purchased from Maclean;

[0045] Polyethylene glycol monomethyl ether 1: average molecular weight 1000, purchased from Maclean;

[0046] Polyethylene glycol monomethyl ether 2: average molecular weight 2000, purchased from Maclean;

[0047] Polyethylene glycol monomethyl ether 3: average molecular weight 350, purchased from MacLean;

[0048] Polyethylene glycol monomethyl ether 4: average molecular weight 5000, purchased from Maclean;

[0049] Imidazole: purchased from Maclean;

[0050] Phenol: purchased from Maclean.

[0051] Aminopolyethylene glycol monomethyl ether 1 (self-made or commercially available): The self-made method is to prepare polyethylene glycol monomethyl ether 1 by a conventional hydroxyl amination method, first reacting p-toluenesulfonyl chloride with the hydroxyl group, and then dispersing the product in ammonia water for reaction.

[0052] Aminopolyethylene glycol monomethyl ether 2~4 (self-made or commercially available): Compared with 1, the same preparation method is used, except that polyethylene glycol monomethyl ether 1 is replaced by polyethylene glycol monomethyl ether 2~4.

[0053] Receptor monomer 1

[0054] (1) Perylene-3,4,9,10-tetracarboxylic dianhydride was dissolved in 5 wt.% potassium hydroxide solution at 90 °C and stirred until it was completely dissolved. 10 wt.% acetic acid solution was slowly added dropwise over 3 h until the pH was in the range of 4.5-5.5. The addition was stopped and the reactant was burgundy. Stirring was continued at 90 °C for 2 h. The mixture was cooled to room temperature and filtered. The filter cake was repeatedly washed with deionized water and vacuum dried at 80 °C overnight to obtain a burgundy powder solid.

[0055] (2) Deionized water, 4 eq of ethanolamine, and 1 eq of the reddish-brown powder solid obtained in step (1) were added to the reactor, and the mixture was stirred at 30 °C for 2 h. After the color changed from green to red, the solution was heated to 90 °C for 2 h, and 1 mol / L hydrochloric acid solution was added. The mixture was stirred at 90 °C for 2 h, cooled to room temperature, filtered, and the filter cake was repeatedly washed with deionized water. The filter cake was vacuum dried at 80 °C overnight to obtain a reddish-purple powder solid.

[0056] (3) Under argon atmosphere, 1 eq of the purple-red powder solid obtained in step (2), 1 eq of aminopolyethylene glycol monomethyl ether, and 20 eq of imidazole were dissolved in dimethylacetamide, heated to 130 °C, and stirred for 22 h. After the solution was cooled, the solid was filtered out, and dimethylacetamide was removed by vacuum distillation to obtain a solid. The solid was dissolved in DCM, and the excess imidazole was removed with 1 mol / L hydrochloric acid. The organic phase was collected, dried over anhydrous magnesium sulfate, filtered, and the excess solvent was removed by rotary evaporation to obtain a red solid.

[0057] (4) Weigh 1 eq of the red solid obtained in step (3) and add it to a reactor. Add anhydrous dichloromethane and 2 eq of triethylamine. Disperse 1.8 eq of acryloyl chloride in dichloromethane and slowly add it dropwise to the mixture at 0-5 °C under an argon atmosphere. After reacting for 12 h, wash the organic phase with 1 mol / L hydrochloric acid and 1 mol / L sodium hydroxide solution, respectively. Collect the organic phase, dry it with anhydrous magnesium sulfate, filter it, and remove the excess solvent on a rotary evaporator to obtain the receptor monomer 1.

[0058] Receptor monomers 2~4

[0059] Compared with the preparation method of the receptor monomer 1, the difference is that the amino polyethylene glycol monomethyl ether 1 in step (3) is replaced by amino polyethylene glycol monomethyl ethers 2 to 4.

[0060] Donor monomer 1~4

[0061] Compared with the preparation method of the receptor monomers 1 to 4, the difference is that (I) in step (1), perylene-3,4,9,10-tetracarboxylic dianhydride is replaced with tetrachloroperylene anhydride; (II) before performing step (4), the product obtained in step (3) is reacted with phenol, and then the reaction in step (4) is performed. The specific operation is as follows:

[0062] 1 eq of the product obtained in step (3), 15 eq of phenol and 15 eq of potassium carbonate were dispersed in N-methylpyrrolidone at 140 °C under argon protection and stirred for 16 h. The reaction mixture was then poured into a 1 mol / L aqueous hydrochloric acid solution and stirred at room temperature for 2 h. The precipitate was collected by vacuum filtration and washed with water. The purple solid was vacuum dried at 130 °C to obtain the target product. The reaction was then carried out in step (4) to obtain donor monomer 1 (the preparation method of donor monomer 1 corresponds to that of acceptor monomer 1, the preparation method of donor monomer 2 corresponds to that of acceptor monomer 2, and so on).

[0063] The following are the test methods for the performance parameters involved in the present invention:

[0064] Peel test: The evaluation of adhesion performance is usually carried out through peel strength test. When performing the peel strength test, the pre-prepared electrode sheet is first attached to the aluminum plate substrate, and then firmly attached to the electrode-coated surface with 3M tape. The specific operation is to stick a 120×25 mm electrode sample on 3M transparent tape, stick it on the coating and pull it at a 180° angle. The force required to pull the tape at a fixed speed of 100 mm / min was recorded. The electrode sheet was prepared by weighing graphite, acetylene black, SBR, and modified carboxymethyl cellulose lithium (or other binder) in a mass ratio of 95:1.5:1.5:2. The modified carboxymethyl cellulose lithium (binder) was dissolved in a solvent, and solvent was added as needed based on the solution viscosity. The weighed graphite, acetylene black, and SBR were ground in an agate mortar and pestle. After mixing thoroughly, the dissolved modified carboxymethyl cellulose lithium (or other binder) was added. An appropriate amount of solvent was added again based on the slurry viscosity. The beaker was sealed with plastic wrap and stirred on a stirrer for 12 hours. The stirred electrode slurry was then coated on copper foil that had been wiped with anhydrous ethanol and dried to produce the electrode sheet. The electrode sheet was then dried in a 50°C oven for 12 hours to obtain the electrode sheet.

[0065] Electrochemical impedance spectroscopy: The self-made negative electrode sheet was used, the electrolyte was 1.0 mol / L LiPF6 ethylene carbonate: diethyl carbonate: dimethyl carbonate = 1:1:1 (mass ratio), and LiFePO4 was used as the counter electrode. Conventional PVDF was used as a binder to adhere to aluminum foil. The test was performed using an electrochemical workstation (CHI660D) with a frequency range of 0.01-100 kHz. The semicircular area observed at high frequencies corresponds to the Li + The resistance to charge transfer.

[0066] Example 1

[0067] S1. Under an inert atmosphere, disperse 25 g of sodium carboxymethyl cellulose, 15 g of propylene carboxylic acid monomer, 0.5 g of acceptor monomer 1, 0.05 g of donor monomer 1, and 3 g of peroxide in 1000 g of water. Disperse 1 g of silver nitrate in 1000 g of acetonitrile. Mix and stir at 70°C for 5 h. Vacuum filter the mixture and wash it twice with methanol, dilute acid, and deionized water. Filter to obtain a solid.

[0068] S2. The solid obtained in step S1 was added with 10 wt.% lithium hydroxide aqueous solution and methanol in sequence for lithiation, the volume ratio of lithium hydroxide aqueous solution to methanol being 1:1, the temperature being 45°C, and stirred for 3 h to obtain a crude product, which was then adjusted to pH 8 by adding glacial acetic acid, washed twice with water and ethanol in sequence, dried, and crushed to a particle size of not less than 200 mesh to obtain modified carboxymethyl cellulose lithium 1.

[0069] Example 2

[0070] Compared with the preparation method of Example 1, the difference is that “25 g of sodium carboxymethyl cellulose, 15 g of propylene carboxylic acid monomer, 0.5 g of acceptor monomer 1, 0.05 g of donor monomer 1 and 3 g of peroxide are dispersed in 1000 g of water” is replaced by “40 g of sodium carboxymethyl cellulose, 30 g of propylene carboxylic acid monomer, 1 g of acceptor monomer, 0.1 g of donor monomer and 3 g of peroxide are dispersed in 1000 g of water”.

[0071] Example 3

[0072] Compared with the preparation method of Example 1, the difference is that the acceptor monomer 1 is replaced by the acceptor monomer 2, and the donor monomer 1 is replaced by the donor monomer 2.

[0073] Example 4

[0074] Compared with the preparation method of Example 1, the difference is that 0.5 g of acceptor monomer 1 and 0.05 g of donor monomer 1 are replaced by 0.75 g of acceptor monomer 1 and 0.075 g of donor monomer 1.

[0075] Example 5

[0076] Compared with the preparation method of Example 1, the difference is that 0.5 g of acceptor monomer 1 and 0.05 g of donor monomer 1 are replaced by 1.0 g of acceptor monomer 1 and 0.1 g of donor monomer 1.

[0077] Comparative Example 1

[0078] Compared with the preparation method of Example 1, the difference is that the acceptor monomer 1 is replaced by the acceptor monomer 3, and the donor monomer 1 is replaced by the donor monomer 3.

[0079] Comparative Example 2

[0080] Compared with the preparation method of Example 1, the difference is that the acceptor monomer 1 is replaced by the acceptor monomer 4, and the donor monomer 1 is replaced by the donor monomer 4.

[0081] Comparative Example 3

[0082] Compared with the preparation method of Example 1, the difference is that 0.05 g of donor monomer 1 is replaced by 0.05 g of acceptor monomer 1.

[0083] Comparative Example 4

[0084] Compared with the preparation method of Example 1, the difference is that 0.5 g of acceptor monomer 1 is replaced by 0.5 g of donor monomer 1.

[0085] Comparative Example 5

[0086] Lithium carboxymethyl cellulose obtained by acidifying, lithiating and treating sodium carboxymethyl cellulose is used as a binder.

[0087] Table 1 Performance test of examples and comparative examples

[0088]

[0089] As can be seen from the data of Example 1, Example 3, Comparative Example 1, and Comparative Example 2 in Table 1, when the molecular weight of the polyethylene glycol chain modified with the acceptor monomer and the donor monomer is too large or too small, it will affect the peel strength of the adhesive and the internal resistance of the battery. If the molecular weight of the polyethylene glycol chain is too large, the internal resistance of the battery will increase; while if the molecular weight is too small, the water solubility of the molecules with large π conjugated structures is poor, which reduces the peel strength of the adhesive. As can be seen from the data of Example 1, Example 4, and Example 5, within a certain range, as the content of the acceptor monomer and the donor monomer increases, the peel strength first increases and then decreases, and the internal resistance of the battery gradually decreases. As can be seen from the data of Comparative Examples 3 and 4, the internal resistance of the battery is relatively large. This is because it contains only one monomer structure, which reduces the electron transfer ability between its molecules, thereby increasing the internal resistance.

[0090] The preferred embodiments of the present invention disclosed above are intended only to help illustrate the present invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the present invention to the specific embodiments described. Obviously, many modifications and variations are possible based on the content of this specification. These embodiments are selected and described in detail in this specification to better explain the principles and practical applications of the present invention, thereby enabling those skilled in the art to better understand and utilize the present invention. The present invention is limited only by the claims and their full scope and equivalents.

Claims

1. A lithium battery adhesive, characterized in that: The lithium battery binder includes modified lithium carboxymethyl cellulose; the preparation method of the modified lithium carboxymethyl cellulose is as follows: S1. Under an inert atmosphere, disperse sodium carboxymethyl cellulose, propylene carboxylic acid monomer, acceptor monomer, donor monomer, and peroxide in water, and disperse silver nitrate in acetonitrile. Mix and stir at 60-80°C for at least 4 h, then vacuum filter. Wash sequentially with alcohol, dilute acid, and deionized water at least twice, and filter to obtain a solid. S2. The solid obtained in step S1 is sequentially added with a lithium hydroxide aqueous solution and an alcohol for lithiation and stirred for at least 2 h to obtain a crude product, which is then neutralized, washed, dried, and pulverized to obtain modified lithium carboxymethyl cellulose; The receptor monomer has one or more of the following molecular structures: ; In formula I, R1 is at least one of methyl and hydrogen; a=1~5; b=20~60; The donor monomer has one or more of the following molecular structures: ; In formula II, R2 is at least one of methyl and hydrogen; c=1~5; d=20~60.

2. A lithium battery adhesive according to claim 1, characterized in that: The mass ratio of the sodium carboxymethyl cellulose, peroxide and silver nitrate is (1-3): (2-4): (0.05-0.25); the mass ratio of water to acetonitrile is (0.8-1.2): (0.8-1.2).

3. The lithium battery adhesive according to claim 1, wherein The mass ratio of the sodium carboxymethyl cellulose, the carboxylic acid monomer, the acceptor monomer and the donor monomer is (250-400): (150-300): (5-10): (0.5-1).

4. The lithium battery adhesive according to claim 1, wherein The propylene carboxylic acid monomer has one or more of the following molecular structures: , ; In formula III, R3 and R4 are independently at least one of methyl and hydrogen, and e=1~5.

5. The lithium battery adhesive according to claim 1, wherein In step S1, the alcohol is methanol, and the dilute acid is 1-2 mol / L hydrochloric acid; in step S2, the mass fraction of the lithium hydroxide aqueous solution is 5-12 wt.%, the volume ratio of the alcohol to the lithium hydroxide aqueous solution is (1:1)-(1:3), the alcohol is at least one of methanol, ethanol and isopropanol, and the temperature of the lithiation reaction is 20-50°C.

6. The lithium battery adhesive according to claim 1, wherein: The neutralization treatment in step S2 is to add glacial acetic acid to adjust the pH to 7-9, the washing is performed by at least one of water and ethanol; the drying is performed by at least one of drying at 60-70°C under vacuum and drying at 90-110°C under normal pressure; and the particle size of the modified lithium carboxymethyl cellulose obtained after the pulverization treatment is not less than 200 mesh.

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