CN115246889A - Lithium carboxymethyl cellulose and preparation method and application thereof - Google Patents
Lithium carboxymethyl cellulose and preparation method and application thereof Download PDFInfo
- Publication number
- CN115246889A CN115246889A CN202211164265.6A CN202211164265A CN115246889A CN 115246889 A CN115246889 A CN 115246889A CN 202211164265 A CN202211164265 A CN 202211164265A CN 115246889 A CN115246889 A CN 115246889A
- Authority
- CN
- China
- Prior art keywords
- lithium
- cellulose
- carboxymethyl cellulose
- lithium hydroxide
- chloroacetic acid
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Images
Classifications
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08B—POLYSACCHARIDES; DERIVATIVES THEREOF
- C08B11/00—Preparation of cellulose ethers
- C08B11/02—Alkyl or cycloalkyl ethers
- C08B11/04—Alkyl or cycloalkyl ethers with substituted hydrocarbon radicals
- C08B11/10—Alkyl or cycloalkyl ethers with substituted hydrocarbon radicals substituted with acid radicals
- C08B11/12—Alkyl or cycloalkyl ethers with substituted hydrocarbon radicals substituted with acid radicals substituted with carboxylic radicals, e.g. carboxymethylcellulose [CMC]
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
- C08G65/00—Macromolecular compounds obtained by reactions forming an ether link in the main chain of the macromolecule
- C08G65/02—Macromolecular compounds obtained by reactions forming an ether link in the main chain of the macromolecule from cyclic ethers by opening of the heterocyclic ring
- C08G65/26—Macromolecular compounds obtained by reactions forming an ether link in the main chain of the macromolecule from cyclic ethers by opening of the heterocyclic ring from cyclic ethers and other compounds
- C08G65/2603—Macromolecular compounds obtained by reactions forming an ether link in the main chain of the macromolecule from cyclic ethers by opening of the heterocyclic ring from cyclic ethers and other compounds the other compounds containing oxygen
- C08G65/2606—Macromolecular compounds obtained by reactions forming an ether link in the main chain of the macromolecule from cyclic ethers by opening of the heterocyclic ring from cyclic ethers and other compounds the other compounds containing oxygen containing hydroxyl groups
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
- C08G65/00—Macromolecular compounds obtained by reactions forming an ether link in the main chain of the macromolecule
- C08G65/02—Macromolecular compounds obtained by reactions forming an ether link in the main chain of the macromolecule from cyclic ethers by opening of the heterocyclic ring
- C08G65/26—Macromolecular compounds obtained by reactions forming an ether link in the main chain of the macromolecule from cyclic ethers by opening of the heterocyclic ring from cyclic ethers and other compounds
- C08G65/2696—Macromolecular compounds obtained by reactions forming an ether link in the main chain of the macromolecule from cyclic ethers by opening of the heterocyclic ring from cyclic ethers and other compounds characterised by the process or apparatus used
-
- 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
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Health & Medical Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Medicinal Chemistry (AREA)
- Polymers & Plastics (AREA)
- Engineering & Computer Science (AREA)
- Biochemistry (AREA)
- Materials Engineering (AREA)
- Life Sciences & Earth Sciences (AREA)
- Polysaccharides And Polysaccharide Derivatives (AREA)
- Compositions Of Macromolecular Compounds (AREA)
- Battery Electrode And Active Subsutance (AREA)
Abstract
The invention discloses a preparation method of lithium carboxymethyl cellulose, which comprises the following steps: adding cellulose and lithium hydroxide into an alcohol-containing aqueous solution, uniformly stirring, and reacting at 20-40 ℃ for 2-4h; adding bis-epoxidized butadiene, continuously controlling the temperature to be 20-40 ℃, and stirring for reaction for 1-3h; adding alcoholic solution of chloroacetic acid, raising the temperature to 40-75 ℃ after adding, and reacting for 1-3h; obtaining crude carboxymethyl cellulose lithium; neutralizing the crude lithium carboxymethyl cellulose with an acidic substance to be neutral, washing with an ethanol water solution, drying and crushing to obtain the lithium carboxymethyl cellulose. According to the preparation method of the lithium carboxymethyl cellulose, the structure of the cellulose molecule is subjected to flexible chain modification, so that the rigidity of the cellulose structure is overcome, and the product has certain flexibility; can improve the flexibility and the bendability of the product prepared by adding the lithium carboxymethyl cellulose.
Description
Technical Field
The invention relates to the technical field of cellulose chemical modification, in particular to a preparation method of lithium carboxymethyl cellulose, lithium carboxymethyl cellulose prepared by the preparation method and application of the lithium carboxymethyl cellulose in a lithium battery.
Background
Lithium carboxymethyl cellulose is a carboxymethylated derivative of cellulose, which is chemically modified to obtain a water-soluble ionic cellulose ether. Because the carboxymethyl cellulose lithium has the characteristics of thickening, water retention, emulsification and dispersion in water, the carboxymethyl cellulose lithium is applied to lithium batteries. However, the carbon chain skeleton of the natural cellulose is a chair-type six-membered ring structure connected by beta-1,4-glycosidic bonds, the ring-type main chain molecule of the structure cannot rotate freely, and the appearance is that the prepared film and other products have rigidity, and the main chain structure cannot be changed even if carboxymethylation modification is adopted. Therefore, the colloid containing the lithium carboxymethyl cellulose has certain brittleness after dehydration, and has the problems of difficult bending, easy powder falling after bending, easy fracture after folding and the like.
In the preparation of graphite negative electrodes for batteries, a combination of lithium carboxymethyl cellulose and Styrene Butadiene Rubber (SBR) is often used as a binder. Although SBR is a soft binding material, the added lithium carboxymethyl cellulose has rigidity, and particularly, when a pole piece with a relatively thick coating or the added lithium carboxymethyl cellulose with a high proportion is used, the phenomena of powder falling and cracking of a graphite layer and a basal layer can occur in the folding and bending process of the battery at the later stage, so that the quality problem of the battery is caused.
Chinese patent application CN 102206286A discloses a preparation method of lithium carboxymethyl cellulose for a lithium battery. The sodium carboxymethyl cellulose is firstly acidified and washed to obtain carboxymethyl cellulose hydrogen, and then the carboxymethyl cellulose hydrogen reacts with lithium hydroxide to prepare the lithium carboxymethyl cellulose. The carboxymethyl cellulose lithium prepared by the method still has a chair-type six-membered ring structure connected by beta-1,4-glycosidic bonds of cellulose, and is easy to lose powder when folded and bent when the use concentration of the carboxymethyl cellulose lithium is high or the battery graphite coating is relatively thick.
Chinese patent CN106336461B discloses another preparation method of lithium carboxymethyl cellulose. Namely, cellulose is alkalized in lithium hydroxide and then chloroacetic acid is added for etherification, and finally, the carboxymethyl cellulose lithium is obtained. The structure of the carboxymethyl cellulose lithium prepared by the method is also a six-membered ring structure connected by glycosidic bonds, and the prepared colloid has rigidity after being dried, so that the application of the colloid in the battery is also limited.
The above background disclosure is only for the purpose of assisting understanding of the inventive concept and technical solutions of the present invention, and does not necessarily belong to the prior art of the present patent application, and should not be used for evaluating the novelty and inventive step of the present application in the case that there is no clear evidence that the above content has been disclosed before the filing date of the present patent application.
Disclosure of Invention
In view of the above, in order to overcome the defects of the prior art, the present invention provides an improved method for preparing lithium carboxymethyl cellulose, which performs flexible chain modification on the structure of cellulose molecules.
In order to achieve the purpose, the invention adopts the following technical scheme:
a preparation method of lithium carboxymethyl cellulose comprises the following steps:
adding cellulose and lithium hydroxide such as lithium hydroxide monohydrate or lithium hydroxide into alcohol-containing aqueous solution, stirring, and reacting at 20-40 deg.C for 2-4 hr;
adding double-epoxidation butadiene, continuously controlling the temperature to be 20-40 ℃, and stirring for reacting for 1-3h;
adding alcoholic solution of chloroacetic acid, raising the temperature to 40-75 ℃ after adding, and reacting for 1-3h; obtaining crude carboxymethyl cellulose lithium;
and carrying out post-treatment on the crude lithium carboxymethyl cellulose to obtain the lithium carboxymethyl cellulose.
Lithium hydroxide is added into cellulose to activate the cellulose, for example, crystalline regions of the cellulose are destroyed, hydroxyl groups in the crystalline regions are fully exposed, the contact chance with small molecule reactants is increased, the reactivity and uniformity of the cellulose at the later stage are increased, and the subsequent alkaline condition also needs to be provided with the lithium hydroxide. The method adopts the bis-epoxidized butadiene to flexibly modify cellulose molecules, on one hand, the bis-epoxidized butadiene has moderate reaction activity, is relatively stable under neutral conditions, is easy to generate nucleophilic substitution reaction under alkaline conditions, can be matched with the preparation process of the lithium carboxymethyl cellulose, and has simple steps and controllable reaction; on the other hand, the molecular weight of butadiene diepoxide is relatively small, and when finished products with the same viscosity (the same viscosity can be approximately regarded as the same molecular weight) are prepared, more embedding points can be provided, so that the products have better flexibility.
According to some preferred embodiments of the invention, when the lithium hydroxide material is lithium hydroxide monohydrate, the mass ratio of the cellulose to the lithium hydroxide monohydrate is 1.
According to some preferred embodiments of the invention, the cellulose has a molecular weight of 2000 to 250000. If cellulose with larger molecular weight is selected as a basic reactant, the molecular weight of a final product is increased sharply, so that insoluble substances in an aqueous solution of the final product are increased, the phenomenon of net blocking of battery slurry at a later stage is caused, and the production efficiency of the battery is reduced.
According to some preferred aspects of the invention, the concentration of cellulose in the system after addition of cellulose and lithium hydroxide monohydrate to the alcoholic aqueous solution is from 400 to 1000g/L. If the cellulose concentration is too high, the absorption and extrusion effects of the cellulose in the kneader are poor, and the kneading resistance during the kneading process is obviously increased; if the cellulose concentration is too low, the reactant concentration is diluted, the conversion rate of the reaction decreases, and the cost increases.
According to some preferred embodiments of the invention, the alcohol concentration of the alcohol-containing aqueous solution is 50 to 98% by volume.
According to some preferred embodiments of the invention, the mass ratio of the cellulose to butadiene dioxide is 1. If the mass ratio of the selected bis-epoxybutadiene to the cellulose is too high, the reaction can be continuously carried out, the molecular weight of the product after the reaction is continuously increased, and finally, insoluble substances in the aqueous solution of the product are increased, so that the production efficiency of the battery is influenced; if the mass ratio of the diepoxybutadiene to the cellulose is too small, the molecular weight of the generated product is small, the viscosity of the aqueous solution of the product is low, and when battery slurry with the same viscosity is prepared, the use amount of the product needs to be increased, so that the energy density of the battery is indirectly influenced.
According to some preferred embodiments of the invention, the mass ratio of the cellulose to the chloroacetic acid is 1. If the mass ratio of the selected chloroacetic acid to the cellulose is too low, the hydroxyl substitution degree of the product after reaction is too low, the water solubility of the product is poor, a large amount of insoluble substances appear, and the later-stage screening and coating are affected; if the mass ratio of the selected chloroacetic acid to the cellulose is too high, the degree of hydroxyl substitution of the product is very high, so that the adsorption force of the product on the graphite surface is reduced, graphite powder in the battery slurry is easy to settle and delaminate, and the coating uniformity and the battery quality are affected.
According to some preferred aspects of the invention, the alcoholic solution of chloroacetic acid has a mass fraction of 50-90% in terms of chloroacetic acid in the alcoholic solution.
According to some preferred aspects of the invention, the alcoholic solution of chloroacetic acid is added for a period of 30-60min. If the chloroacetic acid is added for too short time, the reaction is not uniform, and a large amount of insoluble substances appear in the product aqueous solution; too long chloroacetic acid addition time increases reaction time and increases production cost.
According to some preferred embodiments of the invention, the alcohol in the alcoholic solution of alcoholic solution and chloroacetic acid is one or more of ethanol, propanol, butanol, isopropanol.
According to some preferred embodiments of the present invention, the post-treatment step is to neutralize the crude lithium carboxymethyl cellulose with an acidic substance, and then wash, dry and pulverize the neutralized product.
According to some preferred embodiments of the invention, the acidic substance is acetic acid and/or hydrochloric acid.
According to some preferred embodiments of the present invention, the washing is performed by washing with an aqueous ethanol solution for a plurality of times, preferably, an aqueous ethanol solution having a mass concentration of 75%.
According to some preferred implementation aspects of the invention, the drying condition is constant temperature in a forced air oven for 2 hours at 100-110 ℃.
The invention also provides the lithium carboxymethyl cellulose prepared by the preparation method of the lithium carboxymethyl cellulose and the application of the lithium carboxymethyl cellulose in a lithium battery. Specifically, in the preparation process of the negative electrode slurry of the battery, the lithium carboxymethyl cellulose is added to prepare a lithium carboxymethyl cellulose aqueous solution, then graphite, conductive graphite powder and SBR are added, the mixture is uniformly stirred and coated on a copper foil, and then the negative electrode of the battery is prepared through drying, extruding and curling in sequence.
The basic principle of the invention is as follows: under alkaline condition, the bis-epoxidized butadiene can generate nucleophilic substitution reaction with hydroxyl on cellulose, a flexible chain connected by ether bonds is embedded between the small molecular weight cellulose, and finally the obtained cellulose contains two molecular chains of rigid six-membered ring chain and flexible ether chain. The macromolecular structure containing the two chain segments has high strength and high flexibility, and after further carboxymethylation, the obtained carboxymethyl cellulose lithium also has the performance, so that the bending resistance of the carboxymethyl cellulose lithium can be improved, and the problems that the coating is easy to break and fall off after being bent are solved.
The reaction principle of the invention is shown as the following formula:
wherein R is 1 Is H or Li, R 2 Is H or CH 2 COOLi, m and n are natural numbers larger than 0.
By adopting the technical scheme, compared with the prior art, the invention has the advantages that: according to the preparation method of the lithium carboxymethyl cellulose, disclosed by the invention, the structure of cellulose molecules is subjected to flexible chain modification through bis-epoxidized butadiene, so that the rigidity of the cellulose structure is overcome, and the product has certain flexibility; in practical application, the flexibility and the bendability of the product prepared by adding the lithium carboxymethyl cellulose can be improved, the condition limitation of the application of the lithium carboxymethyl cellulose is reduced, and the application range of the lithium carboxymethyl cellulose is expanded.
Drawings
In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the description below are only some embodiments of the present invention, and it is obvious for those skilled in the art that other drawings can be obtained according to the drawings without creative efforts.
FIG. 1 is a photograph of a lithium battery prepared using lithium carboxymethyl cellulose of example 2 of the present invention after U-crimping the negative electrode;
fig. 2 is a photograph after U-crimping of a negative electrode of a lithium battery prepared using commercially available lithium carboxymethyl cellulose.
Detailed Description
In order to make those skilled in the art better understand the technical solutions of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
The invention aims to provide a preparation method of embedded flexible group modified lithium carboxymethyl cellulose, which is used for carrying out flexible chain modification on a structure of a cellulose molecule, overcomes the rigidity of the cellulose structure, and ensures that a product has certain flexibility so as to solve the problems of rigidity generated after colloid dehydration of the conventional lithium carboxymethyl cellulose and easy powder falling and cracking of a coating after bending. In order to achieve such an object, the method for preparing lithium carboxymethyl cellulose of the present invention comprises the steps of:
(1) Alkalization of cellulose
Adding cellulose with the molecular weight of 2000-250000 and lithium hydroxide monohydrate into an alcohol-containing aqueous solution together, wherein the mass ratio of the cellulose to the lithium hydroxide monohydrate is (1) from 0.3 to 1, the concentration of the cellulose in the system is 400-1000g/L, stirring uniformly, reacting for 2-4h, and controlling the temperature to be 20-40 ℃. The alcohol volume concentration of the alcohol-containing aqueous solution is 50-98%.
(2) Grafting of cellulose
Adding the double epoxidation butadiene, continuously controlling the temperature at 20-40 ℃, and stirring for reaction for 1-3h. The mass ratio of cellulose to butadiene diepoxide is 1.
(3) Cellulose etherification
Adding alcoholic solution of chloroacetic acid, and controlling the adding time at 30-60min. Then raising the temperature to 40-75 ℃ and reacting for 1-3h; crude lithium carboxymethylcellulose was obtained.
The mass ratio of the cellulose to the chloroacetic acid is 1; the mass concentration of the chloroacetic acid in the alcoholic solution is 50-90%.
(4) Post-treatment
After the reaction is finished, neutralizing the crude lithium carboxymethyl cellulose to be neutral by using acetic acid or hydrochloric acid, washing for 3 times by using 75% ethanol water solution, drying and pulverizing to obtain the finished lithium carboxymethyl cellulose.
The alcohol in the alcoholic aqueous solution and chloroacetic acid alcoholic solution is one or more of ethanol, propanol, butanol, and isopropanol. The cellulose is wood pulp, bamboo pulp, cotton pulp, etc. with small molecular weight (molecular weight of 2000-250000).
Example 1
460g of 90 percent ethanol water solution, 120g of water, 200g of lithium hydroxide monohydrate and 300g of wood pulp with the molecular weight of about 20000 are added into a reaction kettle, the stirring is started, the temperature is controlled at 30 ℃, and the reaction is carried out for 3 hours.
After the reaction is finished, 40g of butadiene dioxide is added into the reaction kettle and the temperature is raised to 30 ℃ for reaction for 2 hours.
Then adding 300g of 75% chloroacetic acid alcoholic solution, controlling the adding time to be about 30min, reacting at 40 ℃ for 1h, heating to 70 ℃, and keeping the temperature to react for 1h.
After the reaction is finished, the temperature is reduced to below 40 ℃, acetic acid is used for neutralizing to be neutral, and then 75% alcohol is used for washing, drying and crushing to obtain the finished product of the lithium carboxymethyl cellulose.
Example 2
Adding 500g of 85% ethanol aqueous solution, 120g of water, 200g of lithium hydroxide monohydrate and 300g of wood pulp with the molecular weight of about 20000 into a reaction kettle, starting stirring, controlling the temperature to be 30 ℃ and reacting for 3 hours.
After the reaction is finished, 50g of butadiene dioxide is added into the reaction kettle and the temperature is raised to 40 ℃ for reaction for 2 hours.
Then adding 300g of 75% chloroacetic acid alcoholic solution, controlling the adding time to be about 50min, reacting at 40 ℃ for 1h, heating to 70 ℃, and reacting at the temperature for 1h.
After the reaction is finished, the temperature is reduced to below 40 ℃, acetic acid is used for neutralizing to be neutral, and then 75% alcohol is used for washing, drying and crushing to obtain the finished product of the lithium carboxymethyl cellulose.
Example 3
460g of 98% isopropanol aqueous solution, 120g of water, 200g of lithium hydroxide monohydrate and 300g of wood pulp with the molecular weight of about 20000 are added into a reaction kettle, stirring is started, the temperature is controlled at 30 ℃, and the reaction is carried out for 2 hours.
After the reaction is finished, 40g of butadiene dioxide is added into the reaction kettle and the temperature is raised to 30 ℃ for reaction for 2 hours.
And then adding 350g of 75% chloroacetic acid alcoholic solution, controlling the adding time to be about 50min, reacting at 40 ℃ for 1h, heating to 70 ℃, and reacting at the temperature for 1h.
After the reaction is finished, the temperature is reduced to below 40 ℃, acetic acid is used for neutralizing to be neutral, and then 75% alcohol is used for washing, drying and crushing to obtain the finished product of the lithium carboxymethyl cellulose.
Example 4
460g of 90 percent ethanol water solution, 150g of water, 250g of lithium hydroxide monohydrate and 300g of wood pulp with the molecular weight of about 20000 are added into a reaction kettle, the stirring is started, the temperature is controlled at 40 ℃, and the reaction is carried out for 4 hours.
After the reaction is finished, 40g of butadiene dioxide is added into the reaction kettle and the temperature is raised to 40 ℃ for reaction for 2 hours.
Then adding 300g of 75% chloroacetic acid alcoholic solution, controlling the adding time to be about 30min, reacting at 40 ℃ for 1h, heating to 75 ℃, and keeping the temperature to react for 2h.
And after the reaction is finished, cooling to below 40 ℃, neutralizing with acetic acid to be neutral, washing with 75% alcohol, drying and crushing to obtain the finished product of the lithium carboxymethyl cellulose.
Example 5
460g of 98% isopropanol aqueous solution, 120g of water, 200g of lithium hydroxide monohydrate and 300g of wood pulp with the molecular weight of about 20000 are added into a reaction kettle, stirring is started, the temperature is controlled at 20 ℃, and the reaction is carried out for 2 hours.
After the reaction is finished, 30g of butadiene diepoxide is added into the reaction kettle, and the temperature is raised to 30 ℃ for reaction for 2 hours.
Then adding 280g of 80% chloroacetic acid alcoholic solution, controlling the adding time to be about 30min, reacting at 40 ℃ for 1h, heating to 60 ℃, and keeping the temperature to react for 1h.
And after the reaction is finished, cooling to below 40 ℃, neutralizing with acetic acid to be neutral, washing with 75% alcohol, drying and crushing to obtain the finished product of the lithium carboxymethyl cellulose.
Comparative example 1
460g of 90% ethanol aqueous solution, 120g of water, 200g of lithium hydroxide monohydrate and 300g of wood pulp with small molecular weight of about 20000 are added into a reaction kettle, and stirring is started to react for 3 hours.
After the reaction is finished, 300g of 75% chloroacetic acid alcoholic solution is added into the reaction kettle, the reaction is carried out for 2 hours at the temperature of 40 ℃, then the temperature is increased to 70 ℃, and the temperature is kept for 1 hour.
After the reaction is finished, the temperature is reduced to below 40 ℃, acetic acid is used for neutralizing to be neutral, and then 75% alcohol is used for washing, drying and crushing to obtain the finished product of the lithium carboxymethyl cellulose.
Namely, the comparative example is different from example 1 in that: the double-epoxidized butadiene is not added for modification in the process of preparing the lithium carboxymethyl cellulose.
Comparative example 2
This comparative example differs from example 1 in that: this comparative example used a high molecular weight wood pulp having a molecular weight of about 600000. In the reaction process, gelation is caused due to the large molecular weight of cellulose, and the reaction is difficult to continue.
Comparative example 3
This comparative example differs from example 1 in that: the mass ratio of cellulose to butadiene dioxide in this comparative example was 1. The reaction is difficult to continue because the proportion of the bis-epoxidized butadiene is too high, which causes gelation.
Comparative example 4
This comparative example differs from example 1 in that: the mass ratio of cellulose to butadiene dioxide in this comparative example was 1. Due to the fact that the proportion of the bis-epoxidized butadiene is too low, the obtained product is high in hardness, poor in toughness, small in elongation at break and not obvious in improvement effect.
Comparative example 5
The lithium carboxymethyl cellulose in this comparative example is a common commercial product produced by Chongqing power Macro fine chemistry Co., ltd., model batch is CMC-LiBLCQ15-6 20090882.
Test and results
1) The lithium carboxymethylcellulose in examples and comparative examples was prepared as a 0.3% aqueous solution, and 80.0g of the aqueous solution was accurately weighed, poured into a petri dish, dried at room temperature to obtain a transparent film, and cut into a 6X 1cm long and wide film strip. And testing the tensile mechanical property of the film strip by adopting a universal testing machine, and setting the tensile speed to be 500mm/min. The test results are shown in the following table:
TABLE 1 mechanical Property test results
| Serial number | Tensile breaking force, N | Elongation at break,% |
| Example 1 | 20.9017 | 1.2 |
| Example 2 | 28.7859 | 1.4 |
| Example 3 | 22.4065 | 1.2 |
| Example 4 | 23.6758 | 1.2 |
| Example 5 | 19.8963 | 1.1 |
| Comparative example 1 | 16.4657 | 0.9 |
| Comparative example 4 | 16.9768 | 0.9 |
| Comparative example 5 | 16.8669 | 0.9 |
As can be seen from the results in table 1, the films prepared from the lithium carboxymethylcellulose of the examples have significantly improved tensile breaking force and elongation at break compared to the comparative examples, which indicates that the mechanical properties of the film strips prepared from the examples are enhanced.
2) The lithium carboxymethylcellulose of the examples and comparative examples were tested for curl performance in the preparation of electrical Chi Tongbo-graphite anode applications
The test method is as follows:
adding 98.1g of deionized water, 1.3g of lithium carboxymethyl cellulose in examples or comparative examples, 96.5g of graphite powder, 0.5g of superconducting graphite powder and 3.6g of water-soluble SBR into a beaker;
fully stirring, placing in a constant temperature water tank at 25 ℃ for constant temperature for 4 hours, and removing bubbles;
scraping a slurry film with the thickness of 200um on the copper foil by using a film preparation device;
drying in oven, rolling with 5kg roller in the same direction for 10 times, and cutting into copper foil of 10 × 10 cm;
the U-shaped curled copper foil is laid flat after one time, and the cracking and falling conditions of the graphite layer on the surface of the copper foil are observed.
The results of the experiments are shown in figures 1, 2 and table 2.
TABLE 2 results of U-crimping of copper foil-graphite negative electrode of battery
| Serial number | Cracking and falling off |
| Example 1 | No powder falling from folds |
| Example 2 | No powder falling from folds |
| Example 3 | No powder falling from folds |
| Example 4 | No powder falling from folds |
| Example 5 | No powder falling from wrinkles |
| Comparative example 1 | Powder falling and cracking |
| Comparative example 4 | Powder falling and cracking |
| Comparative example 5 | Powder falling and cracking |
As can be seen from the results of fig. 1, fig. 2 and table 2, the negative electrode film (fig. 2) for lithium batteries prepared using the commercially available lithium carboxymethylcellulose of comparative example 5 exhibited cracking and peeling of graphite layers after U-crimping; in fig. 2, due to the poor toughness of the coating, part of the graphite coating falls off from the copper foil during the bending process, and part of the copper foil is exposed, namely the light-colored part in the drawing. On the other hand, when the lithium carboxymethyl cellulose prepared in example 2 was used to prepare a lithium battery negative electrode film (fig. 1), the graphite layer was not cracked or peeled off, although wrinkles were generated in the U-crimp process.
According to the preparation method of the flexible lithium carboxymethyl cellulose, the structure of cellulose molecules is subjected to flexible chain modification to form a structure with rigidity and flexibility, and then carboxymethylation is carried out to form the lithium carboxymethyl cellulose with a certain molecular weight. In practical application, the flexibility and the bendability of the product prepared by adding the lithium carboxymethyl cellulose can be improved, the application condition limit of the product is reduced, the application range of the product is expanded, and the product can be used as a binder of a lithium battery. The modified molecule contains functional monomer carboxyl, hydroxyl and flexible rotating carbon chain, so that the product has certain flexibility and overcomes the rigidity of the cellulose structure. The modified carboxymethyl cellulose lithium prepared by the invention has the original functions of thickening, dispersing, bonding and lithium supplement, and has better functions of preventing powder falling and cracking between a graphite layer and a metal surface in the folding process of a battery coating.
The equipment and materials used in the above examples are commercially available or commonly used in the art. The methods in the above examples are conventional in the art unless otherwise specified. The starting materials not specifically described in the examples were all obtained commercially. The operation without particular reference to temperature is carried out at room temperature. The operation methods and conditions not specifically described may be those known or customary in the art. The endpoints of the ranges and any values disclosed herein are not limited to the precise range or value, and such ranges or values should be understood to encompass values close to those ranges or values. For ranges of values, between the endpoints of each of the ranges and the individual points, and between the individual points may be combined with each other to give one or more new ranges of values, and these ranges of values should be considered as specifically disclosed herein.
The above embodiments are merely illustrative of the technical concept and features of the present invention, and the purpose thereof is to enable those skilled in the art to understand the content of the present invention and implement the invention, and not to limit the scope of the invention, and all equivalent changes or modifications made according to the spirit of the present invention should be covered by the scope of the present invention.
Claims (12)
1. A preparation method of lithium carboxymethyl cellulose is characterized by comprising the following steps:
adding cellulose and lithium hydroxide into an alcohol-containing aqueous solution, uniformly stirring, and reacting at 20-40 ℃ for 2-4h;
adding double-epoxidation butadiene, continuously controlling the temperature to be 20-40 ℃, and stirring for reacting for 1-3h;
adding alcoholic solution of chloroacetic acid, raising the temperature to 40-75 ℃ after adding, and reacting for 1-3h; obtaining crude carboxymethyl cellulose lithium;
neutralizing the crude lithium carboxymethyl cellulose with an acidic substance to be neutral, washing with an ethanol water solution, drying and crushing to obtain the lithium carboxymethyl cellulose.
2. The production method according to claim 1, wherein the lithium hydroxide-based substance is lithium hydroxide monohydrate or lithium hydroxide; when the lithium hydroxide substance is lithium hydroxide monohydrate, the mass ratio of the cellulose to the lithium hydroxide monohydrate is 1.
3. The method according to claim 1, wherein the cellulose has a molecular weight of 2000 to 250000.
4. The method according to claim 2, wherein the concentration of the cellulose in the system after the addition of the cellulose and the lithium hydroxide monohydrate to the alcohol-containing aqueous solution is 400 to 1000g/L.
5. The method according to claim 1, wherein the alcohol-containing aqueous solution has an alcohol concentration of 50 to 98% by volume.
6. The method according to claim 1, wherein the mass ratio of the cellulose to the butadiene diepoxide is 1.
7. The preparation method according to claim 1, wherein the mass ratio of the cellulose to the chloroacetic acid is 1.
8. The method according to claim 1, wherein the alcoholic solution of chloroacetic acid has a concentration of 50 to 90% by mass.
9. The method according to claim 1, wherein the alcoholic chloroacetic acid solution is added for 30 to 60min.
10. The method according to claim 1, wherein the alcohol in the alcoholic solution of the alcoholic solution and chloroacetic acid is one or more of ethanol, propanol, butanol, and isopropanol.
11. Lithium carboxymethyl cellulose prepared by the method for preparing lithium carboxymethyl cellulose according to any one of claims 1 to 10.
12. Use of the lithium carboxymethyl cellulose of claim 11 in a lithium battery.
Priority Applications (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202310169197.0A CN116207256A (en) | 2022-09-23 | 2022-09-23 | Negative electrode slurry of battery and copper foil-graphite negative electrode |
| CN202211164265.6A CN115246889B (en) | 2022-09-23 | 2022-09-23 | Lithium carboxymethyl cellulose and preparation method and application thereof |
| CN202310169115.2A CN116217742B (en) | 2022-09-23 | 2022-09-23 | Carboxymethyl cellulose lithium |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211164265.6A CN115246889B (en) | 2022-09-23 | 2022-09-23 | Lithium carboxymethyl cellulose and preparation method and application thereof |
Related Child Applications (2)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202310169197.0A Division CN116207256A (en) | 2022-09-23 | 2022-09-23 | Negative electrode slurry of battery and copper foil-graphite negative electrode |
| CN202310169115.2A Division CN116217742B (en) | 2022-09-23 | 2022-09-23 | Carboxymethyl cellulose lithium |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN115246889A true CN115246889A (en) | 2022-10-28 |
| CN115246889B CN115246889B (en) | 2023-01-10 |
Family
ID=83699601
Family Applications (3)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202310169115.2A Active CN116217742B (en) | 2022-09-23 | 2022-09-23 | Carboxymethyl cellulose lithium |
| CN202211164265.6A Active CN115246889B (en) | 2022-09-23 | 2022-09-23 | Lithium carboxymethyl cellulose and preparation method and application thereof |
| CN202310169197.0A Pending CN116207256A (en) | 2022-09-23 | 2022-09-23 | Negative electrode slurry of battery and copper foil-graphite negative electrode |
Family Applications Before (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202310169115.2A Active CN116217742B (en) | 2022-09-23 | 2022-09-23 | Carboxymethyl cellulose lithium |
Family Applications After (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202310169197.0A Pending CN116207256A (en) | 2022-09-23 | 2022-09-23 | Negative electrode slurry of battery and copper foil-graphite negative electrode |
Country Status (1)
| Country | Link |
|---|---|
| CN (3) | CN116217742B (en) |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1774450A (en) * | 2003-04-17 | 2006-05-17 | 阿特尔休提克斯R&D有限公司 | Cross-linked polysaccharide composition |
| CN1796655A (en) * | 2004-12-29 | 2006-07-05 | 韦尔豪泽公司 | Method of making carboxyalkyl cellulose polymer network |
| CN102206286A (en) * | 2011-05-16 | 2011-10-05 | 北京理工大学 | Preparation method of lithium carboxymethyl cellulose for lithium battery |
| CN113265008A (en) * | 2021-07-02 | 2021-08-17 | 重庆力宏精细化工有限公司 | High-viscosity lithium carboxymethyl cellulose and preparation method and application thereof |
| CN114920853A (en) * | 2022-06-29 | 2022-08-19 | 重庆力宏精细化工有限公司 | Flexible carboxymethyl cellulose ether and preparation method and application thereof |
Family Cites Families (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP3396961B2 (en) * | 1994-08-09 | 2003-04-14 | 王子製紙株式会社 | Method for producing water-absorbing cellulose material |
| CN101280023B (en) * | 2008-01-31 | 2010-12-01 | 重庆力宏精细化工有限公司 | Preparation of acid-resistant sodium carboxymethylcellulose |
| CN102492178B (en) * | 2011-11-29 | 2014-12-24 | 中国科学院过程工程研究所 | Konjac glucomannan microballoon with uniform dimension and preparation method thereof |
| CN105330751A (en) * | 2015-11-05 | 2016-02-17 | 重庆力宏精细化工有限公司 | Continuous production method of carboxymethylcellulose lithium for lithium batteries |
| CN108118023B (en) * | 2016-11-28 | 2021-06-29 | 广东乾晖生物科技有限公司 | Fiber scaffold and preparation method and application thereof |
| JP2022550778A (en) * | 2019-10-01 | 2022-12-05 | バイオポリメリ エス．アール．エル． | Hyperbranched polyglycerol polyglycidyl ethers and their use as crosslinkers for polysaccharides |
| CN112724266A (en) * | 2020-12-28 | 2021-04-30 | 常熟威怡科技有限公司 | Preparation method of lithium carboxymethyl cellulose for lithium battery |
| CN113773510A (en) * | 2021-09-07 | 2021-12-10 | 重庆理工大学 | Production method of lithium carboxymethyl cellulose grafted lithium polyacrylate |
-
2022
- 2022-09-23 CN CN202310169115.2A patent/CN116217742B/en active Active
- 2022-09-23 CN CN202211164265.6A patent/CN115246889B/en active Active
- 2022-09-23 CN CN202310169197.0A patent/CN116207256A/en active Pending
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1774450A (en) * | 2003-04-17 | 2006-05-17 | 阿特尔休提克斯R&D有限公司 | Cross-linked polysaccharide composition |
| CN1796655A (en) * | 2004-12-29 | 2006-07-05 | 韦尔豪泽公司 | Method of making carboxyalkyl cellulose polymer network |
| CN102206286A (en) * | 2011-05-16 | 2011-10-05 | 北京理工大学 | Preparation method of lithium carboxymethyl cellulose for lithium battery |
| CN113265008A (en) * | 2021-07-02 | 2021-08-17 | 重庆力宏精细化工有限公司 | High-viscosity lithium carboxymethyl cellulose and preparation method and application thereof |
| CN114920853A (en) * | 2022-06-29 | 2022-08-19 | 重庆力宏精细化工有限公司 | Flexible carboxymethyl cellulose ether and preparation method and application thereof |
Also Published As
| Publication number | Publication date |
|---|---|
| CN115246889B (en) | 2023-01-10 |
| CN116207256A (en) | 2023-06-02 |
| CN116217742A (en) | 2023-06-06 |
| CN116217742B (en) | 2024-03-26 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN107403941B (en) | Hydrotalcite coated carbon nanotube composite alkaline polyelectrolyte membrane and preparation method thereof | |
| CN112724266A (en) | Preparation method of lithium carboxymethyl cellulose for lithium battery | |
| JP6127446B2 (en) | Battery electrode composition and method for producing the same, battery electrode and method for producing the same | |
| KR102368398B1 (en) | Method for producing carboxymethyl cellulose salt for electrodes of nonaqueous electrolyte secondary batteries, electrode for nonaqueous electrolyte secondary batteries, and nonaqueous electrolyte secondary battery | |
| JP6111800B2 (en) | Battery electrode composition and battery | |
| Hussin et al. | Isolation of microcrystalline cellulose (MCC) from oil palm frond as potential natural filler for PVA-LiClO4 polymer electrolyte | |
| CN105131349A (en) | Preparation method of graphene oxide-chitosan composite material | |
| CN115246889B (en) | Lithium carboxymethyl cellulose and preparation method and application thereof | |
| CN101768224A (en) | Preparation method of hydroxypropyl starch | |
| Vega-Rios et al. | Synthesis and electrical properties of polyaniline/iota-carrageenan biocomposites | |
| CN114920853A (en) | Flexible carboxymethyl cellulose ether and preparation method and application thereof | |
| Azahar et al. | Physicochemical and conductivity studies of chitosan-tapioca flour-LiBF4 gel polymer electrolytes | |
| CN114695933B (en) | Semi-interpenetrating anion exchange membrane and preparation method and application thereof | |
| CN110846925A (en) | Graphene-nanocellulose conductive paper and preparation method thereof | |
| CN114276461B (en) | Sodium carboxymethylcellulose and preparation method thereof, and battery cathode slurry and preparation method thereof | |
| CN105461968B (en) | A kind of preparation method of starch/chitosan solid electrolytic thin-membrane | |
| CN113372456B (en) | Ultralow-viscosity carboxymethyl cellulose lithium and preparation method and application thereof | |
| CN114957492A (en) | Preparation method of low-insoluble substance fast-dispersing carboxymethyl cellulose ether | |
| CN114108368A (en) | Environment-friendly coating, preparation method and application | |
| US3067141A (en) | Dielectric plastic composition | |
| JP6811929B2 (en) | Cellulose-based viscous composition, its production method, and its use | |
| CN110864941A (en) | Method for preparing and testing hydrogel performance | |
| Chatap et al. | Synthesis and Characterization of Hydroxypropyl Sesbania Galactamannan Seed Gum for Pharmaceutical Application | |
| CN113999329B (en) | Chitosan gel electrolyte grafted with nanoparticles and preparation method and application thereof | |
| CN109535264A (en) | A kind of preparation method and application of CMCLi |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |