CN109216699B - Lithium battery adhesive with three-dimensional structure and lithium battery negative electrode material containing same - Google Patents
Lithium battery adhesive with three-dimensional structure and lithium battery negative electrode material containing same Download PDFInfo
- Publication number
- CN109216699B CN109216699B CN201710549677.4A CN201710549677A CN109216699B CN 109216699 B CN109216699 B CN 109216699B CN 201710549677 A CN201710549677 A CN 201710549677A CN 109216699 B CN109216699 B CN 109216699B
- Authority
- CN
- China
- Prior art keywords
- group
- negative electrode
- silicon substrate
- chitin
- triethoxysilane
- 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.)
- Active
Links
Images
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M4/62—Selection of inactive substances as ingredients for active masses, e.g. binders, fillers
- H01M4/621—Binders
- H01M4/622—Binders being polymers
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M4/13—Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof
- H01M4/134—Electrodes based on metals, Si or alloys
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M2004/026—Electrodes composed of, or comprising, active material characterised by the polarity
- H01M2004/027—Negative electrodes
-
- 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
Abstract
The invention provides a lithium battery adhesive with a three-dimensional structure and a lithium battery negative electrode material containing the same. The conjugate comprises: a chitin group; a polymeric group having at least one functional group selected from the group consisting of: hydroxyl (-OH), carboxyl (-COOH), and amino (-NH)2) (ii) a Having aldehyde (-CHO) and/or amine (-NH) groups2) A group of (1). The adhesive of the invention uses a three-dimensional network structure formed by conjugates in the negative electrode material of the lithium battery, and overcomes the defects of the prior negative electrode material.
Description
Technical Field
The invention relates to a negative electrode material adhesive; in particular to an adhesive applied to a lithium battery cathode material.
Background
With the rapid development of electronic industry in recent years, the convenience requirement of electronic devices is also increased, and portable electronic products are receiving great attention. Lithium batteries are one of the most widely used portable power sources in development today. Compared with nickel-hydrogen batteries and the like, lithium ion batteries have the characteristics of high power, high energy density, long cycle life and the like, and are applied to electronic equipment such as mobile phones, cameras, notebook computers and the like for many years.
The lithium battery consists of an anode, a cathode, a separation film and an electrolyte, wherein the anode material and the cathode material have direct influence on the lithium battery. Therefore, the development of electrode materials and the development of electrode-related processes are very important for the development of the electrode materials and the electrode-related processes. The currently used negative electrode material is a Carbon-based material, i.e., a Graphite material, such as Artificial Graphite (NG), Natural Graphite (AG), Hard Carbon (HC), Soft Carbon (SC), or mesocarbon microbeads (MCMB), for example. The carbon-based material has a layered structure, so that lithium ions can be inserted and extracted, and the carbon-based material has stable properties, so that the carbon-based material is taken as a negative electrode material and is a key breakthrough of the commercial application of the lithium battery. However, the capacity of the graphite material is only 372mAh/g at most, and the preparation cost of the mesocarbon microbeads is relatively high, so that other materials are required to replace carbon materials to serve as the negative electrode materials of the lithium battery.
Silicon materials have attracted attention in pursuit of high capacitance and low cost. The silicon material has the following advantages as the lithium ion negative electrode material:
(1) the silicon material has the capacitance of about 3579 mAh/g. Besides lithium metal, the capacitance has the capacitance advantage which is not comparable with other high-capacity materials.
(2) The microstructure of a silicon material is converted to Amorphous (Amorphous) upon first intercalation of lithium and remains in this Amorphous state during subsequent cycles, and is therefore considered to be structurally relatively stable.
(3) In the process of electrochemical lithium intercalation and deintercalation, the material is not easy to agglomerate.
(4) The discharge plateau is slightly higher than the carbon-based material.
(5) Rich in content, low in cost and no environmental pollution. The silicon material has the advantages, and thus becomes one of the best cathode materials for new-generation high-capacity lithium batteries.
However, the silicon material still has several technical difficulties to be overcome:
(1) when lithium is inserted and extracted, the volume change of the electrode material is great, and further the electrode material is loosened and pulverized, so that the cycle life performance is poor. This is a significant impediment to the commercial development of silicon materials.
(2) The silicon material has low conductivity, and needs to be matched with a proper conductive aid to improve the conductivity of the electrode.
In order to overcome the above-mentioned silicon material problem, the solution strategy is to improve the material structure. However, the process of improving the material structure is complicated, energy-consuming and high in preparation cost, so that the problem of volume expansion of the silicon-based negative electrode material is solved by developing the three-dimensional network structure adhesive and utilizing the network structure and the coating characteristic, and the operation is only required to be carried out in the preparation process of the polar plate, which is a feasible method with great industrial mass production process.
Disclosure of Invention
The invention aims to provide a negative electrode material for a lithium battery, an adhesive added to the negative electrode material and a modified negative electrode material, so as to solve the problems of pulverization of the negative electrode material, excessive initial charge and discharge irreversible capacity and poor cycle life.
To achieve the above object, the present invention provides a negative electrode material for a lithium battery, comprising:
5 to 50 weight percent of a conjugate comprising:
a chitin group;
a polymeric group having at least one functional group selected from the group consisting of: hydroxyl (-OH), carboxyl (-COOH), and amino (-NH)2)；
Having aldehyde (-CHO) and/or amine (-NH) groups2) A group of (a);
wherein the chitin group and the polymer group form a covalent bond;
wherein the polymer group forms a covalent bond with the group having an aldehyde group and/or an amine group;
wherein the chitin group and the group with aldehyde group and/or amino group form a carbon-nitrogen double bond or a peptide bond; and
50 to 90 weight percent of a silicon substrate;
wherein the weight percentages are based on the total weight of the anode material.
Preferably, the anode material further comprises 1 to 40 weight percent of a conductive aid.
Preferably, the polymer group is polysaccharide, polyvinyl alcohol, polyethylene glycol, polyacrylic acid, carboxymethyl cellulose, methyl cellulose, polyallylamine, sodium alginate or a combination thereof.
Preferably, the aforementioned compound has an aldehyde group (-CHO) and/or an amine group (-NH)2) The groups of (a) are silanes, aldehydes, or combinations thereof.
Preferably, the aforementioned compound has an aldehyde group (-CHO) and/or an amine group (-NH)2) Is Glutaraldehyde (GA) or (3-aminopropyl) triethoxysilane (APTES) or a combination thereof.
Preferably, the silicon substrate is a nanoscale silicon substrate, a microscale silicon substrate, a silicon-metal composite silicon substrate, a silicon-carbon composite silicon substrate, a silicon-metal oxide composite silicon substrate, or a combination thereof.
Preferably, the conductive aid is graphite (graphite), Vapor Grown Carbon Fiber (VGCF), Carbon Nanotube (CNT), Acetylene Black (AB), Carbon Black (CB), or a combination thereof.
The present invention also provides an anode material adhesive composition for a lithium battery, comprising:
a conjugate comprising:
a chitin group;
a polymeric group having at least one functional group selected from the group consisting of: hydroxyl (-OH), carboxyl (-COOH), and amino (-NH)2)；
Having aldehyde (-CHO) and/or amine (-NH) groups2) A group of (a);
wherein the chitin group and the polymer group form a covalent bond;
wherein the polymer group forms a covalent bond with the group having an aldehyde group and/or an amine group;
wherein the chitin group and the group with aldehyde group and/or amino group form a carbon-nitrogen double bond or a peptide bond.
Preferably, the polymer group is polysaccharide, polyvinyl alcohol, polyethylene glycol, polyacrylic acid, carboxymethyl cellulose, methyl cellulose, polyallylamine, sodium alginate or a combination thereof.
Preferably, the aforementioned compound has an aldehyde group (-CHO) and/or an amine group (-NH)2) The groups of (a) are silanes, aldehydes, or combinations thereof.
Preferably, the aforementioned compound has an aldehyde group (-CHO) and/or an amine group (-NH)2) Is Glutaraldehyde (GA) or (3-aminopropyl) triethoxysilane (APTES) or a combination thereof.
The present invention further provides a modified lithium battery negative electrode comprising:
a silicon substrate; and
a conjugate modified on the silicon substrate;
wherein the conjugate comprises:
a chitin group;
a polymeric group having at least one functional group selected from the group consisting of: hydroxyl (-OH), carboxyl (-COOH), and amino (-NH)2)；
Having aldehyde (-CHO) and/or amine (-NH) groups2) A group of (a);
wherein the chitin group and the polymer group form a covalent bond;
wherein the polymer group forms a covalent bond with the group having an aldehyde group and/or an amine group;
wherein the chitin group and the group with aldehyde group and/or amino group form a carbon-nitrogen double bond or a peptide bond;
wherein the above-mentioned compound has aldehyde group (-CHO) and/or amino group (-NH)2) The group (2) forms a covalent bond with the aforementioned silicon substrate.
Preferably, the polymer group is polysaccharide, polyvinyl alcohol, polyethylene glycol, polyacrylic acid, carboxymethyl cellulose, methyl cellulose, polyallylamine, sodium alginate or a combination thereof.
Preferably, the aforementioned compound has an aldehyde group (-CHO) and/or an amine group (-NH)2) The groups of (a) are silanes, aldehydes, or combinations thereof.
Preferably, the aforementioned compound has an aldehyde group (-CHO) and/or an amine group (-NH)2) Is Glutaraldehyde (GA) or (3-aminopropyl) triethoxysilane (APTES) or a combination thereof.
The invention further provides a preparation method of the adhesive composition, which comprises the following steps:
(a) adding a polymer into a carrier to prepare a solution in the step (a);
(b) adding chitin into the solution in the step (a) to prepare a solution in the step (b);
(c) having aldehyde group (-CHO) and/or amino group (-NH)2) Adding the compound of (c) to the solution of step (b) to form a solution of step (c);
wherein the preparation method is carried out in an acidic environment.
Preferably, the acidic solution is hydrochloric acid, sulfuric acid, nitric acid, formic acid, acetic acid, phosphoric acid, citric acid, or a combination thereof.
Preferably, the preparation method is carried out at normal temperature.
In summary, the present invention provides an adhesive and a method for preparing the same. Aiming at the cathode material taking silicon base material as one of raw materials, the invention successfully adds the adhesive into the cathode material to modify the surface structure of the cathode material, thereby reducing the first irreversible capacity and prolonging the cycle life. The adhesive is applied to the cathode material, so that the technical bottleneck of the silicon substrate in the development of lithium batteries can be broken through, and the industrial application value of the silicon substrate is improved.
Drawings
FIG. 1 shows electrochemical performance at different current densities of button cells fabricated using adhesives of examples 1 to 3 of the present invention and comparative examples 1 to 2.
FIG. 2 shows the charge and discharge cycle life at a current density of 50mA/g of a button cell fabricated using the adhesives of examples 1 to 3 and comparative examples 1 to 2 of the present invention.
FIG. 3 shows the charge and discharge cycle life at a current density of 500mA/g for button cells fabricated using the adhesives of examples 1 to 3 and comparative examples 1 to 2 of the present invention.
Detailed Description
The technical problem to be solved by the invention is that the silicon substrate used as the negative electrode material of the lithium ion battery has violent volume change when lithium is inserted and extracted. This characteristic causes loosening and powdering of the negative electrode material, which in turn causes problems such as an excessive first charge-discharge irreversible capacity and a poor cycle life performance.
In order to solve the problems, the invention develops a proper adhesive for the silicon-based negative electrode material so as to modify the surface of the negative electrode material. Further, an adhesive made of specific materials is developed to successfully solve the technical problems of the material.
Accordingly, the present invention provides a negative electrode material for a lithium battery, comprising: 5 to 50 weight percent of the conjugate, 50 to 90 weight percent of a silicon substrate. The raw materials of the cathode material are calculated by weight percentage based on the total weight of the cathode material. The conjugate is the adhesive of the invention.
The invention is mainly characterized in that the conjugate in the negative electrode material is composed of the following components: chitin group, polymer group, and aldehyde group (-CHO) and/or amino group (-NH)2) A group of (1).
In a preferred embodiment, the chitin group is derived from the group of poly (methylene chloride) and International Inc. The chitin group is yellow to brown in appearance, odorless, and has a particle size of > 40 Mesh. The deacetylation ratio of the chitin group is 70 to 90%, the water content as measured by Loss on drying (Loss on drying) is about 10% or less, and the ash content as measured by Residue on ignition (Residue on ignition) is about 1% or less. The content of arsenic and heavy metal in the chitin group components is less than 0.5ppm and less than 10ppm respectively.
For the aforementioned polymer group, it is desirable to have at least one polar functional group selected from the following group: hydroxyl (-OH), carboxyl (-COOH), and amino (-NH)2). These groups can be matched and combined with each other according to experimental requirements. Specific examples of the polymer include: polysaccharide, polyvinyl alcohol, polyethylene glycol, polyacrylic acid, carboxymethyl cellulose, methyl cellulose, polyallylamine, sodium alginate or a combination thereof, preferably sodium alginate.
The compound has aldehyde group (-CHO) and/or amino group (-NH)2) The group of (c) may be selected from silanes, aldehydes or combinations thereof. The compound has aldehyde group (-CHO) and/or amino group (-NH)2) Specifically, examples of the group (b) include: glutaraldehyde (GA) or (3-aminopropyl) triethoxysilane (APTES) or combinations thereof.
The essential components of the conjugate are bonded to each other. Forming a covalent bond between the chitin group and the polymer group; forming covalent bonds between the polymer groups and the aldehyde groups and/or amine groups; the formation of carbon-nitrogen double bonds or peptide bonds between the chitin groups and the aldehyde and/or amine groups plays an important role in bonding to the stable silicon-based electrode.
The conjugate composed of the above components is contained in an amount of 5 to 50 weight percent (wt%), preferably 5 to 30 wt%, and more preferably 5 to 20 wt%, calculated on the basis of the total weight of the constituent anode materials.
Polymer group and aldehyde group (-CHO) and/or amino group (-NH) of conjugate in negative electrode material2) The groups can be selected according to the carrier, so that various combinations can be derived. Specifically, for example, the anode materials shown in table 1 can be formulated.
Table 1: examples of combinations of groups of different kinds in conjugates
| Examples of the invention | M2 | M3 |
| 1 | -OH | -CHO |
| 2 | -COOH | -CHO |
| 3 | -NH2 | -CHO |
| 4 | -OH | -NH2 |
| 5 | -COOH | -NH2 |
| 6 | -NH2 | -NH2 |
| 7 | -OH+-COOH | -CHO |
| 8 | -OH+-NH2 | -CHO |
| 9 | -COOH+-NH2 | -CHO |
| 10 | -OH+-COOH | -NH2 |
| 11 | -OH+-NH2 | -NH2 |
| 12 | -COOH+-NH2 | -NH2 |
| 13 | -OH+-COOH+-NH2 | -CHO |
| 14 | -OH+-COOH+-NH2 | -NH2 |
| 15 | -OH | -CHO+-NH2 |
| 16 | -COOH | -CHO+-NH2 |
| 17 | -NH2 | -CHO+-NH2 |
| 18 | -OH | -CHO+-NH2 |
| 19 | -COOH | -CHO+-NH2 |
| 20 | -NH2 | -CHO+-NH2 |
| 21 | -OH+-COOH | -CHO+-NH2 |
| 22 | -OH+-NH2 | -CHO+-NH2 |
| 23 | -COOH+-NH2 | -CHO+-NH2 |
| 24 | -OH+-COOH | -CHO+-NH2 |
| 25 | -OH+-NH2 | -CHO+-NH2 |
| 26 | -COOH+-NH2 | -CHO+-NH2 |
| 27 | -OH+-COOH+-NH2 | -CHO+-NH2 |
| 28 | -OH+-COOH+-NH2 | -CHO+-NH2 |
Polymer radical abbreviated as M in this table2。
Having aldehyde groups (-CHO) and/or amine groups (-NH)2) In this table, the radicals are abbreviated to M3。
For the silicon substrate, a single component material or a composite component material can be selected. The single-component material may specifically be exemplified by: a nanoscale silicon substrate, a microscale silicon substrate, or a combination thereof. The composite component material may be, for example: a silicon-metal composite silicon substrate, a silicon-carbon composite silicon substrate, a silicon-metal oxide composite silicon substrate, or a combination thereof.
The silicon substrate is contained in an amount of 50 to 90 weight percent (wt%), preferably 60 to 80 wt%, and more preferably 70 to 75 wt%, based on the total weight of the constituent anode materials.
Besides the conjugate and the silicon substrate, the negative electrode material may further comprise a conductive aid.
As the aforementioned co-agent, specifically, for example: graphite (graphite), Vapor Grown Carbon Fiber (VGCF), Carbon Nanotubes (CNT), Acetylene Black (AB), Carbon Black (CB), or combinations thereof. Under the condition of not influencing the use of the conjugate, the conjugate can be matched and combined with each other according to experimental requirements.
The conductive aid is used in an amount of 1 to 40 weight percent (wt%), preferably 5 to 30 wt%, and more preferably 10 to 20 wt%, based on the total weight of the anode material.
The invention also provides an adhesive for the negative electrode material of the lithium battery, which comprises a conjugate. The aforementioned conjugates are as described in the preceding paragraphs and will not be repeated here.
The preparation method of the adhesive comprises the following steps:
(a) adding a polymer into a carrier to prepare a solution in the step (a);
(b) adding chitin into the solution in the step (a) to prepare a solution in the step (b);
(c) having aldehyde group (-CHO) and/or amino group (-NH)2) Adding the compound of (c) to the solution of step (b) to form a solution of step (c);
aiming at chitin, polymer, aldehyde group (-CHO) and/or amino group (-NH) in the step2) The choice of compound(s), and carrier, as described in the preceding paragraph, is not repeated here.
For the carrier, N-methylpyrrolidone (NMP), water or a combination thereof can be used. The carrier is selected according to the components of the adhesive, so that the carrier can be selected according to the respective experimental requirements without damaging the effect of the adhesive, and is not particularly limited. The adhesive according to the present invention is preferably water as the carrier of the present invention.
In a preferred embodiment, the adhesive preparation method is performed in an acidic environment. The experimental results of the subsequent examples prove that the adhesive prepared in the acidic environment can improve the battery performance of the adhesive. The acidic environment can be adjusted to an appropriate ph by adding the following acidic solutions, such as: hydrochloric acid, sulfuric acid, nitric acid, formic acid, acetic acid, phosphoric acid, citric acid, and the like; preferably citric acid, acetic acid, more preferably acetic acid. Although the characteristics of the negative electrode material can be more effectively improved under the limit of the acid environment, the adhesive prepared under the acid environment still has the excellent effect claimed by the invention.
In the preparation method of the adhesive, the conditions of temperature and air pressure are set to normal temperature and normal pressure, namely, the temperature and the pressure do not need to be specially adjusted so as to create a preparation environment of a specific adhesive or a negative electrode material. The preparation of the present invention can be carried out in the environment of one of ordinary skill in the art for practicing the present invention. In one possible embodiment, the Normal Temperature and Pressure (NTP) is currently defined as 25 deg.C, 1 atm. The invention also provides the advantage that the adhesive can be widely applied to the preparation of the cathode material.
In one possible embodiment, the above-described preparation method is carried out with stirring for each addition of the components, so that the added components can be mixed thoroughly. The stirring time and/or the stirring rate need not be particularly limited, and the purpose of uniform mixing can be achieved.
In a preferred embodiment, the bubble removal is performed on the negative electrode material after all the components constituting the negative electrode material are added and the negative electrode material is sufficiently stirred.
And (4) after the preparation of the negative electrode material is finished, carrying out the process of the negative electrode pole piece. The process can be roughly divided into the following steps:
(1) preparing a copper foil: the copper foil is wiped clean and cut to a proper size and laid on a platform of a coating machine.
(2) Coating: and uniformly coating the negative electrode material on the copper foil at a fixed speed by using a scraper with adjustable spacing.
(3) Preheating: and placing the copper foil of the coated negative electrode material on a heating plate, and pre-baking to remove the carrier in the negative electrode material.
(4) Rolling: and rolling the negative electrode material by using a rolling machine to adjust the thickness of the negative electrode material. And finishing the negative pole plate after rolling.
(5) Cutting: and cutting the negative pole plate by a cutting machine to obtain a circular negative pole piece with a fixed diameter.
(6) Heating: and placing the negative pole piece in a vacuum oven to remove the residual carrier.
(7) And (3) assembling: and moving the heated negative pole piece into a glove box in a specific gas environment. And (5) assembling the button-type battery.
The process of the negative pole piece is not the key point of the technology, so the experimental conditions in the steps can be adjusted according to the actual conditions and the existing process in the field.
The modified lithium battery cathode is completed by adding the adhesive, preparing the cathode material and performing the cathode pole piece process. The modified lithium battery negative electrode comprises: silicon substrates and conjugates for modifying the substrates. For the bond between the component contained in the conjugate and the component, reference is made to the above description of the negative electrode material, and the description is not repeated here. The modified negative electrode material for lithium battery is characterized in that besides the components in the conjugate can form a bond, the conjugate contains aldehyde group (-CHO) and/or amino group (-NH)2) The group also forms a covalent bond with the silicon substrate. Therefore, by adding the adhesive of the invention, the coating property of the adhesive can be exerted, and various bonds are formed between the negative electrodes, thereby forming a three-dimensional network structure which is complicated, stable and elastic. The three-dimensional network structure is a coating layer on the surface of the negative electrode, and the composition of a Solid Electrolyte Interface (SEI) on the surface of the negative electrode can be changed.
The invention has the beneficial effects that the problems of loosening and pulverization of the negative electrode material caused by severe volume change of the silicon substrate used as the negative electrode material of the lithium battery when lithium is inserted and inserted are further solved through negative electrode surface modification. The negative electrode material is improved by adding the adhesive, so that the first charge-discharge reversible capacitance is reduced, and the cycle life performance of the lithium battery is obviously improved.
The following embodiments are provided as specific examples of the present invention to further illustrate the advantages of the present invention, but are not intended to limit the present invention.
The first process comprises the following steps: preparation of the adhesive of the invention.
Example 1, a conjugate adhesive of the present invention, will be prepared in this process. Firstly, adding sodium alginate into deionized water, adding a prepared chitin aqueous solution (2 wt%), and mixing uniformly. Then, liquid Glutaraldehyde (GA) containing no solvent was added thereto, and the mixture was stirred again until it was uniform, thereby completing example 1 of the adhesive of the present invention.
Example 2, a conjugate adhesive of the present invention, will be prepared in this process. Firstly, adding sodium alginate into deionized water, adding a prepared chitin aqueous solution (2 wt%) and mixing uniformly. Then, liquid (3-aminopropyl) triethoxysilane (APTES) was added, and the mixture was stirred and mixed again until uniform, thereby completing example 2 of the adhesive of the present invention.
Adhesive example 3 with the conjugate of the invention will be prepared in this process. Firstly, adding sodium alginate into deionized water, adding a prepared chitin aqueous solution (2 wt%) and mixing uniformly. Then, liquid (3-aminopropyl) triethoxysilane (APTES) was added, and the mixture was stirred and mixed until uniform. Then, an acetic acid aqueous acid solution was added to adjust the mixture, and the mixture was stirred and mixed until uniform, thereby completing adhesive example 3 of the present invention.
Comparative example 1 of an adhesive was produced in this process. Firstly, adding sodium alginate into deionized water, stirring and mixing until uniform, and then completing comparative example 1.
Comparative example 2 of an adhesive will be produced in this process. Firstly, sodium alginate is added into deionized water, and a prepared chitin aqueous solution (2 wt%) is added and mixed uniformly, thus completing comparative example 2.
The above examples and comparative examples were all prepared under a gas atmosphere at normal temperature and pressure, and the operating apparatus was a stirrer.
The components of examples 1 to 3 and comparative examples and the experimental conditions were as set forth in Table 2.
Table 2: example and comparative example compositions and conditions.
Chitin radical abbreviated as M in the table1。
Polymer radical abbreviated as M in this table2。
Having aldehyde groups (-CHO) and/or amine groups (-NH)2) In this table, the radicals are abbreviated to M3。
And a second process: the negative pole piece using the adhesive is prepared.
First, an appropriate amount of deionized water (DI water) was weighed, and then a silicon-metal composite negative electrode material was sequentially added to deionized water in an amount of 70 weight percent (wt%), graphite (trade name KS-6, manufactured by Timcal corporation) in an amount of 15 weight percent (wt%), an adhesive prepared in process one in an amount of 12 weight percent (wt%), and carbon black (trade name super P, manufactured by Timcal corporation) in an amount of 3 weight percent (wt%). And (3) stirring the mixture to be uniform, and then removing bubbles to obtain the coating slurry for preparing the negative electrode plate (namely the negative electrode material of the invention).
And wiping the copper foil, cutting the copper foil into a proper size, paving the copper foil on a platform of a coating machine, and uniformly coating the negative electrode slurry on the copper foil at a fixed speed by using a scraper with adjustable spacing. And placing the copper foil coated with the negative electrode slurry on a heating plate for pre-drying to remove a carrier, then adjusting the thickness of a negative electrode material by using a rolling machine, cutting the rolled electrode into a circular pole piece with the diameter of 13mm by using a cutting machine, then placing the cut pole piece in a vacuum oven to remove the residual carrier, and after the completion, placing the pole piece in a glove box filled with argon (the moisture and oxygen are less than 1ppm) to assemble the button cell.
And a third process: the invention relates to a battery assembly of a negative pole piece by using the adhesive.
And cleaning and drying the upper cover, the lower cover, the spring piece and the stainless steel sheet of the battery by using alcohol, and after the battery is completely dried, sending the battery into a glove box for assembling the lithium battery. First, a negative electrode plate was placed at the center of a lower cap, and an electrolyte solution (obtained by dissolving a Lithium hexafluorophosphate solution in a 1: 2 volume ratio mixture of ethyl carbonate (ethyl carbonate) and ethyl methyl carbonate (ethyl methyl carbonate), adding 2 wt% of vinylene carbonate (vinylene carbonate), and Fluoroethylene carbonate (Fluoroethylene carbonate)) was dropped. And then, soaking the isolating membrane in the electrolyte for wetting, and then covering the isolating membrane on the negative pole piece. Sequentially placing lithium metal or a positive pole piece on the isolating membrane, confirming that the lithium metal or the positive pole piece is positioned at the central position and does not exceed the isolating membrane, then placing a stainless steel sheet on the lithium metal (if the positive pole piece is used, the stainless steel sheet does not need to be placed), and placing a spring piece at the central position of the stainless steel sheet. Finally, the upper cover is closed, and the button cell is sealed by using a press machine dedicated to the button cell.
And a fourth process: electrochemical testing of button cells.
The micro-current battery automatic charge and discharge test host (manufactured by Jiayou science and technology Co., Ltd.) is used as an electrochemical test instrument for testing.
Electrochemical results of the button cell assembled by the negative electrode plate prepared in the above examples of the present invention and comparative examples are shown in table 3.
Table 3: electrochemical test results of button cells fabricated using the adhesives of the invention
The results of table 3, in which the button cell using example 1 as an adhesive is abbreviated as example 1 in the discussion of the results below, and so on, are discussed below. As shown in Table 3, in comparative example 1, which uses only a single component adhesive, the first charge capacity (i.e., first reversible capacity) was 720mAh/g, and the first coulombic efficiency was 78.6%. Comparative example 2 is similar to comparative example 1 in that the first reversible capacity and the first coulombic efficiency are 720mAh/g and 77.9%, respectively, using the two-component adhesive.
In example 1, the first coulombic efficiency of the adhesive of the present invention was 78.7%, which is not much different from that of comparative examples 1 and 2, but the first reversible capacity was up to 737 mAh/g. Example 2 the first reversible capacity was 766mAh/g, which is about 50mAh/g higher than that of comparative examples 1 and 2. Moreover, the first coulombic efficiency has even reached 80.8%. Example 3 an adhesive of the present invention prepared by modifying the experimental conditions of example 2 was similar to example 2 in that the first reversible capacity and coulombic efficiency were 765mAh/g and 81.4%, respectively, but the capacity retention after 100 charges and discharges was 70%, compared to sample 2, which was only 59% after 100 charges and discharges.
From the above results, the adhesive with a three-dimensional network structure can not only improve the connectivity and stability between the silicon-based negative electrode material and the adhesive, but also has a coating property on the surface of the silicon-based negative electrode material, so as to change the composition of a Solid Electrolyte Interface (SEI), thereby achieving the results of improving the reversible capacity and the battery performance.
The results of the electrical tests of the button cell assembled by the negative electrode plate prepared in the above examples of the present invention and comparative examples are shown in fig. 1, fig. 2 and fig. 3.
The results of fig. 1 and 2 are discussed below, wherein a button cell using example 1 as an adhesive is abbreviated as example 1 in the discussion of the results below, and so on. As shown in FIG. 1, comparative example 2 has the best capacitance performance at high current density, followed by example 3. As shown in FIG. 2, the results of electrochemical tests performed at low current density in the above examples and comparative examples are not very different. As shown in fig. 3, comparing the cycle life test under 500mAh/g, it can be seen that the capacity retention rate of example 3 is still 70% after 100 times of charging and discharging, while the capacity retention rates of comparative examples 1 and 2 are only about 55%.
In summary, it can be seen that the three-dimensional network structure adhesive disclosed by the present invention not only can modify the surface of a silicon-based negative electrode, change the composition of a solid electrolyte film on the surface of an electrode material by surface modification, but also can strengthen the overall structure of the electrode, and improve the problems of high initial charge-discharge irreversible capacity and poor cycle life.
Claims (11)
1. A negative electrode material for a lithium battery, comprising:
5 to 50 weight percent of a conjugate comprising:
a chitin group;
a polymeric group having at least one functional group selected from the group consisting of: hydroxyl, carboxyl, and amino;
(3-aminopropyl) triethoxysilane;
wherein the chitin group forms a covalent bond with the polymer group;
wherein the polymeric group forms a covalent bond with the (3-aminopropyl) triethoxysilane;
said chitin group forming a peptide bond with said (3-aminopropyl) triethoxysilane; and
50 to 90 weight percent of a silicon substrate;
wherein the weight percentages are based on the total weight of the constituent anode materials;
wherein the conjugate is prepared at normal temperature.
2. The anode material of claim 1, further comprising 1 to 40 weight percent of a conductivity aid.
3. The negative electrode material of claim 1, wherein the polymer group is a polysaccharide, polyvinyl alcohol, polyethylene glycol, polyacrylic acid, carboxymethyl cellulose, methyl cellulose, polyallylamine, sodium alginate, or a combination thereof.
4. The anode material of claim 1, wherein the silicon substrate is a nano-scale silicon substrate, a micro-scale silicon substrate, a silicon-metal composite silicon substrate, a silicon-carbon composite silicon substrate, a silicon-metal oxide composite silicon substrate, or a combination thereof.
5. The anode material according to claim 2, wherein the conductive aid is graphite, vapor grown carbon fiber, carbon nanotube, acetylene black, carbon black, or a combination thereof.
6. An adhesive composition for a negative electrode material of a lithium battery, comprising:
a conjugate comprising:
a chitin group;
a polymeric group having at least one functional group selected from the group consisting of: hydroxyl, carboxyl, and amino;
(3-aminopropyl) triethoxysilane;
wherein the chitin group forms a covalent bond with the polymer group;
wherein the polymeric group forms a covalent bond with the (3-aminopropyl) triethoxysilane;
said chitin group forming a peptide bond with said (3-aminopropyl) triethoxysilane;
wherein the adhesive composition is prepared at normal temperature.
7. The adhesive composition of claim 6, wherein the polymeric group is a polysaccharide, polyvinyl alcohol, polyethylene glycol, polyacrylic acid, carboxymethyl cellulose, methyl cellulose, polyallylamine, sodium alginate, or a combination thereof.
8. A modified lithium battery anode, comprising:
a silicon substrate; and
a conjugate modified to the silicon substrate;
wherein the conjugate comprises:
a chitin group;
a polymeric group having at least one functional group selected from the group consisting of: hydroxyl, carboxyl, and amino;
(3-aminopropyl) triethoxysilane;
wherein the chitin group forms a covalent bond with the polymer group;
wherein the polymeric group forms a covalent bond with the (3-aminopropyl) triethoxysilane;
said chitin group forming a peptide bond with said (3-aminopropyl) triethoxysilane;
wherein the (3-aminopropyl) triethoxysilane forms a covalent bond with the silicon substrate;
wherein the conjugate is prepared at normal temperature.
9. The lithium battery negative electrode as claimed in claim 8, wherein the polymer group is a polysaccharide, polyvinyl alcohol, polyethylene glycol, polyacrylic acid, carboxymethyl cellulose, methyl cellulose, polyallylamine, sodium alginate, or a combination thereof.
10. A method of preparing the adhesive composition of claim 6, comprising the steps of:
(a) adding a polymer into a carrier to prepare a solution in the step (a);
(b) adding chitin into the solution in the step (a) to prepare a solution in the step (b);
(c) adding (3-aminopropyl) triethoxysilane to the solution of step (b) to form a solution of step (c);
wherein the preparation method is carried out in an acidic environment and at normal temperature.
11. The method of claim 10, wherein the acidic environment is created by adding an acidic solution that is hydrochloric acid, sulfuric acid, nitric acid, formic acid, acetic acid, phosphoric acid, citric acid, and combinations thereof.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201710549677.4A CN109216699B (en) | 2017-07-07 | 2017-07-07 | Lithium battery adhesive with three-dimensional structure and lithium battery negative electrode material containing same |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201710549677.4A CN109216699B (en) | 2017-07-07 | 2017-07-07 | Lithium battery adhesive with three-dimensional structure and lithium battery negative electrode material containing same |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN109216699A CN109216699A (en) | 2019-01-15 |
| CN109216699B true CN109216699B (en) | 2022-04-19 |
Family
ID=64991071
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201710549677.4A Active CN109216699B (en) | 2017-07-07 | 2017-07-07 | Lithium battery adhesive with three-dimensional structure and lithium battery negative electrode material containing same |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN109216699B (en) |
Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103242595A (en) * | 2012-02-09 | 2013-08-14 | 三星Sdi株式会社 | Composite binder for battery, and anode and battery including the composite |
| CN103337656A (en) * | 2013-07-05 | 2013-10-02 | 中国科学院青岛生物能源与过程研究所 | Modified biomass lithium ion battery adhesive |
| CN103342974A (en) * | 2013-07-05 | 2013-10-09 | 中国科学院青岛生物能源与过程研究所 | Simulated mussel protein environment-friendly lithium ion battery adhesive |
| CN103427083A (en) * | 2013-08-20 | 2013-12-04 | 宁波奈克斯特新材料科技有限公司 | Adhesive for lithium battery and preparation method thereof |
| CN104919634A (en) * | 2013-01-21 | 2015-09-16 | 昭和电工株式会社 | Binder for lithium ion secondary battery electrodes, slurry, electrode, and lithium ion secondary battery |
| WO2016010056A1 (en) * | 2014-07-15 | 2016-01-21 | 川上総一郎 | Negative electrode material for power storage device, electrode structure, power storage device, and production method for each |
| CN105637695A (en) * | 2013-07-29 | 2016-06-01 | 宾夕法尼亚州研究基金会 | Elastic gel polymer binder for silicon-based anode |
| CN105702963A (en) * | 2016-01-29 | 2016-06-22 | 长沙理工大学 | Application of carboxymethyl chitosan self-crosslinking polymer in silicon negative electrode of lithium ion battery |
| CN105914376A (en) * | 2016-06-24 | 2016-08-31 | 辽宁九夷锂能股份有限公司 | Reinforced type composite binder for negative electrode of lithium ion battery and application of reinforced type composite binder |
| CN106356534A (en) * | 2015-07-18 | 2017-01-25 | 宁波大学 | Adhesive for lithium ion battery and preparation method of adhesive |
-
2017
- 2017-07-07 CN CN201710549677.4A patent/CN109216699B/en active Active
Patent Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103242595A (en) * | 2012-02-09 | 2013-08-14 | 三星Sdi株式会社 | Composite binder for battery, and anode and battery including the composite |
| CN104919634A (en) * | 2013-01-21 | 2015-09-16 | 昭和电工株式会社 | Binder for lithium ion secondary battery electrodes, slurry, electrode, and lithium ion secondary battery |
| CN103337656A (en) * | 2013-07-05 | 2013-10-02 | 中国科学院青岛生物能源与过程研究所 | Modified biomass lithium ion battery adhesive |
| CN103342974A (en) * | 2013-07-05 | 2013-10-09 | 中国科学院青岛生物能源与过程研究所 | Simulated mussel protein environment-friendly lithium ion battery adhesive |
| CN105637695A (en) * | 2013-07-29 | 2016-06-01 | 宾夕法尼亚州研究基金会 | Elastic gel polymer binder for silicon-based anode |
| CN103427083A (en) * | 2013-08-20 | 2013-12-04 | 宁波奈克斯特新材料科技有限公司 | Adhesive for lithium battery and preparation method thereof |
| WO2016010056A1 (en) * | 2014-07-15 | 2016-01-21 | 川上総一郎 | Negative electrode material for power storage device, electrode structure, power storage device, and production method for each |
| CN106356534A (en) * | 2015-07-18 | 2017-01-25 | 宁波大学 | Adhesive for lithium ion battery and preparation method of adhesive |
| CN105702963A (en) * | 2016-01-29 | 2016-06-22 | 长沙理工大学 | Application of carboxymethyl chitosan self-crosslinking polymer in silicon negative electrode of lithium ion battery |
| CN105914376A (en) * | 2016-06-24 | 2016-08-31 | 辽宁九夷锂能股份有限公司 | Reinforced type composite binder for negative electrode of lithium ion battery and application of reinforced type composite binder |
Also Published As
| Publication number | Publication date |
|---|---|
| CN109216699A (en) | 2019-01-15 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN114142011B (en) | Hard carbon composite material and preparation method and application thereof | |
| CN105845906B (en) | Phosphorous anode material and preparation method thereof and lithium ion battery | |
| CN108075125A (en) | A kind of graphene/silicon anode composite and its preparation method and application | |
| CN109301248B (en) | Battery negative plate, preparation method thereof and lithium ion battery | |
| CN107403905B (en) | Lithium ion battery positive plate and preparation method thereof | |
| Sun et al. | Effect of poly (acrylic acid)/poly (vinyl alcohol) blending binder on electrochemical performance for lithium iron phosphate cathodes | |
| CN103074007B (en) | The preparation method of lithium ion battery silicium cathode use tackiness agent and silicium cathode | |
| CN112103468B (en) | Negative plate and lithium ion battery comprising same | |
| KR20140044409A (en) | Electrode for electricity storage device, slurry for electrode, binder composition for electrode, and electricity storage device | |
| CN109698354B (en) | Binder, negative electrode slurry using binder, and preparation method and application of negative electrode slurry | |
| CN106992299B (en) | Aqueous binder and lithium battery containing same | |
| Wang et al. | Xanthan gum as a potential binder for graphite anode in lithium-ion batteries | |
| CN114122357A (en) | Lithium salt-coated graphene-doped silicon-carbon composite material and preparation method thereof | |
| CN108493452B (en) | Water-based binder for inhibiting expansion of pole piece material, lithium ion battery negative electrode material based on water-based binder and preparation method | |
| CN113328098A (en) | Negative plate and lithium ion battery comprising same | |
| CN112133916A (en) | Silicon-based negative electrode material binder of lithium ion battery and preparation method and application thereof | |
| CN115101741A (en) | Nitrogen-doped graphene-coated silicon-carbon composite material and preparation method and application thereof | |
| CN111916746A (en) | Negative pole piece containing modified polyimide binder, preparation method and application | |
| CN109216699B (en) | Lithium battery adhesive with three-dimensional structure and lithium battery negative electrode material containing same | |
| CN108470909B (en) | Crosslinked network composite adhesive, application thereof, lithium ion battery cathode material prepared based on crosslinked network composite adhesive and preparation method of lithium ion battery cathode material | |
| CN113764645B (en) | Preparation method of hard carbon composite material with three-dimensional structure | |
| CN113363482B (en) | Composite binder for silicon-based negative electrode of lithium ion battery and preparation method and application thereof | |
| CN115295756A (en) | Negative plate and battery comprising same | |
| KR101141060B1 (en) | Composite Binder having Conductivity and Secondary Battery Employing the Same | |
| CN108461728B (en) | Composite adhesive, application thereof, lithium ion battery cathode material prepared based on composite adhesive and preparation method |
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 |