CN110767878B - Conductive polymer coated silicon-based negative electrode plate and preparation method and application thereof - Google Patents

Conductive polymer coated silicon-based negative electrode plate and preparation method and application thereof Download PDF

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CN110767878B
CN110767878B CN201910900192.4A CN201910900192A CN110767878B CN 110767878 B CN110767878 B CN 110767878B CN 201910900192 A CN201910900192 A CN 201910900192A CN 110767878 B CN110767878 B CN 110767878B
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silicon
based negative
pole piece
conductive polymer
negative electrode
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CN110767878A (en
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王辉
王庆莉
林少雄
许家齐
周勇岐
辛昱
高玉仙
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Hefei Gotion High Tech Power Energy Co Ltd
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Hefei Guoxuan High Tech Power Energy Co Ltd
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    • 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
    • H01M4/139—Processes of manufacture
    • H01M4/1395—Processes of manufacture of 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
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/05—Accumulators with non-aqueous electrolyte
    • H01M10/052—Li-accumulators
    • H01M10/0525—Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
    • 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
    • H01M4/36—Selection of substances as active materials, active masses, active liquids
    • H01M4/38—Selection of substances as active materials, active masses, active liquids of elements or alloys
    • H01M4/386—Silicon or alloys based on silicon
    • 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
    • H01M4/624—Electric conductive fillers
    • 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
    • H01M4/628—Inhibitors, e.g. gassing inhibitors, corrosion inhibitors
    • 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 discloses a conductive polymer coated silicon-based negative pole piece and a preparation method and application thereof.A silicon-based negative pole piece is taken as a matrix, ionic liquid is taken as a reaction medium, a polymer monomer is subjected to electrochemical self-polymerization reaction in gaps and surfaces of the matrix through electrochemical polymerization reaction, and a conductive polymer film with controllable thickness is generated on the surface of the matrix so as to improve the interface performance and the cycling stability of the silicon-based negative pole piece; and then connecting the pole piece as a positive electrode and a metal lithium piece as a negative electrode with an external circuit to control current to perform electrochemical pre-lithium so as to improve the first coulombic efficiency of the matrix and prepare the conductive polymer coated silicon-based negative pole piece. In the electrochemical polymerization reaction process, the thickness of the conductive polymer film can be controlled by electric quantity, a catalyst is not needed, and large-scale production can be realized; and the reaction medium is ionic liquid, which has almost no vapor pressure and wide liquid temperature range, and is more environment-friendly, green and pollution-free compared with other organic/inorganic solvents.

Description

Conductive polymer coated silicon-based negative electrode plate and preparation method and application thereof
Technical Field
The invention belongs to the technical field of negative pole pieces for lithium batteries, and particularly relates to a conductive polymer coated silicon-based negative pole piece and a preparation method and application thereof.
Background
With the development of electric vehicles and portable electric appliances, the demand of high-energy density lithium ion batteries is increasing day by day. The theoretical specific capacity of the traditional graphite negative electrode material is only 372mAh/g, and the market demand is difficult to meet. The first gram capacity of the silicon material is 4200mAh/g, the lithium embedding platform is higher, the earth crust is rich in storage, the silicon material is environment-friendly and the like, and gradually attracts the wide attention of researchers.
However, the volume expansion of silicon is as high as 300%, which not only causes the silicon to separate from the surrounding conductive carbon network and form "dead silicon" during cycling, but also causes the silicon to delaminate from the current collector. Secondly, the larger volume expansion can also cause the continuous recombination damage of the SEI film on the surface, so that the SEI film becomes thicker and thicker, and the Li of the anode is continuously consumed+The coulomb efficiency decreases. Finally, the large volume expansion leads to dusting of the silicon material late in the cycle, and these problems ultimately lead to a dramatic deterioration in cycle performance.
Due to the above problems, the academia and industry have moved some attention to the field of silicon oxide. Although partial capacity is sacrificed, the expansion of the silicon monoxide is relatively small (-100%) compared with that of nano-silicon, and by-products of lithium oxide, lithium silicate, lithium metasilicate, and the like generated during charge and discharge can provide a buffer effect, thereby greatly improving the cycle performance of the material. But the conductivity of the material is relatively poor, and the first effect is low. Lee D J [ Lee D J, Ryou M H, Lee J N, et al, nitrogen-doped carbon coating for a high-performance SiO and in lithium-ion batteries [ J ]. electrochemical Communications,2013,34:98-101 ], and the like, prepare nitrogen-doped carbon-coated SiO materials by liquid phase mixing and high temperature carbonization, which have relatively good cycle but low first efficiency. The method improves the first coulombic efficiency of the material, but has relatively poor cycle performance, and has relatively harsh synthetic conditions due to the use of lithium metal as a reactant, so that the method has safety risks and has the risk of gas generation in the battery slurry mixing process.
Disclosure of Invention
In order to overcome the defects in the prior art, the invention aims to provide a conductive polymer coated silicon-based negative electrode plate and a preparation method and application thereof.
In order to realize the purpose, the invention adopts the technical scheme that:
a preparation method of a conductive polymer coated silicon-based negative pole piece comprises the following steps:
s1, dissolving lithium salt in the ionic liquid, and then adding a polymer monomer to mix uniformly to obtain a mixed solution;
s2, preparing a silicon-based negative pole piece, then placing the silicon-based negative pole piece, a metal lithium piece and the mixed solution prepared in the S1 into an electrolytic bath, applying an external power supply to the electrolytic bath to perform electrochemical polymerization reaction, performing electrochemical self-polymerization reaction on polymer monomers in the gap and the surface of the silicon-based negative pole piece, and generating a conductive polymer film with controllable thickness on the surface of the silicon-based negative pole piece;
s3, after the electrochemical self-polymerization reaction is finished, connecting a silicon-based negative electrode plate as a positive electrode and a metal lithium plate as a negative electrode with an external circuit to perform electrochemical pre-lithium;
and S4, drying the silicon-based negative electrode plate after the electrochemical pre-lithium reaction is finished to obtain a target product.
The silicon material (Si or SiO) has large expansion, poor conductivity and low first-order efficiency, so the wide application of the silicon material in the field of lithium ion batteries is limited, the current common method is to compound the silicon material and graphite or metal and other materials to buffer the expansion of the material and improve the conductivity of the material, but the first-order efficiency and the cycle are still better than those of graphite cathodes. Aiming at the defects of the silicon-based negative electrode material, the invention takes a silicon-based negative electrode pole piece as a matrix, takes ionic liquid as a reaction medium, carries out pre-lithium on the pole piece in an electrochemical mode to improve the first coulombic efficiency, and carries out self-polymerization on polymer monomers in gaps and surfaces of the pole piece to generate a conductive polymer film with controllable thickness, thereby improving the interface performance and the cycling stability. In addition, the thickness of the conductive polymer film obtained by electrochemical polymerization can be controlled by electric quantity, the reaction rate is controllable, no catalyst is needed, and the conductive polymer film can be produced in a large scale. The medium is ionic liquid, which has almost no vapor pressure and wide liquid temperature range, and compared with other organic/inorganic solvents, the ionic liquid is more environment-friendly, green and pollution-free.
Further, in step S1, the lithium salt is LiCl or LiPF6、LiAsF6、LiTFSI、LiFSI、LiBF4One or more of them. The ionic liquid is 1-ethyl-3-methylimidazolium tetrafluoroborate ([ EMIm][BF4]) 1-ethyl-3-methylimidazolium hexafluorophosphate ([ EMIm][PF6]) 1-Ethyl-3-methylimidazolium trifluoromethanesulfonate ([ EMIm ]][OTf]) 1-butyl-3-methylimidazolium hexafluorophosphate ([ BMIm)][PF6]) 1-butyl-3-methylpyridine bis (trifluoromethanesulfonyl) imide salt ([ BMPy)][NTf2]) 1-ethyl-3-methylimidazolium bistrifluoromethylsulfonyl imide salt ([ EMIm][TFSI]) One or more of them. The polymer monomer is one or more of pyrrole, pyridine, aniline, thiophene, selenophene and p-benzene. The ionic liquid is selected as a reaction medium mainly because the ionic liquid almost has no vapor pressure and has a wide liquid temperature range, and compared with other organic/inorganic solvents, the ionic liquid is more environment-friendly and green and has no pollution.
In a further scheme, in step S2, the method for preparing the silicon-based negative electrode plate includes: and weighing the SiO/C material, the conductive agent and the binder, and then sequentially carrying out slurry mixing, coating, rolling, slitting and die cutting to obtain the silicon-based negative pole piece. The voltage of the electrochemical self-polymerization reaction is 0.5V-2.0V, and the time is 0.5 h-6 h; the thickness of the polymer film is 1 nm-50 nm; compared with chemical polymerization, the thickness of the conductive polymer film obtained by electrochemical polymerization can be controlled by electric quantity, the reaction rate is controllable, a catalyst is not needed, and large-scale production can be realized. In addition, the polymer film is too small, and the film is damaged due to too large expansion of the material in the charging and discharging processes of the battery, so that the cycling stability of the material cannot be improved; the electronic conductivity and energy density of the silicon-based negative electrode plate are affected by the excessive thickness of the film, so that the control to a proper value is needed, and the electrochemical polymerization is important in order to achieve the effect.
Further, in step S3, the pre-lithium depth is 5% SOC to 30% SOC (state of charge), and the current density of the external circuit is 3 to 10mA/cm2The time of the electrochemical pre-lithium is 1-12 h. Through external circuit connection, can carry out the electrochemistry in advance lithium reaction voluntarily, through control current and time, control in advance the lithium degree of depth, and then the degree that the first coulomb efficiency of control battery promoted.
Further, in step S4, the drying is vacuum drying; the temperature of vacuum drying is 60-100 ℃, and the time is 6-12 h. The vacuum drying is mainly used for preventing the prelithiated pole piece from being exposed in air and oxidized so as to lose the function of improving the first coulombic efficiency by the prelithiated pole piece.
The invention also aims to provide the conductive polymer coated silicon-based negative pole piece prepared by the preparation method.
The third purpose of the invention is to provide the application of the conductive polymer coated silicon-based negative electrode plate as a negative electrode in a lithium ion battery. The silicon-based negative pole piece is used as a negative pole, the NCM ternary material or the lithium iron phosphate material is used as a positive pole to assemble the lithium ion battery, and the electrochemical performance of the prepared lithium ion battery is tested, so that the capacity, the first effect and the cycling stability of the prepared lithium ion battery are improved.
Compared with the prior art, the invention has the following beneficial effects:
according to the invention, a silicon-based negative pole piece is taken as a matrix, ionic liquid is taken as a reaction medium, firstly, a polymer monomer is subjected to electrochemical self-polymerization reaction in the gap and the surface of the silicon-based negative pole piece through electrochemical polymerization reaction, and a conductive polymer film with controllable thickness is generated on the surface of the silicon-based negative pole piece, so that the interface performance and the cycling stability of the silicon-based negative pole piece are improved; and then, connecting a silicon-based negative electrode plate as a positive electrode and a metal lithium plate as a negative electrode with an external circuit to control current to perform electrochemical pre-lithium so as to improve the first coulombic efficiency of the silicon-based negative electrode plate and prepare the conductive polymer coated silicon-based negative electrode plate. In the electrochemical polymerization reaction process, the thickness of the conductive polymer film can be controlled by electric quantity, the reaction rate is controllable, a catalyst is not needed, and the large-scale production can be realized; and the reaction medium adopts ionic liquid, which has almost no vapor pressure and wide liquid temperature range, and is more environment-friendly, green and pollution-free compared with other organic/inorganic solvents.
Drawings
FIG. 1 is a chemical composition capacity curve of the batteries manufactured in example 1 and comparative example 1;
FIG. 2 is a normal temperature cycle curve at a current density of 1C/1C for the batteries manufactured in example 1 and comparative example 1.
Detailed Description
The present invention will be further described with reference to the following examples. It is to be understood that the embodiments described are only a few embodiments of the present invention, and not all 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.
Unless otherwise specified, the reagents and materials used in the present invention are commercially available products or products obtained by a known method.
The conductive agent used in the following examples was super P and the binder was polyacrylic acid.
Example 1
Mixing commercial SiO/C material (600 mAh/g in example 1), conductive agent and adhesive according to the mass ratio of 94.5:2:3.5, coating, rolling, slitting and die cutting to obtain the silicon-based negative pole piece.
1mol of LiCl was dissolved in 1L of 1-ethyl-3-methylimidazolium tetrafluoroborate ([ EMIm ]][BF4]) And adding 1mol of pyrrole (py) monomer, and magnetically stirring, dissolving and uniformly dispersing to obtain a mixed solution. Respectively adding the mixed solution, the silicon-based negative electrode plate and the metal lithium plate into an electrolytic bath,applying an external power supply, controlling the voltage to be 0.5V, and reacting for 6h, wherein the polymer monomer performs electrochemical self-polymerization reaction in the gaps and the surface of the silicon-based negative pole piece, and a conductive polymer film with the thickness of 20nm is generated on the surface of the silicon-based negative pole piece; after the reaction is finished, a silicon-based negative pole piece is taken as a positive pole, a metal lithium piece is taken as a negative pole, an external circuit is connected, and the current density is controlled to be 3mA/cm2The reaction time is 1 h. And after the reaction is finished, placing the silicon-based negative electrode plate in a vacuum drying oven, and treating for 12 hours at the temperature of 60 ℃ to obtain the conductive polymer coated silicon-based negative electrode plate.
Assembling the prepared 11 silicon-based negative electrode plates coated by the conductive polymer and 10 nickel-cobalt-manganese (NCM622) electrode plates into a soft-package laminated battery, wherein the electrolyte uses 1mol/L LiPF6The EC + DEC solution of (1), in which the amount of FEC added was 10%, was subjected to chemical composition at a current density of 0.2C, and the results are shown in FIG. 1. The charge capacity was 8.7Ah, the discharge capacity was 7.64Ah, and the first coulombic efficiency of the battery was 87.88%. And then, a normal-temperature cycle test is carried out at 25 ℃, the charge-discharge current density is 1C/1C, and the test result is shown in figure 2, and the capacity retention rate of the battery after 400 cycles is 94.06%.
Comparative example 1
The same silicon-based negative electrode sheet was prepared as in example 1.
Assembling the prepared 11 silicon-based negative electrode plates and 10 nickel-cobalt-manganese (NCM622) electrode plates into a soft-package laminated battery, wherein 1mol/L LiPF is used as electrolyte6The EC + DEC solution of (1), in which the amount of FEC added was 10%, was subjected to chemical composition at a current density of 0.2C, and the results are shown in FIG. 1. The charge capacity was 8.87Ah, the discharge capacity was 7.3Ah, and the first coulombic efficiency of the battery was 82.28%. And then, a normal-temperature cycle test is carried out at 25 ℃, the charge-discharge current density is 1C/1C, and the test result is shown in figure 2, and the capacity retention rate of the battery after 400 cycles is 89.33%. By comparing the example 1 with the comparative example 1, it can be found that after the synthesis is performed by using the method in the example 1, the first coulombic efficiency of the battery is improved by 5.6%, and after 400 weeks, the capacity retention rate of the battery manufactured by using the negative electrode sheet in the example 1 is improved by 4.73%. The first coulombic efficiency and capacity retention rate are improved mainly by electrochemical pre-lithiumReplenishing Li consumed by SEI film formation and O position in SiO in advance+In addition, the thickness of a film formed by electrochemical polymerization of the polymer monomer is controllable, so that the interface performance of the battery is improved, the electric contact between the polymer and the material is always kept in the charge and discharge processes of the material, and the cycle stability of the battery is improved.
Example 2
Mixing commercial SiO/C material (420 mAh/g in example 2), conductive agent and adhesive according to the mass ratio of 94.5:2:3.5, coating, rolling, slitting and die cutting to obtain the silicon-based negative electrode plate.
Taking 1mol of LiPF6Dissolved in 1L 1-ethyl-3-methylimidazolium hexafluorophosphate ([ EMIm ]][PF6]) And adding 1mol of pyridine monomer, and magnetically stirring, dissolving and dispersing uniformly to obtain a mixed solution. Respectively adding the mixed solution, the silicon-based negative pole piece and the metal lithium piece into an electrolytic bath, applying an external power supply, controlling the voltage to be 2V, controlling the reaction time to be 0.5h, carrying out electrochemical self-polymerization reaction on polymer monomers in gaps and surfaces of the silicon-based negative pole piece, generating a conductive polymer film with the thickness of 1nm on the surface of the silicon-based negative pole piece, and after the reaction is finished, taking the silicon-based negative pole piece as a positive pole, taking the lithium piece as a negative pole, and controlling the current density to be 10mA/cm2The reaction time is 12 h. And finally, after the reaction is finished, placing the silicon-based negative electrode plate in a vacuum drying oven, and treating for 6 hours at the temperature of 100 ℃ to obtain the conductive polymer coated silicon-based negative electrode plate.
Example 3
Mixing commercial SiO/C material (450 mAh/g in example 3), conductive agent and adhesive according to the mass ratio of 94.5:2:3.5, coating, rolling, slitting and die cutting to obtain the silicon-based negative electrode plate.
Taking 1mol of LiPF6Dissolved in 1L 1-ethyl-3-methylimidazolium trifluoromethanesulfonate ([ EMIm ]][OTf]) And adding 1mol of thiophene monomer, and magnetically stirring, dissolving and dispersing uniformly to obtain a mixed solution. Respectively adding the mixed solution, the silicon-based negative electrode plate and the metal lithium plate into an electrolytic bath, applying an external power supply, controlling the voltage to be 1.5V, reacting for 4h, and carrying out polymer monomer in the gap and the surface of the silicon-based negative electrode plateElectrochemical self-polymerization reaction, generating a conductive polymer film with the thickness of 50nm on the surface of the silicon-based negative pole piece, and after the reaction is finished, taking the silicon-based negative pole piece as a positive pole, taking a lithium piece as a negative pole, and controlling the current density to be 5mA/cm2The reaction time is 6 h. And finally, after the reaction is finished, placing the silicon-based negative electrode plate in a vacuum drying oven, and treating for 10 hours at 80 ℃ to obtain the conductive polymer coated silicon-based negative electrode plate.
Example 4
Mixing commercial SiO/C material (800 mAh/g in example 4), conductive agent and adhesive according to the mass ratio of 94.5:2:3.5, coating, rolling, slitting and die cutting to obtain the silicon-based negative electrode plate.
Taking 1mol of LiBF4Dissolved in 1L 1-ethyl-3-methylimidazolium bistrifluoromethanesulfonylimide salt ([ EMIm ]][TFSI]) And adding 1mol of selenophen monomer, and dissolving and dispersing uniformly by magnetic stirring to obtain a mixed solution. Respectively adding the mixed solution, the silicon-based negative pole piece and the metal lithium piece into an electrolytic bath, applying an external power supply, controlling the voltage to be 1V, controlling the reaction time to be 6h, carrying out electrochemical self-polymerization reaction on polymer monomers in gaps and surfaces of the silicon-based negative pole piece, generating a conductive polymer film with the thickness of 40nm on the surface of the silicon-based negative pole piece, and after the reaction is finished, taking the silicon-based negative pole piece as a positive pole, the lithium piece as a negative pole, and controlling the current density to be 5mA/cm2The reaction time is 6 h. And finally, after the reaction is finished, placing the silicon-based negative electrode plate in a vacuum drying oven, and treating for 10 hours at 80 ℃ to obtain the conductive polymer coated silicon-based negative electrode plate.
Example 5
Mixing commercial SiO/C material (1600 mAh/g in example 5), conductive agent and adhesive according to the mass ratio of 94.5:2:3.5, coating, rolling, slitting and die cutting to obtain the silicon-based negative electrode plate.
1mol of LiTFSI was dissolved in 1L of 1-butyl-3-methylimidazolium hexafluorophosphate ([ BMIm)][PF6]) And adding 1mol of p-benzene monomer, and magnetically stirring, dissolving and dispersing uniformly to obtain a mixed solution. Adding the mixed solution, the silicon-based negative electrode plate and the metal lithium plate into an electrolytic bath respectively, applying an external power supply, and controllingThe voltage is 1.5V, the reaction time is 4h, the polymer monomer carries out electrochemical self-polymerization reaction in the gaps and the surface of the silicon-based negative pole piece, a conductive polymer film with the thickness of 50nm is generated on the surface of the silicon-based negative pole piece, after the reaction is finished, the silicon-based negative pole piece is taken as the positive pole, the lithium piece is taken as the negative pole, and the current density is controlled to be 5mA/cm2The reaction time is 6 h. And finally, after the reaction is finished, placing the silicon-based negative electrode plate in a vacuum drying oven, and treating for 10 hours at 80 ℃ to obtain the conductive polymer coated silicon-based negative electrode plate.

Claims (9)

1. A preparation method of a conductive polymer coated silicon-based negative pole piece is characterized by comprising the following steps: the method comprises the following steps:
s1, dissolving lithium salt in the ionic liquid, and then adding a polymer monomer to mix uniformly to obtain a mixed solution; the polymer monomer is one or more of pyrrole, pyridine, aniline, thiophene, selenophene and p-benzene;
s2, preparing a silicon-based negative pole piece, then placing the silicon-based negative pole piece, a metal lithium piece and the mixed solution prepared in the S1 into an electrolytic bath, applying an external power supply to the electrolytic bath to perform electrochemical polymerization reaction, performing electrochemical self-polymerization reaction on polymer monomers in the gap and the surface of the silicon-based negative pole piece, and generating a conductive polymer film with controllable thickness on the surface of the silicon-based negative pole piece; the voltage of the electrochemical self-polymerization reaction is 0.5V-2.0V;
s3, after the electrochemical self-polymerization reaction is finished, taking a silicon-based negative electrode plate with a conductive polymer film with controllable thickness generated on the surface as a positive electrode, taking a metal lithium plate as a negative electrode, and connecting an external circuit for electrochemical pre-lithium;
and S4, drying the silicon-based negative electrode plate after the electrochemical pre-lithium reaction is finished to obtain a target product.
2. The method of claim 1, wherein: in step S1, the lithium salt is LiCl or LiPF6、LiAsF6、LiTFSI、LiFSI、LiBF4One or more of them.
3. The method of claim 1, wherein: in step S1, the ionic liquid is one or more of 1-ethyl-3-methylimidazole tetrafluoroborate, 1-ethyl-3-methylimidazole hexafluorophosphate, 1-ethyl-3-methylimidazole trifluoromethanesulfonate, 1-butyl-3-methylimidazole hexafluorophosphate, 1-butyl-3-methylpyridine bis (trifluoromethanesulfonyl) imide salt, and 1-ethyl-3-methylimidazole bis (trifluoromethanesulfonyl) imide salt.
4. The method of claim 1, wherein: in step S2, the method for preparing the silicon-based negative electrode plate includes: and weighing the SiO/C material, the conductive agent and the binder, and then sequentially carrying out slurry mixing, coating, rolling, slitting and die cutting to obtain the silicon-based negative pole piece.
5. The production method according to claim 1, characterized in that: in the step S2, the time of the electrochemical self-polymerization reaction is 0.5-6 h; the thickness of the conductive polymer film is 1 nm-50 nm.
6. The method of claim 1, wherein: in step S3, the current density of the external circuit is 3-10 mA/cm2And the time of electrochemical pre-lithium is 1-12 h.
7. The production method according to claim 1, characterized in that: in step S4, the drying is vacuum drying; the temperature of vacuum drying is 60-100 ℃, and the time is 6-12 h.
8. The conductive polymer-coated silicon-based negative electrode plate prepared by the preparation method according to any one of claims 1 to 7.
9. The use of the conductive polymer coated silicon-based negative electrode sheet of claim 8 as a negative electrode in a lithium ion battery.
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Citations (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2008171588A (en) * 2007-01-09 2008-07-24 Sumitomo Electric Ind Ltd Lithium battery
CN101252043A (en) * 2007-04-25 2008-08-27 北京理工大学 Pre-embedding method of lithium ion super capacitor cathode
CN101447562A (en) * 2007-11-28 2009-06-03 三星Sdi株式会社 Negative electrodes for rechargeable lithium batteries, and rechargeable lithium batteries including the same
CN101794907A (en) * 2009-11-20 2010-08-04 无锡欧力达新能源电力科技有限公司 Aluminium polymer secondary battery and preparation method thereof
CN104081573A (en) * 2011-12-01 2014-10-01 那诺思卡乐康母庞特公司 Method for alkaliating anodes
CN105870404A (en) * 2016-04-29 2016-08-17 太原理工大学 Conducting polymer-coated open-cell foamed antimony electrode for anode of lithium ion battery and preparation method of antimony electrode
CN106797051A (en) * 2014-06-12 2017-05-31 安普瑞斯股份有限公司 For the solution of the prelithiation of lithium-ions battery
CN107743659A (en) * 2015-01-30 2018-02-27 科罗拉多州立大学董事会（法人团体） Ion liquid type high-performance lithium ion battery
CN109952670A (en) * 2016-04-07 2019-06-28 存点有限公司 Lithium ion battery and its anode
CN109997261A (en) * 2016-10-13 2019-07-09 西利昂公司 Large-sized battery pack anode comprising silicon particle

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2019511103A (en) * 2016-04-07 2019-04-18 ストアドット リミテッド Lithium ion cell and anode therefor
KR102587062B1 (en) * 2017-12-18 2023-10-11 삼성전자주식회사 Negative electrode for metal battery, metal battery comprising the same, and method of preparing the negative electrode for metal battery

Patent Citations (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2008171588A (en) * 2007-01-09 2008-07-24 Sumitomo Electric Ind Ltd Lithium battery
CN101252043A (en) * 2007-04-25 2008-08-27 北京理工大学 Pre-embedding method of lithium ion super capacitor cathode
CN101447562A (en) * 2007-11-28 2009-06-03 三星Sdi株式会社 Negative electrodes for rechargeable lithium batteries, and rechargeable lithium batteries including the same
CN101794907A (en) * 2009-11-20 2010-08-04 无锡欧力达新能源电力科技有限公司 Aluminium polymer secondary battery and preparation method thereof
CN104081573A (en) * 2011-12-01 2014-10-01 那诺思卡乐康母庞特公司 Method for alkaliating anodes
CN106797051A (en) * 2014-06-12 2017-05-31 安普瑞斯股份有限公司 For the solution of the prelithiation of lithium-ions battery
CN107743659A (en) * 2015-01-30 2018-02-27 科罗拉多州立大学董事会（法人团体） Ion liquid type high-performance lithium ion battery
CN109952670A (en) * 2016-04-07 2019-06-28 存点有限公司 Lithium ion battery and its anode
CN105870404A (en) * 2016-04-29 2016-08-17 太原理工大学 Conducting polymer-coated open-cell foamed antimony electrode for anode of lithium ion battery and preparation method of antimony electrode
CN109997261A (en) * 2016-10-13 2019-07-09 西利昂公司 Large-sized battery pack anode comprising silicon particle

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
Functionalization of silicon nanowires by conductive and non-conductive polymers;S. Belhousse 等;《Applied Surface Science》;20170106;第421卷(第Part A期);第134-141页 *
锂离子电池硅基负极改性研究新进展;邹幽兰 等;《材料导报》;20110910;第25卷(第9期);第144-147页 *

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