CN111416102B - Gel composite negative plate and preparation method and application thereof - Google Patents

Gel composite negative plate and preparation method and application thereof Download PDF

Info

Publication number
CN111416102B
CN111416102B CN202010303715.XA CN202010303715A CN111416102B CN 111416102 B CN111416102 B CN 111416102B CN 202010303715 A CN202010303715 A CN 202010303715A CN 111416102 B CN111416102 B CN 111416102B
Authority
CN
China
Prior art keywords
negative electrode
gel
composite negative
electrode sheet
gel composite
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
Application number
CN202010303715.XA
Other languages
Chinese (zh)
Other versions
CN111416102A (en
Inventor
李峥
冯玉川
何泓材
周柯
王丹丹
杨帆
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Suzhou Qingtao New Energy S&T Co Ltd
Original Assignee
Suzhou Qingtao New Energy S&T Co Ltd
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Suzhou Qingtao New Energy S&T Co Ltd filed Critical Suzhou Qingtao New Energy S&T Co Ltd
Priority to CN202010303715.XA priority Critical patent/CN111416102B/en
Publication of CN111416102A publication Critical patent/CN111416102A/en
Application granted granted Critical
Publication of CN111416102B publication Critical patent/CN111416102B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

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
    • H01M4/13—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
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
    • C08F20/00—Homopolymers and copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and only one being terminated by only one carboxyl radical or a salt, anhydride, ester, amide, imide or nitrile thereof
    • C08F20/02—Monocarboxylic acids having less than ten carbon atoms, Derivatives thereof
    • C08F20/10—Esters
    • C08F20/12—Esters of monohydric alcohols or phenols
    • C08F20/16—Esters of monohydric alcohols or phenols of phenols or of alcohols containing two or more carbon atoms
    • C08F20/18—Esters of monohydric alcohols or phenols of phenols or of alcohols containing two or more carbon atoms with acrylic or methacrylic acids
    • 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
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/05—Accumulators with non-aqueous electrolyte
    • H01M10/056—Accumulators with non-aqueous electrolyte characterised by the materials used as electrolytes, e.g. mixed inorganic/organic electrolytes
    • H01M10/0564—Accumulators with non-aqueous electrolyte characterised by the materials used as electrolytes, e.g. mixed inorganic/organic electrolytes the electrolyte being constituted of organic materials only
    • H01M10/0565—Polymeric materials, e.g. gel-type or solid-type
    • 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
    • H01M10/058—Construction or manufacture
    • 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
    • H01M2300/00—Electrolytes
    • H01M2300/0017—Non-aqueous electrolytes
    • H01M2300/0065—Solid electrolytes
    • H01M2300/0082—Organic polymers
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M2300/00—Electrolytes
    • H01M2300/0085—Immobilising or gelification of electrolyte
    • 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
    • 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
    • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P70/00—Climate change mitigation technologies in the production process for final industrial or consumer products
    • Y02P70/50—Manufacturing or production processes characterised by the final manufactured product

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Electrochemistry (AREA)
  • General Chemical & Material Sciences (AREA)
  • Manufacturing & Machinery (AREA)
  • Materials Engineering (AREA)
  • Condensed Matter Physics & Semiconductors (AREA)
  • Physics & Mathematics (AREA)
  • Dispersion Chemistry (AREA)
  • General Physics & Mathematics (AREA)
  • Inorganic Chemistry (AREA)
  • Health & Medical Sciences (AREA)
  • Medicinal Chemistry (AREA)
  • Polymers & Plastics (AREA)
  • Organic Chemistry (AREA)
  • Secondary Cells (AREA)

Abstract

The invention provides a gel composite negative plate and a preparation method and application thereof, wherein the preparation method of the gel composite negative plate comprises the following steps: (1) soaking the metal lithium negative electrode piece in an ester electrolyte containing a first polymerization monomer to obtain a metal lithium negative electrode piece containing a protective layer; (2) coating gel electrolyte containing a second polymerization monomer on the surface of the metal lithium negative electrode piece containing the protective layer obtained in the step (1), and heating to polymerize and crosslink the gel electrolyte to obtain the gel composite negative electrode piece; by adding the first polymerized monomer into the ester electrolyte, the second polymerized monomer in the gel electrolyte can be weakly polymerized and hardened with the first polymerized monomer in the protective layer besides being subjected to in-situ polymerization, so that the interface performance between the protective layer and the gel electrolyte layer is improved, and the first efficiency and the cycle performance of the gel electrolyte battery are improved.

Description

Gel composite negative plate and preparation method and application thereof
Technical Field
The invention belongs to the field of batteries, and relates to a gel composite negative plate and a preparation method and application thereof.
Background
The lithium ion battery as a new generation clean energy has the advantages of high output voltage, large energy density, small self-discharge, long cycle life, no memory effect, quick charge and discharge, environmental protection and the like, and is widely applied to various fields. The reason is that the lithium metal cathode has a good high energy density (3800mAh/g), and the selection of the corresponding cathode material is wide, so that the lithium ion battery industry chain has formed an industry chain system with high specialization degree and clear division of labor through the development of the last two decades.
Compared with the traditional graphite cathode, the lithium metal has the advantage of high energy density, but the lithium metal cathode has very high reactivity and can react with the electrolyte and the components in the electrolyte to generate loss; meanwhile, the lithium metal negative electrode may also generate powdering and dead lithium due to its unstable SEI film. The solid electrolyte is considered to have good matching property with the lithium metal negative electrode, but the problems of the fragile and unstable SEI film on the surface of the lithium metal negative electrode still cannot be completely solved.
Therefore, it is necessary to provide a composite negative electrode sheet which can protect the metal lithium, suppress the dendrite of the negative electrode lithium, and improve the battery performance.
Disclosure of Invention
The invention aims to provide a gel composite negative plate and a preparation method and application thereof, and the gel composite negative plate is characterized in that a first polymeric monomer is added into an ester electrolyte, so that a second polymeric monomer in the gel electrolyte can perform weak polymerization reaction with the first polymeric monomer in the ester electrolyte besides in-situ polymerization, the interface performance between a protective layer and a gel electrolyte layer is improved, in addition, the components in the gel electrolyte are mixed more uniformly by a repeated coating-crosslinking mode when the gel electrolyte layer is formed, the possibility of forming pits or unevenness between the gel electrolyte layer and the protective layer due to interface compatibility is reduced, and the electrochemical performance of a gel electrolyte battery is further improved; the gel electrolyte battery prepared by the gel composite negative plate has high first-effect efficiency and good cycle performance.
In order to achieve the purpose, the invention adopts the following technical scheme:
one of the purposes of the invention is to provide a preparation method of a gel composite negative plate, which comprises the following steps:
(1) soaking the metal lithium negative electrode piece in an ester electrolyte containing a first polymerization monomer to obtain a metal lithium negative electrode piece containing a protective layer;
(2) and (2) coating the surface of the metal lithium negative electrode piece containing the protective layer obtained in the step (1) with gel electrolyte containing a second polymerization monomer, and heating to polymerize and crosslink the gel electrolyte to obtain the gel composite negative electrode piece.
According to the invention, the metal lithium negative pole piece is immersed in the ester electrolyte containing the first polymeric monomer for immersion, so that on one hand, metal lithium is passivated, an inorganic layer and an organic layer can be sequentially generated on the surface of the metal lithium negative pole piece, the reaction of the metal lithium and the electrolyte can be reduced, and the growth of lithium dendrites can be inhibited, on the other hand, the first polymeric monomer in the ester electrolyte can perform weak polymerization reaction with the second polymeric monomer in the gel electrolyte, the interface performance between the protective layer and the gel electrolyte layer is improved, and the cycle performance of the gel electrolyte battery can be improved when the lithium negative pole piece is used in the gel electrolyte battery.
According to the invention, the electrolyte layer is formed on the metal lithium negative electrode plate containing the protective layer in a coating-crosslinking manner, so that the components in the gel electrolyte are mixed more uniformly, the possibility of forming pits and unevenness between the gel electrolyte and the negative electrode protective layer due to interface compatibility is reduced, and the overall performance of the battery is further improved.
According to the invention, the protective layer and the gel electrolyte layer are cooperatively used, so that the gel electrolyte battery prepared from the composite negative plate has higher first efficiency and better cycle performance.
In the invention, the ester electrolyte containing the first polymeric monomer in the step (1) comprises a solute, a solvent and the first polymeric monomer.
In the present invention, the solute comprises LiNO3、KNO3Or NaNO3Any one or a combination of at least two of them.
In the present invention, the solvent includes any one of ethylene carbonate, propylene carbonate, dimethyl carbonate, ethyl methyl carbonate, or diethyl carbonate, or a combination of at least two thereof.
In the present invention, the first polymerized monomer is acrylate, preferably methacrylate and/or ethyl acrylate.
In the present invention, the content of the first polymeric monomer in the ester electrolyte containing the first polymeric monomer in step (1) is 1 to 5%, for example, 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, 5%, etc.; when the content of the first polymer monomer is too low, effective weak crosslinking with the gel electrolyte layer cannot be formed, so that the interaction between the protective layer and the gel electrolyte layer is weakened, and the interface performance is deteriorated.
In the present invention, the solute concentration in the ester electrolyte containing the first polymerized monomer in the step (1) is 1-10mol/L, for example, 1mol/L, 2mol/L, 3mol/L, 4mol/L, 5mol/L, 6mol/L, 7mol/L, 8mol/L, 9mol/L, 10mol/L, etc.
In the invention, the soaking time in the step (1) is 1-48h, such as 1h, 5h, 8h, 10h, 12h, 15h, 18h, 20h, 24h, 25h, 28h, 30h, 32h, 35h, 38h, 40h, 42h, 45h, 48h and the like; when the soaking time is too short, the formed protective layer is thin, so that the protective layer cannot play a good protection role on the lithium metal, and when the soaking time is too long, the formed protective layer is too thick, so that the performance of the final battery is influenced.
In the present invention, the step (1) further comprises: and after soaking the metal lithium negative pole piece, drying the metal lithium negative pole piece.
In the present invention, the drying is performed in a glove box.
In the present invention, the drying temperature is 60 to 80 ℃, for example, 60 ℃, 62 ℃, 65 ℃, 68 ℃, 70 ℃, 72 ℃, 75 ℃, 77 ℃, 80 ℃ and the like.
In the invention, the times of coating the gel electrolyte containing the second polymeric monomer and the polymerization crosslinking in the step (2) are both n times, and n is more than or equal to 1.
In the invention, when n is more than or equal to 2, the compositions of the gel electrolyte coated for n times are the same or different.
In the invention, when n is more than or equal to 2, the step (2) comprises the following steps: coating 1 layer of gel electrolyte containing a second polymerization monomer on the surface of the metal lithium negative pole piece containing the protective layer, heating to enable the gel electrolyte to be polymerized and crosslinked to obtain the metal lithium negative pole piece with 1 layer of gel electrolyte layer, and repeating the steps for n-1 times to obtain the gel composite negative pole piece.
According to the invention, when the multi-layer gel electrolyte layer is formed, the multi-layer gel electrolyte layer is realized by a repeated coating-crosslinking mode instead of one-time coating and then crosslinking, so that on one hand, all components in the gel electrolyte can be mixed more uniformly, and meanwhile, the possibility of forming pits and unevenness between the gel electrolyte and a protective layer due to interface compatibility can be reduced, and the first efficiency and the cycle performance of the gel electrolyte battery are further improved.
In the present invention, the n-times coated gel electrolytes each independently include a solute, a solvent, and a second polymeric monomer.
In the invention, when n is more than or equal to 2, the concentration of the second polymeric monomer in the gel electrolyte close to the metal lithium negative electrode piece is lower than that of the second polymeric monomer in the gel electrolyte far away from the metal lithium negative electrode piece.
In the invention, the concentration of the second polymer monomer in each gel electrolyte layer can be adjusted according to the actual effect in the gel electrolyte layer, and only a small amount of monomer concentration is needed to perform weak crosslinking with the polymer monomer in the ester protective layer on the side close to the lithium metal negative pole piece, so that the interface performance between the protective layer and the gel electrolyte layer is improved.
Preferably, the solute comprises LiNO3、LiPF6、LiClO4Or LiFSI or a combination of at least two thereof.
In the present invention, the concentration of the solute in the gel electrolyte is 1 to 10mol/L, for example, 1mol/L, 2mol/L, 3mol/L, 4mol/L, 5mol/L, 6mol/L, 7mol/L, 8mol/L, 9mol/L, 10 mol/L.
Preferably, the solvent comprises any one of diethylene glycol dimethyl ether, dimethyl carbonate or ethyl methyl carbonate or a combination of at least two thereof.
Preferably, the second polymeric monomer comprises any one of acrylate, ethylene oxide, propylene oxide or butylene oxide or a combination of at least two thereof, preferably a combination of acrylate and ethylene oxide.
Preferably, the molar ratio of acrylate to ethylene oxide is (1-5: 1, e.g., 1:1, 1.5:1, 2:1, 2.5:1, 3:1, 3.5:1, 4:1, 4.5:1, 5:1, etc., preferably 3: 1; when the molar ratio of the protective layer to the gel electrolyte layer is too low, the content of the polymer with a long-chain structure is too low, which affects the battery performance, and when the molar ratio of the protective layer to the gel electrolyte layer is too high, the bonding strength between the protective layer and the gel electrolyte layer is too low.
Preferably, the gel electrolyte in step (2) further comprises an initiator, and the initiator is azobisisobutyronitrile.
Preferably, the initiator is present in an amount of 1 to 5 wt%, such as 1 wt%, 1.5 wt%, 2 wt%, 2.5 wt%, 3 wt%, 3.5 wt%, 4 wt%, 4.5 wt%, 5 wt%, etc., of the total mass of the gel electrolyte.
Preferably, the gel electrolyte in step (2) further comprises an additive, wherein the additive comprises any one or a combination of at least two of Vinylene Carbonate (VC), Propylene Sulfite (PS) or NaODFB.
In the present invention, the heating temperature in the step (2) is 50 to 100 ℃, for example, 50 ℃, 55 ℃, 60 ℃, 65 ℃, 70 ℃, 75 ℃, 80 ℃, 85 ℃, 90 ℃, 95 ℃, 100 ℃ and the like.
Preferably, the heating time in step (2) is 2-5h, such as 2h, 2.5h, 3h, 3.5h, 4h, 4.5h, 5h, etc.
As a preferred technical scheme of the present invention, when n is 1, the preparation method of the gel composite negative electrode sheet comprises the following steps:
(1) immersing the metal lithium negative electrode piece into ester electrolyte containing a first polymerization monomer and having a solute concentration of 1-10mol/L for soaking for 1-48h, and drying at 60-80 ℃ in a glove box to obtain the metal lithium negative electrode piece containing a protective layer;
(2) coating the surface of the metal lithium negative electrode piece containing the protective layer obtained in the step (1) with gel electrolyte containing a second polymerization monomer, and heating at 50-100 ℃ to enable the gel electrolyte to be polymerized and crosslinked for 2-5 hours to obtain a gel composite negative electrode piece;
and (3) when n is more than or equal to 2, repeating the process of the step (2) for n-1 times on the metal lithium negative electrode piece with 1 gel electrolyte layer obtained by coating and crosslinking the step (2) for 1 time to obtain the gel composite negative electrode piece.
The invention also aims to provide the gel composite negative electrode sheet prepared by the preparation method of the gel composite negative electrode sheet.
In the invention, the gel composite negative plate comprises metallic lithium, a protective layer and a gel electrolyte layer from bottom to top, wherein the number of the gel electrolyte layer is n, n is more than or equal to 1, for example, n is 1, 2, 3, 4, 5, 6, 7, 8, 9 and the like.
Preferably, the protective layer and the gel electrolyte layer are connected by a chemical bond.
The third purpose of the invention is to provide a gel electrolyte battery, which comprises a positive pole piece, a diaphragm and the gel composite negative pole piece.
The fourth purpose of the invention is to provide the application of the gel electrolyte battery as the third purpose in electric vehicles or electronic products.
Compared with the prior art, the invention has the following beneficial effects:
according to the invention, the first polymeric monomer is added into the ester electrolyte, so that the second polymeric monomer in the gel electrolyte can generate weak polymerization reaction with the first polymeric monomer in the ester electrolyte besides in-situ polymerization, the interface performance between the protective layer and the gel electrolyte layer is improved, in addition, the components in the gel electrolyte are mixed more uniformly by a repeated coating-crosslinking mode when the gel electrolyte layer is formed, the possibility of forming pits or unevenness between the gel electrolyte layer and the protective layer due to interface compatibility is reduced, and the electrochemical performance of the gel electrolyte battery is further improved; the gel electrolyte battery prepared by the gel composite negative plate has high first-effect efficiency and good cycle performance.
Detailed Description
The technical solution of the present invention is further explained by the following embodiments. It should be understood by those skilled in the art that the examples are only for the understanding of the present invention and should not be construed as the specific limitations of the present invention.
Example 1
Ester electrolyte containing polymerized monomer in this example: the solute is LiNO3And KNO3The electrolyte is a mixed material obtained by mixing diethylene glycol dimethyl ether and dimethyl carbonate according to the mass ratio of 1:1, a solvent is a mixed solution obtained by mixing diethylene glycol dimethyl ether and dimethyl carbonate according to the mass ratio of 1:1, a polymerization monomer is a methacrylate monomer, and the content of the methacrylate monomer is 3 wt% of the total mass of the ester electrolyte;
gel electrolyte: the solute is LiPF6The gel electrolyte is prepared by mixing the raw materials and LFSI according to a mass ratio of 1:1, wherein a solvent is a mixed solution obtained by mixing diethylene glycol dimethyl ether and dimethyl carbonate according to a mass ratio of 1:1, an additive is a mixture obtained by mixing VC, PS and NaODFB according to a mass ratio of 1:1:1, a monomer composition is a mixture obtained by mixing Ethylene Oxide (EO) and methacrylate according to a molar ratio of 1:3, an initiator is azobisisobutyronitrile, and the content of the azobisisobutyronitrile is 2 wt% of the total mass of the gel electrolyte;
the preparation method of the positive pole piece in the embodiment comprises the following steps: a positive electrode active material (lithium iron phosphate): conductive carbon black: mixing the PVDF binder at a mass ratio of 90:5:5, removing NMP as a solvent, mixing the slurry, coating the slurry on an aluminum foil, and performing vacuum drying at 90 ℃ to obtain a positive pole piece; the separator used in this example was Celgard 2400;
the preparation method of the gel composite negative plate in the embodiment comprises the following steps:
(1) soaking the metal lithium negative electrode piece in 5mol/L polymer monomer ester-containing electrolyte for 24h, and drying at 70 ℃ in a glove box to obtain the metal lithium negative electrode piece containing the carbonate organic layer;
(2) coating gel electrolyte on the metal lithium negative electrode piece obtained in the step (1), and heating at 80 ℃ to enable the gel electrolyte to be polymerized and crosslinked for 3 hours to obtain a gel composite negative electrode piece;
in this embodiment, the gel composite negative electrode sheet, the positive electrode sheet, and the separator are assembled to obtain the gel electrolyte battery.
Example 2
Ester electrolyte containing polymerized monomer in this example: the solute is LiNO3And NaNO3Mixing according to the mass ratio of 1:1The mixed material is obtained by synthesis, the solvent is a mixed solution obtained by mixing ethylene carbonate and dimethyl carbonate according to the mass ratio of 1:1, the polymerized monomer is a methacrylate monomer, and the content of the methacrylate monomer is 1 wt% of the total mass of the ester electrolyte;
gel electrolyte: the solute is LiPF6The gel electrolyte is prepared by mixing a mixed material obtained by mixing ethyl methyl carbonate and dimethyl carbonate according to a mass ratio of 1:1 with LFSI, wherein a solvent is a mixed solution obtained by mixing ethyl methyl carbonate and dimethyl carbonate according to a mass ratio of 1:1, an additive is a mixture obtained by mixing VC, PS and NaODFB according to a mass ratio of 1:1:1, a monomer composition is a mixture obtained by mixing Ethylene Oxide (EO) and methacrylate according to a molar ratio of 1:5, an initiator is azobisisobutyronitrile, and the content of the azobisisobutyronitrile is 1 wt% of the total mass of the gel electrolyte;
the preparation method of the positive pole piece in the embodiment comprises the following steps: a positive electrode active material (lithium iron phosphate): conductive carbon black: mixing the PVDF binder at a mass ratio of 90:5:5, removing NMP as a solvent, mixing the slurry, coating the slurry on an aluminum foil, and performing vacuum drying at 90 ℃ to obtain a positive pole piece; the separator used in this example was Celgard 2400;
the preparation method of the gel composite negative plate in the embodiment comprises the following steps:
(1) soaking the metal lithium negative electrode piece in 10mol/L polymer monomer ester-containing electrolyte for 1h, and drying at 60 ℃ in a glove box to obtain the metal lithium negative electrode piece containing the carbonate organic layer;
(2) coating gel electrolyte on the metal lithium negative electrode piece obtained in the step (1), and heating at 50 ℃ to enable the gel electrolyte to be polymerized and crosslinked for 5 hours to obtain a gel composite negative electrode piece;
in this embodiment, the gel composite negative electrode sheet, the positive electrode sheet, and the separator are assembled to obtain the gel electrolyte battery.
Example 3
Ester electrolyte containing polymerized monomer in this example: the solute is LiNO3And KNO3Mixing the materials according to the mass ratio of 1:1, wherein the solvent is a mixed solution obtained by mixing propylene carbonate and ethyl methyl carbonate according to the mass ratio of 1:1, the polymerization monomer is acrylate monomer, and ethyl propyleneThe content of the acid monomer is 1 wt% of the total mass of the ester electrolyte;
gel electrolyte: the solute is LiPF6And LiClO4The gel electrolyte is prepared by mixing a mixed material according to a mass ratio of 1:1, wherein a solvent is a mixed solution obtained by mixing methyl ethyl carbonate and dimethyl carbonate according to a mass ratio of 1:1, an additive is a mixture obtained by mixing VC, PS and NaODFB according to a mass ratio of 1:1:1, a monomer composition is a mixture obtained by mixing Ethylene Oxide (EO) and methacrylate according to a molar ratio of 1:1, an initiator is azobisisobutyronitrile, and the content of the azobisisobutyronitrile is 5 wt% of the total mass of the gel electrolyte;
the preparation method of the positive pole piece in the embodiment comprises the following steps: a positive electrode active material (lithium iron phosphate): conductive carbon black: mixing the PVDF binder at a mass ratio of 90:5:5, removing NMP as a solvent, mixing the slurry, coating the slurry on an aluminum foil, and performing vacuum drying at 90 ℃ to obtain a positive pole piece; the separator used in this example was Celgard 2400;
the preparation method of the gel composite negative plate in the embodiment comprises the following steps:
(1) soaking the metal lithium negative electrode piece in 1mol/L polymer monomer ester-containing electrolyte for 48h, and drying at 80 ℃ in a glove box to obtain the metal lithium negative electrode piece containing the carbonate organic layer;
(2) coating gel electrolyte on the metal lithium negative electrode piece obtained in the step (1), and heating at 100 ℃ to enable the gel electrolyte to be polymerized and crosslinked for 2 hours to obtain a gel composite negative electrode piece;
in this embodiment, the gel composite negative electrode sheet, the positive electrode sheet, and the separator are assembled to obtain the gel electrolyte battery.
Example 4
The difference from example 1 is only that the polymerized monomers in the gel electrolyte of step (2) include only methacrylate, wherein the amount of the added methacrylate is equal to the sum of the amounts of the added methacrylate and EO in example 1.
Example 5
The difference from example 1 is only that the polymerized monomers in the gel electrolyte of step (2) include only EO, wherein the addition amount of EO is equal to the sum of the addition amounts of the methacrylate and EO in example 1.
Example 6
The only difference from example 1 is that the number of coating-heating crosslinkings in step (2) was 2.
Comparative example 1
The difference from example 1 is only that the ester electrolyte in step (1) does not include a methacrylate monomer.
Test example
The batteries obtained in the embodiment and the comparative example are subjected to the following performance tests of the first efficiency, 10-circle capacity retention rate, 20-circle capacity retention rate and 30-circle capacity retention rate, and the charge and discharge tests are carried out on a NEWARE BTS type charge and discharge tester produced by Shenzhen NewWille electronics Limited company, wherein the charge and discharge voltage is 2.6-4.35V, the current is 1C, and the test results are shown in Table 1:
TABLE 1
Figure BDA0002454991290000101
Figure BDA0002454991290000111
As can be seen from table 1, the gel electrolyte battery of the present invention has better electrochemical properties;
it can be seen from the comparison between example 1 and examples 4-5 that if only ethylene oxide is added, the battery performance is significantly reduced because effective crosslinking cannot be formed between the protective layer and the gel electrolyte layer, and if only acrylate polymerized monomer is added, the battery performance is also reduced because the rigidity of acrylate is high, which affects the lithium ion transport property, as is known from examples 1 and 6, when the gel electrolyte battery is formed by using a multi-coating method, the crosslinking between the gel electrolyte layer and between the first layer and the protective layer is tighter, and the battery performance is improved.
As can be seen from comparison of example 1 with comparative example 1, the performance of the battery can be effectively improved by introducing the polymerized monomer into the protective layer to form weak cross-linking between the protective layer and the gel electrolyte layer, as compared with the prior art.
The applicant declares that the above description is only a specific embodiment of the present invention, but the scope of the present invention is not limited thereto, and it should be understood by those skilled in the art that any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present invention are within the scope and disclosure of the present invention.

Claims (28)

1. The preparation method of the gel composite negative plate is characterized by comprising the following steps of:
(1) soaking the metal lithium negative electrode piece in an ester electrolyte containing a first polymerization monomer to obtain a metal lithium negative electrode piece containing a protective layer;
(2) coating gel electrolyte containing a second polymerization monomer on the surface of the metal lithium negative electrode piece containing the protective layer obtained in the step (1), and heating to polymerize and crosslink the gel electrolyte to obtain the gel composite negative electrode piece;
the soaking time in the step (1) is 1-48 h;
the step (1) further comprises: after soaking the metal lithium negative pole piece, drying the metal lithium negative pole piece;
the drying is carried out in a glove box;
the drying temperature is 60-80 ℃;
the gel electrolyte in the step (2) further comprises an initiator, wherein the initiator is azobisisobutyronitrile;
the content of the initiator is 1-5 wt% of the total mass of the gel electrolyte.
2. The preparation method of the gel composite negative electrode sheet according to claim 1, wherein the ester electrolyte containing the first polymeric monomer in the step (1) comprises a solute, a solvent and the first polymeric monomer.
3. The gel composite negative plate of claim 2The preparation method is characterized in that the solute comprises LiNO3、KNO3Or NaNO3Any one or a combination of at least two of them.
4. The method for preparing the gel composite negative electrode sheet according to claim 2, wherein the solvent comprises any one of or a combination of at least two of diethylene glycol dimethyl ether, ethylene carbonate, propylene carbonate, dimethyl carbonate, ethyl methyl carbonate or diethyl carbonate.
5. The preparation method of the gel composite negative electrode sheet according to claim 2, wherein the first polymerized monomer is acrylate.
6. The preparation method of the gel composite negative electrode sheet according to claim 2, wherein the content of the first polymeric monomer in the ester electrolyte containing the first polymeric monomer in the step (1) is 1-5%.
7. The preparation method of the gel composite negative electrode sheet according to claim 2, wherein the concentration of the solute in the ester electrolyte containing the first polymeric monomer in the step (1) is 1-10 mol/L.
8. The preparation method of the gel composite negative electrode sheet according to claim 1, wherein the coating of the gel electrolyte containing the second polymeric monomer and the polymerization crosslinking in step (2) are both performed n times, and n is greater than or equal to 1.
9. The preparation method of the gel composite negative electrode sheet according to claim 8, wherein n is greater than or equal to 2, and the compositions of the gel electrolytes coated n times are the same or different.
10. The preparation method of the gel composite negative electrode sheet according to claim 9, wherein n is greater than or equal to 2, and the step (2) comprises: coating 1 layer of gel electrolyte containing a second polymerization monomer on the surface of the metal lithium negative pole piece containing the protective layer, heating to enable the gel electrolyte to be polymerized and crosslinked to obtain the negative pole piece with 1 layer of gel electrolyte layer, and repeating the steps for n-1 times to obtain the gel composite negative pole piece.
11. The method for preparing the gel composite negative electrode sheet according to claim 8, wherein the gel electrolyte coated n times each independently comprises a solute, a solvent and a second polymeric monomer.
12. The preparation method of the gel composite negative electrode plate according to claim 11, wherein n is greater than or equal to 2, and the concentration of the second polymeric monomer in the gel electrolyte near the metal lithium negative electrode plate is lower than the concentration of the second polymeric monomer in the gel electrolyte far from the metal lithium negative electrode plate.
13. The method for preparing a gel composite negative electrode sheet according to claim 11, wherein the solute comprises LiNO3、LiPF6、LiClO4Or LiFSI or a combination of at least two thereof.
14. The preparation method of the gel composite negative electrode sheet according to claim 11, wherein the concentration of solute in the gel electrolyte is 1-10 mol/L.
15. The method for preparing the gel composite negative electrode sheet according to claim 11, wherein the solvent comprises any one of or a combination of at least two of diethylene glycol dimethyl ether, dimethyl carbonate or ethyl methyl carbonate.
16. The preparation method of the gel composite negative electrode sheet according to claim 11, wherein the second polymeric monomer comprises any one of acrylate, ethylene oxide, propylene oxide or butylene oxide or a combination of at least two of the above.
17. The method for preparing the gel composite negative electrode sheet according to claim 16, wherein the second polymeric monomer is a combination of acrylate and ethylene oxide.
18. The preparation method of the gel composite negative electrode sheet according to claim 17, wherein the molar ratio of the acrylate to the ethylene oxide is (1-5): 1.
19. The preparation method of the gel composite negative electrode sheet according to claim 18, wherein the molar ratio of the acrylate to the ethylene oxide is 3: 1.
20. The method for preparing the gel composite negative electrode sheet according to claim 1, wherein the gel electrolyte in the step (2) further comprises an additive, and the additive comprises any one or a combination of at least two of vinylene carbonate, propylene sulfite or NaODFB.
21. The preparation method of the gel composite negative electrode sheet according to claim 1, wherein the heating temperature in the step (2) is 50-100 ℃.
22. The preparation method of the gel composite negative electrode sheet according to claim 1, wherein the heating time in the step (2) is 2-5 h.
23. The preparation method of the gel composite negative electrode sheet according to claim 8, wherein when n is 1, the preparation method of the gel composite negative electrode sheet comprises the following steps:
(1) immersing the metal lithium negative electrode piece into ester electrolyte containing a first polymerization monomer and having a solute concentration of 1-10mol/L for soaking for 1-48h, and drying at 60-80 ℃ in a glove box to obtain the metal lithium negative electrode piece containing a protective layer;
(2) coating the surface of the metal lithium negative electrode piece containing the protective layer obtained in the step (1) with gel electrolyte containing a second polymerization monomer, and heating at 50-100 ℃ to enable the gel electrolyte to be polymerized and crosslinked for 2-5 hours to obtain a gel composite negative electrode piece;
when n is more than or equal to 2, the preparation method of the gel composite negative plate further comprises the following steps: and (3) repeating the process of the step (2) for n-1 times on the metal lithium negative electrode piece with 1 gel electrolyte layer obtained by coating and crosslinking for 1 time in the step (2), so as to obtain the gel composite negative electrode piece.
24. The preparation method of the gel composite negative electrode sheet according to any one of claims 1 to 23.
25. The gel composite negative electrode sheet according to claim 24, wherein the gel composite negative electrode sheet comprises metallic lithium, a protective layer and a gel electrolyte layer from bottom to top, the number of the gel electrolyte layer is n, wherein n is greater than or equal to 1.
26. The gel composite negative electrode sheet according to claim 25, wherein said protective layer and gel electrolyte layer are chemically bonded.
27. A gel electrolyte battery comprising a positive electrode sheet, a separator and the gel composite negative electrode sheet according to any one of claims 24 to 26.
28. Use of the gel electrolyte battery according to claim 27 in an electric vehicle or an electronic product.
CN202010303715.XA 2020-04-17 2020-04-17 Gel composite negative plate and preparation method and application thereof Active CN111416102B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202010303715.XA CN111416102B (en) 2020-04-17 2020-04-17 Gel composite negative plate and preparation method and application thereof

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202010303715.XA CN111416102B (en) 2020-04-17 2020-04-17 Gel composite negative plate and preparation method and application thereof

Publications (2)

Publication Number Publication Date
CN111416102A CN111416102A (en) 2020-07-14
CN111416102B true CN111416102B (en) 2022-04-12

Family

ID=71493649

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202010303715.XA Active CN111416102B (en) 2020-04-17 2020-04-17 Gel composite negative plate and preparation method and application thereof

Country Status (1)

Country Link
CN (1) CN111416102B (en)

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN104868165A (en) * 2014-07-08 2015-08-26 深圳市贝特瑞新能源材料股份有限公司 Preparation method of gel-phase polymer lithium battery and gel-phase polymer lithium battery
CN110212166A (en) * 2019-06-12 2019-09-06 苏州大学 A method of double shielding interface is constructed on lithium an- ode surface
CN110911740A (en) * 2019-11-29 2020-03-24 苏州清陶新能源科技有限公司 Gel electrolyte battery and preparation method thereof

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN104868165A (en) * 2014-07-08 2015-08-26 深圳市贝特瑞新能源材料股份有限公司 Preparation method of gel-phase polymer lithium battery and gel-phase polymer lithium battery
CN110212166A (en) * 2019-06-12 2019-09-06 苏州大学 A method of double shielding interface is constructed on lithium an- ode surface
CN110911740A (en) * 2019-11-29 2020-03-24 苏州清陶新能源科技有限公司 Gel electrolyte battery and preparation method thereof

Also Published As

Publication number Publication date
CN111416102A (en) 2020-07-14

Similar Documents

Publication Publication Date Title
US9722249B2 (en) Use of conductive polymers in battery electrodes
KR20190039993A (en) Acrylonitrile Copolymer Adhesives and Their Applications in Lithium Ion Batteries
CN111533851A (en) Preparation method of polymer electrolyte and application of polymer electrolyte in all-solid-state battery
CN111725509B (en) Negative electrode material, negative electrode slurry, negative electrode plate and lithium ion battery
KR102260940B1 (en) Dispersant of conductive carbon material for lithium ion battery, slurry for electrode of lithium ion battery, electrode for lithium ion battery and lithium ion battery
US11978905B2 (en) Secondary battery, apparatus containing the secondary battery, method for the preparation of the secondary battery, and binder composition
CN110808360A (en) Silicon-carbon negative electrode material, preparation method thereof, battery negative electrode plate and lithium ion battery
CN113571709B (en) Adhesive, preparation method and application thereof
CN109216659A (en) Binder, electrode plate using same and secondary battery
KR20220017994A (en) In situ polymerization polymer electrolyte for lithium ion batteries
CN114039097A (en) Lithium ion battery
CN116093415A (en) Lithium ion battery
CN115020806A (en) Electrolyte and lithium ion battery containing same
CN112670566B (en) Polymer solid electrolyte membrane and preparation method and application thereof
CN111342048B (en) Adhesive, preparation method and application thereof
CN117038847A (en) Lithium metal negative electrode, preparation method thereof and lithium metal battery
CN110492101B (en) Lithium ion battery cathode binder and preparation method and application thereof
CN116742129A (en) Electrolyte for sodium ion battery and sodium ion battery
CN111416102B (en) Gel composite negative plate and preparation method and application thereof
CN114300737A (en) Preparation method of in-situ curing battery and lithium ion battery
CN114725514A (en) Lithium or sodium ion battery electrolyte additive and application thereof
CN114142039A (en) Binder and lithium ion battery comprising same
CN113594465A (en) Negative electrode binder and preparation method and application thereof
CN113937287A (en) Negative pole piece and secondary battery containing same
KR102071593B1 (en) Composition for gel polymer electrolyte and lithium secondary battery comprising the gel polymer electrolyte formed therefrom

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