CN114122400A - Negative pole piece and lithium ion battery containing same - Google Patents

Negative pole piece and lithium ion battery containing same Download PDF

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Publication number
CN114122400A
CN114122400A CN202111296240.7A CN202111296240A CN114122400A CN 114122400 A CN114122400 A CN 114122400A CN 202111296240 A CN202111296240 A CN 202111296240A CN 114122400 A CN114122400 A CN 114122400A
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Prior art keywords
silane
polyethylene glycol
negative electrode
derivatives
negative
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Inventor
唐伟超
李素丽
赵伟
莫肇华
张赵帅
董德锐
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Zhuhai Cosmx Battery Co Ltd
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Zhuhai Cosmx Battery 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
    • H01M4/62—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
    • 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
    • H01M10/42—Methods or arrangements for servicing or maintenance of secondary cells or secondary half-cells
    • H01M10/4235—Safety or regulating additives or arrangements in electrodes, separators or electrolyte
    • 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
    • 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 negative pole piece and a lithium ion battery containing the same, wherein the negative pole piece comprises a negative current collector and a negative active material layer coated on the surface of one side or two sides of the negative current collector, and the negative active material layer comprises a negative active material, a conductive agent, a binder and an additive; wherein the additive comprises a silane-modified polyethylene glycol. The additive can form a film on the surface of a negative active material, can effectively improve the composition of a solid electrolyte film on the surface of the negative electrode/negative active material, improves the lithium ion conductivity and the high molecular component content in a solid interface film, improves the electron and lithium ion conduction in a negative pole piece of a battery, improves the lithium ion dynamics in the negative pole piece, avoids the increase of internal resistance of the battery in the circulating process, and improves the circulating life and the capacity retention rate.

Description

Negative pole piece and lithium ion battery containing same
Technical Field
The invention relates to the technical field of lithium ion batteries, in particular to a negative pole piece and a lithium ion battery containing the same.
Background
Lithium ion batteries are currently applied to the fields of energy storage products, power batteries, digital products and the like, and mainly comprise a positive electrode material, a negative electrode material, a diaphragm and electrolyte, wherein the negative electrode material is used as an important material in the lithium ion batteries, and the performance of the lithium ion batteries directly influences the performance of the batteries.
The lithium ion negative electrode material mainly comprises graphite, hard carbon, lithium titanate, silicon oxide, tin, lithium metal and the like. In the first charge and discharge process of the negative electrode material, large volume change and interface film generation of the negative electrode can be caused along with the reaction of lithium ions on the surface of the negative electrode, the generated interface film mainly comprises inorganic and organic materials, and the effective transmission of the lithium ions and electrons on the surface of the pole piece is directly influenced by the composition of the interface film. How to directionally improve the composition of the interface film and improve the performance of the battery is an important research point in the industry.
Disclosure of Invention
The invention provides a negative pole piece and a lithium ion battery comprising the same, aiming at overcoming the defects that the generation and consumption of a continuous solid interface film in the charging and discharging process of a negative pole, the effective transmission capability of lithium ions and electrons in the pole piece is reduced and the like in the prior art. The negative pole piece can effectively improve the composition of a negative pole surface and an internal interface film, form a solid interface film with a stable structure, improve the transmission of lithium ions and electrons, and improve the cycle performance of the lithium ion battery.
The purpose of the invention is realized by the following technical scheme:
the negative pole piece comprises a negative pole current collector and a negative pole active substance layer coated on the surface of one side or two sides of the negative pole current collector, wherein the negative pole active substance layer comprises a negative pole active substance, a conductive agent, a binder and an additive; wherein the additive comprises a silane-modified polyethylene glycol.
In the conventional battery system, as the battery is charged and discharged, especially during the first charging and discharging process, the electrochemical reaction of lithium ions exists in the negative electrode, so that the volume expansion of the negative electrode material occurs, and a solid interface film is generated on the surface of the negative electrode. According to the invention, silane modified polyethylene glycol is used as an additive, the additive can generate electrochemical polymerization on the surface of the negative electrode, and a stable solid interfacial film is formed on the surface of the negative electrode, and the solid interfacial film has the characteristics of high lithium ion conductivity, high molecular weight, a plurality of active groups and good stability, and can effectively slow down the occurrence of negative electrode interfacial side reactions, reduce the increase of internal resistance in the battery cycle process and improve the battery cycle performance.
Wherein, the silane modified polyethylene glycol is selected from at least one of the compounds shown in the following formula 1:
Figure BDA0003336699340000021
in formula 1, n is the degree of polymerization; r1And R1' is a capping group, and R1And R1At least one of which comprises-SiR2R3R4Group, R2、R3、R4Identical or different, independently of one another, from organofunctional groups; r and R' are linking groups.
Wherein the number average molecular weight of the silane modified polyethylene glycol is 200-20000.
Wherein, the silane modified polyethylene glycol is selected from at least one of the following compounds: polyethylene glycol trimethoxysilylpropyl ether, silane-polyethylene glycol-diphenylcyclooctyne, silane-polyethylene glycol-silane, mercapto-polyethylene glycol-silane, carboxyl-polyethylene glycol-silane, silane polyethylene glycol monomethyl ether, eight-arm polyethylene glycol-silane, active ester-polyethylene glycol-silane, azide-polyethylene glycol-silane, four-arm polyethylene glycol-silane, amino-polyethylene glycol-silane, alkynyl-polyethylene glycol-silane, hydroxyl-polyethylene glycol-silane, maleimide-polyethylene glycol-silane.
Wherein the silane may include an end capping group selected from alkoxy groups.
The negative electrode active material layer comprises the following components in percentage by mass:
70-99 wt% of negative electrode active material, 0.5-16 wt% of conductive agent, 0.499-12 wt% of binder and 0.001-2 wt% of additive.
Wherein the surface density of the negative pole piece is 1-18 mg/cm2。
Wherein the thickness of the negative electrode current collector is 3-12 μm.
Wherein the thickness of the negative electrode active material layer (thickness after rolling) is 15 to 150 μm.
Wherein the negative electrode active material includes at least one of silicon, SiOx (0< X <2), lithium silicon alloy, artificial graphite, natural graphite, hard carbon, soft carbon, mesophase microspheres, fullerene, graphene, coke, carbon fibers, boron and derivatives thereof, aluminum and derivatives thereof, magnesium and derivatives thereof, bismuth and derivatives thereof, nickel and derivatives thereof, silver and derivatives thereof, zinc and derivatives thereof, titanium and derivatives thereof, gallium and derivatives thereof, indium and derivatives thereof, tin and derivatives thereof, lithium nitride, and copper nitride.
The invention also provides a lithium ion battery which comprises the negative pole piece.
The invention has the beneficial effects that:
the invention provides a negative pole piece and a lithium ion battery containing the same. The negative pole piece of the invention adopts a negative active substance, a conductive agent, a binder and an additive containing silane modified polyethylene glycol, the substances are dissolved in a solvent, evenly mixed, coated on the surface of a negative current collector, and dried to obtain the negative pole piece of the invention. The additive can be fully mixed with a negative active material, a conductive agent and an adhesive due to the characteristics of small molecular weight, short polymer chain segment and the like, and the additive can fully contact each component in a negative electrode and is immersed in pores in a pole piece, namely the additive can form a film on the surface of the negative active material, can effectively improve the composition of a solid electrolyte film on the surface of the negative electrode/negative active material, improve the conductivity of lithium ions and the content of high molecular components in a solid interface film, improve the conduction of electrons and lithium ions in the negative pole piece of a battery, improve the dynamics of the lithium ions in the negative pole piece, avoid the increase of internal resistance of the battery in the circulation process, and improve the circulation life and the capacity retention rate.
Detailed Description
< negative electrode Pole sheet >
As described above, the present invention provides a negative electrode plate, which includes a negative electrode current collector and a negative electrode active material layer coated on one or both surfaces of the negative electrode current collector, wherein the negative electrode active material layer includes a negative electrode active material, a conductive agent, a binder and an additive; wherein the additive comprises a silane-modified polyethylene glycol.
In one embodiment of the present invention, the silane-modified polyethylene glycol is selected from at least one of the compounds represented by the following formula 1:
Figure BDA0003336699340000041
in formula 1, n is the degree of polymerization; r1And R1' is a capping group, and R1And R1At least one of which comprises-SiR2R3R4Group, R2、R3、R4Identical or different, independently of one another, from organofunctional groups; r and R' are linking groups.
In one embodiment of the invention, R2、R3、R4Same or different, independently from each other selected from H, C1-6Alkyl radical, C1-6An alkoxy group.
In one embodiment of the present invention, in formula 1, the linking group may or may not be present, and when present, R and R' are organic functional groups.
In one embodiment of the invention, the number average molecular weight of the silane modified polyethylene glycol is 200-20000.
In one embodiment of the present invention, the silane-modified polyethylene glycol is selected from at least one of the following compounds: polyethylene glycol trimethoxysilylpropyl ether, silane-polyethylene glycol-diphenylcyclooctyne, silane-polyethylene glycol-silane, mercapto-polyethylene glycol-silane, carboxyl-polyethylene glycol-silane, silane polyethylene glycol monomethyl ether, eight-arm polyethylene glycol-silane, active ester-polyethylene glycol-silane, azide-polyethylene glycol-silane, four-arm polyethylene glycol-silane, amino-polyethylene glycol-silane, alkynyl-polyethylene glycol-silane, hydroxyl-polyethylene glycol-silane, maleimide-polyethylene glycol-silane.
In one embodiment of the present invention, the silane may include a capping group selected from alkoxy groups; specifically, the alkoxy group may be, for example, a methoxy group, an ethoxy group or a propoxy group.
In the present invention, the silane-modified polyethylene glycol may be prepared by a method conventional in the art, or may be commercially available.
In one aspect of the present invention, the negative electrode active material layer includes the following components in percentage by mass:
70-99 wt% of negative electrode active material, 0.5-16 wt% of conductive agent, 0.499-12 wt% of binder and 0.001-2 wt% of additive.
Illustratively, the negative active material is present in an amount of 70 wt%, 73 wt%, 75 wt%, 76 wt%, 77 wt%, 78 wt%, 79 wt%, 80 wt%, 81 wt%, 82 wt%, 83 wt%, 84 wt%, 85 wt%, 86 wt%, 87 wt%, 88 wt%, 89 wt%, 90 wt%, 91 wt%, 92 wt%, 93 wt%, 94 wt%, 95 wt%, 96 wt%, 97 wt%, 98 wt%, 98.5 wt%, or 99 wt% by mass.
Illustratively, the conductive agent is present in an amount of 0.5 wt%, 0.8 wt%, 1 wt%, 2 wt%, 3 wt%, 4 wt%, 5 wt%, 6 wt%, 7 wt%, 8 wt%, 9 wt%, 10 wt%, 11 wt%, 12 wt%, 13 wt%, 14 wt%, 15 wt%, or 16 wt% by mass.
Illustratively, the binder is present in an amount of 0.499, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, or 12 weight percent by mass.
Illustratively, the additive is present in an amount of 0.001 wt%, 0.05 wt%, 0.1 wt%, 0.15 wt%, 0.25 wt%, 0.55 wt%, 0.65 wt%, 0.70 wt%, 0.75 wt%, 0.85 wt%, 0.90 wt%, 1.0 wt%, 1.2 wt%, 1.5 wt%, or 2 wt% by mass. When the additive content is more than 2 wt%, the additive content is too high, which can cause the additive content in the interfacial film on the surface of the negative electrode/negative electrode active material to be too high, and can cause the interfacial film on the surface of the negative electrode/negative electrode active material to be too thick, which can cause the internal resistance of the battery to be increased, thereby causing the capacity of the pole piece to be low, the lithium-conducting network of the pole piece to be poor, the lithium loss in the pole piece to be increased, the capacity of the battery to be low, and the performance of the battery to be influenced; when the additive content is less than 0.001 wt%, the additive content is too low, the content of the generated interfacial film is insufficient, the structure of the formed solid interfacial film on the surface of the negative electrode/negative electrode active material is unstable, and the battery performance is reduced.
In one scheme of the invention, the surface density of the negative pole piece is 1-18 mg/cm2。
In one embodiment of the present invention, the thickness of the negative electrode current collector is 3 μm to 12 μm, preferably 4 μm to 10 μm, such as 3 μm, 4 μm, 5 μm, 8 μm, 10 μm or 12 μm.
According to the present invention, the thickness of the negative electrode active material layer (thickness after rolling) is 15 μm to 150 μm, preferably 30 μm to 100 μm, such as 15 μm, 20 μm, 25 μm, 30 μm, 35 μm, 40 μm, 45 μm, 50 μm, 55 μm, 60 μm, 70 μm, 80 μm, 90 μm, 100 μm, 110 μm, 120 μm, 130 μm, 140 μm or 150 μm.
In one aspect of the present invention, the negative active material includes silicon, SiOx (0< X <2), lithium silicon alloy, artificial graphite, natural graphite, hard carbon, soft carbon, mesophase microspheres, fullerene, graphene, coke, carbon fiber, boron and its derivatives (e.g., boron powder, boron oxide), aluminum and its derivatives (e.g., aluminum powder, lithium aluminum alloy), magnesium and its derivatives (e.g., magnesium aluminum alloy), bismuth and its derivatives (e.g., bismuth, lithium bismuth alloy), nickel and its derivatives (e.g., nickel, lithium nickel alloy, lithium nickel nitride), silver and its derivatives (e.g., silver powder, lithium silver alloy), zinc and its derivatives (e.g., zinc powder, zinc lithium alloy, zinc nitride), titanium and its derivatives (e.g., titanium powder, lithium titanate, titanium dioxide, lithium titanium alloy, etc.), gallium and its derivatives (e.g., gallium, lithium gallium alloy), indium and its derivatives (e.g., indium powder, lithium indium alloy), Tin and its derivatives (such as tin powder, stannous oxide, tin oxide, and tin sulfate), lithium nitride, and copper nitride.
In one aspect of the present invention, the conductive agent includes at least one of conductive carbon black, ketjen black, conductive fibers, conductive polymers, acetylene black, carbon nanotubes, graphene, flake graphite, conductive oxides, and metal particles.
In one aspect of the present invention, the binder includes at least one of polyvinylidene fluoride and its copolymerized derivatives, polytetrafluoroethylene and its copolymerized derivatives, polyacrylic acid and its copolymerized derivatives, polyvinyl alcohol and its copolymerized derivatives, poly styrene-butadiene rubber and its copolymerized derivatives, polyimide and its copolymerized derivatives, polyethyleneimine and its copolymerized derivatives, polyacrylate and its copolymerized derivatives, and sodium carboxymethyl cellulose and its copolymerized derivatives.
< preparation method of negative electrode sheet >
The invention also provides a preparation method of the negative pole piece, which comprises the following steps:
uniformly mixing a solvent, a negative electrode active material, a conductive agent, a binder and an additive to prepare negative electrode slurry; and coating the negative electrode slurry on the surface of a negative electrode current collector, and drying to obtain the negative electrode piece.
In one embodiment of the present invention, the negative electrode slurry contains 100 to 300 parts by mass of a solvent, 70 to 99 parts by mass of a negative electrode active material, 0.5 to 16 parts by mass of a conductive agent, 0.001 to 2 parts by mass of an additive, and 0.499 to 12 parts by mass of a binder.
In one embodiment of the present invention, the solvent is at least one selected from the group consisting of water, acetonitrile, benzene, toluene, xylene, acetone, tetrahydrofuran, hydrofluoroethers, and N-methylpyrrolidone.
In one aspect of the present invention, the negative electrode slurry is preferably sieved, for example, 200-mesh.
In one scheme of the invention, the drying temperature is 80-115 ℃, and the drying time is 6-36 hours.
< lithium ion Battery >
The invention also provides a lithium ion battery which comprises the negative pole piece.
The present invention will be described in further detail with reference to specific examples. It is to be understood that the following examples are only illustrative and explanatory of the present invention and should not be construed as limiting the scope of the present invention. All the technologies realized based on the above-mentioned contents of the present invention are covered in the protection scope of the present invention.
The experimental methods used in the following examples are all conventional methods unless otherwise specified; reagents, materials and the like used in the following examples are commercially available unless otherwise specified.
Example 1
1) Preparing a positive pole piece:
mixing 96g of a positive active material nickel-cobalt-manganese ternary material (NCM811), 1.5g of a binder polyvinylidene fluoride (PVDF), 1.5g of a conductive agent conductive carbon black and 1g of a conductive agent carbon nano tube, adding 150g of N-methyl pyrrolidone (NMP), and stirring under the action of a vacuum stirrer until a mixed system becomes a positive slurry with uniform fluidity; uniformly coating the positive electrode slurry on an aluminum foil with the thickness of 13 mu m; drying the positive electrode plate at 100 ℃ for 36 hours, then carrying out vacuum treatment to obtain a pole piece, rolling the pole piece, and cutting to obtain a positive electrode piece;
2) preparing a negative pole piece:
preparing slurry from 70g of silica, 6g of single-walled carbon nanotube (SWCNT) serving as a conductive agent, 10g of conductive carbon black (SP) serving as a conductive agent, 2g of polyethylene glycol trimethoxysilylpropyl ether, 6g of carboxymethyl cellulose sodium (CMC) serving as a binder, 6g of Styrene Butadiene Rubber (SBR) serving as a binder and 300g of deionized water by a wet process, coating the slurry on the surface of copper foil of a negative current collector, and drying, rolling and die-cutting to obtain a negative pole piece;
3) preparing an electrolyte:
uniformly mixing ethylene carbonate, propylene carbonate, diethyl carbonate and n-propyl propionate according to the mass ratio of 40:10:10:40 in a glove box filled with argon and having qualified water oxygen content, and quickly adding 1.08mol/L of fully dried lithium hexafluorophosphate (LiPF)6) Uniformly stirring to prepare electrolyte;
4) preparing a lithium ion battery:
and preparing a lithium ion battery cell from the obtained positive pole piece, negative pole piece and diaphragm, and performing liquid injection packaging and welding to obtain the lithium ion battery.
Comparative example 1.1
Specific process of comparative example 1.1 referring to example 1, mainly different from adding polyethylene glycol with equal mass and equal molecular weight as polyethylene glycol trimethoxysilylpropyl ether in comparative example 1.1, other conditions are consistent with example 1.
Comparative example 1.2
Specific process of comparative example 1.2 referring to example 1, the main difference is that no trimethoxysilylpropyl ether polyethylene glycol is added in comparative example 1.2, and the other conditions are the same as in example 1.
Examples 2-6 and other comparative examples
The specific processes of examples 2-6 and other comparative examples refer to example 1, mainly distinguishing the process conditions of the negative electrode plate, the addition amount of each component and the types of materials of each component, and the specific details are shown in tables 1 and 2.
TABLE 1 compositions of negative electrode sheets of examples and comparative examples
Figure BDA0003336699340000081
Figure BDA0003336699340000091
TABLE 2 compositions of negative electrode sheets of examples and comparative examples
Figure BDA0003336699340000092
Figure BDA0003336699340000101
The batteries prepared in the above examples and comparative examples were subjected to performance tests:
(1) the battery internal resistance alternating current impedance test method comprises the following steps: the alternating current impedance test was performed on 50% SOC lithium ion batteries using a Metrohm Switzerland PGSTAT302N chemical workstation at 25 ℃ in the range of 100KHz-0.1mHz, and the test results are listed in Table 3.
Table 3 results of ac impedance test of internal resistance of battery of examples and comparative examples
Figure BDA0003336699340000102
The internal resistance test result in the battery circulation process shows that: in the cycle process of the lithium ion battery prepared by the embodiment of the invention, the internal resistance is smaller than that of the lithium ion battery prepared by the comparative example. The main reason is that the additive added in the invention can form a solid interface film on the surface of the cathode/cathode active material, and the solid interface film of the invention is different from the solid interface film on the surface of the conventional cathode/cathode active material, has the characteristics of high-speed lithium conduction and the like, and can rapidly conduct lithium ions to pass through, so that the prepared lithium ion battery has lower internal resistance, and meanwhile, the internal resistance of the lithium ion battery is slightly increased in the circulating process, and the lithium ion battery has a certain application prospect.
(2) The battery cycle performance test method comprises the following steps: the lithium ion battery is subjected to a charge-discharge cycle test on a blue battery charge-discharge test cabinet under the test conditions of 25 ℃ and 1C/1C charge-discharge, and the test results are listed in Table 4.
Table 4 results of battery cycle performance test of examples and comparative examples
Figure BDA0003336699340000111
The results of the cycle performance tests of the above examples and comparative examples show that: the lithium ion battery prepared by the embodiment of the invention has higher capacity retention rate than the lithium ion battery prepared by the comparative example in the circulation process. The main reason is that the additive added in the invention can form a solid interfacial film on the surface of the cathode/cathode active material, and the solid interfacial film of the invention is different from the solid interfacial film on the surface of the conventional cathode/cathode active material, and has the characteristics of large molecular weight, high-speed lithium conduction, better stability and the like. The solid interface film on the surface of the conventional negative electrode/negative electrode active material is formed on the surface of the negative electrode/negative electrode active material by consuming an electrolyte and a lithium salt as lithium ions react during battery cycling. Due to the addition of the additive, a more stable solid interface film with higher lithium conductivity can be formed on the surface of the negative electrode/negative electrode active material, and the performance of the lithium ion battery can be greatly improved.
The results of the cyclic charge and discharge performance tests of the examples and the comparative examples show that: the lithium ion battery negative pole piece prepared by the invention has small internal resistance in the circulation process, and the lithium ions have good lithium conducting and conducting channels in the negative pole piece, so that the prepared lithium ion battery has good circulation performance.
The embodiments of the present invention have been described above. However, the present invention is not limited to the above embodiment. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims (10)

1. The negative pole piece comprises a negative pole current collector and a negative pole active substance layer coated on the surface of one side or two sides of the negative pole current collector, wherein the negative pole active substance layer comprises a negative pole active substance, a conductive agent, a binder and an additive; wherein the additive comprises a silane-modified polyethylene glycol.
2. The negative electrode sheet of claim 1, wherein the silane-modified polyethylene glycol is at least one selected from compounds represented by the following formula 1:
Figure FDA0003336699330000011
in formula 1, n is the degree of polymerization; r1And R1' is a capping group, and R1And R1At least one of which comprises-SiR2R3R4Group, R2、R3、R4Identical or different, independently of one another, from organofunctional groups; r and R' are linking groups.
3. The negative electrode plate of claim 1 or 2, wherein the silane-modified polyethylene glycol has a number average molecular weight of 200 to 20000.
4. The negative electrode tab of any one of claims 1 to 3, wherein the silane-modified polyethylene glycol is selected from at least one of the following compounds: polyethylene glycol trimethoxysilylpropyl ether, silane-polyethylene glycol-diphenylcyclooctyne, silane-polyethylene glycol-silane, mercapto-polyethylene glycol-silane, carboxyl-polyethylene glycol-silane, silane polyethylene glycol monomethyl ether, eight-arm polyethylene glycol-silane, active ester-polyethylene glycol-silane, azide-polyethylene glycol-silane, four-arm polyethylene glycol-silane, amino-polyethylene glycol-silane, alkynyl-polyethylene glycol-silane, hydroxyl-polyethylene glycol-silane, maleimide-polyethylene glycol-silane.
5. The negative electrode tab of claim 4, wherein the silane may include a capping group selected from alkoxy groups.
6. The negative electrode plate of any one of claims 1 to 5, wherein the negative electrode active material layer comprises the following components in percentage by mass:
70-99 wt% of negative electrode active material, 0.5-16 wt% of conductive agent, 0.499-12 wt% of binder and 0.001-2 wt% of additive.
7. The negative electrode plate of any one of claims 1 to 6, wherein the surface density of the negative electrode plate is 1-18 mg/cm2。
8. The negative electrode tab of claims 1-7, wherein the negative electrode current collector has a thickness of 3 μ ι η to 12 μ ι η;
and/or the thickness of the negative electrode active material layer is 15 to 150 [ mu ] m.
9. The negative electrode tab of any one of claims 1 to 8, wherein the negative electrode active material comprises at least one of silicon, SiOx (0< X <2), lithium silicon alloys, artificial graphite, natural graphite, hard carbon, soft carbon, mesogenic microspheres, fullerenes, graphene, coke, carbon fibers, boron and its derivatives, aluminum and its derivatives, magnesium and its derivatives, bismuth and its derivatives, nickel and its derivatives, silver and its derivatives, zinc and its derivatives, titanium and its derivatives, gallium and its derivatives, indium and its derivatives, tin and its derivatives, lithium nitride, copper nitride.
10. A lithium ion battery comprising the negative electrode tab of any one of claims 1-9.
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Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN115108560A (en) * 2022-06-14 2022-09-27 深圳市德方纳米科技股份有限公司 Silicon oxide and method for regulating and controlling silicon-oxygen ratio in silicon oxide and application of silicon oxide
CN115188922A (en) * 2022-06-24 2022-10-14 江苏正力新能电池技术有限公司 Silicon-based negative pole piece, secondary battery containing same and electricity utilization device
CN115651158A (en) * 2022-11-15 2023-01-31 浙江大象新能源科技有限公司 Adhesive for silicon-based negative electrode of lithium battery and preparation method of adhesive

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20050019656A1 (en) * 2002-03-22 2005-01-27 Yoon Sang Young Method for fabricating composite electrodes
CN103413972A (en) * 2013-08-23 2013-11-27 中国科学院广州能源研究所 Alkoxy silane electrolyte material containing oligopolyethylene glycol chain and application of electrolyte material in lithium battery propylene carbonate based electrolyte
CN104066776A (en) * 2012-01-23 2014-09-24 巴斯夫欧洲公司 Composite, its production and its use in separators for electrochemical cells
CN104072533A (en) * 2014-06-10 2014-10-01 中国科学院广州能源研究所 Silicone-nitrile compounds containing low polyoxyethylene units as well as preparation method thereof and application thereof in lithium battery
JP2015018775A (en) * 2013-07-12 2015-01-29 日本電気株式会社 Negative electrode for secondary battery and manufacturing method therefor, and secondary battery using the same
CN109326767A (en) * 2017-07-31 2019-02-12 宁德时代新能源科技股份有限公司 Positive plate, secondary battery and preparation method thereof

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20050019656A1 (en) * 2002-03-22 2005-01-27 Yoon Sang Young Method for fabricating composite electrodes
CN104066776A (en) * 2012-01-23 2014-09-24 巴斯夫欧洲公司 Composite, its production and its use in separators for electrochemical cells
JP2015018775A (en) * 2013-07-12 2015-01-29 日本電気株式会社 Negative electrode for secondary battery and manufacturing method therefor, and secondary battery using the same
CN103413972A (en) * 2013-08-23 2013-11-27 中国科学院广州能源研究所 Alkoxy silane electrolyte material containing oligopolyethylene glycol chain and application of electrolyte material in lithium battery propylene carbonate based electrolyte
CN104072533A (en) * 2014-06-10 2014-10-01 中国科学院广州能源研究所 Silicone-nitrile compounds containing low polyoxyethylene units as well as preparation method thereof and application thereof in lithium battery
CN109326767A (en) * 2017-07-31 2019-02-12 宁德时代新能源科技股份有限公司 Positive plate, secondary battery and preparation method thereof

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN115108560A (en) * 2022-06-14 2022-09-27 深圳市德方纳米科技股份有限公司 Silicon oxide and method for regulating and controlling silicon-oxygen ratio in silicon oxide and application of silicon oxide
CN115108560B (en) * 2022-06-14 2024-01-30 深圳市德方纳米科技股份有限公司 Silicon oxide and method for regulating and controlling silicon-oxygen ratio in silicon oxide and application thereof
CN115188922A (en) * 2022-06-24 2022-10-14 江苏正力新能电池技术有限公司 Silicon-based negative pole piece, secondary battery containing same and electricity utilization device
CN115651158A (en) * 2022-11-15 2023-01-31 浙江大象新能源科技有限公司 Adhesive for silicon-based negative electrode of lithium battery and preparation method of adhesive

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