Sealing material, method for its production and use

Abstract

The application provides a sealing material and a preparation method and application thereof, and the structural formula of the sealing material is: wherein n is greater than or equal to m, and m+n=1, R1 and R2 are independently selected from substituted or unsubstituted alkyl, substituted or unsubstituted aryl or substituted or unsubstituted cycloalkyl. The sealing material provided by the application has high stability, good sealing effect, improved structural stability and safety performance of the battery, and prolonged cycle life of the battery.

Description

Technical Field

[0001] This application relates to the field of batteries, specifically to sealing materials, their preparation methods, and applications. Background Technology

[0002] Currently, batteries are widely used in transportation, aerospace, electronic devices, and large-scale energy storage devices, leading to increasingly stringent safety requirements. One related technology uses solid-state electrolytes instead of liquid electrolytes to reduce the risks of flammability and leakage, while improving energy density and safety. However, after a severe impact, solid-state electrolytes, such as sulfide-based solid-state electrolytes, exhibit reduced stability, readily react with water, and produce highly toxic substances. Therefore, a highly reliable and well-sealing material is needed to isolate the solid-state electrolyte from water, thereby enhancing battery safety. Summary of the Invention

[0003] In view of this, this application provides a sealing material, its preparation method and application. The sealing material has high reliability and excellent sealing performance, which can improve the safety performance of the battery.

[0004] Firstly, this application provides a sealing material.

[0005] The structural formula of the sealing material is: Wherein, n is greater than or equal to m, and m+n=1, and R1 and R2 are independently selected from substituted or unsubstituted alkyl, substituted or unsubstituted aryl, or substituted or unsubstituted cycloalkyl.

[0006] Optionally, m is 0.2-0.4 and n is 0.6-0.8.

[0007] Optionally, the substituents in the substituted alkyl, substituted aryl, and substituted cycloalkyl groups include one or more of halogen atoms, cyano groups, substituted or unsubstituted alkyl groups, substituted or unsubstituted aryl groups, and substituted or unsubstituted cycloalkyl groups.

[0008] Optionally, the substituent group includes one or more of halogen atoms, cyano, alkyl, aryl, and cycloalkyl.

[0009] Optionally, the halogen atom is selected from fluorine, chlorine, bromine or iodine.

[0010] Optionally, the sealing material undergoes chemical cross-linking under heating conditions, wherein the heating temperature is 80℃-200℃.

[0011] The sealing material provided in this application can improve the hydrophobicity and elasticity of the sealing material by adjusting m and n, thereby affecting the sealing performance and stability of the sealing material. This is beneficial for isolating the solid electrolyte layer from the external environment and improving the safety performance and service life of the battery.

[0012] Secondly, this application provides a method for preparing a sealing material, comprising: mixing a first monomer, a second monomer, and a reducing agent, and reacting the mixture to obtain the sealing material; the structural formula of the first monomer is as follows: The structural formula of the second monomer is

[0013] Optionally, the reaction temperature is 90℃-180℃, and the reaction time is 4h-24h.

[0014] Optionally, the reducing agent includes one or more of sodium borohydride and lithium aluminum hydride.

[0015] The sealing material provided in this application has a novel preparation method, a simple preparation process, and produces a product with excellent performance.

[0016] Thirdly, this application provides a battery comprising a positive electrode, a solid electrolyte layer, and a negative electrode stacked together, and a sealing layer disposed on the side of the positive electrode, the side of the solid electrolyte layer, and / or the side of the negative electrode, the sealing layer comprising the sealing material described in the first aspect or the sealing material prepared by the preparation method described in the second aspect.

[0017] Optionally, the sealing layer is further disposed between the positive electrode and the solid electrolyte layer, and / or the sealing layer is further disposed between the negative electrode and the solid electrolyte layer.

[0018] Optionally, the solid electrolyte layer includes a sulfide electrolyte.

[0019] The battery provided in this application has a sealing layer with high stability and good sealing performance, which can isolate the electrolyte from external contact and improve the structural stability and safety of the battery.

[0020] Fourthly, this application provides an electrical device, which includes the battery described in the third aspect.

[0021] The electrical equipment provided in this application has a long service life and high safety performance, which is conducive to commercial application. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below. The specific embodiments described herein are merely illustrative of the present invention and are not intended to limit the present invention.

[0023] Figure 1 A schematic diagram of the cross-sectional structure of a battery provided in one embodiment of this application;

[0024] Figure 2 for Figure 1 A magnified view of region A in the middle. Detailed Implementation

[0025] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0026] This application provides a sealing material, the structural formula of which is: Wherein, n is greater than or equal to m, and m+n=1, and R1 and R2 are independently selected from substituted or unsubstituted alkyl, substituted or unsubstituted aryl, or substituted or unsubstituted cycloalkyl groups. The sealing material provided in this application, by adjusting m and n, can improve the hydrophobicity and mechanical properties of the sealing material, enhance its sealing performance and reliability, and effectively isolate the solid electrolyte layer from the external environment, thereby improving battery safety and lifespan. The sealing material includes phenylboronic acid groups, which, upon heating, can form cyclic boron-oxygen bonds. These bonds can be repeatedly opened and formed, giving the sealing material self-healing capabilities and good mechanical properties. This prevents cracking after battery expansion, blocks electrolyte contact with the external environment, and improves battery structural stability.

[0027] In one embodiment of this application, n is greater than or equal to m, and m+n=1. m can improve the elasticity and toughness of the sealing material, but will reduce its hydrophobicity. n can improve the rigidity and hydrophobicity of the sealing material, but will reduce its toughness and elasticity. By adjusting the values ​​of m and n, the sealing material can have excellent hydrophobicity, elasticity and toughness, thereby improving the sealing performance of the sealing material and improving the safety performance of the battery.

[0028] In one embodiment of this application, m is 0.2-0.4 and n is 0.6-0.8, which is beneficial to improving the safety performance of the battery. Specifically, m can be, but is not limited to, 0.2, 0.25, 0.3, or 0.4; n can be, but is not limited to, 0.6, 0.65, 0.7, 0.75, or 0.8. In one embodiment of this application, m can be 0.3 and n can be 0.7. In another embodiment of this application, m can be 0.4 and n can be 0.6. In one embodiment of this application, R1 and R2 can improve the hydrophobicity of the sealing material and isolate the electrolyte from external contact. R1 and R2 can be the same group or different groups. Specifically, R1 and R2 can be, but are not limited to, selected from substituted or unsubstituted alkyl, substituted or unsubstituted aryl, and substituted or unsubstituted cycloalkyl. In one embodiment of this application, R1 can be a substituted or unsubstituted alkyl, and R2 can be a substituted or unsubstituted aryl. In another embodiment of this application, R1 and R2 can be substituted or unsubstituted cycloalkyl.

[0029] Alkyl groups are alkane molecules with one hydrogen atom removed, including straight-chain alkyl groups and branched-chain alkyl groups. In one embodiment of this application, the number of carbon atoms in the alkyl group is 2-20. Specifically, the number of carbon atoms in the alkyl group can be, but is not limited to, 2, 3, 4, 5, 6, 7, or 8. Exemplarily, the alkyl group can include, but is not limited to, one or more of ethyl, n-propyl, n-butyl, isobutyl, n-pentyl, 2-methylbutyl, 2,2-dimethylpropyl, n-hexyl, heptyl, 2-methylhexyl, 5-methylpentyl, 2-ethylbutyl, 3-ethylbutyl, nonyl, and decyl. In one embodiment of this application, the alkyl group can be ethyl. In another embodiment of this application, the alkyl group can be isobutyl. In some embodiments, R1, R2, and R... 9 Independently selected from substituted or unsubstituted alkyl groups having 1-20 carbon atoms. In another embodiment, R 1 R 2 R 3 R 4 R 5 R 6 and R 7 It is independently selected from substituted or unsubstituted alkyl groups having 1 to 6 carbon atoms.

[0030] Aryl groups are aromatic groups. In one embodiment of this application, the aryl group has 6-12 carbon atoms. Specifically, the aryl group may have, but is not limited to, 6, 8, 9, 10, 11, or 12 carbon atoms. Specifically, the aryl group may include, but is not limited to, one or more of the naphthyl groups in a phenyl group. In one embodiment of this application, the aryl group may be a phenyl group. In another embodiment of this application, the aryl group may be a naphthyl group.

[0031] In one embodiment of this application, the cycloalkyl group has 3-12 carbon atoms. Specifically, the cycloalkyl group may have, but is not limited to, 3, 6, 7, 8, 9, 10, 11, or 12 carbon atoms. For example, the cycloalkyl group may include, but is not limited to, one or more of cyclopropane, cyclobutane, cyclopentane, cyclohexane, and cyclopentane. In one embodiment of this application, the cycloalkyl group may be cyclopropane. In another embodiment of this application, the cycloalkyl group may be cyclopentane.

[0032] In one embodiment of this application, the substituents in the substituted alkyl, substituted aryl, and substituted cycloalkyl groups include one or more of halogen atoms, cyano groups, substituted or unsubstituted alkyl groups, substituted or unsubstituted aryl groups, and substituted or unsubstituted cycloalkyl groups. Specifically, the halogen atom may be, but is not limited to, a fluorine atom, a chlorine atom, a bromine atom, or an iodine atom. In one embodiment of this application, the substituent may be a fluorine atom. In one embodiment of this application, the substituent may be a substituted or unsubstituted alkyl group.

[0033] In one embodiment of this application, after the sealing material is heated, the boron-oxygen bonds in the phenylboronic acid groups undergo a chemical cross-linking reaction. The heating temperature is 80℃-200℃, which can improve the mechanical properties and sealing performance of the sealing material. Specifically, the heating temperature can be, but is not limited to, 80℃, 100℃, 120℃, 140℃, 160℃, 180℃, or 200℃. In one embodiment of this application, the heating temperature can be 80℃-150℃. In another embodiment of this application, the heating temperature can be 140℃-200℃.

[0034] In one embodiment of this application, the sealing material uses phenylboronic acid groups. After the cross-linking reaction occurs and the mixture solidifies, it can form The structure improves the mechanical properties and structural stability of the sealing material. This represents the junction between this group and other groups.

[0035] In one embodiment of this application, the molecular weight of the sealing material is 50,000-1,000,000. A suitable molecular weight can improve the mechanical properties and self-healing ability of the sealing material. Specifically, the molecular weight of the sealing material can be, but is not limited to, 50,000, 100,000, 200,000, 400,000, 600,000, 700,000, or 1,000,000. In one embodiment of this application, the molecular weight of the sealing material can be 50,000-700,000. In another embodiment of this application, the molecular weight of the sealing material can be 500,000-1,000,000.

[0036] This application also provides a method for preparing a sealing material, including:

[0037] The first monomer, the second monomer, and the reducing agent are mixed and reacted to obtain a sealing material; the structural formula of the first monomer is as follows. The structural formula of the second monomer is: The preparation method provided in this application is novel and the preparation process is simple. The resulting sealing material has good sealing performance and high stability, which can improve the structural stability and service life of the battery.

[0038] In one embodiment of this application, a reducing agent can promote the reaction. Specifically, the reducing agent may include, but is not limited to, one or more of sodium borohydride and lithium aluminum hydride. In one embodiment of this application, the reducing agent may be sodium borohydride.

[0039] In one embodiment of this application, the reaction formulas for the first monomer and the second monomer are as follows:

[0040]

[0041] The reaction temperature is 90℃-180℃, and the reaction time is 4h-24h. Suitable reaction temperature and time can promote the reaction and the formation of the sealing material. Specifically, the reaction temperature can be, but is not limited to, 90℃, 100℃, 120℃, 140℃, or 180℃; the reaction time can be, but is not limited to, 4h, 6h, 8h, 15h, 20h, or 24h. In one embodiment of this application, the reaction temperature can be 90℃-150℃, and the reaction time can be 4h-16h. In another embodiment of this application, the reaction temperature can be 100℃-180℃, and the reaction time can be 12h-24h.

[0042] In one embodiment of this application, the first monomer can be obtained by reacting according to formulas (I) to (IV):

[0043]

[0044] Formulas (I) and (II) are carried out under acidic conditions, provided by an acid, which may include, but is not limited to, one or more of hydrochloric acid, sulfuric acid, and acetic acid; the catalyst in formula (III) may include, but is not limited to, one or more of KOH, NaOH, LiOH, (CH3)4NOH, and silanolates; formula (IV) is carried out under alkaline conditions, provided by a base, which may include, but is not limited to, one or more of potassium hydroxide, sodium hydroxide, potassium tert-butoxide, and sodium tert-butoxide, and X may be, but is not limited to, Cl, Br, or I. Please refer to [link to relevant documentation]. Figure 1This is a cross-sectional structural diagram of a battery provided according to an embodiment of this application. The battery 100 includes a positive electrode 11, a solid electrolyte layer 12, and a negative electrode 13 stacked together, and a sealing layer 14 disposed on the side of the positive electrode 11, the side of the solid electrolyte layer 12, and / or the side of the negative electrode 13. The sealing layer 14 is formed by curing the sealing material described in any of the above embodiments. The battery provided by this application has a sealing layer on its side, which isolates the solid electrolyte layer from contact with the external environment (water or air, etc.), improves the safety performance and structural stability of the battery, extends the cycle life of the battery, and is beneficial to the commercial application of the battery.

[0045] In one embodiment of this application, a sealing layer is disposed around the stacked structure composed of a positive electrode, a solid electrolyte, and a negative electrode, completely enclosing the stacked structure to form a battery.

[0046] Please see Figure 2 ,for Figure 1 In the enlarged view of region A, a gap exists between the positive electrode 11 and the solid electrolyte layer 12. A sealing layer 14 can also be disposed in the gap between the positive electrode 11 and the solid electrolyte layer 12, as well as on the sides of the positive electrode 11 and the solid electrolyte layer 12, which can further prevent leakage of the solid electrolyte layer and improve the battery's safety performance and cycle life. In another embodiment of this application, a gap exists between the negative electrode and the solid electrolyte layer, and a sealing layer can be disposed in the gap between the negative electrode and the solid electrolyte layer, as well as on the sides of the negative electrode and the solid electrolyte layer.

[0047] In one embodiment of this application, sealing materials can be placed in a battery using methods such as bottom filling with a thin tube, injection molding, transfer molding, or impregnation molding. In one embodiment of this application, liquid sealing material is placed on the sides of the positive electrode, the solid electrolyte layer, and the negative electrode using the bottom filling with a thin tube, and then solidified to form a sealing layer.

[0048] In one embodiment of this application, the positive electrode sheet includes a positive current collector and a positive active material layer disposed on the surface of the positive current collector. Specifically, the positive current collector may be, but is not limited to, one or more of copper, aluminum, nickel, and stainless steel. In one embodiment of this application, the positive current collector may be aluminum foil.

[0049] In one embodiment of this application, the positive electrode active material layer includes a positive electrode active material, which may include, but is not limited to, lithium cobalt oxide (LiCoO2), lithium nickel oxide (LiNiO2), lithium iron phosphate (LiFePO4), lithium cobalt phosphate (LiCoPO4), lithium manganese phosphate (LiMnPO4), lithium nickel phosphate (LiNiPO4), lithium manganese oxide (LiMnO2), and binary materials such as LiNi x A (1-x)O2 (A is Co or Mn, 0 < x < 1), ternary material LiNi m B n C (1-m-n) O2 (B and C are independently selected from one or more of Co, Al, Mn, and B and C are different, 0 < m < 1, 0 < n < 1). In one embodiment of the present application, the positive electrode active material can be lithium iron phosphate (LiFePO4). In another embodiment of the present application, the positive electrode active material can be lithium manganate (LiMnO2).

[0050] In one embodiment of the present application, in the positive electrode active material layer, the mass percentage of the positive electrode active material is 50% - 90%, which is beneficial to improving the energy density and capacity of the battery and enhancing the electrochemical performance of the battery. Specifically, in the positive electrode active material layer, the mass percentage of the positive electrode active material can be but is not limited to 50%, 60%, 70%, 80% or 90%, etc. In one embodiment of the present application, in the positive electrode active material layer, the mass percentage of the positive electrode active material can be 50% - 70%. In another embodiment of the present application, in the positive electrode active material layer, the mass percentage of the positive electrode active material can be 65% - 90%.

[0051] In one embodiment of the present application, the positive electrode active material layer further includes a sulfide electrolyte, which can improve the conductivity of the positive electrode sheet. Specifically, the sulfide electrolyte can be but is not limited to including one or more of Li3PS4, Li7P3S 11 、Li 11 GeP2S 12 、Li6PS5Cl, Li7P2S8I, Li 10 SnP2S 12 、Li 3.25 Ge 0.25 P 0.75 S4. In one embodiment of the present application, the sulfide electrolyte can be Li6PS5Cl. In another embodiment of the present application, the sulfide electrolyte can be Li 11 GeP2S 12 .

[0052] In one embodiment of the present application, the positive electrode active material layer further includes a positive electrode conductive agent. The positive electrode conductive agent can increase the conductivity between the active materials and improve the electronic conductivity. Specifically, the positive electrode conductive agent can be but is not limited to including one or more of graphite, carbon black, acetylene black and graphene. In one embodiment of the application, the positive electrode conductive agent can be graphite. In another embodiment of the present application, the positive electrode conductive agent can be carbon black.

[0053] In one embodiment of this application, the positive electrode active material layer further includes a positive electrode binder, which can improve the bonding ability between the positive electrode active material layer and the positive electrode current collector. Specifically, the positive electrode binder may be, but is not limited to, one or more of polyvinylidene fluoride, polyvinylidene fluoride, polytetrafluoroethylene, polyethylene, polypropylene, polystyrene, polybutadiene, acrylic resin, epoxy resin, polyethylene oxide, sodium carboxymethyl cellulose, and styrene-butadiene rubber. In one embodiment of this application, the positive electrode binder may be polyvinylidene fluoride.

[0054] In one embodiment of this application, the negative electrode sheet includes a negative electrode current collector and a negative electrode active material layer disposed on the surface of the negative electrode current collector. Specifically, the negative electrode current collector may include, but is not limited to, one or more of copper, aluminum, nickel, and stainless steel. In one embodiment of this application, the negative electrode current collector may be copper foil.

[0055] In one embodiment of this application, the negative electrode active material layer includes a negative electrode active material, which may include, but is not limited to, one or more of carbon materials, tin alloys, silicon alloys, silicon, tin, germanium, lithium, and lithium-indium alloys. In one embodiment of this application, the negative electrode active material may be a carbon material, which may include, but is not limited to, one or more of non-graphitized carbon, graphite, carbon or pyrolytic carbon obtained by high-temperature oxidation of polyacetylenic polymers, coke, sintered organic polymers, and activated carbon. In another embodiment of this application, the negative electrode active material may be a silicon alloy.

[0056] In one embodiment of this application, the negative electrode active material layer further includes a sulfide electrolyte, which can improve the conductivity of the negative electrode sheet. Specifically, the sulfide electrolyte may include, but is not limited to, Li3PS4 and Li7P3S. 11 Li 11 GeP2S 12 Li6PS5Cl, Li7P2S8I, Li 10 SnP2S 12 Li 3.25 Ge 0.25 P 0.75 One or more of S4. In one embodiment of this application, the sulfide electrolyte may be Li6PS5Cl. In another embodiment of this application, the sulfide electrolyte may be Li 11 GeP2S 12 .

[0057] In one embodiment of this application, the negative electrode active material layer further includes a negative electrode conductive agent. The negative electrode conductive agent can increase the conductivity between active materials and improve electronic conductivity. Specifically, the negative electrode conductive agent may include, but is not limited to, one or more of graphite, carbon black, acetylene black, and graphene. In one embodiment of this application, the negative electrode conductive agent may be graphite. In another embodiment of this application, the negative electrode conductive agent may be carbon black.

[0058] In one embodiment of this application, the negative electrode active material layer further includes a negative electrode binder, which can improve the bonding ability between the negative electrode active material layer and the negative electrode current collector. Specifically, the negative electrode binder may be, but is not limited to, one or more of polyvinylidene fluoride, polyvinylidene fluoride, polytetrafluoroethylene, polyethylene, polypropylene, polystyrene, polybutadiene, acrylic resin, epoxy resin, polyethylene oxide, and styrene-butadiene rubber. In one embodiment of this application, the negative electrode binder may be polyvinylidene fluoride.

[0059] In one embodiment of this application, the negative electrode active material layer further includes a negative electrode thickener, which can improve the bonding ability between the negative electrode active material layer and the current collector, and enhance the uniformity of the negative electrode active material layer. Specifically, the negative electrode thickener may include, but is not limited to, one or more of sodium carboxymethyl cellulose and potassium carboxymethyl cellulose. In one embodiment of this application, the negative electrode thickener may be sodium carboxymethyl cellulose.

[0060] In one embodiment of this application, the solid electrolyte layer includes a sulfide electrolyte, which can improve the electrochemical performance and safety of the battery. Specifically, the sulfide electrolyte may include, but is not limited to, Li3PS4 and Li7P3S4. 11 Li 11 GeP2S 12 Li6PS5Cl, Li7P2S8I, Li 10 SnP2S 12 Li 3.25 Ge 0.25 P 0.75 One or more of S4. In one embodiment of this application, the sulfide electrolyte may be Li6PS5Cl. In another embodiment of this application, the sulfide electrolyte may be Li 11 GeP2S 12 In some embodiments, the sulfide electrolyte in the solid electrolyte layer may be the same as or different from the sulfide electrolyte in the positive electrode.

[0061] In one embodiment of this application, the solid electrolyte layer further includes a binder, which can improve the adhesion between the solid electrolyte layer and the positive and / or negative electrode sheets, thereby enhancing the structural stability of the battery. Specifically, the binder may be, but is not limited to, one or more of polyvinylidene fluoride, polyvinylidene fluoride, polytetrafluoroethylene, polyethylene, polypropylene, polystyrene, polybutadiene, acrylic resin, epoxy resin, polyethylene oxide, sodium carboxymethyl cellulose, and styrene-butadiene rubber. In one embodiment of this application, the binder may be styrene-butadiene rubber.

[0062] This application also provides an electrical device, which includes the battery provided in any of the above embodiments. The electrical device provided in this application has excellent overall performance and strong market competitiveness. The electrical device in this application can refer to vehicles, electronic devices, energy storage systems, etc., and the electrochemical device can be installed in the electrical device in the form of a single cell, battery module, battery pack, capacitor, etc. In one embodiment of this application, the battery can be used in a vehicle, which can improve the safety of vehicle power consumption. In another embodiment of this application, the battery can also be applied to electronic devices, which can increase the high-temperature cycle stability of electronic device batteries and improve battery life.

[0063] The effects of the technical solution in this application will be further illustrated below with specific examples.

[0064] Example 1

[0065] The structural formula of the sealing material is

[0066] Preparation of positive electrode sheet: The positive active material (ternary positive electrode material), sulfide electrolyte (Li6PS5Cl), binder (styrene-butadiene rubber) and conductive agent (acetylene black) are added to the solvent xylene in a mass ratio of 82:10:5:2. The mixture is dispersed at 2000 RPM for 10 min using a vortex mixer (AS ONE test tube shakers) to obtain a positive electrode slurry. The positive electrode slurry is then uniformly coated on both sides of an aluminum foil and dried at 80℃ to obtain the positive electrode sheet.

[0067] Preparation of the solid electrolyte layer: A sulfide electrolyte (Li6PS5Cl) and an adhesive (styrene-butadiene rubber) were added to xylene solvent at a mass ratio of 90:10. The mixture was dispersed using a vortex mixer (AS ONE test tube shakers) at 2000 RPM for 10 min to obtain an electrolyte slurry. This slurry was uniformly coated onto a release film and then dried at 80℃ to obtain the solid electrolyte layer.

[0068] Preparation of negative electrode sheet: The negative electrode active material (silicon-carbon negative electrode material), sulfide electrolyte (Li6PS5Cl), binder (styrene-butadiene rubber) and conductive agent (acetylene black) are added to the solvent xylene in a mass ratio of 82:10:5:2. The mixture is dispersed at 2000 RPM for 10 min using a vortex mixer (AS ONE test tube shakers) to obtain a negative electrode slurry. The negative electrode slurry is then uniformly coated on both sides of a copper foil and dried at 80℃ to obtain the negative electrode sheet.

[0069] Cut the positive electrode sheet into 4.5×6cm pieces. 2The negative electrode pieces were cut into 4.7×6.2cm pieces. 2 The solid electrolyte layer was cut to a size of 4.8 × 6.3 cm. 2 A solid-state battery is obtained by stacking positive electrode, solid electrolyte layer and negative electrode. Then, the sealing layer material is coated around the stacked battery by impregnation molding method. The battery is then heated to 120°C to form chemical cross-linking and seal the battery.

[0070] Example 2

[0071] The difference from Example 1 is that the structural formula of the sealing material is...

[0072]

[0073] Example 3

[0074] The difference from Example 1 is that the structural formula of the sealing material is...

[0075]

[0076] Example 4

[0077] The difference from Example 1 is that the structural formula of the sealing material is...

[0078]

[0079] Example 5

[0080] The difference from Example 1 is that the structural formula of the sealing material is...

[0081]

[0082] Example 6

[0083] The difference from Example 1 is that the structural formula of the sealing material is...

[0084]

[0085] Example 7

[0086] The difference from Example 1 is that the structural formula of the sealing material is...

[0087]

[0088] Comparative Example 1

[0089] The difference from Example 1 is that the structural formula of the sealing material is...

[0090]

[0091] Comparative Example 2

[0092] The difference from Example 1 is that the structural formula of the sealing material is... Comparative Example 3

[0093] The difference from Example 1 is that the structural formula of the sealing material is... The value of q is chosen to make the molecular weight of the sealing material between 50,000 and 1,000,000.

[0094] Performance testing

[0095] The batteries prepared in Examples 1-7 and Comparative Examples 1-3 were subjected to cycle testing. The test procedure was as follows: 10 batteries from each example and comparative example were taken and subjected to charge-discharge cycle testing at 0.1C on a LANDCT 2001C secondary battery performance testing device at 25°C. The specific steps were: rest for 10 minutes; constant current charging to 4.2V cutoff; rest for 10 minutes; constant current discharging to 2.5V, which constituted one cycle; this step was repeated. During the cycle, the cycle was terminated when the battery capacity was lower than 80% of the initial discharge capacity. The number of cycles was the cycle life of the battery, and the average value of each group was taken. The test results are shown in Table 1.

[0096] Table 1 Battery performance test results

[0097] Number of cycles (laps) Example 1 233 Example 2 207 Example 3 205 Example 4 150 Example 5 138 Example 6 213 Example 7 208 Comparative Example 1 98 Comparative Example 2 45 Comparative Example 3 62

[0098] As can be seen from Examples 1-7 and Comparative Examples 1-3, the sealing material provided in this application has good sealing performance and high stability. When applied to batteries, it can isolate the battery from water, thereby improving the battery's cycle life. According to Examples 1 and 2-6, appropriate selection of functional groups and the values ​​of m and n can further improve the sealing performance and reliability of the sealing material, thereby enhancing the battery's cycle performance. As can be seen from Examples 1 and Comparative Examples 1-3, polymers that satisfy the structural formula of the sealing material provided in this application have good sealing effect, excellent self-healing ability, and can extend the battery's cycle life.

[0099] The above description represents the preferred embodiments of this application, but should not be construed as limiting the scope of this application. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of this application, and these improvements and modifications are also considered to be within the scope of protection of this application.

Claims

1. A sealing material, characterized by, The structural formula of the sealing material is: wherein n is greater than or equal to m, m is 0.2-0.4, n is 0.6-0.8, and m+n=1, R1 is selected from substituted or unsubstituted C6-C20 alkyl, substituted or unsubstituted aryl; R2 is methyl.

2. The sealing material of claim 1, wherein, The substituent groups of the substituted C6-C20 alkyl group include one or more of halogen atoms, cyano groups, aryl groups and cycloalkyl groups; the substituent groups of the substituted aryl group include one or more of halogen atoms, cyano groups, alkyl groups and cycloalkyl groups.

3. The sealing material of claim 2, wherein, The halogen atoms are selected from fluorine atoms, chlorine atoms, bromine atoms or iodine atoms.

4. The sealing material of claim 1, wherein The sealing material is chemically cross-linked under heating conditions, and the temperature of the heating is 80-200℃.

5. The sealing material of claim 1, wherein The sealing material has a molecular weight of 50,000-1,000,000.

6. The method of producing a sealing material according to any one of claims 1 to 5, wherein Comprising: The first monomer, the second monomer and a reducing agent are mixed, and a sealing material is obtained after reaction; the structural formula of the first monomer is , and the structural formula of the second monomer is .

7. The production method according to claim 6, wherein The temperature of the reaction is 90-180℃, and the time of the reaction is 4-24h; The reducing agent includes one or more of sodium borohydride and lithium aluminum hydride.

8. A battery, characterized by The battery includes a positive electrode sheet, a solid-state electrolyte layer and a negative electrode sheet which are arranged in a stack, and a sealing layer which is arranged on the side of the positive electrode sheet, the side of the solid-state electrolyte layer and / or the side of the negative electrode sheet, and is formed by curing the sealing material according to any one of claims 1-5 or the sealing material prepared by the preparation method according to any one of claims 6-7.

9. The battery of claim 8, wherein the cathode is a lithium cobalt oxide cathode. The sealing layer is further arranged between the positive electrode sheet and the solid-state electrolyte layer, and / or the sealing layer is further arranged between the negative electrode sheet and the solid-state electrolyte layer.

10. The battery of claim 9, wherein the electrolyte comprises a lithium salt. The solid-state electrolyte layer includes a sulfide electrolyte.

11. An electrical device, characterized by The electric device includes the battery according to any one of claims 8-10.

Images