Polymer and its preparation method, separator, electrode plate, battery and electric device

Abstract

The present application discloses a polymer and a preparation method thereof, a separator, a polar plate, a battery, and an electric device, the polymer including an organic polymer and an inorganic material, the polymerized monomers of the organic polymer including a first monomer and a second monomer, the structural formula of the first monomer including formula (I), R1 including a hydrogen atom or an alkyl of 1 to 6 carbon atoms, R2 including a hydrogen atom, a substituted or unsubstituted alkyl of 1 to 21 carbon atoms, a cycloalkyl of 3 to 6 carbon atoms, or a substituted or unsubstituted isobornyl, the substituent of the substituted alkyl of 1 to 21 carbon atoms includes hydroxy, and the second monomer includes an alkenyl. JPEG2025537498000022.jpg29170

Description

[Technical Field]

[0001] The present application is in the field of batteries, and specifically relates to polymers and their preparation methods, separators, plates, batteries and electrical devices. [Background technology]

[0002] In recent years, as the application range of batteries has become increasingly wider, batteries have been widely used in many fields, such as energy storage power systems such as hydroelectric, thermal, wind, and solar power plants, as well as in power tools, electric bicycles, electric motorcycles, electric vehicles, military equipment, and aerospace. However, the battery binders used in conventional technologies have a problem of poor adhesive performance, which makes it difficult to effectively bond battery components, thereby deteriorating the dynamic performance of the battery and causing safety issues. Summary of the Invention [Problem to be solved by the invention]

[0003] In view of the technical problems in the background art, the present application provides a polymer that improves the adhesive properties of battery adhesives and improves the dynamic and safety performance of batteries containing the polymer. [Means for solving the problem]

[0004] To achieve the above object, one aspect of the present application provides a polymer, the polymer comprising an organic polymer and an inorganic material, and polymerized monomers of the organic polymer comprising a first monomer and a second monomer; The structural formula of the first monomer is: [ka] wherein R1 comprises a hydrogen atom or an alkyl of 1 to 6 carbon atoms, R2 comprises a hydrogen atom, a substituted or unsubstituted alkyl of 1 to 21 carbon atoms, a cycloalkyl of 3 to 6 carbon atoms, or a substituted or unsubstituted isobornyl, wherein a substituent in the substituted alkyl of 1 to 21 carbon atoms comprises hydroxy, and the second monomer comprises an alkenyl.

[0005] The present invention has at least the following beneficial effects: The polymer of the present invention includes an organic polymer and an inorganic material, and the resulting polymer has good adhesive properties and at the same time an appropriate glass transition temperature, which is suitable for fully demonstrating its adhesive properties under the processing conditions of a battery, and further helps improve the dynamic performance and safety performance of the battery.

[0006] In some embodiments of the present application, the weight ratio of the first monomer to the second monomer is 1:0.05-0.5, and optionally 1:0.1-0.2, so that the polymer can have good adhesive properties and a suitable glass transition temperature.

[0007] In some embodiments of the present application, the first monomer is acrylic acid, methacrylic acid, butenoic acid, heptenoic acid, itaconic acid, maleic acid, methyl acrylate, ethyl acrylate, n-propyl acrylate, n-butyl acrylate, isobutyl acrylate, sec-butyl acrylate, tert-butyl acrylate, cyclohexyl acrylate, lauryl acrylate, 2-ethylhexyl acrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, methyl methacrylate, ethyl methacrylate, n-butyl methacrylate, 2-ethylhexyl methacrylate, meth The first monomer may include at least one of isobornyl acrylate, lauryl methacrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, vinyl acetate, trifluoroethyl methacrylate, glycidyl methacrylate, glycidyl acrylate, ethylene acrylate glycidyl methacrylate, trimethylammonioethyl methacrylate, or trimethylolpropane triacrylate, and optionally, the first monomer may include at least one of methyl methacrylate, lauryl acrylate, lauryl methacrylate, or trimethylolpropane triacrylate, which can improve the toughness of the polymer during application and help to provide better adhesion.

[0008] In some embodiments of the present application, the structural formula of the second monomer is: [ka] wherein R6, R7, R8, and R9 each independently comprise a hydrogen atom, a substituted or unsubstituted phenyl, a substituted or unsubstituted cycloalkyl, or a straight-chain or branched-chain alkyl, which can enhance the adhesion and electrolyte resistance of the polymer and further improve the dynamic performance and safety performance of the battery.

[0009] In some embodiments of the present application, the second monomer comprises at least one of ethylene, styrene, butadiene, or isoprene, which can help to enhance the adhesion and electrolyte resistance of the polymer, as well as improve the dynamic and safety performance of the battery.

[0010] In some embodiments of the present application, the polymerized monomers of the organic polymer include a first monomer, a second monomer, and a third monomer, and the third monomer includes an unsaturated nitrile. Therefore, by using the third monomer including an unsaturated cyano group, the polymer contains a highly polar cyano group, which can help increase the ionic conductivity of the polymer and improve the dynamic performance of the battery.

[0011] In some embodiments of the present application, the structural formula of the third monomer is: [ka] where R3 contains a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, which allows the polymer to contain a highly polar cyano group, thereby increasing the ionic conductivity of the polymer and helping to improve the dynamic performance of the battery.

[0012] In some embodiments of the present application, the third monomer comprises at least one of acrylonitrile, methacrylonitrile, or ethyl acrylonitrile, and optionally at least one of acrylonitrile or methacrylonitrile, which helps to increase the ionic conductivity of the polymer and improve the dynamic performance of the battery.

[0013] In some embodiments of the present application, the weight ratio of the first monomer to the second monomer to the third monomer is 1:0.05-0.5:0.01-0.8, and optionally 1:0.1-0.2:0.05-0.6. The resulting polymer has good adhesive properties and a suitable glass transition temperature, making it suitable for fully demonstrating its adhesive properties under battery processing conditions and further improving the dynamic performance and safety of secondary batteries. Furthermore, when the polymer is applied to a separator, it reduces the separator's resistance, improves the separator's ionic conductivity, and contributes to improving battery performance.

[0014] In some embodiments of the present application, the polymerized monomers of the organic polymer include a first monomer, a second monomer, a third monomer, and a fourth monomer, and the fourth monomer includes an unsaturated amide, thereby adjusting the molecular weight of the organic polymer and improving the adhesiveness of the organic polymer.

[0015] In some embodiments of the present application, the structural formula of the fourth monomer is: [ka] wherein R4 comprises a hydrogen atom or an alkyl group of 1 to 6 carbon atoms, and R5 comprises a hydrogen atom, an alkyl group of 1 to 6 carbon atoms substituted with hydroxy, or an alkoxy group of 1 to 6 carbon atoms, thereby improving the electrolyte resistance of the polymer.

[0016] In some embodiments of the present application, the fourth monomer includes at least one of acrylamide, N-methylolacrylamide, or N-butoxymethacrylamide, and optionally at least one of acrylamide or N-methylolacrylamide, thereby improving the electrolyte resistance of the polymer.

[0017] In some embodiments of the present application, the weight ratio of the first monomer, the second monomer, the third monomer, and the fourth monomer is 1:0.05-0.5:0.01-0.8:0.05-0.7, and optionally 1:0.1-0.2:0.05-0.6:0.1-0.5, thereby lowering the resistance of a separator containing the polymer, improving the ionic conductivity of the separator, and improving battery performance.

[0018] In some embodiments of the present application, the particle size of the inorganic material is 0.0001 μm to 2 μm, preferably 0.01 μm to 0.5 μm, and more preferably 0.01 μm to 0.2 μm, thereby allowing the inorganic material and the organic polymer to be thoroughly mixed, thereby improving the ionic conductivity and electrolyte resistance of the separator containing the polymer.

[0019] In some embodiments of the present application, the inorganic material is attached to the surface of the organic polymer and / or dispersed within the organic polymer, whereby, with the organic polymer as the skeleton, the inorganic material may be simultaneously dispersed within and on the surface of the organic polymer, or may be distributed only within the organic polymer, or may be distributed only on the surface of the organic polymer, and the polymer is suitable for fully exhibiting its adhesive properties under battery processing conditions, and further helps improve the dynamic performance and safety performance of the battery.

[0020] In some embodiments of the present application, the inorganic substance includes at least one of silicon oxide, aluminum oxide, calcium oxide, zinc oxide, magnesium oxide, sodium sulfate, sodium benzoate, calcium carbonate, and modified materials thereof, and optionally includes at least one of silica, aluminum oxide, zinc oxide, magnesium oxide, and sodium benzoate, and more preferably includes at least one of fumed silica, silica powder, aluminum oxide, and sodium benzoate, thereby improving the ionic conductivity and electrolyte resistance of a separator containing the polymer.

[0021] In some embodiments of the present application, the inorganic material includes silica, and the particle size of the silica is 2 nm to 1 μm, optionally 5 nm to 100 nm, more optionally 5 nm to 20 nm, which not only prevents the hole clogging phenomenon but also improves the ionic conductivity and electrolyte resistance of the separator containing the polymer.

[0022] In some embodiments of the present application, the weight ratio of the organic polymer is 50% to 99.9%, preferably 60% to 99%, more preferably 70% to 99%, based on the weight of the polymer, so that the polymer has good adhesive properties and is helpful in improving the dynamic performance and safety performance of the battery.

[0023] In some embodiments of the present application, the particle size of the polymer satisfies 3 μm≦D50≦10 μm, so that when it is used in a separator, the energy density of the cell can be increased and the probability of separator clogging can be reduced.

[0024] In some embodiments of the present application, the particle size distribution of the polymer is (D90-D10) / D50, and the particle size distribution of the polymer is 2.5 or less, preferably less than 2, and more preferably less than 1.8, thereby reducing the probability of hole clogging when the polymer is used in a separator.

[0025] In some embodiments of the present application, the outer surface of the polymer is uneven, which increases the contact area between the polymer and the separator and other components, thereby improving adhesion.

[0026] In some embodiments of the present application, the polymer has a first glass transition temperature and a second glass transition temperature within a range of −10° C. to 95° C., and the first glass transition temperature is higher than the second glass transition temperature, thereby allowing the polymer to fully exhibit its adhesive performance under battery processing conditions and further improving the dynamic performance and safety performance of the battery.

[0027] In some embodiments of the present application, the first glass transition temperature of the polymer is 30° C. to 75° C. and / or the second glass transition temperature of the polymer is −10° C. to 25° C. This allows the polymer of the present application to fully exhibit its adhesive performance under battery processing conditions, and further helps improve the dynamic performance and safety performance of the battery.

[0028] A second aspect of the present application provides a method for preparing a polymer, the method comprising the step of mixing an organic polymer with an inorganic substance, wherein polymerized monomers of the organic polymer comprise a first monomer and a second monomer, and the structural formula of the first monomer is: [ka] wherein R1 comprises a hydrogen atom or an alkyl of 1 to 6 carbon atoms, R2 comprises a hydrogen atom, a substituted or unsubstituted alkyl of 1 to 21 carbon atoms, a cycloalkyl of 3 to 6 carbon atoms, or a substituted or unsubstituted isobornyl, and the substituents in the substituted alkyl of 1 to 21 carbon atoms include hydroxy; The second monomer contains an alkenyl.

[0029] Therefore, by employing the method of the present application, it is possible to prepare a polymer having the above-mentioned good adhesive properties, and the polymer has an appropriate glass transition temperature, which is suitable for fully exhibiting its adhesive properties under the processing conditions of the battery, and further helps to improve the dynamic performance and safety performance of the battery.

[0030] A third aspect of the present application provides a separator, which includes the above polymer or a polymer obtained by the above method, thereby improving the stability, ionic conductivity, and electrolyte resistance of the separator, and thereby improving the dynamic performance and safety performance of the battery.

[0031] In some embodiments of the present application, the separator has an ionic conductivity of 0.3 mS cm -1 ~0.6 mS·cm -1 and selectively 0.4 mS cm -1 ~0.5mS·cm -1 This can improve the dynamic performance of the secondary battery.

[0032] A fourth aspect of the present application provides a plate comprising the above polymer or a polymer obtained by the above method, thereby improving the ionic conductivity and structural stability of the plate and enhancing the dynamic performance and safety performance of the battery.

[0033] A fifth aspect of the present application provides a battery, the battery including the separator and / or the electrode plate, thereby having excellent dynamic performance and safety performance.

[0034] A sixth aspect of the present application provides an electric device, the electric device including the battery described above, thereby providing the electric device with excellent dynamic performance and safety performance.

[0035] Additional aspects and advantages of the present application will be set forth in part in the description that follows, and in part will be obvious from the description, or may be learned by practice of the present application. Various other advantages and benefits will become apparent to those skilled in the art after reading the following detailed description of the preferred embodiments. The drawings are for the purpose of illustrating the preferred embodiments only and are not to be construed as limiting the present application. Furthermore, like reference numerals represent like elements in all drawings. [Brief explanation of the drawings]

[0036] [Figure 1] 1 is a schematic diagram of a battery according to one embodiment of the present application. [Figure 2] 2 is an exploded view of the battery shown in FIG. 1 according to one embodiment of the present application. [Figure 3] 1 is a schematic diagram of a battery module according to an embodiment of the present application; [Figure 4] 1 is a schematic diagram of a battery pack according to an embodiment of the present application. [Figure 5] FIG. 5 is an exploded view of the battery pack shown in FIG. 4 according to an embodiment of the present application. [Figure 6] 1 is a schematic diagram of an electrical device that uses a battery as a power source in accordance with one embodiment of the present application. DETAILED DESCRIPTION OF THE INVENTION

[0037] The following describes in detail the embodiments of the technical solution of the present application. The following embodiments are merely used as examples to more clearly explain the technical solution of the present application, and should not be used to limit the scope of protection of the present application.

[0038] When an "embodiment" is mentioned in this specification, it means that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment of the present application. Appearances of this phrase in various places in the specification do not necessarily all refer to the same embodiment, nor are they mutually exclusive, separate, or alternative embodiments to other embodiments. Those skilled in the art can explicitly and implicitly understand that the embodiments described in this specification can be combined with other embodiments.

[0039] The "ranges" disclosed herein are defined in the form of lower and upper limits. A given range is defined by selecting one lower limit and one upper limit, and the selected lower and upper limits define the boundaries of the particular range. Such defined ranges may be inclusive or exclusive of the endpoints and may be arbitrarily combined; i.e., any lower limit may be combined with any upper limit to form a single range. For example, if ranges of 60 to 120 and 80 to 110 are recited for a given parameter, it is understood that ranges of 60 to 110 and 80 to 120 are also contemplated. Furthermore, if 1 and 2 are recited as minimum range values ​​and 3, 4, and 5 are recited as maximum range values, then the ranges of 1 to 3, 1 to 4, 1 to 5, 2 to 3, 2 to 4, and 2 to 5 are all contemplated. Unless otherwise specified herein, a numerical range "a to b" represents a shorthand notation for any combination of real numbers between a and b, where a and b are both real numbers. For example, the numerical range "0 to 5" means that all real numbers between "0 and 5" are listed herein, and "0 to 5" is simply shorthand for combinations of these numbers. Note that describing a parameter as an integer ≧2 is equivalent to disclosing that the parameter is, for example, the integers 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.

[0040] Unless otherwise stated, all embodiments and alternative embodiments in the present application can be combined with each other to form new technical solutions.

[0041] Unless otherwise stated, all technical features and optional technical features of the present application can be combined with each other to form new technical solutions.

[0042] Unless otherwise specified, all steps herein may be performed in sequence or randomly, preferably in sequence. For example, when the method includes steps (a) and (b), it means that the method may include steps (a) and (b) performed in sequence, or may include steps (b) and (a) performed in sequence. For example, when it is stated that the method may further include step (c), it means that step (c) can be added to the method in any order; for example, the method may include steps (a), (b), and (c), or may include steps (a), (c), and (b), or may include steps (c), (a), and (b).

[0043] Unless otherwise specified, the terms "comprise" and "comprises" used herein may be open-ended or closed-ended. For example, the terms "comprise" and "comprises" may indicate that the compound may further include or include other components not listed, or may include or include only the listed components.

[0044] Unless otherwise stated, the term "or" in this application is inclusive. For example, the phrase "A or B" means "A, B, or both A and B." More specifically, any one of the following conditions satisfies the condition "A or B": A is true (or exists) and B is false (or does not exist); A is false (or does not exist) and B is true (or exists); or A and B are both true (or exist).

[0045] A secondary battery includes a positive electrode plate, a negative electrode plate, a separator, and an electrolyte. To optimize the manufacturing process and cell performance, it is necessary to provide a certain degree of adhesion between the positive electrode plate, the negative electrode plate, and the separator. This can be achieved by applying an adhesive coating material to the surface of the separator to produce an adhesive separator. Currently, the materials applied to the surface of the separator are divided into fluorine-containing polymers and non-fluorine-containing polymers.

[0046] Fluorine-containing polymer-coated separators require the use of fluorine-containing polymers, which are derived from a single source of raw material, resulting in resource depletion and increasing costs. The process also involves the use of ozone-depleting substances, posing a high environmental risk. Furthermore, the fluorine-containing polymers used to coat separators have high melting points. The cell hot-pressing temperature is typically below 100°C, which cannot reach the melting point of the fluorine-containing polymer binder. Therefore, separators using fluorine-containing polymer binders exhibit poor adhesion to the electrode plates during hot-pressing. Furthermore, fluorine-containing polymer binders have high material density and a high coating weight. Non-fluorine-containing polymer-coated separators typically use polyester polymers, but traditional polyester polymers are less adaptable to cell manufacturing processes. For example, emulsions or suspensions with small particle sizes present problems with pore clogging. Polyester powders with large particle sizes and high glass transition temperatures present problems with poor thermocompression bonding and increased internal resistance in batteries.

[0047] In other words, some battery binders used in the prior art have poor adhesive properties, and some have high melting points, making it difficult for them to fully exert their adhesive effect under the operating conditions of the battery. As a result, battery components cannot be effectively bonded, and the components may separate or fall off during use, deteriorating the dynamic properties of the battery and posing safety risks.

[0048] The polymers of the present application include organic polymers and inorganic materials, and the organic polymers are [ka] The organic polymer is obtained by polymerizing a first monomer containing an alkyl group and a second monomer containing an alkenyl group. When combined with an inorganic material, the polymer has good adhesive properties and a suitable glass transition temperature, making it suitable for fully demonstrating its adhesive properties under battery operating conditions. Furthermore, the combination of the organic polymer with an inorganic material increases the ionic conductivity and electrolyte resistance of the polymer, thereby improving the dynamic performance and safety of batteries containing the polymer.

[0049] The polymers disclosed in the embodiments of the present application are suitable for batteries, and the batteries disclosed in the embodiments of the present application can be used in various energy storage systems that use batteries as a power source or as an energy storage element. The electric devices may include, but are not limited to, mobile phones, tablets, laptops, electric toys, power tools, electric motorcycles, electric cars, boats, and spacecraft. The electric toys may include stationary or mobile electric toys such as game consoles, electric car toys, electric propulsion boat toys, and electric plane toys. The spacecraft may include airplanes, rockets, space shuttles, and spaceships.

[0050] A first aspect of the present application provides a polymer, the polymer comprising an organic polymer and an inorganic material, and polymerized monomers of the organic polymer comprising a first monomer and a second monomer; The structural formula of the first monomer is: [ka] wherein R1 comprises a hydrogen atom or an alkyl of 1 to 6 carbon atoms, R2 comprises a hydrogen atom, a substituted or unsubstituted alkyl of 1 to 21 carbon atoms, a cycloalkyl of 3 to 6 carbon atoms, or a substituted or unsubstituted isobornyl, and the substituents in the substituted alkyl of 1 to 21 carbon atoms include hydroxy; The second monomer contains an alkenyl.

[0051] The polymers of the present application include organic polymers and inorganic materials, and the organic polymers are [ka] The organic polymer is obtained by polymerizing a first monomer containing an alkyl group with a second monomer containing an alkenyl group. The unsaturated ester group in the first monomer enhances the polymer's anti-swelling ability and, as a flexible monomer segment in the molecular segment, adjusts the glass transition temperature of the organic polymer, improving the toughness of the polymer during application and providing good adhesion. The second monomer contains an alkenyl group, which polymerizes with the first monomer to provide good adhesive properties. Thus, the present application discloses that by combining an organic polymer obtained by polymerizing the first and second monomers with an inorganic substance, the polymer has good adhesive properties and also has an appropriate glass transition temperature, making it suitable for fully demonstrating its adhesive properties under battery operating conditions. Furthermore, the combination of the organic polymer with the inorganic substance increases the polymer's ionic conductivity and electrolyte resistance, thereby improving the dynamic and safety performance of batteries containing it.

[0052] In some embodiments of the present application, the structural formula of the first monomer is: [ka] wherein R1 comprises a hydrogen atom or an alkyl group of 1 to 6 carbon atoms, and R2 comprises a hydrogen atom, a substituted or unsubstituted alkyl group of 1 to 21 carbon atoms, a cycloalkyl group of 3 to 6 carbon atoms, or a substituted or unsubstituted isobornyl, and the substituent in the substituted alkyl group of 1 to 21 carbon atoms comprises a hydroxyl group. Thus, the unsaturated ester group in the first monomer can enhance the anti-swelling ability of the polymer and, as a flexible monomer segment in the molecular segment, can adjust the glass transition temperature of the organic polymer, improve the toughness of the polymer during application, and provide good adhesive properties.

[0053] As an example, alkyl of 1 to 6 carbon atoms may be understood to be an alkyl group having 1 to 6 carbon atoms, such as methyl (-CH3), ethyl (-CH2CH3), n-propyl (-CH2CH2CH3), isopropyl (-CH(CH3)2), n-butyl (-CH2CH2CH2CH3), tert-butyl (-C(CH3)3), n-pentyl (-CH2CH2CH2CH2CH3), n-hexyl (-CH2CH2CH2CH2CH2CH3), etc.

[0054] As an example, for a substituted or unsubstituted alkyl of 1 to 21 carbon atoms, the substituted alkyl of 1 to 21 carbon atoms may be understood to be a group in which at least one hydrogen atom of an alkyl group having 1 to 21 carbon atoms is substituted with another group, such as, for example, -CHOH, -CHCHOH, -CHCHCHOH, -CH(CHOH)OH, -CHCHCHCHCHOH, -C(CHOH)OH, -CHCHCHCHCHCHOH, and the unsubstituted alkyl of 1 to 21 carbon atoms may be, for example, methyl (-CH), ethyl (-

[0023] Cycloalkyl of 3 to 6 carbon atoms may be understood to be an alkyl group having 1 to 21 carbon atoms, such as, for example, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, etc.

[0055] In some embodiments, the first monomer comprises at least one of acrylic acid, methacrylic acid, butenoic acid, heptenoic acid, itaconic acid, maleic acid, methyl acrylate, ethyl acrylate, n-propyl acrylate, n-butyl acrylate, isobutyl acrylate, sec-butyl acrylate, tert-butyl acrylate, cyclohexyl acrylate, lauryl acrylate, 2-ethylhexyl acrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, methyl methacrylate, ethyl methacrylate, n-butyl methacrylate, 2-ethylhexyl methacrylate, isobornyl methacrylate, lauryl methacrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, vinyl acetate, trifluoroethyl methacrylate, glycidyl methacrylate, glycidyl acrylate, ethylene acrylate-glycidyl methacrylate, trimethylammonioethyl methacrylate, or trimethylolpropane triacrylate. Therefore, by using at least one of the above organic substances as the first monomer, it is possible to adjust the glass transition temperature of the organic polymer, improve the toughness of the polymer during application, and help to exhibit good adhesive properties. In some other embodiments of the present application, the first monomer includes at least one of methyl methacrylate, lauryl acrylate, lauryl methacrylate, and trimethylolpropane triacrylate. This can further adjust the glass transition temperature of the organic polymer, improve the toughness of the polymer during application, and help to exhibit good adhesive properties.

[0056] In some embodiments of the present application, the second monomer contains an alkenyl, and when the second monomer contains an alkenyl and the first monomer are polymerized together, the resulting organic polymer has good adhesive properties and a low glass transition temperature.

[0057] In some embodiments of the present application, the structural formula of the second monomer is: [ka] wherein R6, R7, R8, and R9 each independently include a hydrogen atom, a substituted or unsubstituted phenyl, a substituted or unsubstituted cycloalkyl, or a straight-chain or branched-chain alkyl.

[0058] It should be noted that the substituted phenyl may be understood to be a phenyl group in which at least one hydrogen atom of the phenyl has been replaced with another group, such as benzyl or phenethyl, and the substituted cycloalkyl may be understood to be a group in which at least one hydrogen atom of the cycloalkyl has been replaced with another group, such as cyclopropylmethyl or cyclobutylmethyl.

[0059] The addition of the second monomer of the above composition results in a polymer containing it that has good adhesive properties and a suitable glass transition temperature, making it suitable for fully demonstrating its adhesive properties under battery processing conditions and further contributing to improving the dynamic and safety performance of secondary batteries. Furthermore, when the polymer is applied to a separator, it reduces the separator's resistance, improves the separator's ionic conductivity, and contributes to improving battery performance.

[0060] In some embodiments of the present application, the second monomer comprises at least one of ethylene, styrene, butadiene, or isoprene, thereby adjusting the molecular weight of the organic polymer, improving the adhesive properties of the organic polymer, and ensuring that the organic polymer has a suitable glass transition temperature.

[0061] In some embodiments of the present application, the weight ratio of the first monomer to the second monomer is 1:0.05-0.5, such as 1:0.1-0.45, 1:0.15-0.4, 1:0.2-0.35, or 1:0.25-0.3. Thus, when an organic polymer is produced using the first and second monomers in this ratio, the resulting polymer has good adhesive properties and a suitable glass transition temperature, making it suitable for fully demonstrating its adhesive properties under battery processing conditions and further improving the dynamic performance and safety of secondary batteries. Furthermore, when the polymer is used in a separator, it reduces the separator's resistance, improves the separator's ionic conductivity, and contributes to improving battery performance. In some other embodiments of the present application, the weight ratio of the first monomer to the second monomer is 1:0.1-0.2.

[0062] In some embodiments of the present application, the polymerized monomers of the organic polymer include a first monomer, a second monomer, and a third monomer, and the third monomer includes an unsaturated nitrile, which introduces a highly polar cyano group into the polymer, thereby increasing the ionic conductivity of the polymer and helping to improve the dynamic performance of the battery.

[0063] In some embodiments of the present application, the structural formula of the third monomer is: [ka] where R3 contains a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, which introduces a highly polar cyano group into the polymer, thereby increasing the ionic conductivity of the polymer and helping to improve the dynamic performance of the battery.

[0064] In some embodiments of the present application, the third monomer includes at least one of acrylonitrile, methacrylonitrile, or ethyl acrylonitrile. In other embodiments of the present application, the third monomer includes at least one of acrylonitrile or methacrylonitrile, which increases the ionic conductivity of the polymer and helps improve the dynamic performance of the battery.

[0065] In some embodiments of the present application, the weight ratio of the first monomer, the second monomer, and the third monomer is 1:0.05-0.5:0.01-0.8, for example, 1:0.1-0.45:0.01-0.8, 1:0.15-0.4:0.01-0.8, 1:0.2-0.35:0.01-0.8, or 1: The mixing ratios are 0.25-0.3:0.01-0.8, 1:0.05-0.5:0.05-0.75, 1:0.05-0.5:0.1-0.7, 1:0.05-0.5:0.15-0.65, 1:0.05-0.5:0.2-0.6, 1:0.05-0.5:0.3-0.5, 1:0.05-0.5:0.4-0.5, etc. By using the first monomer, second monomer, and third monomer in these mixing ratios to produce an organic polymer, the obtained polymer has good adhesive performance and ionic conductivity, is suitable for fully exhibiting its adhesive performance under battery processing conditions, and further helps improve the dynamic performance and safety performance of secondary batteries. In some other embodiments of the present application, the weight ratio of the first monomer to the second monomer to the third monomer is 1:0.1-0.2:0.05-0.6, so that the resulting polymer has good adhesive properties and ionic conductivity, is suitable for fully demonstrating its adhesive properties under battery processing conditions, and is also useful for improving the dynamic performance and safety performance of secondary batteries.

[0066] In some embodiments of the present application, the polymerized monomers of the organic polymer include a first monomer, a second monomer, a third monomer, and a fourth monomer, and the fourth monomer includes an unsaturated amide, thereby adjusting the molecular weight of the organic polymer and improving the adhesiveness of the organic polymer.

[0067] In some embodiments of the present application, the structural formula of the fourth monomer is: [ka] wherein R4 comprises a hydrogen atom or an alkyl group of 1 to 6 carbon atoms, and R5 comprises a hydrogen atom, an alkyl group of 1 to 6 carbon atoms substituted with hydroxy, or an alkoxy group of 1 to 6 carbon atoms, so that the fourth monomer contains an unsaturated amide, which can adjust the molecular weight of the organic polymer and improve the adhesiveness of the polymer.

[0068] In some embodiments of the present application, the fourth monomer includes at least one of acrylamide, N-methylolacrylamide, or N-butoxymethacrylamide. By employing the at least one fourth monomer of the present application, the molecular weight of the organic polymer can be adjusted and the adhesive properties of the polymer can be improved. In some embodiments of the present application, the fourth monomer includes at least one of acrylamide or N-methylolacrylamide.

[0069] In some embodiments of the present application, the weight ratio of the first monomer, the second monomer, the third monomer, and the fourth monomer is 1:0.05-0.5:0.01-0.8:0.05-0.7, for example, 1:0.1-0.45:0.01-0.8:0.05-0.7, 1:0.15-0.4:0.01-0.8:0.05-0.7, 1:0.2-0.35:0.01-0.8:0.05-0.7, 1:0.25-0.3:0.01-0.8:0.05-0.7, 1:0.05-0.5:0.05-0.75:0.05-0.7, or 1:0.05-0. 5: 0.1~0.7: 0.05~0.7, 1: 0.05~0.5: 0.15~0.65: 0.05~0.7, 1: 0.05~0.5: 0.2~0.6: 0.05~0.7, 1: 0.05~0.5: 0.3~0.5: 0.05~0.7, 1: 0.05~0.5: 0.4~0.5: 0 Examples of suitable ratios include 1:0.05-0.7, 1:0.05-0.5:0.01-0.8:0.1-0.7, 1:0.05-0.5:0.01-0.8:0.2-0.6, 1:0.05-0.5:0.01-0.8:0.3-0.5, and 1:0.05-0.5:0.01-0.8:0.4-0.5. By mixing the first, second, third, and fourth monomers in the above ratios, organic polymers containing the monomers exhibit good adhesive properties and a suitable glass transition temperature, making them suitable for fully demonstrating their adhesive properties under battery processing conditions and further contributing to improved dynamic and safety performance of secondary batteries. Furthermore, when the polymers are used in separators, they reduce the separator's resistance, improve the separator's ionic conductivity, and contribute to improved battery performance. In some other embodiments of the present application, the weight ratio of the first monomer, the second monomer, the third monomer, and the fourth monomer is 1:0.1-0.2:0.05-0.6:0.1-0.5.

[0070] In some embodiments of the present application, the weight-average molecular weight of the organic polymer is 500,000 to 1,200,000, for example, 550,000 to 1,150,000, 600,000 to 1,100,000, 650,000 to 1,050,000, 700,000 to 1,000,000, 750,000 to 950,000, 800,000 to 900,000, or 850,000 to 900,000. Thus, organic polymers that satisfy this weight-average molecular weight range have excellent adhesive properties, are suitable for fully demonstrating their adhesive properties under battery processing conditions, and further improve the dynamic performance and safety performance of secondary batteries. In some other embodiments of the present application, the weight-average molecular weight of the organic polymer is 800,000 to 1,000,000.

[0071] The weight average molecular weight of the organic polymer can be measured by a method commonly used in the art, for example, by gel permeation chromatography in accordance with GB / T 21863-2008.

[0072] In some embodiments of the present application, the particle size of the inorganic substance is 0.0001 μm to 2 μm, for example, 0.0005 μm to 2 μm, 0.001 μm to 2 μm, 0.005 μm to 2 μm, 0.01 μm to 2 μm, 0.05 μm to 2 μm, 0.08 μm to 2 μm, 0.1 μm to 2 μm, 0.2 μm to 1.8 μm, 0.5 μm to 1.5 μm, 0.7 μm to 1.2 μm, or 1 μm to 1.2 μm. By using an inorganic substance with such particle size, the inorganic substance and the organic polymer can be thoroughly mixed, thereby improving the ionic conductivity and electrolyte resistance of a separator containing the polymer. In some other embodiments of the present application, the particle size of the inorganic substance is 0.01 μm to 0.5 μm, and further, the particle size of the inorganic substance is 0.01 μm to 0.2 μm.

[0073] In some embodiments of the present application, the inorganic material is attached to the surface of the organic polymer and / or dispersed within the organic polymer, whereby, with the organic polymer as the skeleton, the inorganic material may be simultaneously dispersed within and on the surface of the organic polymer, or may be distributed only within the organic polymer, or may be distributed only on the surface of the organic polymer, and the polymer is suitable for fully exhibiting its adhesive performance under the processing conditions of the battery, and further helps to improve the dynamic performance and safety performance of the battery.

[0074] In some embodiments of the present application, the inorganic material includes at least one of silicon oxide, aluminum oxide, calcium oxide, zinc oxide, magnesium oxide, sodium sulfate, sodium benzoate, calcium carbonate, and modified materials thereof. Therefore, a polymer obtained by blending at least one of the above inorganic materials with an organic polymer has good adhesive properties and can improve the dynamic performance and safety performance of the battery. In some other embodiments of the present application, the inorganic material includes at least one of silica, aluminum oxide, zinc oxide, magnesium oxide, and sodium benzoate. Furthermore, the inorganic material includes at least one of fumed silica, silica powder, aluminum oxide, and sodium benzoate.

[0075] In some embodiments of the present application, the inorganic material includes silica, and the particle size of the silica is 2 nm to 1 μm, such as 10 nm to 1 μm, 20 nm to 1 μm, 50 nm to 1 μm, 100 nm to 1 μm, 200 nm to 1 μm, 300 nm to 1 μm, 400 nm to 1 μm, 500 nm to 1 μm, 600 nm to 1 μm, 700 nm to 1 μm, 800 nm to 1 μm, or 900 nm to 1 μm. Therefore, by using a polymer obtained by blending the above-mentioned organic polymer with silica in this particle size range as the inorganic material, the polymer can be used in a separator, preventing hole clogging and improving the ionic conductivity and electrolyte resistance of the separator containing the polymer. In some other embodiments of the present application, the particle size of the silica is 5 nm to 100 nm, and further, the particle size of the silica is 5 nm to 20 nm.

[0076] In some embodiments of the present application, the weight percentage of the organic polymer is 50% to 99.9% based on the weight of the polymer, for example, 55% to 99%, 60% to 95%, 65% to 90%, 70% to 85%, or 75% to 80%, thereby providing the polymer with good adhesion performance and improving the dynamic and safety performance of the battery. In some other embodiments of the present application, the weight percentage of the organic polymer is 60% to 99% based on the weight of the polymer, and further, the weight percentage of the organic polymer is 70% to 99% based on the weight of the polymer.

[0077] In some embodiments of the present application, the particle size of the polymer satisfies 3 μm≦D50≦10 μm, for example, 4 μm≦D50≦9 μm, 5 μm≦D50≦8 μm, 6 μm≦D50≦7 μm, etc. Therefore, when a polymer having such a particle size is used for a separator, the energy density of the cell can be increased and the probability of separator clogging can be reduced.

[0078] In the examples of the present application, D50 of the polymer is the particle size corresponding to the cumulative particle size volume distribution percentage of the particles reaching 50%, and the test method is as follows.

[0079] Refer to the GB / T 19077-2016 / ISO 13320:2009 laser diffraction particle size distribution standard. The test was performed using a laser particle size analyzer (Malvern 3000, MasterSizer 3000) with a helium-neon red light source as the primary light source. Add 1 g of test sample to a clean small beaker, add one drop of surfactant, and add 20 ml of deionized water (ensuring a light-blocking level of 8-12% relative to the sample concentration). Sonicate at 53 kHz / 120 W for 5 minutes to ensure complete dispersion. Turn on the laser particle size analyzer, clean the optical path, and automatically test for background noise. Stir the sonicated test solution until uniformly dispersed. If necessary, add it to the sample cell and begin particle size measurement. The measurement results can be read from the instrument.

[0080] In some embodiments of the present application, the particle size distribution of the polymer is (D90-D10) / D50, and the particle size distribution of the polymer is 2.5 or less. This ensures uniform particle size, and when the polymer is applied to a separator, the probability of hole clogging can be reduced. In other embodiments of the present application, the particle size distribution of the polymer is less than 2, and further, the particle size distribution of the polymer is less than 1.8.

[0081] The test method for D50 is as described above. In the examples of the present application, D90 refers to the particle size corresponding to the cumulative particle size volume distribution percentage of particles reaching 90%, and D10 refers to the particle size corresponding to the cumulative particle size volume distribution percentage of particles reaching 10%, and the test methods are the same as those for D50.

[0082] In some embodiments of the present application, the outer surface of the polymer is uneven, which increases the contact area between the polymer and the separator and other components, thereby improving adhesion.

[0083] In some embodiments of the present application, the polymer comprises a first glass transition temperature and a second glass transition temperature within the range of −10° C. to 95° C., and the first glass transition temperature is greater than the second glass transition temperature.

[0084] The above glass transition temperature is achieved by the cooperation of the organic polymer and the inorganic material. The resulting polymer has good adhesive properties and at the same time an appropriate glass transition temperature, which is suitable for fully exerting its adhesive properties under the processing conditions of the battery, and further helps to improve the dynamic performance and safety performance of the battery.

[0085] The glass transition temperature is the temperature at which a high polymer transforms from a highly elastic state to a glassy state, and refers to the temperature at which an amorphous polymer (including the amorphous portion of a crystalline polymer) transforms from a glassy state to a highly elastic state or from the latter to the former. It is the lowest temperature at which the polymer segments of an amorphous polymer move freely, and is usually expressed as Tg. If the temperature is above the glass transition temperature, the high polymer exhibits elasticity, and if the temperature is below the glass transition temperature, the high polymer exhibits brittleness. The glass transition temperature can be measured by a method commonly used in the art, for example, by differential scanning calorimetry, referring to GB / T 19466.2.

[0086] The first glass transition temperature is greater than the second glass transition temperature, and when the first glass transition temperature is equal to or greater than the second glass transition temperature, the structure within the polymer that includes the second glass transition temperature is in a rubbery state, and when the first glass transition temperature is equal to or less than the first glass transition temperature, the structure within the polymer that includes the first glass transition temperature is in a glassy state.

[0087] For example, when the temperature of a polymer is between the second glass transition temperature and the first glass transition temperature, at this temperature, when no pressure is applied to the polymer, the structure containing the first glass transition temperature in the polymer is in a glassy state, is hard, and functions as a skeleton structure for the polymer powder, preventing the polymer from becoming viscous. At this temperature, the structure containing the second glass transition temperature in the polymer is in a rubbery state, and can have a certain "fluidity" after applying a certain pressure. The second glass transition structure in the polymer can fully penetrate into the pores of the positive and negative electrodes and separator, increasing the mechanical interlocking effect and fully exerting their adhesive properties, further helping to improve the dynamic performance of the battery.

[0088] In some embodiments of the present application, the first glass transition temperature of the polymer is 30°C to 75°C, such as 35°C to 70°C, 40°C to 65°C, 45°C to 60°C, or 50°C to 55°C, and the second glass transition temperature of the polymer is -10°C to 25°C, such as -5°C to 20°C, 0°C to 15°C, or 5°C to 10°C. Therefore, when the first and second glass transition temperatures of a polymer are within the above ranges, at room temperature (25°C < room temperature < 30°C), when no pressure is applied to the polymer, the structure containing the first glass transition temperature in the polymer is in a glassy state because the first glass transition temperature is higher than room temperature, and is hard, acting as a skeleton structure for the polymer powder and preventing the polymer from becoming viscous. At room temperature, the structure containing the second glass transition temperature in the polymer is in a rubbery state because the second glass transition temperature is lower than room temperature, and can have a certain "fluidity" after applying a certain amount of pressure. The structure containing the second glass transition temperature in the polymer can fully penetrate into the pores of the positive and negative electrodes and separator, increasing the mechanical interlocking effect and fully exerting their adhesive properties, further improving the dynamic performance of the battery.

[0089] A second aspect of the present application provides a method for preparing a polymer, the method comprising the step of mixing an organic polymer with an inorganic substance, wherein polymerized monomers of the organic polymer comprise a first monomer and a second monomer, and the structural formula of the first monomer is: [ka] wherein R1 comprises a hydrogen atom or an alkyl of 1 to 6 carbon atoms, R2 comprises a hydrogen atom, a substituted or unsubstituted alkyl of 1 to 21 carbon atoms, a cycloalkyl of 3 to 6 carbon atoms, or a substituted or unsubstituted isobornyl, and the substituents in the substituted alkyl of 1 to 21 carbon atoms include hydroxy; The second monomer contains an alkenyl.

[0090] In some embodiments of the present application, the method for preparing the polymer comprises: blending water, an emulsifier, an initiator, a first monomer, and a second monomer and heating to react and obtain an organic polymer emulsion; and mixing the organic polymer emulsion with an inorganic substance to obtain a polymer.

[0091] In some embodiments of the present application, the organic polymer may be prepared by emulsion polymerization employing a first monomer and a second monomer, or may be prepared by emulsion polymerization employing a first monomer, a second monomer, and a third monomer, or may be prepared by emulsion polymerization employing a first monomer, a second monomer, a third monomer, and a fourth monomer.

[0092] In the present invention, an organic polymer emulsion is obtained by emulsion polymerization, and then the organic polymer emulsion is mixed with an inorganic substance and then spray-dried to obtain a polymer.

[0093] Regarding emulsion polymerization, emulsion polymerization is to disperse monomers in water with an emulsifier and mechanical agitation to form an emulsion, and then add an initiator to start the polymerization of the monomers.

[0094] Regarding emulsifiers, they are substances that can convert incompatible oil and water into emulsions that are difficult to separate. Emulsifiers are usually surfactants that combine the properties of both hydrophilic polar groups and hydrophobic (lipophilic) non-polar groups. For example, emulsifiers include at least one of sodium dodecyl sulfonate, sodium dodecyl benzene sulfonate, sodium dodecyl sulfate, sodium dodecyl benzene sulfate, sodium laurate, sodium stearate, or sodium palm fatty acid.

[0095] Regarding initiators, initiators are substances that can initiate a polymerization reaction of monomers. For example, radical initiators refer to compounds that are easily decomposed into radicals (i.e., primary radicals) when exposed to heat, and can be used to initiate the radical polymerization and copolymerization of vinyl monomers and diene monomers. For example, initiators include at least one of potassium persulfate, ammonium persulfate, azobisisobutyronitrile, 2,2'-azobis(2-methylpropionate)dimethyl, benzoyl peroxide, and di-n-octanoyl peroxide.

[0096] Water, an emulsifier, an initiator, and the constituent monomers of the polymer are blended and stirred, and after the water and the emulsifier are stirred and dispersed, an emulsion is formed; that is, the emulsifier forms micelles in the aqueous phase, and the monomers are solubilized in most of the micelles. Under heating conditions, the initiator initiates polymerization of the monomers inside the micelles, thereby obtaining an emulsion.

[0097] Spray drying is a process in which the material to be dried (a mixture of organic polymer emulsion and dispersant) is dispersed into very fine mist particles through mechanical action, which are then contacted with hot air (which increases the surface area for water evaporation and accelerates the drying process), instantly removing most of the water and drying the solid material into a powder.

[0098] The third aspect of the present application proposes a separator comprising the polymer of the first aspect of the present application or the polymer obtained by the method of the second aspect of the present application, whereby when the polymer of the present application is applied to a separator, it is possible to increase the adhesion between the separator and the electrode plate, reduce the resistance of the separator, improve the ionic conductivity of the separator, and improve battery performance.

[0099] In some embodiments of the present application, the separator has an ionic conductivity of 0.3 mS cm -1 ~0.6 mS·cm -1 For example, 0.35 mS cm -1 ~0.55mS·cm -1 , 0.4 mS·cm -1 ~0.5mS·cm -1 , 0.45 mS·cm -1 ~0.5mS·cm -1 Conductivity represents the ability of a separator to conduct current, and is expressed in units of siemens per meter (S / m). If the ionic conductivity of the separator of the present application is within the above range, the separator can fully exhibit its conductive and adhesive properties, and can further improve the dynamic performance of the secondary battery. In some other embodiments of the present application, the ionic conductivity of the separator is 0.35 mS cm -1 ~0.55mS·cm -1 is.

[0100] The ionic conductivity of the polymers described herein was measured by cutting the separator into 40 mm x 20 mm test pieces, stacking four of the cut separators into a group, and thoroughly wetting the separators with a commercially available electrolyte (a 1:1:1 volumetric mixture of ethylene carbonate (EC), ethyl methyl carbonate (EMC), and diethyl carbonate (DEC) at 25°C. LiPF6 was then dissolved in the mixed solvent to obtain an electrolyte solution with a LiPF6 concentration of 1 mol / L). The separators were then assembled into test batteries in a glove box. The separator impedance was measured using an electrochemical workstation, with a measurement range of 1 Hz to 100,000 Hz and an applied AC signal with a 5 mV polarization. The ionic conductivity was calculated from the AC impedance test results using the following formula: δ=1000L / RA (where δ represents ionic conductivity in mS / cm, and A represents the area of ​​the single-layer separator in cm 2 where L represents the thickness of the test separator in cm, and R represents the resistance of the test separator in Ω.

[0101] In some embodiments of the present application, the separator of the present application includes a base film and an adhesive layer, the adhesive layer being formed on at least one side of the base film, and the adhesive layer including the polymer of the first aspect of the present application or the polymer obtained by the method of the second aspect of the present application. For example, adhesive layers are formed on both opposing sides of the base film.

[0102] In the present application, the type of base film is not particularly limited, and any known base film with a porous structure having good chemical stability and mechanical stability can be selected.

[0103] In some embodiments of the present application, the base film may include at least one of glass fiber, nonwoven fabric, polyethylene, polypropylene, and polyvinylidene fluoride. The base film may be a single-layer film or a multi-layer composite film, and is not particularly limited. When the base film is a multi-layer composite film, the materials of each layer may be the same or different, and are not particularly limited.

[0104] The separator described herein can be produced by a conventional method in the art, for example, by dissolving the polymer described in the first aspect of the present application in an organic solvent to obtain a slurry, applying the slurry to a base film, and then drying to remove the organic solvent, thereby obtaining the separator described herein.

[0105] In some embodiments of the present application, the polymer has a coating density of 0.3 g / m on one side of the base film. 2 ~1.0g / m 2 For example, 0.4 g / m 2 ~0.9g / m 2 , 0.5g / m 2 ~0.8g / m 2 , 0.6g / m 2 ~0.7g / m 2 In some embodiments of the present application, the polymer is applied to one side of the base film at a density of 0.3 g / m or less. 2 ~0.8g / m 2 may be.

[0106] The coating density of the polymer on one side of the base film refers to the amount of polymer applied on one side of the base film. The test method is to take a separator with a certain area, obtain the area S of the separator, and measure it in units of m 2The weight M1 of the separator (having an adhesive layer containing a polymer) is weighed, and the unit is g. The mass M2 of a separator having the same area S but without a binder is weighed, and the unit is g. The coating density of the polymer on one side of the base film is calculated by (M1-M2) / S.

[0107] A fourth aspect of the present application provides a plate comprising the polymer of the first aspect of the present application or the polymer obtained by the method of the second aspect of the present application, thereby improving the ionic conductivity and structural stability of the plate and enhancing the dynamic performance and safety performance of the battery.

[0108] It should be noted that the plates described herein can be positive or negative plates.

[0109] The positive electrode plate includes a positive electrode current collector and a positive electrode active material layer provided on at least one surface of the positive electrode current collector, the positive electrode active material layer including a polymer obtained by the method according to the first or second aspect of the present application. Specifically, the polymer can function as a binder in the positive electrode active material layer.

[0110] As an example, the positive electrode current collector has two surfaces facing each other in the thickness direction thereof, and the positive electrode active material layer is provided on either one or both of the two facing surfaces of the positive electrode current collector.

[0111] In some embodiments of the present application, the positive electrode current collector may be a metal foil or a composite current collector. For example, the metal foil may be an aluminum foil. The composite current collector may include a polymeric material base layer and a metal layer formed on at least one surface of the polymeric material base layer. The composite current collector may be formed by forming a metal material (such as aluminum, an aluminum alloy, nickel, a nickel alloy, titanium, a titanium alloy, silver, or a silver alloy) on a polymeric material substrate (such as a substrate of polypropylene (PP), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polystyrene (PS), or polyethylene (PE)).

[0112] In some embodiments of the present application, the positive electrode active material may be any positive electrode active material for batteries known in the art.

[0113] For example, when the positive electrode plate is used in a lithium-ion battery, the positive electrode active material may be any positive electrode active material known in the art. For example, the positive electrode active material may include at least one of materials such as lithium-containing phosphates with an olivine structure, lithium transition metal oxides, and modified compounds thereof. However, the present application is not limited to these materials, and other conventional materials used as positive electrode active materials in batteries may also be used. These positive electrode active materials may be used alone or in combination of two or more. Examples of lithium transition metal oxides include lithium cobalt oxide (e.g., LiCoO), lithium nickel oxide (e.g., LiNiO), lithium manganese oxide (e.g., LiMnO, LiMnO), lithium nickel cobalt oxide, lithium manganese cobalt oxide, lithium nickel manganese oxide, and lithium nickel cobalt manganese oxide (e.g., LiNi). 1 / 3 Co 1 / 3 Mn 1 / 3 O2(NCM 333 (may be abbreviated as "LiNi") 0.5 Co 0.2 Mn 0.3 O2(NCM 523 (may be abbreviated as "LiNi") 0.5 Co 0.25 Mn 0.25 O2(NCM 211 (may be abbreviated as "LiNi") 0.6 Co 0.2 Mn 0.2 O2(NCM 622 (may be abbreviated as "LiNi") 0.8 Co 0.1 Mn 0.1 O2(NCM 811 ), lithium nickel cobalt aluminum oxide (e.g., LiNi 0.80 Co 0.15 Al 0.05O2) or modified compounds thereof, etc. Examples of the lithium-containing phosphate having an olivine structure may include, but are not limited to, at least one of lithium iron phosphate (e.g., LiFePO4 (which may be abbreviated as LFP)), a composite material of lithium iron phosphate and carbon, lithium manganese phosphate (e.g., LiMnPO4), a composite material of lithium manganese phosphate and carbon, lithium manganese iron phosphate, and a composite material of lithium manganese iron phosphate and carbon.

[0114] For example, when the positive electrode plate is used in a sodium ion battery, the positive electrode active material may be any positive electrode active material for sodium ion batteries known in the art, including, but not limited to, at least one of a layered transition metal oxide, a polyanion compound, and a Prussian blue analog.

[0115] Examples of the layered transition metal oxide include: Na 1-x Cu h Fe k Mn l M 1 m O 2-y (M 1 contains at least one of Li, Be, B, Mg, Al, K, Ca, Ti, Co, Ni, Zn, Ga, Sr, Y, Nb, Mo, In, Sn, or Ba, and 0 <x≦0.33、0<h≦0.24、0≦k≦0.32、0<l≦0.68、0≦m<0.1、h+k+l+m=1、0≦y<0.2である)、 Na 0.67 Mn 0.7 Ni z M 2 0.3-z O2 (M 2 contains at least one of Li, Mg, Al, Ca, Ti, Fe, Cu, Zn, or Ba, and 0 <z≦0.1である)、 Na a Li b Ni c Mnd Fe e O2 (0.67 < a ≤ 1, 0 < b < 0.2, 0 < c < 0.3, 0.67 < d + e < 0.8, b + c + d + e = 1) are exemplified.

[0116] Examples of the above polyanion compound include, for example, A 1 f M 3 g (PO4) i O j X 1 3-j (A 1 includes at least one of H, Li, Na, K, or NH4, M 3 includes at least one of Ti, Cr, Mn, Fe, Co, Ni, V, Cu, or Zn, X 1 is at least one of F, Cl, or Br, and 0 < f ≤ 4, 0 < g ≤ 2, 1 ≤ i ≤ 3, 0 ≤ j ≤ 2), Na n M 4 PO4X 2 (M 4 includes at least one of Mn, Fe, Co, Ni, Cu, or Zn, X 2 is at least one of F, Cl, or Br, and 0 < n ≤ 2), Na p M 5 q (SO4)3 (M 5 includes at least one of Mn, Fe, Co, Ni, Cu, or Zn, and 0 < p ≤ 2, 0 < q ≤ 2), Na s Mn t Fe 3-t (PO4)2(P2O7) (0 < s ≤ 4, 0 ≤ t ≤ 3, for example, t is 0, 1, 1.5, 2, or 3) are exemplified.

[0117] Examples of the above Prussian blue analogs include, for example, Au M 6 v [M 7 (CN)6] w ·xH2O (A is at least one of H + , NH4 + , an alkali metal cation or an alkaline earth metal cation, and M 6 and M 7 each independently contains at least one of transition metal cations, where 0 < u ≦ 2, 0 < v ≦ 1, 0 < w ≦ 1, 0 < x < 6. For example, A is H + , Li + , Na + , K + , NH4 + , Rb + , Cs + , Fr + , Be 2+ , Mg 2+ , Ca 2+ , Sr 2+ , Ba 2+ or Ra 2+ and contains at least one of them, and M 6 and M 7 each independently contains at least a cation of Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Sn or W) may be mentioned.

[0118] In some embodiments of the present application, the positive electrode active material layer optionally further contains a conductive agent. As an example, the conductive agent can include at least one of superconducting carbon, acetylene black, carbon black, ketjen black, carbon dots, carbon nanotubes, graphene or carbon nanofibers.

[0119] In some embodiments of the present application, the positive electrode active material layer optionally further includes another binder, for example, at least one of polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), vinylidene fluoride-tetrafluoroethylene-propylene terpolymer, vinylidene fluoride-hexafluoropropylene-tetrafluoroethylene terpolymer, tetrafluoroethylene-hexafluoropropylene copolymer, or fluorine-containing acrylate resin.

[0120] In some embodiments, a positive electrode plate can be manufactured by the following method. The components for manufacturing the positive electrode plate described above, such as the positive electrode active material, conductive agent, polymer, and any other optional components, are dispersed in a solvent (e.g., N-methylpyrrolidone) to form a positive electrode slurry. The positive electrode slurry is applied to a positive electrode current collector, and after processes such as baking and cold pressing, a positive electrode plate can be obtained.

[0121] In some embodiments of the present application, the mass proportion of the polymer in the positive electrode plate is 1% to 3%, for example, 1.2% to 2.8%, 1.5% to 2.5%, 1.8% to 2.2%, 2% to 2.2%, etc., based on the total mass of the positive electrode active material layer, thereby reducing powder shedding from the positive electrode plate and improving the dynamic performance of the battery containing it.

[0122] Similarly, the electrode plate described herein may be a negative electrode plate. The negative electrode plate includes a negative electrode current collector and a negative electrode active material layer provided on at least one surface of the negative electrode current collector, the negative electrode active material layer including the polymer described in the first aspect of the present application or the polymer obtained by the method described in the second aspect of the present application. Specifically, the polymer can function as a binder in the negative electrode active material layer.

[0123] As an example, the negative electrode current collector has two surfaces that face each other in the thickness direction of the negative electrode current collector, and the negative electrode active material layer is provided on either one or both of the two facing surfaces of the negative electrode current collector.

[0124] In some embodiments of the present application, the negative electrode current collector may be a metal foil or a composite current collector. For example, the metal foil may be a copper foil. The composite current collector may include a polymeric material base layer and a metal layer formed on at least one surface of the polymeric material substrate. The composite current collector may be formed by forming a metal material (such as copper, copper alloy, nickel, nickel alloy, titanium, titanium alloy, silver, or silver alloy) on a polymeric material substrate (such as a substrate of polypropylene (PP), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polystyrene (PS), or polyethylene (PE)).

[0125] In some embodiments of the present application, the negative electrode active material may be a negative electrode active material for batteries known in the art. For example, the negative electrode active material may include at least one of artificial graphite, natural graphite, soft carbon, hard carbon, silicon-based materials, tin-based materials, and lithium titanate. The silicon-based material may include at least one of silicon elemental, silicon-oxygen compounds, silicon-carbon composites, silicon-nitrogen composites, and silicon alloys. The tin-based material may include at least one of tin elemental, tin oxide compounds, and tin alloys. However, the present application is not limited to these materials, and other conventional materials used as negative electrode active materials in batteries may also be used. These negative electrode active materials may be used alone or in combination of two or more.

[0126] In some embodiments of the present application, the negative electrode active material layer optionally further includes a conductive agent, which may include one or more of superconducting carbon, acetylene black, carbon black, ketjen black, carbon dots, carbon nanotubes, graphene, and carbon nanofibers.

[0127] In some embodiments of the present application, the negative electrode active material layer optionally further includes another binder, which may be selected from at least one of styrene butadiene rubber (SBR), polyacrylic acid (PAA), sodium polyacrylate (PAAS), polyacrylamide (PAM), polyvinyl alcohol (PVA), sodium alginate (SA), polymethacrylic acid (PMAA), and carboxymethyl chitosan (CMCS).

[0128] In some embodiments of the present application, the negative electrode active material layer optionally further contains other auxiliary agents such as a thickener (e.g., carboxymethylcellulose sodium (CMC-Na)).

[0129] In some embodiments of the present application, a negative electrode plate can be manufactured as follows: Components for manufacturing the negative electrode plate, such as the negative electrode active material, conductive agent, polymer, and other optional components, are dispersed in a solvent (e.g., deionized water) to form a negative electrode slurry, which is then applied to a negative electrode current collector and subjected to processes such as baking and cold pressing to obtain a negative electrode plate.

[0130] In some embodiments of the present application, the mass proportion of the polymer in the negative electrode plate is 1% to 3%, for example, 1.2% to 2.8%, 1.5% to 2.5%, 1.8% to 2.2%, 2% to 2.2%, etc., based on the total mass of the negative electrode active material layer, thereby reducing powder shedding from the negative electrode plate and improving the dynamic performance of the battery containing it.

[0131] A fifth aspect of the present application provides a battery including the separator of the third aspect and / or the electrode plate of the fourth aspect, thereby providing the battery with excellent dynamic and safety performance.

[0132] A typical battery consists of positive and negative electrodes, an electrolyte, and a separator. During the charge and discharge process, active ions are repeatedly inserted and removed between the positive and negative electrodes. The electrolyte serves to conduct ions between the positive and negative electrodes. The separator, located between the positive and negative electrodes, primarily serves to prevent short circuits between the positive and negative electrodes while allowing ions to pass through.

[0133] In the present application, the type of electrolyte is not specifically limited and can be selected according to needs. For example, the electrolyte may be liquid, gel-like, or all solid.

[0134] In some embodiments of the present application, the electrolyte is an electrolytic solution, which includes an electrolyte salt and a solvent.

[0135] In some embodiments of the present application, when the battery is a lithium-ion battery, the electrolyte salt can include at least one of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium perchlorate, lithium hexafluoroarsenate, lithium bis(fluorosulfonyl)imide, lithium bis(trifluoromethanesulfonyl)imide, lithium trifluoromethanesulfonate, lithium difluorophosphate, lithium difluoro(oxalato)borate, lithium bisoxalatoborate, lithium difluorodioxalatophosphate, or lithium tetrafluorooxalatophosphate.

[0136] In some embodiments of the present application, when the battery is a sodium-ion battery, the electrolyte sodium salt can include at least one of sodium hexafluorophosphate, sodium difluoro(oxalato)borate, sodium tetrafluoroborate, sodium bis(oxalato)borate, sodium perchlorate, sodium hexafluoroarsenate, sodium bis(fluorosulfonyl)imide, sodium trifluoromethanesulfonate, or sodium bis(trifluoromethanesulfonyl)imide.

[0137] In some embodiments of the present application, the solvent can include at least one of ethylene carbonate, propylene carbonate, ethyl methyl carbonate, diethyl carbonate, dimethyl carbonate, dipropyl carbonate, methyl propyl carbonate, ethyl propyl carbonate, butylene carbonate, fluoroethylene carbonate, methyl formate, methyl acetate, ethyl acetate, propyl acetate, methyl propionate, ethyl propionate, propyl propionate, methyl butyrate, ethyl butyrate, 1,4-butyrolactone, sulfolane, dimethyl sulfone, methyl ethyl sulfone, or diethyl sulfone.

[0138] In some embodiments of the present application, the electrolyte solution optionally further contains an additive. For example, the additive may include a negative electrode film-forming additive, a positive electrode film-forming additive, or an additive capable of improving a specific performance of the battery, such as an additive for improving the overcharge performance of the battery, or an additive for improving the high-temperature or low-temperature performance of the battery.

[0139] In some embodiments, the battery includes forms of a battery cell, a battery module, and a battery pack.

[0140] In some embodiments, the positive electrode plates, negative electrode plates, and separator can be manufactured into an electrode assembly by a winding process or a stacking process.

[0141] In some embodiments, the battery cell may include an exterior body that can be used to package the electrode assembly and electrolyte.

[0142] In some embodiments, the battery cell exterior may be a hard case, such as a hard plastic case, an aluminum case, or a steel case. The battery cell exterior may be a soft pack, such as a soft bag. The soft pack may be made of plastic, such as polypropylene, polybutylene terephthalate, or polybutylene succinate.

[0143] In the present application, the shape of the battery cell is not particularly limited, and may be cylindrical, rectangular, or any other shape. For example, Fig. 1 shows a battery cell 1 having a rectangular structure as an example.

[0144] In some embodiments, referring to FIG. 2 , the exterior body may include a case 11 and a cover plate 13. The case 11 may include a bottom plate and side plates connected to the bottom plate, which surround the chamber to form a storage chamber. The case 11 may have an opening communicating with the storage chamber, and the cover plate 13 may cover the opening to seal the storage chamber. The positive electrode plate, the negative electrode plate, and the separator may be formed into an electrode assembly 12 by a winding process or a stacking process. The electrode assembly 12 is packaged in the storage chamber. An electrolyte is impregnated into the electrode assembly 12. The number of electrode assemblies 12 included in the battery cell 1 may be one or more, and can be selected by those skilled in the art according to specific actual needs.

[0145] In some embodiments, the battery cells can be assembled into a battery module, and the number of battery cells included in the battery module can be one or more, and the specific number can be selected by those skilled in the art depending on the application and capacity of the battery module.

[0146] Fig. 3 shows an example of a battery module 2. Referring to Fig. 3, in the battery module 2, the plurality of battery cells 1 may be arranged in order along the longitudinal direction of the battery module 2. Of course, they may be arranged in any other manner. Furthermore, the plurality of battery cells 1 may be fixed by fastening members.

[0147] Optionally, the battery module 2 may further include a housing having an accommodating space, and the plurality of battery cells 1 are accommodated in the accommodating space.

[0148] In some embodiments, the battery modules can be further assembled into a battery pack, and the number of battery modules included in the battery pack can be one or more, and the specific number can be selected by those skilled in the art according to the application and capacity of the battery pack.

[0149] 4 and 5 show an example of a battery pack 3. Referring to FIGS. 4 and 5, the battery pack 1 may include a battery box and a plurality of battery modules 2 provided in the battery box. The battery box may include an upper box 31 and a lower box 32, and the upper box 31 may cover the lower box 32 to form an enclosed space for accommodating the battery modules 2. The plurality of battery modules 2 may be arranged in the battery box according to any method.

[0150] The present application also provides an electric device including the battery provided by the present application. The battery cell, battery module, or battery pack may be used as a power source for the electric device or as an energy storage unit for the electric device. The electric device may include, but is not limited to, mobile devices (e.g., mobile phones, laptops, etc.), electric vehicles (e.g., rechargeable battery electric vehicles, hybrid electric vehicles, plug-in hybrid electric vehicles, electric bicycles, electric scooters, electric golf carts, electric trucks, etc.), electric cars, ships and satellites, energy storage systems, etc.

[0151] The electrical device can be selected as a battery cell, a battery module or a battery pack according to the needs of its use.

[0152] 6 shows an example of an electric device, such as a secondary battery electric vehicle, a hybrid electric vehicle, or a plug-in hybrid electric vehicle. A battery pack or a battery module can be adopted to meet the high power and high energy density requirements of the secondary battery of the electric device.

[0153] Another example of the device may be a mobile phone, a tablet, a laptop, etc. Such devices typically require light weight and thinness and may employ a battery cell as a power source.

[0154] Examples of the present application are described below. The examples described below are illustrative and are intended merely to interpret the present application and should not be understood as limiting the present application. If specific techniques or conditions are not specified in the examples, they are carried out according to the techniques or conditions described in the literature in the field or according to the product specifications. If the manufacturers of the reagents or equipment used are not specified, they are all commercially available ordinary products. [Example]

[0155] Example 1 Preparation of organic polymer 1 The required monomers were mixed uniformly by weight: 25 wt% methyl methacrylate, 55 wt% n-butyl acrylate, 2 wt% acrylic acid, 3 wt% hydroxyethyl acrylate, 5 wt% trimethylolpropane triacrylate, and 10 wt% styrene. A 5000 mL four-neck flask equipped with a mechanical stirrer, thermometer, and condenser was charged with 1000 g of the mixed monomers, 30 g of emulsifier (sodium dodecyl sulfate), 10 g of initiator (ammonium persulfate), and 1200 g of deionized water. The mixture was emulsified with high-speed stirring for 30 min. Under nitrogen protection, the mixture was heated to 75 °C and reacted for 4 h. After that, the pH was adjusted to 6-8, the temperature was lowered to below 40 °C, and the mixture was discharged to obtain Organic Polymer 1.

[0156] Preparation of polymer 1 1 kg of organic polymer 1 was taken, 1 kg of nanosilica and 2 kg of deionized water were added, and after stirring for 1 hour, the mixture was spray-dried to obtain polymer powder, which was then polished and pulverized to obtain polymer 1.

[0157] Preparation of Separator 1 The polymer 1 was dispersed in water to obtain a slurry, which was then applied to a base film (PE base film) and then dried to remove the water, thereby obtaining a separator 1.

[0158] Example 2 Preparation of organic polymer 2 The required monomers were mixed uniformly by weight: 25 wt% methyl methacrylate, 50 wt% n-butyl acrylate, 2 wt% acrylic acid, 3 wt% hydroxyethyl acrylate, 5 wt% trimethylolpropane triacrylate, and 15 wt% styrene. A 5000 mL four-neck flask equipped with a mechanical stirrer, thermometer, and condenser was charged with 1000 g of the mixed monomers, 30 g of emulsifier (sodium dodecyl sulfate), 10 g of initiator (ammonium persulfate), and 1200 g of deionized water. The mixture was emulsified with high-speed stirring for 30 min. Under nitrogen protection, the mixture was heated to 75 °C and reacted for 4 h. After that, the pH was adjusted to 6-8, the temperature was lowered to below 40 °C, and the mixture was discharged to obtain Organic Polymer 2.

[0159] Preparation of polymer 2 1 kg of organic polymer 2, 1 kg of nanosilica, and 2 kg of deionized water were mixed and stirred for 1 hour, then spray-dried to obtain polymer powder, which was then polished and pulverized to obtain polymer 2.

[0160] Preparation of Separator 2 The polymer 2 was dispersed in water to obtain a slurry, which was then applied to a base film (PE base film) and then dried to remove the water, thereby obtaining a separator 2.

[0161] Example 3 Preparation of organic polymer 3 The required monomers were mixed uniformly by weight: 25 wt% methyl methacrylate, 48 wt% n-butyl acrylate, 2 wt% acrylic acid, 3 wt% hydroxyethyl acrylate, 5 wt% trimethylolpropane triacrylate, and 17 wt% styrene. A 5000 mL four-neck flask equipped with a mechanical stirrer, thermometer, and condenser was charged with 1000 g of the mixed monomers, 30 g of emulsifier (sodium dodecyl sulfate), 10 g of initiator (ammonium persulfate), and 1200 g of deionized water. The mixture was emulsified with high-speed stirring for 30 min. Under nitrogen protection, the mixture was heated to 75 °C and reacted for 4 h. After that, the pH was adjusted to 6-8, the temperature was lowered to below 40 °C, and the mixture was discharged to obtain organic polymer 3.

[0162] Preparation of polymer 3 1 kg of organic polymer 3, 1 kg of nanosilica, and 2 kg of deionized water were mixed and stirred for 1 hour, then spray-dried to obtain polymer powder, which was then polished and pulverized to obtain polymer 3.

[0163] Preparation of Separator 3 The polymer 3 was dispersed in water to obtain a slurry, which was then applied to a base film (PE base film) and then dried to remove the water, thereby obtaining a separator 3.

[0164] Example 4 Preparation of organic polymer 4 The required monomers were mixed uniformly by weight: 14.5 wt% methyl methacrylate, 42 wt% n-butyl acrylate, 2 wt% acrylic acid, 3 wt% hydroxyethyl acrylate, 5 wt% trimethylolpropane triacrylate, and 33.5 wt% styrene. A 5000 mL four-neck flask equipped with a mechanical stirrer, thermometer, and condenser was charged with 1000 g of the mixed monomers, 30 g of emulsifier (sodium dodecyl sulfate), 10 g of initiator (ammonium persulfate), and 1200 g of deionized water. The mixture was emulsified with high-speed stirring for 30 min. Under nitrogen protection, the mixture was heated to 75 °C and reacted for 4 h. After that, the pH was adjusted to 6-8, the temperature was lowered to below 40 °C, and the mixture was discharged to obtain Organic Polymer 4.

[0165] Preparation of polymer 4 1 kg of organic polymer 4 was taken, 1 kg of nanosilica and 2 kg of deionized water were added, and after stirring for 1 hour, the mixture was spray-dried to obtain polymer powder, which was then polished and pulverized to obtain polymer 4.

[0166] Preparation of Separator 4 The polymer 4 was dispersed in water to obtain a slurry, which was then applied to a base film (PE base film) and then dried to remove the water, thereby obtaining a separator 4.

[0167] Example 5 Preparation of organic polymer 5 The required monomers were mixed uniformly by weight percentage: 28.5 wt% methyl methacrylate, 56.5 wt% n-butyl acrylate, 2 wt% acrylic acid, 3 wt% hydroxyethyl acrylate, 5 wt% trimethylolpropane triacrylate, 4 wt% styrene, and 1 wt% acrylonitrile. A 5000 mL four-neck flask equipped with a mechanical stirrer, thermometer, and condenser was charged with 1000 g of the mixed monomers, 30 g of emulsifier (sodium dodecyl sulfate), 10 g of initiator (ammonium persulfate), and 1200 g of deionized water. The mixture was emulsified with high-speed stirring for 30 min. Under nitrogen protection, the mixture was heated to 75 °C and reacted for 4 h. After that, the pH was adjusted to 6-8, the temperature was lowered to below 40 °C, and the mixture was discharged to obtain Organic Polymer 5.

[0168] Preparation of polymer 5 1 kg of organic polymer 5 was taken, 667 g of nanosilica and 2 kg of deionized water were added, and after stirring for 1 hour, the mixture was spray-dried to obtain polymer powder, which was then polished and pulverized to obtain polymer 5.

[0169] Preparation of Separator 5 The polymer 5 was dispersed in water to obtain a slurry, which was then applied to a base film (PE base film) and then dried to remove the water, thereby obtaining a separator 5.

[0170] Example 6 Preparation of organic polymer 6 The required monomers were mixed uniformly by weight: 30 wt% methyl methacrylate, 50 wt% n-butyl acrylate, 2 wt% acrylic acid, 3 wt% hydroxyethyl acrylate, 5 wt% trimethylolpropane triacrylate, 5 wt% styrene, and 5 wt% acrylonitrile. A 5000 mL four-neck flask equipped with a mechanical stirrer, thermometer, and condenser was charged with 1000 g of the mixed monomers, 30 g of emulsifier (sodium dodecyl sulfate), 10 g of initiator (ammonium persulfate), and 1200 g of deionized water. The mixture was emulsified with high-speed stirring for 30 min. Under nitrogen protection, the mixture was heated to 75 °C and reacted for 4 h. After that, the pH was adjusted to 6-8, the temperature was lowered to below 40 °C, and the mixture was discharged to obtain organic polymer 6.

[0171] Preparation of polymer 6 1 kg of organic polymer 6 was taken, 429 g of nanosilica and 2 kg of deionized water were added, and after stirring for 1 hour, the mixture was spray-dried to obtain polymer powder, which was then polished and pulverized to obtain polymer 6.

[0172] Preparation of Separator 6 The polymer 6 was dispersed in water to obtain a slurry, which was then applied to a base film (PE base film) and then dried to remove the water, thereby obtaining a separator 6.

[0173] Example 7 Preparation of organic polymer 7 The required monomers were mixed uniformly by weight: 15 wt% methyl methacrylate, 45 wt% n-butyl acrylate, 2 wt% acrylic acid, 3 wt% hydroxyethyl acrylate, 5 wt% trimethylolpropane triacrylate, 10 wt% styrene, and 20 wt% acrylonitrile. A 5000 mL four-neck flask equipped with a mechanical stirrer, thermometer, and condenser was charged with 1000 g of the mixed monomers, 30 g of emulsifier (sodium dodecyl sulfate), 10 g of initiator (ammonium persulfate), and 1200 g of deionized water. The mixture was emulsified with high-speed stirring for 30 min. Under nitrogen protection, the mixture was heated to 75 °C and reacted for 4 h. After that, the pH was adjusted to 6-8, the temperature was lowered to below 40 °C, and the mixture was discharged to obtain organic polymer 7.

[0174] Preparation of polymer 7 1 kg of organic polymer 7 was taken, 250 g of nanosilica and 1 kg of deionized water were added, and after stirring for 1 hour, the mixture was spray-dried to obtain polymer powder, which was then polished and pulverized to obtain polymer 7.

[0175] Preparation of Separator 7 The polymer 7 was dispersed in water to obtain a slurry, which was then applied to a base film (PE base film) and then dried to remove the water, thereby obtaining a separator 7.

[0176] Example 8 Preparation of organic polymer 8 The required monomers were mixed uniformly by weight: 6 wt% methyl methacrylate, 42 wt% n-butyl acrylate, 2 wt% acrylic acid, 3 wt% hydroxyethyl acrylate, 5 wt% trimethylolpropane triacrylate, 7 wt% styrene, and 35 wt% acrylonitrile. A 5000 mL four-neck flask equipped with a mechanical stirrer, thermometer, and condenser was charged with 1000 g of the mixed monomers, 30 g of emulsifier (sodium dodecyl sulfate), 10 g of initiator (ammonium persulfate), and 1200 g of deionized water. The mixture was emulsified with high-speed stirring for 30 min. Under nitrogen protection, the mixture was heated to 75 °C and reacted for 4 h. After that, the pH was adjusted to 6-8, the temperature was lowered to below 40 °C, and the mixture was discharged to obtain organic polymer 8.

[0177] Preparation of polymer 8 1 kg of organic polymer 8 was taken, and 111 g of nanosilica and 1 kg of deionized water were added. After stirring for 1 hour, the mixture was spray-dried to obtain polymer powder, which was then polished and pulverized to obtain polymer 8.

[0178] Preparation of Separator 8 The polymer 8 was dispersed in water to obtain a slurry, which was then applied to a base film (PE base film) and then dried to remove the water, thereby obtaining a separator 8.

[0179] Example 9 Preparation of organic polymer 9 The required monomers were mixed uniformly by weight: 40 wt% n-butyl acrylate, 2 wt% acrylic acid, 3 wt% hydroxyethyl acrylate, 5 wt% trimethylolpropane triacrylate, 10 wt% styrene, and 40 wt% acrylonitrile. A 5000 mL four-neck flask equipped with a mechanical stirrer, thermometer, and condenser was charged with 1000 g of the mixed monomers, 30 g of emulsifier sodium dodecyl sulfate, 10 g of initiator ammonium persulfate, and 1200 g of deionized water. The mixture was emulsified with high-speed stirring for 30 min. Under nitrogen protection, the mixture was heated to 75 °C and reacted for 4 h. After that, the pH was adjusted to 6-8, the temperature was lowered to below 40 °C, and the mixture was discharged to obtain organic polymer 9.

[0180] Preparation of polymer 9 1 kg of organic polymer 9 was taken, 53 g of nanosilica and 1 kg of deionized water were added, and after stirring for 1 hour, the mixture was spray-dried to obtain polymer powder, which was then polished and pulverized to obtain polymer 9.

[0181] Preparation of Separator 9 The polymer 9 was dispersed in water to obtain a slurry, which was then applied to a base film (PE base film) and then dried to remove the water, thereby obtaining a separator 9.

[0182] Example 10 Preparation of organic polymer 10 The required monomers were mixed uniformly by weight: 5 wt% methyl methacrylate, 65 wt% n-butyl acrylate, 2 wt% acrylic acid, 3 wt% hydroxyethyl acrylate, 5 wt% trimethylolpropane triacrylate, 10 wt% styrene, 6 wt% acrylonitrile, and 4 wt% acrylamide. A 5000 mL four-neck flask equipped with a mechanical stirrer, thermometer, and condenser was charged with 1000 g of the mixed monomers, 30 g of emulsifier (sodium dodecyl sulfate), 10 g of initiator (ammonium persulfate), and 1200 g of deionized water. The mixture was emulsified with high-speed stirring for 30 min. Under nitrogen protection, the mixture was heated to 75 °C and reacted for 4 h. After that, the pH was adjusted to 6-8, the temperature was lowered to below 40 °C, and the mixture was discharged to obtain organic polymer 10.

[0183] Preparation of polymer 10 1 kg of organic polymer 10 was taken, 10 g of nanosilica and 1 kg of deionized water were added, and the mixture was stirred for 1 hour. After that, the mixture was spray-dried to obtain polymer powder, which was then polished and pulverized to obtain polymer 10.

[0184] Preparation of separator 10 The polymer 10 was dispersed in water to obtain a slurry, which was then applied to a base film (PE base film) and then dried to remove the water, thereby obtaining a separator 10.

[0185] Example 11 Preparation of organic polymer 11 The necessary monomers were mixed uniformly by weight: 58 wt% n-butyl acrylate, 2 wt% acrylic acid, 3 wt% hydroxyethyl acrylate, 5 wt% trimethylolpropane triacrylate, 10 wt% styrene, 15 wt% acrylonitrile, and 7 wt% acrylamide. A 5000 mL four-neck flask equipped with a mechanical stirrer, thermometer, and condenser was charged with 1000 g of the mixed monomers, 30 g of emulsifier (sodium dodecyl sulfate), 10 g of initiator (ammonium persulfate), and 1200 g of deionized water. The mixture was emulsified by high-speed stirring for 30 min. Under nitrogen protection, the mixture was heated to 75 °C and reacted for 4 h. After that, the pH was adjusted to 6-8, the temperature was lowered to below 40 °C, and the mixture was discharged to obtain organic polymer 11.

[0186] Preparation of polymer 11 1 kg of organic polymer 11 was taken, 53 g of nanosilica and 1 kg of deionized water were added, and the mixture was stirred for 1 hour. After that, the mixture was spray-dried to obtain a polymer powder, which was then polished and pulverized to obtain polymer 11.

[0187] Preparation of separator 11 The polymer 11 was dispersed in water to obtain a slurry, which was then applied to a base film (PE base film) and then dried to remove the water, thereby obtaining a separator 11.

[0188] Example 12 Preparation of organic polymer 12 The required monomers were mixed uniformly by weight: 58 wt% n-butyl acrylate, 2 wt% acrylic acid, 3 wt% hydroxyethyl acrylate, 5 wt% trimethylolpropane triacrylate, 10 wt% styrene, 15 wt% acrylonitrile, and 7 wt% acrylamide. A 5000 mL four-neck flask equipped with a mechanical stirrer, thermometer, and condenser was charged with 1000 g of the mixed monomers, 30 g of emulsifier (sodium dodecyl sulfate), 10 g of initiator (ammonium persulfate), and 1200 g of deionized water. The mixture was emulsified with high-speed stirring for 30 min. Under nitrogen protection, the mixture was heated to 75 °C and reacted for 4 h. After that, the pH was adjusted to 6-8, the temperature was lowered to below 40 °C, and the mixture was discharged to obtain organic polymer 12.

[0189] Preparation of polymer 12 1 kg of organic polymer 12 was taken, 53 g of nanosilica and 1 kg of deionized water were added, and after stirring for 1 hour, the mixture was spray-dried to obtain polymer powder, which was then polished and pulverized to obtain polymer 12.

[0190] Preparation of separator 12 The polymer 12 was dispersed in water to obtain a slurry, which was then applied to a base film (PE base film) and then dried to remove the water, thereby obtaining a separator 12.

[0191] Example 13 Preparation of organic polymer 13 The required monomers were mixed uniformly by weight: 58 wt% n-butyl acrylate, 2 wt% acrylic acid, 3 wt% hydroxyethyl acrylate, 5 wt% trimethylolpropane triacrylate, 10 wt% styrene, 15 wt% acrylonitrile, 7 wt% acrylamide, 8 wt% styrene, 32 wt% acrylonitrile, and 20 wt% acrylamide. A 5000 mL four-neck flask equipped with a mechanical stirrer, thermometer, and condenser was charged with 1000 g of the mixed monomers, 30 g of emulsifier (sodium dodecyl sulfate), 10 g of initiator (ammonium persulfate), and 1200 g of deionized water. The mixture was emulsified by high-speed stirring for 30 min. Under nitrogen protection, the mixture was heated to 75 °C and reacted for 4 h. After that, the pH was adjusted to 6-8, the temperature was lowered to below 40 °C, and the mixture was discharged to obtain organic polymer 13.

[0192] Preparation of polymer 13 1 kg of organic polymer 13 was taken, 53 g of nanosilica and 1 kg of deionized water were added, and after stirring for 1 hour, the mixture was spray-dried to obtain polymer powder, which was then polished and pulverized to obtain polymer 13.

[0193] Preparation of Separator 13 The polymer 13 was dispersed in water to obtain a slurry, which was then applied to a base film (PE base film) and then dried to remove the water, thereby obtaining a separator 13.

[0194] Example 14 Preparation of organic polymer 14 The required monomers were mixed uniformly by weight: 40 wt% n-butyl acrylate, 2 wt% acrylic acid, 3 wt% hydroxyethyl acrylate, 5 wt% trimethylolpropane triacrylate, 10 wt% styrene, 10 wt% acrylonitrile, and 30 wt% acrylamide. A 5000 mL four-neck flask equipped with a mechanical stirrer, thermometer, and condenser was charged with 1000 g of the mixed monomers, 30 g of emulsifier (sodium dodecyl sulfate), 10 g of initiator (ammonium persulfate), and 1200 g of deionized water. The mixture was emulsified with high-speed stirring for 30 min. Under nitrogen protection, the mixture was heated to 75 °C and reacted for 4 h. After that, the pH was adjusted to 6-8, the temperature was lowered to below 40 °C, and the mixture was discharged to obtain organic polymer 14.

[0195] Preparation of polymer 14 1 kg of organic polymer 14 was taken, 53 g of nanosilica and 1 kg of deionized water were added, and after stirring for 1 hour, the mixture was spray-dried to obtain polymer powder, which was then polished and pulverized to obtain polymer 14.

[0196] Preparation of Separator 14 The polymer 14 was dispersed in water to obtain a slurry, which was then applied to a base film (PE base film) and then dried to remove the water, thereby obtaining a separator 14.

[0197] Example 15 Preparation of organic polymer 15 The required monomers were mixed uniformly by weight: 65 wt% butyl acrylate, 5 wt% trimethylolpropane triacrylate, 2 wt% acrylic acid, 3 wt% 2-hydroxyethyl acrylate, 5 wt% styrene, 15 wt% acrylonitrile, and 5 wt% acrylamide. A 5000 mL four-neck flask equipped with a mechanical stirrer, thermometer, and condenser was charged with 1000 g of the mixed monomers, 30 g of emulsifier (sodium dodecyl sulfate), 10 g of initiator (ammonium persulfate), and 1200 g of deionized water. The mixture was emulsified with high-speed stirring for 30 min. Under nitrogen protection, the mixture was heated to 75 °C and reacted for 4 h. After that, the pH was adjusted to 6-8, the temperature was lowered to below 40 °C, and the mixture was discharged to obtain organic polymer 15.

[0198] Preparation of polymer 15 1 kg of organic polymer 15 was taken, 429 g of aluminum oxide and 1 kg of deionized water were added, and the mixture was stirred for 1 hour. After that, the mixture was spray-dried to obtain a polymer powder, which was then polished and pulverized to obtain polymer 15.

[0199] Preparation of Separator 15 The polymer 15 was dispersed in water to obtain a slurry, which was then applied to a base film (PE base film) and then dried to remove the water, thereby obtaining a separator 15.

[0200] Example 16 Preparation of organic polymer 16 The required monomers were mixed uniformly by weight: 55 wt% lauryl methacrylate, 2 wt% acrylic acid, 3 wt% hydroxyethyl acrylate, 5 wt% trimethylolpropane triacrylate, 5 wt% styrene, 20 wt% acrylonitrile, and 10 wt% acrylamide. A 5000 mL four-neck flask equipped with a mechanical stirrer, thermometer, and condenser was charged with 1000 g of the mixed monomers, 30 g of emulsifier (sodium dodecyl sulfate), 10 g of initiator (ammonium persulfate), and 1200 g of deionized water. The mixture was emulsified with high-speed stirring for 30 min. Under nitrogen protection, the mixture was heated to 75 °C and reacted for 4 h. After that, the pH was adjusted to 6-8, the temperature was lowered to below 40 °C, and the mixture was discharged to obtain organic polymer 16.

[0201] Preparation of polymer 16 1 kg of organic polymer 16 was taken, 250 g of aluminum oxide and 1 kg of deionized water were added, and after stirring for 1 hour, the mixture was spray-dried to obtain polymer powder, which was then polished and pulverized to obtain polymer 16.

[0202] Preparation of Separator 16 The polymer 16 was dispersed in water to obtain a slurry, which was then applied to a base film (PE base film) and then dried to remove the water, thereby obtaining a separator 16.

[0203] Example 17 Preparation of organic polymer 17 The required monomers were mixed uniformly by weight: 30 wt% methyl methacrylate, 40 wt% lauryl methacrylate, 3 wt% acrylic acid, 2 wt% hydroxyethyl acrylate, 5 wt% trimethylolpropane triacrylate, 10 wt% styrene, 5 wt% acrylonitrile, and 5 wt% acrylamide. A 5000 mL four-neck flask equipped with a mechanical stirrer, thermometer, and condenser was charged with 1000 g of the mixed monomers, 30 g of emulsifier (sodium dodecyl sulfate), 10 g of initiator (ammonium persulfate), and 1200 g of deionized water. The mixture was emulsified with high-speed stirring for 30 min. Under nitrogen protection, the mixture was heated to 75 °C and reacted for 4 h. After that, the pH was adjusted to 6-8, the temperature was lowered to below 40 °C, and the mixture was discharged to obtain organic polymer 17.

[0204] Preparation of polymer 17 1 kg of organic polymer 17 was taken, 53 g of nanosilica and 1 kg of deionized water were added, and after stirring for 1 hour, the mixture was spray-dried to obtain polymer powder, which was then polished and pulverized to obtain polymer 17.

[0205] Preparation of Separator 17 The polymer 17 was dispersed in water to obtain a slurry, which was then applied to a base film (PE base film) and then dried to remove the water, thereby obtaining a separator 17.

[0206] Example 18 Preparation of organic polymer 18 The required monomers were mixed uniformly by weight: 20 wt% methyl methacrylate, 50 wt% n-butyl acrylate, 2 wt% acrylic acid, 3% hydroxyethyl acrylate, 5 wt% trimethylolpropane triacrylate, 15 wt% styrene, and 5 wt% acrylonitrile. A 5000 mL four-neck flask equipped with a mechanical stirrer, thermometer, and condenser was charged with 1000 g of the mixed monomers, 30 g of emulsifier (sodium dodecyl sulfate), 10 g of initiator (ammonium persulfate), and 1200 g of deionized water. The mixture was emulsified with high-speed stirring for 30 min. Under nitrogen protection, the mixture was heated to 75 °C and reacted for 4 h. After that, the pH was adjusted to 6-8, the temperature was lowered to below 40 °C, and the mixture was discharged to obtain organic polymer 18.

[0207] Preparation of polymer 18 1 kg of organic polymer 18 was taken, 53 g of nanosilica and 1 kg of deionized water were added, and after stirring for 1 hour, the mixture was spray-dried to obtain polymer powder, which was then polished and pulverized to obtain polymer 18.

[0208] Preparation of Separator 18 The polymer 18 was dispersed in water to obtain a slurry, which was then applied to a base film (PE base film) and then dried to remove the water, thereby obtaining a separator 18.

[0209] Example 19 Preparation of organic polymer 19 10 g of sodium dodecyl sulfate, 1200 g of deionized water, 10 g of cumene hydroperoxide, 15 g of Rongalite, 0.05 g of ferrous sulfate, and 2 g of EDTA disodium salt (ethylenediaminetetraacetic acid disodium salt) were added, and a monomer mixture of 20 wt% methyl methacrylate, 40 wt% n-butyl acrylate, 2 wt% acrylic acid, 3% hydroxyethyl acrylate, 5 wt% trimethylolpropane triacrylate, 10 wt% styrene, and 10 wt% acrylonitrile was added according to weight percentage. The mixture was placed in a high-pressure reactor and purged with nitrogen three times. 10 wt% butadiene was then added and emulsified at 25°C for 30 min with high-speed stirring. The mixture was then heated to 65°C and reacted at 0.2 MPa for 6 h. The pH was adjusted to 6-8, cooled to below 40°C, and discharged to obtain organic polymer 19.

[0210] Preparation of polymer 19 1 kg of organic polymer 19 was taken, 53 g of nanosilica and 1 kg of deionized water were added, and after stirring for 1 hour, the mixture was spray-dried to obtain polymer powder, which was then polished and pulverized to obtain polymer 19.

[0211] Preparation of Separator 19 The polymer 19 was dispersed in water to obtain a slurry, which was then applied to a base film (PE base film) and then dried to remove the water, thereby obtaining a separator 19.

[0212] Example 20 Preparation of organic polymer 20 The required monomers were mixed uniformly by weight: 26.7 wt% butyl acrylate, 2 wt% acrylic acid, 2 wt% 2-hydroxyethyl acrylate, 5 wt% trimethylolpropane triacrylate, 17.85 wt% styrene, 28.6 wt% acrylonitrile, and 17.85 wt% acrylamide. A 5000 mL four-neck flask equipped with a mechanical stirrer, thermometer, and condenser was charged with 1000 g of the mixed monomers, 30 g of emulsifier (sodium dodecyl sulfate), 10 g of initiator (ammonium persulfate), and 1200 g of deionized water. The mixture was emulsified with high-speed stirring for 30 min. Under nitrogen protection, the mixture was heated to 75 °C and reacted for 4 h. After that, the pH was adjusted to 6-8, the temperature was lowered to below 40 °C, and the mixture was discharged to obtain organic polymer 20.

[0213] Preparation of polymer 20 1 kg of organic polymer 20 was taken, 250 g of aluminum oxide and 1 kg of deionized water were added, and after stirring for 1 hour, the mixture was spray-dried to obtain polymer powder, which was then polished and pulverized to obtain polymer 20.

[0214] Preparation of separator 20 The polymer 20 was dispersed in water to obtain a slurry, which was then applied to a base film (PE base film) and then dried to remove the water, thereby obtaining a separator 20.

[0215] Example 21 Preparation of organic polymer 21 The required monomers were mixed uniformly by weight: 38.6 wt% butyl acrylate, 2 wt% acrylic acid, 2 wt% 2-hydroxyethyl acrylate, 5 wt% trimethylolpropane triacrylate, 9.5 wt% styrene, 28.6 wt% acrylonitrile, and 14.35 wt% acrylamide. A 5000 mL four-neck flask equipped with a mechanical stirrer, thermometer, and condenser was charged with 1000 g of the mixed monomers, 30 g of emulsifier (sodium dodecyl sulfate), 10 g of initiator (ammonium persulfate), and 1200 g of deionized water. The mixture was emulsified with high-speed stirring for 30 min. Under nitrogen protection, the mixture was heated to 75 °C and reacted for 4 h. After that, the pH was adjusted to 6-8, the temperature was lowered to below 40 °C, and the mixture was discharged to obtain organic polymer 21.

[0216] Preparation of polymer 21 1 kg of organic polymer 21 was taken, 250 g of aluminum oxide and 1 kg of deionized water were added, and the mixture was stirred for 1 hour. After that, the mixture was spray-dried to obtain a polymer powder, which was then polished and pulverized to obtain polymer 21.

[0217] Preparation of separator 21 The polymer 21 was dispersed in water to obtain a slurry, which was then applied to a base film (PE base film) and then dried to remove the water, thereby obtaining a separator 21.

[0218] Comparative Example 1 Preparation of organic polymer 22 The required monomers were mixed uniformly by weight: 77 wt% methyl methacrylate, 16 wt% butyl acrylate, 2 wt% acrylic acid, and 5 wt% trimethylolpropane triacrylate. A 5000 mL four-neck flask equipped with a mechanical stirrer, thermometer, and condenser was charged with 1000 g of the mixed monomers, 30 g of emulsifier (sodium dodecyl sulfate), 10 g of initiator (ammonium persulfate), and 1200 g of deionized water. The mixture was emulsified with high-speed stirring for 30 min. Under nitrogen protection, the mixture was heated to 75 °C and reacted for 4 h. After that, the pH was adjusted to 6-8, the temperature was lowered to below 40 °C, and the mixture was discharged to obtain organic polymer 22.

[0219] Preparation of polymer 22 1 kg of organic polymer 22 was taken, 1 kg of nanosilica and 2 kg of deionized water were added, and after stirring for 1 hour, the mixture was spray-dried to obtain polymer powder, which was then polished and pulverized to obtain polymer 22.

[0220] Preparation of separator 22 The polymer 22 was dispersed in water to obtain a slurry, which was then applied to a base film (PE base film) and then dried to remove the water, thereby obtaining a separator 22.

[0221] Comparative Example 2 Preparation of organic polymer 23 The required monomers were mixed uniformly by weight: 50 wt% methyl methacrylate, 43 wt% butyl acrylate, 2 wt% acrylic acid, and 5 wt% trimethylolpropane triacrylate. A 5000 mL four-neck flask equipped with a mechanical stirrer, thermometer, and condenser was charged with 1000 g of the mixed monomers, 30 g of emulsifier (sodium dodecyl sulfate), 10 g of initiator (ammonium persulfate), and 1200 g of deionized water. The mixture was emulsified with high-speed stirring for 30 min. Under nitrogen protection, the mixture was heated to 75 °C and reacted for 4 h. After that, the pH was adjusted to 6-8, the temperature was lowered to below 40 °C, and the mixture was discharged to obtain organic polymer 23.

[0222] Preparation of polymer 23 1 kg of organic polymer 23 was taken, 1 kg of nanosilica and 2 kg of deionized water were added, and after stirring for 1 hour, the mixture was spray-dried to obtain polymer powder, which was then polished and pulverized to obtain polymer 23.

[0223] Preparation of Separator 23 The polymer 23 was dispersed in water to obtain a slurry, which was then applied to a base film (PE base film) and then dried to remove the water, thereby obtaining a separator 23.

[0224] Comparative Example 3 Preparation of organic polymer 24 The required monomers were mixed uniformly by weight: 18 wt% methyl methacrylate, 75 wt% butyl acrylate, 2 wt% acrylic acid, and 5 wt% trimethylolpropane triacrylate. A 5000 mL four-neck flask equipped with a mechanical stirrer, thermometer, and condenser was charged with 1000 g of the mixed monomers, 30 g of emulsifier (sodium dodecyl sulfate), 10 g of initiator (ammonium persulfate), and 1200 g of deionized water. The mixture was emulsified with high-speed stirring for 30 min. Under nitrogen protection, the mixture was heated to 75 °C and reacted for 4 h. After that, the pH was adjusted to 6-8, the temperature was lowered to below 40 °C, and the mixture was discharged to obtain organic polymer 24.

[0225] Preparation of polymer 24 1 kg of organic polymer 24 was taken, 1 kg of nanosilica and 2 kg of deionized water were added, and after stirring for 1 hour, the mixture was spray-dried to obtain polymer powder, which was then polished and pulverized to obtain polymer 24.

[0226] Preparation of separator 24 The polymer 24 was dispersed in water to obtain a slurry, which was then applied to a base film (PE base film) and then dried to remove the water, thereby obtaining a separator 24.

[0227] Comparative Example 4 Preparation of organic polymer 25 The required monomers were mixed uniformly by weight: 15 wt% methyl methacrylate, 78 wt% butyl acrylate, 2 wt% acrylic acid, and 5 wt% trimethylolpropane triacrylate. A 5000 mL four-neck flask equipped with a mechanical stirrer, thermometer, and condenser was charged with 1000 g of the mixed monomers, 30 g of emulsifier (sodium dodecyl sulfate), 10 g of initiator (ammonium persulfate), and 1200 g of deionized water. The mixture was emulsified with high-speed stirring for 30 minutes. Under nitrogen protection, the mixture was heated to 75°C and reacted for 4 hours. After that, the pH was adjusted to 6-8, the temperature was lowered to below 40°C, and the mixture was discharged to obtain organic polymer 25.

[0228] Preparation of polymer 25 1 kg of organic polymer 25 was taken, 1 kg of nanosilica and 2 kg of deionized water were added, and after stirring for 1 hour, the mixture was spray-dried to obtain polymer powder, which was then polished and pulverized to obtain polymer 25.

[0229] Preparation of Separator 25 The polymer 25 was dispersed in water to obtain a slurry, which was then applied to a base film (PE base film) and then dried to remove the water, thereby obtaining a separator 25.

[0230] Another difference in the preparation of the organic polymers, polymers and separators of Examples 1-21 and Comparative Examples 1-4 is that the parameters in Table 1 are followed.

[0231] [Table 1]

[0232] The separators of Examples 1 to 21 and Comparative Examples 1 to 4 were subjected to the following tests. 1. Ionic conductivity test: The separator was cut into 40mm x 20mm test pieces, and four layers of the cut separators were stacked together to form a group. The separators were then thoroughly wetted with commercially available electrolyte and assembled into a control battery for testing in a glove box. The separator impedance was tested using an electrochemical workstation, with a measurement range of 1Hz to 100,000Hz and an applied AC signal with a polarization of 5mV. The ionic conductivity was calculated from the AC impedance test results using the following formula: δ=1000L / RA where δ represents ionic conductivity in mS / cm, and A represents the area of ​​the separator under test in cm. 2 where L represents the thickness of the test separator in cm, R represents the resistance of the test separator in Ω, and the results are shown in Table 2.

[0233] 2. Particle size test: Refer to the GB / T 19077-2016 / ISO 13320:2009 laser diffraction particle size distribution standard. The test was performed using a laser particle size analyzer (Malvern 3000, MasterSizer 3000) with a helium-neon red light source as the primary light source. Add 1 g of test sample to a clean small beaker, add one drop of surfactant (Dow Chemical TERGITOL TMN-6), and add 20 ml of deionized water (ensuring a light-blocking level of 8%-12% relative to the sample concentration). Sonicate at 53 kHz / 120 W for 5 minutes to ensure complete dispersion. Turn on the laser particle size analyzer, clean the optical path, and automatically test for background noise. Stir the sonicated test solution until uniformly dispersed. If necessary, add it to the sample cell and begin particle size measurement. The measurement results can be read from the instrument.

[0234] The particle size distribution was calculated based on the particle size test and the results are shown in Table 1.

[0235] 3. Glass transition temperature test (DSC method) Reference standard: GB / T 19466.2 Differential scanning calorimetry (DSC) - Determination of glass transition temperature. Test conditions: (1) Sample preparation: Weigh out 6±0.05 mg of sample and place it in an Al crucible. Shake it evenly, put the lid on, and place it on the measuring instrument. (2) Parameter settings: nitrogen atmosphere, purge gas flow rate of 50 mL / min, and protective gas flow rate of 100 mL / min. (3) Temperature increase conditions: The temperature increase rate is 10°C / min, and the temperature range is -40 to 200°C.

[0236] 4. Lithium-ion battery manufacturing (1) Manufacturing of positive electrode plates The binder polyvinylidene fluoride was dissolved sufficiently in N-methylpyrrolidone, and the conductive material carbon black and the positive electrode active material LiNi 0.7 Co 0.2 Mn 0.1O2 was added to prepare a uniformly dispersed positive electrode slurry (the mass ratio of polyvinylidene fluoride as a binder, carbon black as a conductive agent, and positive electrode active material was 3:2:95). The positive electrode slurry was uniformly applied to the top and bottom surfaces of an aluminum foil, which was then transferred to a vacuum drying oven and completely dried. The resulting electrode plate was rolled and then punched out to obtain a positive electrode plate.

[0237] (2) Manufacturing of negative electrodes The carbon nanotube material and the binder sodium carboxymethyl cellulose were added to water in a mass ratio of 4:1.6 and stirred to form a uniform negative electrode slurry. The negative electrode slurry was then applied to the top and bottom surfaces of copper foil, which was then transferred to a vacuum drying oven to completely dry it, and then punched out to obtain a negative electrode plate.

[0238] (3) Electrolyte production In an argon atmosphere glove box (H2O<0.1 ppm, O2<0.1 ppm), the lithium salt lithium hexafluorophosphate NaPF6 was dissolved in the organic solvent ethylene glycol dimethyl ether DME and stirred uniformly to obtain an electrolyte solution with a lithium salt concentration of 1 mol / L.

[0239] (4) Separator The separators manufactured in the above examples and comparative examples were used as separators.

[0240] (5) Lithium-ion battery manufacturing The positive electrode plate, separator, and negative electrode plate are stacked in this order, with a separator interposed between the positive and negative electrodes to isolate them. The stack is then wound up to obtain a bare cell, the tabs are welded, the bare cell is placed in an outer casing, the electrolyte solution produced above is injected into the dried cell, and the cell is then packaged, left to stand, chemically formed, shaped, and tested for capacity, completing the production of a lithium-ion battery.

[0241] The cycle capacity retention rate of the lithium ion battery was measured, and the measurement method was as follows.

[0242] For the lithium-ion batteries in the examples and comparative examples, at least two parallel samples were used for each example. First, the batteries were placed in a constant temperature environment at 25°C and allowed to rest for one hour. The batteries were then subjected to constant current charging at a charge rate of 2C until they reached 3.65V, after which they were converted to constant voltage charging. When the charging current was lower than 0.05C, the batteries were stopped and allowed to rest for five minutes. Subsequently, the batteries were subjected to constant current discharge at a discharge rate of 1C until they reached 2.5V and then allowed to rest for five minutes. This process was repeated for a certain number of cycles (here, 1000 cycles). The capacity retention rate was calculated as follows: Capacity retention rate at the nth cycle = Discharge capacity at the nth cycle / Discharge capacity at the 2nd cycle * 100%.

[0243] The test results are shown in Table 2.

[0244] (6) Adhesion test: The negative electrode plate and separator of the battery were stacked and placed in a hot press. The hot press parameters were set to a temperature of 55°C, a pressure of 7T, and a time of 15 seconds. A bonded separator / negative electrode sample was obtained by pressing, and the separator / electrode sample was cut into a 150mm x 20mm rectangular strip. One side of the rectangular strip was attached to a steel plate with double-sided tape, and the separator and electrode were separated by a length of 2cm at one end of the rectangular strip to obtain a test sample.

[0245] The steel plate was held horizontally and fixed in the lower clamp of a universal testing machine (Xieqiang Instrument Manufacturing (Shanghai) Co., Ltd., Model CTM2100). The peeled end of the separator described above was fixed in the upper clamp of the universal testing machine, and a tensile tester was connected. The test conditions were set to a tensile speed of 20 mm / min and a horizontal pull of 10 cm. After the tensile force stabilized, the value was recorded, and the ratio of the tensile force to the sample width was used to determine the adhesive strength between the separator and the electrode plate. The test results are shown in Table 2.

[0246] [Table 2]

[0247] As can be seen from Table 2, the polymers of Examples 1 to 21 have two glass transition temperatures, and the hot-press adhesive strength between the separator and the negative electrode plate and the battery capacity retention rate are all higher than those of Comparative Examples 1 to 4. However, the polymers of Comparative Examples 1 to 4 have only one glass transition temperature, and while the adhesive strength between the separator and the negative electrode plate is high in Comparative Examples 2 to 4, the ionic conductivity and the battery capacity retention rate are both low. This indicates that when the polymers of the present application are used as separators, the separator has high ionic conductivity and the adhesive strength between the separator and the electrode plate is appropriate, which can improve the dynamic performance of the battery.

[0248] In the description herein, references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples" mean that the specific feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the present application. In the description herein, schematic expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific feature, structure, material, or characteristic described may be combined in an appropriate manner in any one or more embodiments or examples. Furthermore, unless mutually inconsistent, those skilled in the art may combine or combine different embodiments or examples and features of different embodiments or examples described herein.

[0249] Although the embodiments of the present application have been shown and described above, it should be understood that the above embodiments are illustrative and should not be construed as limitations on the present application, and that those skilled in the art may make changes, modifications, substitutions and variations to the above embodiments within the scope of the present application. [Explanation of symbols]

[0250] 1 battery cell 11 cases 12 Electrode assembly 13 Cover plate 2 Battery Module 3 Battery pack 31 Upper Box 32 Lower Box

Claims

1. A polymer comprising an organic polymer and an inorganic material, the polymerized monomers of the organic polymer include a first monomer and a second monomer; The structural formula of the first monomer is: 【Chemistry 1】 and R １ contains a hydrogen atom or an alkyl of 1 to 6 carbon atoms, and R ２ includes a hydrogen atom, a substituted or unsubstituted alkyl of 1 to 21 carbon atoms, a cycloalkyl of 3 to 6 carbon atoms, and a substituted or unsubstituted isobornyl, wherein the substituents on the substituted alkyl of 1 to 21 carbon atoms include hydroxy; The polymer wherein the second monomer contains an alkenyl.

2. 2. The polymer of claim 1, wherein the weight ratio of the first monomer to the second monomer is 1:0.05-0.

5.

3. 3. The polymer according to claim 1, wherein the weight ratio of the first monomer to the second monomer is 1:0.1-0.

2.

4. The first monomer may be acrylic acid, methacrylic acid, butenoic acid, heptenoic acid, itaconic acid, maleic acid, methyl acrylate, ethyl acrylate, n-propyl acrylate, n-butyl acrylate, isobutyl acrylate, sec-butyl acrylate, tert-butyl acrylate, cyclohexyl acrylate, lauryl acrylate, 2-ethylhexyl acrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, methyl methacrylate, ethyl methacrylate, n-butyl methacrylate, 2-ethylhexyl methacrylate, isobornyl methacrylate, lauryl methacrylate, 4. The polymer of claim 1, wherein the first monomer comprises at least one of methyl methacrylate, lauryl acrylate, lauryl methacrylate, or trimethylolpropane triacrylate, and optionally the first monomer comprises at least one of methyl methacrylate, lauryl acrylate, lauryl methacrylate, or trimethylolpropane triacrylate.

5. The structural formula of the second monomer is: 【Chemistry 2】 and R ６ , R ７ , R ８ , R ９ wherein each independently comprises a hydrogen atom, a substituted or unsubstituted phenyl, a substituted or unsubstituted cycloalkyl, or a straight or branched chain alkyl.

6. The polymer of any one of claims 1 to 5, wherein the second monomer comprises at least one of ethylene, styrene, butadiene, or isoprene.

7. 7. The polymer of claim 1, wherein the polymerized monomers of the organic polymer include a first monomer, a second monomer, and a third monomer, and the third monomer comprises an unsaturated nitrile.

8. The structural formula of the third monomer is: 【Transformation 3】 and R ３ The polymer of claim 7, wherein comprises a hydrogen atom or an alkyl of 1 to 6 carbon atoms.

9. 9. The polymer of claim 7 or 8, wherein the third monomer comprises at least one of acrylonitrile, methacrylonitrile, or ethyl acrylonitrile.

10. The polymer according to any one of claims 7 to 9, wherein a weight ratio of the first monomer to the second monomer to the third monomer is 1:0.05-0.5:0.01-0.

8.

11. The polymer according to any one of claims 7 to 10, wherein a weight ratio of the first monomer to the second monomer to the third monomer is 1:0.1-0.2:0.05-0.

6.

12. 12. The polymer of claim 7, wherein the polymerized monomers of the organic polymer comprise a first monomer, a second monomer, a third monomer, and a fourth monomer, and the fourth monomer comprises an unsaturated amide.

13. The structural formula of the fourth monomer is: 【Chemistry 4】 and R ４ contains a hydrogen atom or an alkyl of 1 to 6 carbon atoms, and R ５ The polymer of claim 12, wherein comprises a hydrogen atom, an alkyl of 1 to 6 carbon atoms substituted with a hydroxy, or an alkoxy of 1 to 6 carbon atoms.

14. 14. The polymer of claim 12 or 13, wherein the fourth monomer comprises at least one of acrylamide, N-methylolacrylamide, or N-butoxymethacrylamide.

15. 15. The polymer according to claim 12, wherein a weight ratio of the first monomer, the second monomer, the third monomer, and the fourth monomer is 1:0.05-0.5:0.01-0.8:0.05-0.

7.

16. 16. The polymer according to claim 12, wherein a weight ratio of the first monomer, the second monomer, the third monomer, and the fourth monomer is 1:0.1-0.2:0.05-0.6:0.1-0.

5.

17. The particle size of the polymer satisfies the condition of 3 μm≦D50≦10 μm, the particle size distribution of the polymer is (D90-D10) / D50, and the particle size distribution of the polymer is 2.5 or less; The particle size of the inorganic substance is 0.0001 μm to 2 μm. The polymer according to any one of claims 1 to 16, which satisfies at least one of the following conditions.

18. The polymer according to any one of claims 1 to 17, wherein the inorganic substance is attached to the surface of the organic polymer and / or dispersed within the organic polymer.

19. 19. The polymer of any one of claims 1 to 18, wherein the inorganic material comprises at least one of oxides of silicon, oxides of aluminum, oxides of calcium, oxides of zinc, oxides of magnesium, sodium sulfate, sodium benzoate, calcium carbonate and modified materials thereof.

20. The polymer according to any one of claims 1 to 19, wherein the inorganic material comprises silica, and the particle size of the silica is from 2 nm to 1 μm.

21. 21. The polymer according to claim 1, wherein the mass proportion of the organic polymer is 50% to 99.9%, based on the mass of the polymer.

22. The polymer of any one of claims 1 to 21, wherein the outer surface of the polymer is rough.

23. 23. The polymer of any one of claims 1 to 22, wherein the polymer comprises a first glass transition temperature and a second glass transition temperature in the range of -10°C to 95°C, the first glass transition temperature being greater than the second glass transition temperature.

24. the first glass transition temperature of the polymer is from 30° C. to 75° C.; and / or 24. The polymer of claim 23, wherein the second glass transition temperature of the polymer is from -10°C to 25°C.

25. 1. A method for preparing a polymer, comprising the step of mixing an organic polymer with an inorganic substance, the polymerized monomers of the organic polymer include a first monomer and a second monomer; The structural formula of the first monomer is: 【Transformation 5】 and R １ contains a hydrogen atom or an alkyl of 1 to 6 carbon atoms, and R ２ includes a hydrogen atom, a substituted or unsubstituted alkyl of 1 to 21 carbon atoms, a cycloalkyl of 3 to 6 carbon atoms, and a substituted or unsubstituted isobornyl, wherein the substituents on the substituted alkyl of 1 to 21 carbon atoms include hydroxy; The method for preparing a polymer wherein the second monomer contains an alkenyl.

26. A separator comprising a polymer according to any one of claims 1 to 24 or a polymer obtained by the method according to claim 25.

27. The ionic conductivity of the separator is 0.3 mS cm －１ ~0.6 mS cm －１ 27. The separator of claim 26, wherein:

28. 26. An electrode plate comprising a polymer according to any one of claims 1 to 24 or a polymer obtained by the method according to claim 25.

29. A battery comprising the separator according to claim 26 or 27 and / or the electrode plate according to claim 28.

30. 30. An electrical device comprising the battery of claim 29.

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