Polymer, method for preparing the same, gel polymer electrolyte, battery, and electric device

Abstract

The present application discloses a polymer, a preparation method thereof, a gel polymer electrolyte, a battery and an electric device. The general formula of the polymer is shown as formula I: wherein: m includes 0 and / or 1; n is a positive integer; X1, X2 respectively independently include oxygen, sulfur or imido; X3 includes oxygen or sulfur; Y includes oxygen, sulfur, imido, -S-C 1～8 alkylene, -NH-C 1～8 alkylene, C 1～8 alkylene, C 1～8 alkylene, C 1～10 alkylene, C 1～10 alkylene, C 1～10 alkyl, C 1～10 alkyl. The polymer is beneficial to improve the thermal stability of the battery.

Description

Technical Field

[0001] This application belongs to the field of batteries, specifically relating to polymers and their preparation methods, gel polymer electrolytes, batteries and electrical devices. Background Technology

[0002] Lithium-ion batteries are characterized by being green, environmentally friendly, high-energy, and low-carbon. They are not only used in energy storage systems for hydropower, thermal power, wind power, and solar power plants, but also widely used in electric vehicles such as electric bicycles, electric motorcycles, and electric cars, as well as in military equipment and aerospace. With the development of society, the demands on lithium-ion batteries are also increasing. Summary of the Invention

[0003] In view of the technical problems existing in the background art, this application provides a polymer that aims to improve the thermal stability of batteries and reduce the probability of thermal runaway.

[0004] To achieve the above objectives, a first aspect of this application provides a polymer, the polymer having the general formula shown in Formula I:

[0005]

[0006] Where: m includes 0 and / or 1; n is a positive integer; X1 and X2 independently include oxygen, sulfur or imino, respectively; X3 includes oxygen or sulfur;

[0007] Y includes oxygen, sulfur, imino, unsubstituted or substituted with any group -SC 1～8 Alkylene, unsubstituted or substituted with any group -NH-C 1～8 Alkylene, unsubstituted or substituted C 1～8 Alkylene, unsubstituted or substituted C 1～8 Any one of the alkeneoxy groups; R1, R2, R3, and R4 each independently include hydrogen, fluorine, and an unsubstituted or substituted C group. 1～10 Alkyl, unsubstituted or substituted C 1～10 Any of the alkoxy groups; R5 includes unsubstituted or substituted C groups. 1～10 alkyl, Any one of them; R9 includes unsubstituted or substituted C groups. 1～10 Alkyl group; the arbitrary group includes at least one of halogen, alkyl, alkoxy, ester, and carbonyl groups.

[0008] Compared to existing technologies, the polymer of the first aspect of this application can have the following beneficial effects: The polymer possesses flame-retardant properties. When used in batteries (e.g., by introducing a polymeric monomer comprising a cyclic phosphate ester compound containing a double bond into the electrolyte and polymerizing it under the action of an initiator to obtain a polymer network), on the one hand, the polymer can undergo ring-opening polymerization under abusive conditions such as high temperature or battery overcharging, causing the electrolyte to gel, increasing the battery's internal resistance, and reducing the probability of thermal runaway. On the other hand, the substituent groups of the polymer can be used to further achieve the desired effects; for example, halogen substitution can be used to improve the flame-retardant effect or reduce battery side reactions. In summary, introducing this polymer into batteries is beneficial for improving the battery's thermal stability and reducing the probability of battery combustion and thermal runaway.

[0009] The second aspect of this application provides a method for preparing the polymer described in the first aspect of this application, comprising: self-polymerizing a cyclic phosphate compound containing double bonds; and / or copolymerizing the cyclic phosphate compound containing double bonds with a second polymerizable compound. Compared with the prior art, this method can not only obtain polymers with cyclic phosphate structures, but also select the specific type or structure of the polymerizing monomers and / or the second polymerizable compound according to actual needs to meet different additional requirements. It can be used in the battery field to improve the thermal stability of batteries and reduce the probability of battery combustion and thermal runaway.

[0010] A third aspect of this application provides a gel polymer electrolyte comprising a polymer matrix and an electrolyte, wherein the polymer matrix comprises the polymer described in the first aspect of this application or a polymer obtained by using the method described in the second aspect of this application.

[0011] A fourth aspect of this application provides a battery comprising: the gel polymer electrolyte of the third aspect of this application, and / or a polymer obtained by the method of the second aspect of this application, and / or the polymer of the first aspect of this application.

[0012] The fifth aspect of this application provides an electrical device comprising: the battery described in the fourth aspect of this application.

[0013] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0014] The above and / or additional aspects and advantages of this application will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0015] Figure 1 This is a schematic diagram of the structure of a battery according to an embodiment of this application.

[0016] Figure 2 This is a schematic diagram of the structure of a battery module according to an embodiment of this application.

[0017] Figure 3 This is a schematic diagram of the structure of a battery pack according to an embodiment of this application.

[0018] Figure 4 This is an exploded view of a battery pack according to an embodiment of this application.

[0019] Figure 5 This is a schematic diagram of one embodiment of an electrical device in which a battery is used as a power source, according to an embodiment of this application.

[0020] Figure label:

[0021] 1: Secondary battery; 2: Battery module; 3: Battery pack; 4: Upper casing; 5: Lower casing. Detailed Implementation

[0022] The present application will be further described below with reference to specific embodiments. It should be understood that these specific embodiments are for illustrative purposes only and are not intended to limit the scope of the present application.

[0023] In this application, the reference to "embodiment" means that a specific feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a mutually exclusive, independent, or alternative embodiment. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described in this application can be combined with other embodiments.

[0024] The "range" disclosed in this application is defined in the form of a lower limit and / or an upper limit. A given range is defined by selecting a lower limit and / or an upper limit, which defines the boundary of the particular range. Ranges defined in this way may or may not include endpoints and can be arbitrarily combined; that is, any lower limit can be combined with any upper limit to form an undefined range, and any lower limit can be combined with other lower limits to form an undefined range. Similarly, any upper limit can be combined with any other upper limit to form an undefined range. Furthermore, each individually disclosed point or single value can itself serve as a lower limit or upper limit, combined with any other point or single value, or combined with other lower limits or upper limits to form an undefined range.

[0025] Unless otherwise specified, all embodiments and optional embodiments of this application may be combined with each other to form new technical solutions, and such technical solutions should be considered to be included in the disclosure of this application.

[0026] Unless otherwise specified, all technical features and optional technical features of this application may be combined to form new technical solutions, and such technical solutions shall be deemed to be included in the disclosure of this application.

[0027] Unless otherwise specified, all steps in this application may be performed sequentially or randomly, preferably sequentially. For example, the method includes steps S1 and S2, indicating that the method may include steps S1 and S2 performed sequentially, or it may include steps S2 and S1 performed sequentially. For example, the method may also include step S3, indicating that step S3 may be added to the method in any order. For example, the method may include steps S1, S2, and S3, or it may include steps S1, S3, and S2, or it may include steps S3, S1, and S2, etc.

[0028] Unless otherwise specified, the terms "comprising" and "including" as used in this application can be open-ended or closed-ended. For example, "comprising" and "including" may mean that other components not listed may also be included, or that only the listed components may be included. Furthermore, in this application, the terms "a plurality of" or "multiple" refer to two or more types.

[0029] Unless otherwise specified, in this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship.

[0030] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used in this application is for the purpose of describing particular embodiments only and is not intended to limit this application; the terms "comprising" and "having," and any variations thereof, in the specification, claims, and foregoing description of the drawings, are intended to cover non-exclusive inclusion. Unless otherwise stated, the terms used in this application have their commonly understood meanings as understood by one of ordinary skill in the art. Unless otherwise stated, the numerical values ​​of the parameters mentioned in this application can be measured using various measurement methods commonly used in the art (e.g., they can be tested according to the methods given in the embodiments of this application).

[0031] Currently, with the continuous advancement of green and environmentally friendly themes, the application of lithium-ion batteries has penetrated into all aspects of life, including vehicles, electronic devices, and energy storage devices. However, as their application deepens, some potential problems have also received increasing attention. Lithium-ion batteries can accumulate internal heat due to overcurrent, internal dendrites causing internal short circuits, or overcharging. When the heat accumulates to a certain level, it can trigger an exothermic chain reaction in the electrolyte, positive electrode, and other internal materials, ultimately leading to thermal runaway.

[0032] In this application, by using a polymer having the structure shown in Formula I in a battery, the characteristic of the polymer undergoing ring-opening polymerization under abusive conditions such as high temperature or battery overcharging, causing the electrolyte to gel and increasing the battery's internal resistance, can be utilized to reduce the probability of thermal runaway and improve the battery's thermal stability. At the same time, the desired effect can be further achieved by carrying substituent groups in the polymer, such as using halogen substitution to improve flame retardancy or reduce battery side reactions.

[0033] In view of the above, a first aspect of this application provides a polymer having the general formula shown in Formula I:

[0034]

[0035] Where: m includes 0 and / or 1; n is a positive integer; X1 and X2 independently include oxygen, sulfur, or imino (-NH-); X3 includes oxygen or sulfur; Y includes oxygen, sulfur, imino, unsubstituted or substituted -SC groups. 1～8 Alkylene, unsubstituted or substituted with any group -NH-C 1～8 Alkylene, unsubstituted or substituted C 1～8 Alkylene, unsubstituted or substituted C 1～8 alkeneoxy group (i.e. -OC) 1～8 Any one of the alkylene groups; R1, R2, R3, and R4 each independently include hydrogen, fluorine, and C1 or C2 that is unsubstituted or substituted with any group. 1～10 Alkyl, unsubstituted or substituted C 1～10 Any of the alkoxy groups; R5 includes unsubstituted or substituted C groups. 1～10 alkyl, Any one of them; R9 includes unsubstituted or substituted C groups. 1～10 Alkyl group; the arbitrary group includes at least one of halogen, alkyl, alkoxy, ester, and carbonyl groups.

[0036] Unless otherwise stated, in this application, "*" indicates a connecting portion between the same or different atoms or end portions of a chemical formula. It should be understood that the elements or groups located at positions X1, X2, and X3 can be the same or different. The optional range for the term "halogen" includes fluorine, chlorine, bromine, and iodine. The term "C"... 1～8 "Alkyl" should be understood to refer to a straight-chain or branched saturated monovalent hydrocarbon group having 1, 2, 3, 4, 5, 6, 7, or 8 carbon atoms; the term "C" 1～8 "Alkoxy" should be understood as -OC 1～8 Alkyl group indicates that the alkyl group is attached to the rest of the molecule via an oxygen atom. The term "C" indicates that the alkyl group is attached to the rest of the molecule. 1～8 "Alkylene" should be understood to refer to a straight-chain or branched saturated divalent hydrocarbon group having 1, 2, 3, 4, 5, 6, 7, or 8 carbon atoms; the term "C" 1～8 "alkoxide" should be understood as -OC 1～8 Alkylene. Accordingly, the term "C" 1～10 "Alkyl" should be understood to refer to a straight-chain or branched saturated monovalent hydrocarbon group having 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 carbon atoms; the term "C" 1～10 "Alkoxy" should be understood as -OC 1～10 Alkyl group. The term "C" 3～10 "Alkyl" should be understood as representing a straight-chain or branched saturated monovalent hydrocarbon group having 3, 4, 5, 6, 7, 8, 9 or 10 carbon atoms.

[0037] In the term "unsubstituted or substituted by any group," "substituted by any group" means that at least one hydrogen atom bonded to a carbon atom is substituted by any group other than hydrogen, such as fluorine substitution, in the context of "unsubstituted or substituted C". 1～10 Taking "alkyl" as an example, it should be understood as C 1～10Alkyl groups may be unsubstituted or substituted at any position by one or more (e.g., 1, 2, 3, or 4) substituents. When two or more substituents are present, the substituents may be the same or different, and may be located at the same or different positions. In the phrase "substituted by any group" as used in this application, the arbitrary group includes, but is not limited to, at least one of halogens, alkyl groups, alkoxy groups, ester groups, and carbonyl groups. The alkyl or alkoxy groups included in the arbitrary group may be chain-like or cyclic. For example, the arbitrary group may include one or more of halogens, chain-like alkyl groups, cyclic alkyl groups, chain-like alkoxy groups, and cyclic alkoxy groups. Furthermore, it should be understood that when one or more of "R1", "R2", "R3", "R4", "R5", and "R9" are substituted by an "arbitrary group", the substituents on "R1", "R2", "R3", "R4", "R5", and "R9" may be the same or different, and the number and substitution positions of the substituents on "R1", "R2", "R3", "R4", "R5", and "R9" are also independent.

[0038] In the polymer of the first aspect of this application, when m is 0 or 1, even if the polymer has a five-membered or six-membered ring structure, the polymer can have good stability. The polymer having the structure of Formula I has a cyclic structure that is the same as or similar to that of cyclic phosphates (e.g., the oxygen in cyclic phosphates is replaced by sulfur, (imino) groups, etc.), i.e. This polymer exhibits good flame retardancy and can improve battery thermal stability. Under conditions of abuse such as high temperature or overcharging, it can undergo ring-opening polymerization, causing electrolyte gelation, increasing battery internal resistance, and reducing the probability of thermal runaway. Furthermore, the substituent groups of the polymer can be used to further achieve the desired effects; for example, halogen substitution can be used to improve flame retardancy or reduce battery side reactions. In summary, introducing this polymer into batteries is beneficial for improving battery thermal stability and reducing the probability of battery combustion and thermal runaway. The structural characterization of the polymer can be combined with infrared spectroscopy (IR) and nuclear magnetic resonance (NMR), for example... 1 H, 13 C 19 F, 31 Commonly used methods include P, mass spectrometry (MS), elemental analysis, gel permeation chromatography (GPC), and laser Raman spectroscopy (LR).

[0039] It is understood that in the general formula shown in Formula I, n represents the number of repeating units in the general formula shown in Formula I, and the value of n can be selected within a reasonable range of polymer molecular weight. The polymer of the first aspect of this application may include multiple compounds that satisfy the general formula shown in Formula I, or it may include only a single compound that satisfies the general formula shown in Formula I. When the polymer includes only a single compound that satisfies the general formula shown in Formula I, the value of n in Formula I may be greater than 1, for example, it may be not less than 5 or not less than 10, etc.

[0040] It is understood that the polymer of the first aspect of this application can be a single compound or a combination of compounds satisfying the general formula structure shown in Formula I.

[0041] Furthermore, through in-depth research, the inventors have discovered that, in addition to meeting the above conditions, the polymer of the first aspect of this application can further improve its performance by controlling the type, range, average molecular weight, type, and specific selection of its substituent groups, including but not limited to flame retardancy, electrolyte retention, and improvement on battery thermal stability. That is, in addition to meeting the above conditions, one or more of the following conditions may also be optionally met.

[0042] In some embodiments of this application, the "halogen" includes fluorine. That is, in Formula I, Y may include oxygen, sulfur, imino, unsubstituted or fluorine-substituted -NH-C. 1～8 Alkylene, unsubstituted or fluorinated C 1～8 Alkylene, unsubstituted or fluorinated C 1～8 Any one of the alkeneoxy groups; R1, R2, R3, and R4 can each independently include hydrogen, fluorine, unsubstituted or fluorinated C. 1～10 Alkyl, unsubstituted or fluorinated C 1～10 Any of the alkoxy groups; R5 may include unsubstituted or fluorinated C. 1～10 alkyl, Any one of the following. Polymers with the structure described in Formula I, when combined with fluorinated substituents (such as fluorinated or fluorinated alkyl groups), exhibit better antioxidant stability. This not only reduces the battery's exothermic value and auto-ignition rate, thereby lowering the probability of combustion and thermal runaway, but also further improves the battery's flame retardancy and thermal stability. Furthermore, it can passivate the negative electrode, reduce side reactions between the negative electrode and the electrolyte, and improve the electrolyte's liquid retention.

[0043] In some embodiments of this application, X1 and X2 may each independently comprise oxygen or sulfur; Y may comprise oxygen, unsubstituted or fluorine-substituted C. 1～8 Alkylene, unsubstituted or fluorinated C 1～8Any one of the alkeneoxy groups; R1, R2, R3, and R4 can each independently include hydrogen, fluorine, unsubstituted or fluorinated C. 1～10 Alkyl, unsubstituted or fluorinated C 1～10 Any of the alkoxy groups; R5 may include unsubstituted or fluorinated C. 1～10 alkyl, Any one of them; R9 includes unsubstituted or fluorinated C 1～10 Alkyl group. Optionally, X1 and X2 may each independently include oxygen; X3 includes oxygen; Y may include oxygen, unsubstituted or fluorinated C. 1～8 Alkylene, unsubstituted or fluorinated C 1～8 Any one of the alkeneoxy groups. Selecting X1, X2, X3, Y, R1, R2, R3, R4, R5, and R9 within the given range can further reduce the probability of battery combustion and thermal runaway.

[0044] In some embodiments of this application, the average molecular weight of the polymer can be between 20,000 and 60,000, such as 25,000, 30,000, 35,000, 40,000, 45,000, 50,000, 55,000, etc., or a range of any of the above values. The method for testing the average molecular weight of the polymer includes, but is not limited to, gel permeation chromatography (GPC). This polymer can be used in electrolytes to improve the thermal stability of the battery. If its average molecular weight is too low, it is difficult to form a network polymer, affecting the improvement effect on the battery's thermal stability. If its average molecular weight is too high, it is difficult to dissolve in the electrolyte. By keeping the average molecular weight of the polymer within the given range, its dispersibility in the electrolyte can be improved. This is beneficial for its uniform film formation on the surfaces of the positive and negative electrode sheets, improving the compatibility between the electrolyte and the positive and negative electrode sheets. Furthermore, when it undergoes ring-opening polymerization, it also promotes the gelation of the electrolyte, improving the battery's thermal stability and reducing the probability of battery combustion and thermal runaway.

[0045] In some embodiments of this application, in the polymer represented by Formula I, R1, R2, R3, and R4 may each independently include unsubstituted or fluorinated C. 1～10 Alkyl, unsubstituted or fluorinated C 1～10 Any one of the alkoxy groups; optionally, R1, R2, R3, and R4 may each independently include a C group substituted with fluorine. 1～10 Alkyl groups, fluorine-substituted C groups 1～10Any one of the alkoxy groups. Compared to direct substitution with hydrogen or fluorine, substitution with (fluoro)alkyl or (fluoro)alkoxy groups having 1 to 10 carbon atoms further enhances the molecular weight of the polymer and the formation of a network polymer, thereby further improving the thermal stability of the battery. Furthermore, substitution with fluoroalkyl (oxy) groups not only significantly improves the polymer's oxidation resistance and flame retardancy by utilizing the strong electronegativity of fluorine atoms, thus improving the battery's thermal stability, but also reduces side reactions between the electrolyte and the negative electrode. Therefore, selecting R1, R2, R3, and R4 within the given range can further reduce the probability of battery combustion and thermal runaway.

[0046] In some embodiments of this application, the polymer monomer of the polymer of the general formula I may include a cyclic phosphate compound containing a double bond, which can give the polymer a cyclic phosphate ester or a cyclic structure similar to a cyclic phosphate ester (the cyclic phosphate ester or a cyclic structure similar to a cyclic phosphate ester includes...). This is beneficial for improving the thermal stability of batteries. Cyclic phosphate ester compounds containing double bonds can self-polymerize or graft copolymerize with other polymerizable compounds to form network polymers under initiator or high voltage. When used in batteries, they can form films on the surfaces of the positive and negative electrode sheets, improving the compatibility between the electrolyte and the electrode sheets, suppressing side reactions between the electrode sheets and the electrolyte, and reducing electrolyte consumption. Furthermore, the self-polymerization or copolymerization with other polymerizable compounds of cyclic phosphate ester compounds containing double bonds to form network polymers can further increase the polymer molecular weight, improving the thermal stability of the battery. It should be noted that the "cyclic phosphate ester compounds" mentioned in this application may include, but are not limited to, compounds containing cyclic phosphate esters, compounds with any group (such as fluorine, (imino), sulfur, (imino), (alkyl), -NH-C 1～8 Compounds having cyclic phosphate esters substituted with at least one of alkylene groups, and compounds having a similar cyclic structure to cyclic phosphate esters (such as any oxygen in the cyclic phosphate ester being replaced by sulfur, (imino), (imino), (imino), (alkoxy), -NH-C 1～8 Alkylene, -SC 1～8 The compound can be a cyclic phosphate ester compound that has at least one of the alkylene groups replaced, provided that the compound contains a double bond and can self-polymerize or copolymerize with other polymerizable compounds to obtain a polymer of the general formula shown in Formula I. For example, "cyclic phosphate ester compound" can include

[0047] In some embodiments of this application, the polymer monomers of Formula I can be solely cyclic phosphate compounds containing double bonds. These cyclic phosphate compounds can be the same type of compound or comprise multiple different cyclic phosphate compounds containing double bonds. When used in batteries, the monomers can be polymerized before being introduced into the electrolyte, or the monomers can be added directly to the electrolyte and allowed to self-polymerize by adding an initiator or under high pressure. Using only cyclic phosphate compounds containing double bonds as monomers further enhances the polymer's flame-retardant properties, thereby significantly improving the battery's thermal stability.

[0048] In some embodiments of this application, the polymer monomers of the polymer represented by Formula I may include: For example, the polymer monomers of the polymer shown in Formula I may include, but are not limited to, those shown in Formula I. One or more of the following. In practice, polymers that satisfy this general formula can be self-polymerized to obtain the polymer shown in Formula I, or polymers that satisfy this general formula can be copolymerized with other polymerizable compounds to obtain the polymer shown in Formula I.

[0049] In some embodiments of this application, the polymer represented by Formula I may include at least one of the 276 compounds represented by structural formulas I-1 to I-276. All 276 compounds represented by structural formulas I-1 to I-276 can be used alone in the battery, or any combination of them can be used in the battery. The 276 compounds represented by structural formulas I-1 to I-276 have a five-membered or six-membered ring structure of cyclic phosphate esters, which have good stability and can be further improved by using fluorine substituents to improve their antioxidant properties and passivation effect on the negative electrode. Using them in the battery can improve the thermal stability of the battery and reduce the probability of battery combustion and thermal runaway.

[0050] The structures of the 276 compounds represented by structural formulas I-1 to I-276 are as follows:

[0051]

[0052]

[0053]

[0054]

[0055]

[0056]

[0057]

[0058]

[0059]

[0060]

[0061]

[0062] In some embodiments of this application, the polymer monomers of the polymer shown in Formula I may include a second polymerizable compound in addition to cyclic phosphate ester compounds containing double bonds. The second polymerizable compound is a polymerizable compound different from cyclic phosphate ester compounds containing double bonds. In this case, the general formula of the polymer can be as shown in Formula II:

[0063]

[0064] Where: a and b are independent positive integers, and 0.5 ≤ a / b ≤ 4. For example, the value of a / b can be 0.5, 1, 1.5, 2, 2.5, 3, 3.5, or 4, or a range of any of the above values. R6 is C that is unsubstituted or substituted by any of the aforementioned groups. 3～10 Alkyl, unsubstituted or substituted C groups 3～10 Epoxy groups, unsubstituted or substituted C groups 3～10 Allyl, unsubstituted or substituted C 3～10 (meth)acryloyl, unsubstituted or substituted by any of the groups, C 3～10Any of the acrylates. The polymer shown in Formula II, like the polymer shown in Formula I, has a cyclic phosphate ester structure. It can also undergo ring-opening polymerization under abusive conditions such as high temperature or overcharging to gel the electrolyte, improving battery thermal stability and reducing the probability of battery combustion and thermal runaway. Furthermore, this polymer can also possess the properties of a second polymerizable compound, such as a monomer for a gel-type polymer electrolyte. Thus, copolymerizing the cyclic phosphate ester compound containing double bonds with the monomer of a gel-type polymer can result in a polymer that combines good flame retardant properties with the characteristics of a gel-type polymer electrolyte. Using it in batteries also helps reduce the probability of liquid electrolyte leakage and the probability of electrode corrosion and oxidative combustion caused by leakage, improving the volume expansion of the battery during charging and discharging, and further improving the battery's thermal stability. In the compound represented by Formula II, a is the degree of polymerization of the cyclic phosphate ester compound containing double bonds, and b is the degree of polymerization of the second polymerizable compound. If a is too small relative to b, it is not conducive to improving the flame retardant properties of the polymer. If a is too large relative to b, it is not conducive to making the polymer meet the characteristics of the second polymerizable compound. Controlling the value of a / b within the given range is conducive to making the polymer represented by Formula II have both good flame retardant properties and the characteristics of the second polymerizable compound.

[0065] In some embodiments of this application, the second polymerizable compound may include at least one of the polymeric monomers, oligomers, and copolymers of gel-like polymeric electrolytes. The second polymerizable compound within the given range may copolymerize with a cyclic phosphate ester compound containing a double bond to form a gel phase. The second polymerizable compound may include, but is not limited to, methyl methacrylate, styrene, methyl acrylate, ethyl acrylate, acrylic acid, trimethylsilyl methacrylate, acrolein dimethyl acetal, acrolein diethanolamide, 2-phenoxyethyl acrylate, tridecafluoro-2-hydroxynonyl acrylate, trifluoroethyl methacrylate, acrylonitrile-1,3-sulfonyl lactone, glycidyl methacrylate, acrylamide, trifluoroethyl acrylate, and (acrylate-oxymethyl)dimethylmethoxysilyl Alkane, ethyl cyanoacrylate, hydroxyethyl acrylate, triallyl benzotriazine, hydroxypropyl acrylate, 3-(perfluoro-3-methylbutyl)-2-hydroxypropyl acrylate, 1-vinyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide, 1-allyl-3-ethylimidazolium bis(trifluoromethanesulfonyl)imide, 1-allyl-1-methylpyrrolidone bis(trifluoromethanesulfonyl)imide, 1,6-di(acryloyloxy)-2,2,3,3,4,4,5,5-octadecyl The polymerizable compound is selected from at least one of the following: fluorohexane, pentafluorophenol acrylate, vinylene carbonate, maleic anhydride, ethyl cyanoacrylate, butyl acrylate, hexafluoroisopropyl methacrylate, hexafluorobutyl methacrylate, 2-hydroxy-3-phenoxypropyl acrylate, hydroxyethyl methacrylate, and vinyl vinyl carbonate; further, the second polymerizable compound may be selected from at least one of the following: vinylene carbonate, maleic anhydride, ethyl cyanoacrylate, butyl acrylate, hexafluoroisopropyl methacrylate, hexafluorobutyl methacrylate, hydroxypropyl acrylate, 2-hydroxy-3-phenoxypropyl acrylate, hydroxyethyl methacrylate, and vinyl vinyl carbonate. Selecting the second polymerizable compound within the given range can enable the polymer to possess both good flame retardant properties and the properties of a gel polymer electrolyte, thereby improving the thermal stability of the battery, reducing the probability of battery combustion and thermal runaway, and also improving the liquid retention of the electrolyte, buffering the volume expansion generated by the battery during charging and discharging.

[0066] The second aspect of this application provides a method for preparing the polymer described in the first aspect of this application, comprising: self-polymerizing a cyclic phosphate compound containing double bonds; and / or copolymerizing the cyclic phosphate compound containing double bonds with a second polymerizable compound. Both methods can produce polymers containing cyclic phosphate structures. It is understood that the features and effects described for the polymer described in the first aspect of this application are also applicable to the method for preparing the polymer described in the second aspect of this application, and will not be repeated here. In summary, compared with the prior art, this method can not only obtain polymers with cyclic phosphate structures, but also select the specific type or structure of the polymerizing monomer and / or the second polymerizable compound according to actual needs to meet different additional requirements. It can be used in the battery field to improve the thermal stability of batteries and reduce the probability of battery combustion and thermal runaway.

[0067] In some embodiments of this application, before self-polymerizing or copolymerizing the cyclic phosphate compound containing double bonds with a second polymerizable compound, a monomer for polymerizing the cyclic phosphate compound containing double bonds can be prepared first. For example, an intermediate product can be prepared first, and then the intermediate product can undergo a cyclization or substitution reaction. For example:

[0068] General reaction formula I:

[0069]

[0070] General Reaction Formula II:

[0071]

[0072] In some specific embodiments of this application, as understood with reference to general reaction formula I, a method for preparing polymeric monomers of cyclic phosphate ester compounds containing double bonds may include: making A cyclization reaction occurs, yielding the general formula: Compounds.

[0073] In some specific embodiments of this application, as understood with reference to general reaction formula II, a method for preparing polymeric monomers of cyclic phosphate ester compounds containing double bonds may include: making It undergoes a substitution reaction with Y′-R8 to give the product with the general formula: and / or The compound. It is understood that Y′-R8 can be a single compound or a mixture of multiple compounds that satisfy the requirements of Y′-R8.

[0074] Wherein, m includes 0 and / or 1; X1' and X2' independently include hydroxyl, mercapto, or amino groups respectively; X1 and X2 independently include oxygen, sulfur, or imino groups respectively; R1, R2, R3, and R4 independently include hydrogen, fluorine, unsubstituted or substituted C groups respectively. 1～10Alkyl, unsubstituted or substituted C 1～10 Any one of the alkoxy groups; R7 and R8 each independently include an unsubstituted or substituted C group. 2～11 Alkenes; Y' includes hydrogen, hydroxyl, mercapto, or amino groups; Y" includes oxygen, sulfur, or imino groups; R9 includes unsubstituted or substituted C groups. 1～10 Alkyl group; the arbitrary group includes at least one selected from halogen, alkyl, alkoxy, ester, and carbonyl groups. It is understood that... Both can be used as monomers for polymerizing cyclic phosphate compounds containing double bonds.

[0075] In some embodiments of this application, reaction formulas I and II... It may include, but is not limited to, at least one of ethylene glycol, ethylenedithiol, 2-mercaptoethanol, mercaptoethylamine, ethanolamine, ethylenediamine, 1,3-propanediol, 1,3-propanedithiol, 3-mercapto-1-propanol, 3-amino-1-propanol, 3-mercapto-1-propaneamine, and 1,3-propanediamine, as long as it can react with... The reaction can form a five-membered or six-membered ring.

[0076] In some embodiments of this application, the compounds in general formula I are reacted and compounds in general formula II

[0077] The synthetic methods include, but are not limited to, those shown in reaction formulas III and IV. In reaction formula III, as a specific example, Br-R7 can be allyl bromide, P(OEt)3 (triethyl phosphite) can be reacted with allyl bromide, and the resulting allyl phosphate diethyl ester can be dissolved in an organic solvent (such as acetonitrile). Anhydrous potassium iodide is added, and under argon protection, trimethylchlorosilane (TMSCl) is added dropwise at room temperature. After reacting for a period of time, trimethylchlorosilane and the solvent are removed, and dichloromethane is added. Oxaloyl chloride is then added dropwise at room temperature. After reacting for a period of time, the product is obtained by vacuum distillation.

[0078] General Reaction Formula III:

[0079]

[0080] General reaction formula IV:

[0081]

[0082] In some specific embodiments of this application, referring to the following reaction formulas, the methods for preparing polymeric monomers of cyclic phosphate ester compounds containing double bonds may include, but are not limited to, the following:

[0083]

[0084] The obtained polymer monomers I-12', I-49', I-192', I-84', and I-108' can be used as polymer monomers for polymers I-12, I-49, I-192, I-84, and I-108, respectively.

[0085] As a specific example, a method for preparing the polymeric monomer I-12' may include: (a) synthesis Specifically, triethyl phosphite (19.5 g, 117 mmol) and allyl bromide (17.3 g, 143 mmol) were heated at 70 °C for 24 h, and the mixture was distilled to remove impurities, yielding a colorless liquid (19.5 g, yield: 93.56%), which was directly used in the next step. The above colorless liquid, diethyl allyl phosphite (25.0 g, 150 mmol), was dissolved in acetonitrile (100 mL), and anhydrous potassium iodide (42.0 g, 300 mmol) was added under argon protection. Trimethylchlorosilane (68.0 g, 600 mmol) was added dropwise at room temperature, and the reaction was carried out at 40 °C for 2 h. Excess trimethylchlorosilane and acetonitrile were removed by vacuum distillation, and 100 mL of dichloromethane was added. Oxaloyl chloride (51.0 g, 600 mmol) and (0.5 mL) DMF were added dropwise at room temperature, and the mixture was stirred at room temperature for 16 h. Vacuum distillation yields a colorless liquid, and the product is obtained. (14.3 g, yield: 60%). (b) Cycling reaction: Specifically, 3,3,3-trifluoro-1,2-propanediol (10.52 g, 80.9 mmol) and triethylamine (22.5 mL, 161.8 mmol) were dissolved in anhydrous tetrahydrofuran (100 mL) under argon protection and stirred at room temperature for 5 min. The mixture was then cooled to -20 °C and added dropwise. (12.86 g, 80.9 mmol), stirred at room temperature for 3 h, after which the reaction was complete, quenched with water (50 mL), extracted with ethyl acetate (100 mL × 2 times), and washed with 0.1 M hydrochloric acid (100 mL × 2 times) and saturated brine (50 mL × 2 times). The organic phase was dried over anhydrous sodium sulfate, filtered, and concentrated under reduced pressure to remove the organic solvent, yielding a colorless liquid (10.89 g, 62.34%), which gave the polymer monomer I-12'.

[0086] The target product is obtained by 1 H NMR, 13 C NMR, 19 F NMR, 31 The characterization and analysis were performed using methods such as pNMR and HRMS, and the results are as follows: 1H NMR (CDCl3, 400MHz), δ (ppm): 5.70 (m, 1H), 5.01 (m, 2H), 4.74 (m, 2H), 4.12 (m, 1H), 3.68 (m, 2H); 13 C NMR (CDCl3, 100MHz), δ (ppm): 132.7, 115.9, 114.5, 100.4, 64.9, 28.8; 19 F NMR (CDCl3, 376MHz), δ (ppm): -78.9; 31 P NMR (CDCl3, 160MHz), δ (ppm): 44.2; HRMS (ESI + )m / z[M] + calcd.for C6H8F3O3P:216.0163.found:216.0169.

[0087] As a specific example, the synthesis method of polymer I-12 includes: placing 1.5 g of the monomer I-12' and 32 mg of AIBN (azobisisobutyronitrile) in a 25 mL single-necked flask, solidifying the system in liquid nitrogen, then evacuating to vacuum with an oil pump and maintaining the vacuum for 10 min, followed by melting and purging with argon gas. This process is repeated four times. Finally, the mixture is stirred at 70 °C for 22 h in an oil bath. After the reaction is complete, the mixture is added dropwise to 20 mL of n-hexane for precipitation, resulting in the precipitation of a solid. The solid is then filtered to obtain 1.23 g of solid (yield: 82%). Elemental analysis of the target product is as follows: calcd: C, 33.35; H, 3.75; F, 26.38; O, 22.21; P, 14.33. Found: C, 34.15; H, 3.65; O, 21.28; P, 14.52. n 36000, PDI: 1.8.

[0088] As a specific example, a method for preparing the polymeric monomer I-49' may include: (a) synthesis As shown above. (b) Make The cyclization reaction was carried out; for detailed procedures, refer to the method for preparing polymeric monomer I-12'. The obtained target product was then subjected to... 1 H NMR, 13 C NMR, 31 The characterization and analysis were performed using methods such as pNMR and HRMS, and the results are as follows: 1 H NMR (CDCl3, 400MHz), δ (ppm): 5.70 (m, 1H), 5.01 (m, 2H), 2.86 (m, 4H), 2.02 (m, 2H); 13C NMR (CDCl3, 100MHz), δ (ppm): 132.7, 115.9, 31.7, 31.1; 31 P NMR (CDCl3, 160MHz), δ (ppm): 43.6; HRMS (ESI + )m / z[M] + calcd.for C5H9S2OP:179.9832.found:179.9837.

[0089] As a specific example, a method for preparing the polymeric monomer I-192' may include: (a) synthesis Specifically, 3,3,3-trifluoro-1,2-propanediol (10.52 g, 80.9 mmol) and triethylamine (15.23 g, 150.5 mmol) were dissolved in dichloromethane (80 ml), and phosphorus oxychloride (11.78 g, 76.8 mmol) was added dropwise at 5 °C. After the addition was complete, the reaction was continued for 2 h. The triethylamine hydrochloride was removed by filtration, and the filtrate was dried over anhydrous magnesium sulfate and concentrated under reduced pressure to remove dichloromethane. The product was then recrystallized from toluene to obtain... (11.51g, yield: 70.12%). (b) Make To carry out a substitution reaction, specifically, to... (11.15 g, 53.0 mmol) and triethylamine (2.46 mL, 17.7 mmol) were dissolved in anhydrous dichloromethane (50 mL) under argon protection and stirred at room temperature for 5 min. Allyl mercaptan (4.33 g, 58.3 mmol) was added dropwise, and the mixture was stirred at room temperature for 2 h. After the reaction was complete, the mixture was quenched with water (50 mL), extracted with ethyl acetate (100 mL × 2 times), and washed with 0.1 M hydrochloric acid (100 mL × 2 times) and saturated brine (50 mL × 2 times). The organic phase was dried over anhydrous sodium sulfate, filtered, and concentrated under reduced pressure to remove the organic solvent, yielding a white solid (8.49 g, yield: 64.58%), which was used to obtain the polymer monomer I-192'. The obtained target product was analyzed by... 1 H NMR, 13 C NMR, 19 F NMR, 31 The characterization and analysis were performed using methods such as pNMR and HRMS, and the results are as follows: 1 H NMR (CDCl3, 400MHz), δ (ppm): 5.96 (m, 1H), 5.06 (m, 2H), 4.12 (m, 1H), 3.68 (m, 2H), 3.23 (m, 2H); 13 C NMR (CDCl3, 100MHz), δ (ppm): 132.7, 115.9, 113.8, 99.2, 63.7, 21.0;19 F NMR (CDCl3, 376MHz), δ (ppm): -76.8; 31 P NMR (CDCl3, 160MHz), δ (ppm): 43.2; HRMS (ESI + )m / z[M] + calcd.for C6H8F3O3PS:247.9884.found:247.9879.

[0090] As a specific example, a method for preparing the polymeric monomer I-84' may include: (a) synthesis As shown above. (b) Make The substitution reaction is carried out; specifically, for detailed procedures, refer to the method for preparing polymeric monomer I-192'. The obtained target product is then subjected to... 1 H NMR, 13 C NMR, 19 F NMR, 31 The characterization and analysis were performed using methods such as pNMR and HRMS, and the results are as follows: 1 H NMR (CDCl3, 400MHz), δ (ppm): 5.89 (m, 1H), 5.23 (m, 2H), 4.70 (m, 2H), 4.18 (m, 2H), 4.12 (m, 1H); 13 C NMR (CDCl3, 100MHz), δ (ppm): 137.5, 115.1, 114.5, 96.6, 69.0, 61.1; 19 F NMR (CDCl3, 376MHz), δ (ppm): -74.3; 31 P NMR (CDCl3, 160MHz), δ (ppm): 46.7; HRMS (ESI + )m / z[M] + calcd.for C6H8F3O4P:232.0112.found:232.0118.

[0091] As a specific example, a method for preparing the polymeric monomer I-108' may include: (a) synthesis As shown above. (b) Make The substitution reaction is carried out; specifically, for detailed procedures, refer to the method for preparing polymeric monomer I-192'. The obtained target product is then subjected to... 1 H NMR, 13 C NMR, 19 F NMR, 31 The characterization and analysis were performed using methods such as pNMR and HRMS, and the results are as follows: 1H NMR (DMSO-d6, 400MHz), δ (ppm): 5.83 (m, 1H), 5.16 (m, 2H), 4.12 (m, 1H), 3.68 (m, 2H), 3.32 (m, 2H), 2.12 (s, 1H); 13 C NMR (DMSO-d6, 100MHz), δ (ppm): 134.3, 114.9, 114.2, 97.7, 62.2, 37.4; 19 FNMR(DMSO-d6,376MHz), δ(ppm):-73.2; 31 P NMR ((DMSO-d6,160MHz), δ (ppm): 44.8; HRMS (ESI + )m / z[M] + calcd.for C6H9F3NO3P:231.0272.found:231.0268.

[0092] As a specific example, a method for preparing the polymeric monomer I-60' may include: (a) synthesis As shown above. (b) Make A substitution reaction is carried out to obtain the polymeric monomer I-60', i.e. For detailed procedures, refer to the method for preparing polymeric monomer I-12'. The obtained target product is then subjected to... 1 H NMR, 13 C NMR, 19 F NMR, 31 The characterization and analysis were performed using methods such as pNMR and HRMS, and the results are as follows: 1 H NMR (DMSO-d6, 400MHz), δ (ppm): 5.70 (s, 1H), 5.03 (s, 1H), 4.97 (s, 1H), 3.62 (m, 1H), 2.82 (m, 2H), 2.0 (s, 2H); 13 C NMR (DMSO-d6, 100MHz), δ (ppm): 132.7, 120.1, 115.9, 53.7, 31.4, 18.2; 19 F NMR (DMSO-d6, 376MHz), δ (ppm): -72.8; 31 P NMR ((DMSO-d6,160MHz), δ (ppm): 46.8; HRMS (ESI + )m / z[M] + calcd.forC6H8F3OPS2:247.9706.found:247.9748.

[0093] As a specific example, a method for preparing the polymeric monomer I-125' may include: (a) synthesis As shown above. (b) Make A substitution reaction was carried out to obtain the polymeric monomer I-125', i.e. For detailed procedures, refer to the method for preparing polymeric monomer I-12'. The obtained target product is then subjected to... 1 H NMR, 13 C NMR, 19 F NMR, 31 The cells were characterized and analyzed using methods such as PNMR and HRMS, and the results are as follows: 1 H NMR (DMSO-d6, 400MHz), δ (ppm): 5.70 (s, 1H), 5.03 (s, 1H), 4.97 (s, 1H), 4.74 (m, 2H), 3.85 (s, 4H); 13 C NMR (DMSO-d6, 100MHz), δ (ppm): 132.7, 115.9, 114.4, 81.1, 28.8; 19 F NMR (DMSO-d6, 376MHz), δ (ppm): -89.2; 31 P NMR ((DMSO-d6,160MHz), δ (ppm): 47.4; HRMS (ESI + )m / z[M] + calcd.for C6H9F2O3P:198.0257.found:198.0271.

[0094] As a specific example, a method for preparing the polymeric monomer I-137' may include: (a) synthesis refer to The synthesis of, by (b) Prepared by reaction. A substitution reaction was carried out to obtain the polymeric monomer I-137', i.e. For detailed procedures, refer to the method for preparing polymerizable monomer I-192'. The obtained target product is then subjected to... 1 H NMR, 13 C NMR, 19 F NMR, 31 The characterization and analysis were performed using methods such as pNMR and HRMS, and the results are as follows: 1 H NMR (DMSO-d6, 400MHz), δ (ppm): 5.89 (s, 1H), 5.23 (s, 2H), 4.70 (m, 2H), 4.35 (s, 4H); 13C NMR (DMSO-d6, 100MHz), δ (ppm): 137.5, 115.1, 114.4, 77.3, 69.0; 19 F NMR (DMSO-d6, 376MHz), δ (ppm): -87.5; 31 P NMR ((DMSO-d6,160MHz), δ (ppm): 47.9; HRMS (ESI + )m / z[M] + calcd.forC6H9F2O4P:214.0207.found:214.0241.

[0095] As a specific example, a method for preparing the polymeric monomer I-149' may include: (a) synthesis Referring to the synthesis of monomer I-137', from (b) Prepared by reaction. A substitution reaction was carried out to obtain the polymeric monomer I-149', i.e. For detailed procedures, refer to the method for preparing polymerizable monomer I-192'. The obtained target product is then subjected to... 1 H NMR, 13 C NMR, 19 F NMR, 31 The characterization and analysis were performed using methods such as pNMR and HRMS, and the results are as follows: 1 H NMR (DMSO-d6, 400MHz), δ (ppm): 5.89 (s, 1H), 5.23 (s, 2H), 4.20 (m, 2H), 2.88 (s, 4H); 13 C NMR (DMSO-d6, 100MHz), δ (ppm): 137.5, 118.7, 115.1, 74.2, 31.9; 19 F NMR (DMSO-d6, 376MHz), δ (ppm): -88.3; 31 P NMR ((DMSO-d6,160MHz), δ (ppm): 46.5; HRMS (ESI + )m / z[M] + calcd.forC6H9F2O2PS2:245.9750.found:245.9721.

[0096] As a specific example, a method for preparing the polymeric monomer I-173' may include: (a) synthesis As shown above. (b) Make A substitution reaction was carried out to obtain the polymeric monomer I-173', i.e. For detailed procedures, refer to the method for preparing polymerizable monomer I-192'. The obtained target product is then subjected to... 1 H NMR, 13 C NMR, 19 F NMR, 31 The characterization and analysis were performed using methods such as pNMR and HRMS, and the results are as follows: 1 H NMR (DMSO-d6, 400MHz), δ (ppm): 5.96 (s, 1H), 5.12 (s, 1H), 5.03 (s, 1H), 3.85 (s, 4H), 3.23 (m, 2H); 13 C NMR (DMSO-d6, 100MHz), δ (ppm): 132.7, 115.9, 113.7, 79.9, 21.0; 19 F NMR (DMSO-d6, 376MHz), δ (ppm): -73.2; 31 P NMR ((DMSO-d6,160MHz), δ (ppm): 44.8; HRMS (ESI + )m / z[M] + calcd.for C6H9F2O3PS:229.9978.found:229.9986

[0097] As a specific example, a method for preparing the polymeric monomer I-205' may include: (a) synthesis As shown above. (b) Make A substitution reaction was carried out to obtain the polymeric monomer I-205', i.e. For detailed procedures, refer to the method for preparing polymeric monomer I-12'. The obtained target product is then subjected to... 1 H NMR, 13 C NMR, 31 The characterization and analysis were performed using methods such as pNMR and HRMS, and the results are as follows: 1 H NMR (DMSO-d6, 400MHz), δ (ppm): 5.70 (s, 1H), 5.03 (s, 1H), 4.97 (s, 1H), 3.83 (m, 2H), 2.75 (m, 2H), 2.0 (s, 2H); 13 C NMR (DMSO-d6, 100MHz), δ (ppm): 132.7, 115.9, 79.7, 29.8, 23.5; 31 P NMR ((DMSO-d6,160MHz), δ (ppm): 43.3; HRMS (ESI + )m / z[M] +calcd.for C5H9O2PS:164.0061.found:164.0037.

[0098] As a specific example, a method for preparing the polymeric monomer I-229' may include: (a) synthesis As shown above. (b) Make A substitution reaction was carried out to obtain the polymeric monomer I-229', i.e. For detailed procedures, refer to the method for preparing polymeric monomer I-12'. The obtained target product is then subjected to... 1 H NMR, 13 C NMR, 31 The cells were characterized and analyzed using methods such as PNMR and HRMS, and the results are as follows: 1 H NMR (DMSO-d6, 400MHz), δ (ppm): 5.70 (s, 1H), 5.03 (s, 1H), 4.97 (s, 1H), 3.79 (m, 2H), 2.84 (m, 2H), 2.0 (m, 3H); 13 C NMR (DMSO-d6, 100MHz), δ (ppm): 132.7, 115.9, 79.6, 39.9, 29.7; 31 P NMR ((DMSO-d6,160MHz), δ (ppm): 42.6; HRMS (ESI + )m / z[M] + calcd.for C5H 10 NO2P:147.0449.found:147.0468.

[0099] In some specific embodiments of this application, the method for preparing cyclic phosphate compounds containing double bonds may further include: reacting the compound obtained from general formula I... Perform a vulcanization reaction; and / or react with the product obtained by general formula II. The sulfidation reaction can be carried out, for example, using a tetrahydrofuran (THF) solution of Lawesson's reagent (2,4-bis(p-methoxyphenyl)-1,3-dithiodiphosphonobutane-2,4-sulfide) under heating conditions (such as isothermal heating) to obtain the product of the general formula [formula missing]. The polymerized monomers, and / or obtained by the general formula: The monomers are polymerized. The following reaction equation can be used as a reference for understanding:

[0100]

[0101] In some embodiments of this application, the cyclic phosphate compound containing double bonds may include one or more polymeric monomers, such as at least one of polymeric monomer I-12' of polymer I-12, polymeric monomer I-49' of polymer I-49, polymeric monomer I-84' of polymer I-84, polymeric monomer I-108' of polymer I-108, and polymeric monomer I-192' of polymer I-192.

[0102] In some embodiments of this application, the self-polymerization of cyclic phosphate compounds containing double bonds and / or the copolymerization of cyclic phosphate compounds containing double bonds with a second polymerizable compound can be carried out under initiator conditions. The initiator may include at least one of azobisisobutyronitrile, azobisisoheptanenitrile, 2,2”-azabis(2-imidazoline) dihydrochloride, 2,2'-azobisisobutyranine dihydrochloride, benzoyl peroxide, benzoyl tert-butyl peroxide, and methyl ethyl ketone peroxide. Self-polymerization and / or copolymerization reactions under the action of initiators within the given range are beneficial for forming network polymers and can also facilitate... By adjusting the amount of initiator and the conditions, the polymerization rate and degree of polymerization can be controlled, thereby facilitating the acquisition of polymers within the desired molecular weight range. Optionally, based on the total mass of the cyclic phosphate ester compound containing double bonds and the second polymerizable compound, the amount of initiator can be 1 wt% to 10 wt%, for example, 2 wt%, 4 wt%, 6 wt%, 8 wt%, 10 wt%, or any range of the above values. Controlling the amount of initiator within the given range can further improve the polymerization rate and degree of polymerization, thereby further facilitating the acquisition of polymers with the desired molecular weight range.

[0103] The third aspect of this application provides a gel polymer electrolyte, comprising: a polymer matrix and an electrolyte. The polymer matrix includes the polymer of the first aspect of this application or a polymer prepared using the method of the second aspect of this application. It is understood that the electrolyte may include a solvent and a lithium salt. The solvent may be a non-aqueous solvent. Optionally, the solvent may include a main solvent and an auxiliary solvent. The main solvent may dissolve the lithium salt and improve the electrochemical stability of the electrolyte, while the auxiliary solvent may reduce the viscosity of the electrolyte and further improve the ionic conductivity. It should be noted that the features and effects described for the polymer of the first aspect of this application and the method for preparing the polymer of the second aspect of this application also apply to the gel polymer electrolyte of the third aspect of this application, and will not be repeated here. In summary, this gel polymer electrolyte can not only improve the thermal stability of the battery and reduce the probability of combustion and thermal runaway, but also alleviate the volume expansion caused during charging and discharging to a certain extent and improve the volume stability during cycling.

[0104] In some embodiments of this application, the main solvent in the electrolyte may include, but is not limited to, one or more of ester solvents, ether solvents, sulfone solvents, nitrile solvents, and ionic liquid solvents. Among them, ester solvents may include, but are not limited to, ethylene carbonate (EC), propylene carbonate (PC), butenyl carbonate (BC), vinylene carbonate (VC), ethylene sulfite (ES), propylene sulfite (PS), dimethyl sulfite (DMS), diethyl sulfite (DES), γ-butyrolactone (BL), dimethyl carbonate (DMC), diethyl carbonate (DEC), methyl ethyl carbonate (EMC), methyl propyl carbonate (MPC), methyl formate (MF), ethyl formate (EF), methyl acetate (MA), ethyl acetate (EA), ethyl propionate (EP), ethyl butyrate (EB), and one or more of their fluorinated derivatives. Ether solvents may include, but are not limited to, one or more of dimethoxymethane (DMM), ethylene glycol dimethyl ether (DME), ethylene glycol diethyl ether (DEE), 1,2-dimethoxypropane (DMP), diethylene glycol dimethyl ether (DGM), tetrahydrofuran (THF), tetrahydropyran (THP), 1,3-dioxolane (DOL), 1,3-dioxane (1,3-DXA), 1,4-dioxane (1,4-DXA), and their fluorinated derivatives. Sulfone solvents include, but are not limited to, one or more of dimethyl sulfone, dimethyl sulfoxide, sulfolane, ethyl methyl sulfone, tetramethylene sulfoxide, ethyl methyl sulfoxide, diethyl sulfone, diethyl sulfoxide, methyl phenyl sulfone, methyl phenyl sulfoxide, ethyl phenyl sulfone, ethyl phenyl sulfoxide, vinyl phenyl sulfone, vinyl phenyl sulfoxide, and their fluorinated derivatives. Using the main solvents within the range given above can improve lithium salt solubility and give the electrolyte good ion transport performance.

[0105] In some embodiments of this application, the auxiliary solvent in the electrolyte can be a solvent that does not dissolve lithium salts but is miscible with the main solvent. Generally, electrolytes with low lithium salt concentrations have lower viscosity and higher conductivity, but slightly lower electrochemical stability. High-concentration electrolytes, on the other hand, have most solvent molecules that can react with Li... + The combination of a solvated shell structure and a high electrochemical stability results in high viscosity and low ion mobility due to high concentration, which degrades the electrolyte's electrical performance. The auxiliary solvent, which is insoluble in lithium salt but miscible with the main solvent, is considered as a diluent. The gel polymer electrolyte of the third aspect of this application forms a locally high-concentration electrolyte by adding a diluent to a high-concentration electrolyte. This retains the characteristics of a high-concentration electrolyte while also achieving the advantages of low viscosity and high ionic conductivity found in low-concentration electrolytes. In other words, the electrolyte combines the advantages of both low-concentration and high-concentration electrolytes, resulting in a combination of high ion mobility and good electrochemical stability, thereby further improving the battery's kinetic performance.

[0106] In some embodiments of this application, the auxiliary solvent in the electrolyte may include, but is not limited to, cyclohexane, benzene, toluene, p-xylene, m-xylene, o-xylene, fluorobenzene, p-difluorobenzene, m-difluorobenzene, o-difluorobenzene, trifluorotoluene, trifluoromethoxybenzene, decafluoropentane, perfluoropentanone, 1,1,2,2-tetrafluoroethyl-2,2,3,3-tetrafluoropropyl ether, 1,2-bis(1,1,2,2-tetrafluoroethoxy)ethane, bis(2,2,2-trifluoroethyl) ether, 1,1,2,3,3,3-hexafluoropropylethyl ether, 1H, One or more of the following: 1H,5H-octafluoropentyl-1,1,2,2-tetrafluoroethyl ether, ethyl trifluoromethyl ether, difluoromethyl-2,2,3,3,3-pentafluoropropyl ether, heptafluoropropyl-1,2,2,2-tetrafluoroethyl ether, difluoromethyl 2,2,3,3-tetrafluoropropyl ether, perfluoroisopropylmethyl ether, 1,1,2,2-tetrafluoroethyl-2,2,2-trifluoroethyl ether, ethyl-1,1,2,2-tetrafluoroethyl ether, ethyl-2,2,2-tetrafluoroethyl ether, bis(1,1,2,2-tetrafluoroethyl) ether. Optionally, the auxiliary solvent in the electrolyte may include one or more of trifluoromethoxybenzene, 1,1,2,2-tetrafluoroethyl-2,2,3,3-tetrafluoropropyl ether, and 1,2-bis(1,1,2,2-tetrafluoroethoxy)ethane. The auxiliary solvents within the given range have a high electrochemical window, good compatibility, and good ability to promote the formation of fluorine-rich SEI. Combining them with the main solvent can improve the ionic conductivity and electrochemical stability of the electrolyte, and also help reduce the side reactions between the electrolyte and the negative electrode.

[0107] In some embodiments of this application, the lithium salt in the electrolyte may include, but is not limited to, one or more of lithium bis(fluorosulfonyl)imide (LiFSI), lithium hexafluorophosphate (LiPF6), lithium tetrafluoroborate (LiBF4), lithium hexafluoroarsenate (LiAsF6), lithium bis(trifluoromethanesulfonyl)imide (LiTFSI), lithium trifluoromethanesulfonate (LiOTF), lithium difluorophosphate (LiDFP), lithium dioxolane-borate (LiBOB), lithium difluorooxolane-borate (LiDFOB), lithium difluorodioxolane-phosphate, and lithium tetrafluorooxolane-phosphate. For example, lithium bis(fluorosulfonyl)imide may be selected. The above-mentioned lithium salts can decompose on the negative electrode surface to form an SEI component rich in inorganic fluorine. At the same time, they have good dissociation ability, which is beneficial to achieving a high electrolyte ion conductivity and a low electrolyte viscosity, thereby improving the electrochemical performance of the battery.

[0108] In some embodiments of this application, the electrolyte may further include an initiator and polymer monomers of the polymer matrix. The initiator is used to initiate the polymerization of the polymer monomers of the polymer matrix to form the polymer matrix. Optionally, additives may be added to the electrolyte as needed to achieve the desired effect. For example, additives that inhibit the dissolution of transition metals may be added, and / or additives that promote film formation may be added. The additives that promote film formation may include, but are not limited to, one or more of propane sulpholactone, vinyl sulfate, vinyl sulfite, tris(trimethylsilane) phosphate, tris(trimethylsilane) phosphite, tris(trifluoroethyl) phosphate, tris(trifluoroethyl) phosphite, tris(trimethylsilane) borate, dimethyl maleic anhydride, and butyl 1,4-diisocyanate. Selecting additives within the given range further helps to improve the stability of the positive and negative electrodes of the battery and extend the battery life.

[0109] In some embodiments of this application, the mass percentage of the polymer matrix in the gel polymer electrolyte can be from 0.5 wt% to 25 wt%, for example, it can be 1 wt%, 3 wt%, 5 wt%, 7 wt%, 9 wt%, 11 wt%, 13 wt%, 15 wt%, 17 wt%, 19 wt%, 21 wt%, 23 wt%, 25 wt%, etc., or it can be any range of the above values. Optionally, the mass percentage of the polymer matrix in the gel polymer electrolyte can be from 5 wt% to 25 wt%, and more preferably from 5 wt% to 12 wt%. Regarding the polymer composition used in this application, if the mass percentage of the polymer matrix in the gel polymer electrolyte is too small, it is difficult to achieve good flame retardancy and improve battery thermal stability. If the mass percentage of the polymer matrix is ​​too large, it is easy to lead to increased polarization and decreased ionic conductivity, affecting the cycle life of the battery. By controlling the mass percentage of the polymer matrix in the gel polymer electrolyte within the given range, the electrochemical performance and thermal stability of the battery can be balanced simultaneously, which is beneficial to reducing the probability of battery combustion and thermal runaway, and also to obtaining a longer battery life.

[0110] A fourth aspect of this application provides a battery comprising: the gel polymer electrolyte described in the third aspect of this application, and / or a polymer obtained by the method described in the second aspect of this application, and / or the polymer described in the first aspect of this application. Optionally, the battery can be a secondary battery, for example, a lithium metal secondary battery or a lithium-ion battery.

[0111] In some embodiments of this application, the formation process of the gel polymer electrolyte during battery fabrication includes, but is not limited to: mixing the main solvent, auxiliary solvent, and lithium salt of the gel polymer electrolyte, as well as the polymer monomers and initiator of the polymer matrix, and injecting the resulting mixture into the battery cell for encapsulation and curing. For example, the curing operation can be maintained at 50°C to 70°C for 8 to 12 hours to allow the polymer monomers to polymerize and form the polymer matrix, followed by standing. When characterizing the polymer matrix in the battery, the battery can be disassembled, and the obtained gel polymer electrolyte can be vacuum dried to remove the solvent, washed to remove the lithium salt, dissolved in an appropriate amount of good solvent, and finally filtered with n-hexane to obtain the polymer matrix. The structure of the polymer matrix can be characterized using infrared spectroscopy (IR) and nuclear magnetic resonance (NMR, for example...). 1 H, 13 C 19 F, 31 Commonly used methods include P, mass spectrometry (MS), elemental analysis, gel permeation chromatography (GPC), and laser Raman spectroscopy (LR).

[0112] In some embodiments of this application, the battery may include a positive electrode, a negative electrode, a separator, and the gel polymer electrolyte. During battery charging and discharging, active ions repeatedly insert and extract between the positive and negative electrode. The separator is disposed between the positive and negative electrode, serving as an isolation layer. The gel polymer electrolyte conducts ions between the positive and negative electrode.

[0113] [Positive electrode plate]

[0114] In a battery, the positive electrode typically includes a positive current collector and a layer of positive active material disposed on the positive current collector, the positive active material layer comprising the positive active material. The positive current collector can be a conventional metal foil or a composite current collector (a composite current collector can be formed by depositing metal material on a polymer substrate). As an example, the positive current collector can be aluminum foil.

[0115] In this application, the specific type of positive electrode active material is not limited; any active material known in the art that can be used for battery positive electrodes can be used, and those skilled in the art can select according to actual needs. For example, the positive electrode active material may include, but is not limited to, positive electrode active materials containing lithium transition metal oxides and / or lithium phosphates with olivine structures. The lithium transition metal oxides may include undoped and / or optionally doped modified lithium transition metal oxides, uncoated and / or coated modified lithium transition metal oxides, and the lithium phosphates with olivine structures may include undoped and / or optionally doped modified lithium phosphates, uncoated and / or coated modified lithium phosphates. The positive electrode active materials within the given range can be prepared or obtained commercially.

[0116] In some specific embodiments of this application, the positive electrode active material can be selected from lithium transition metal oxides. Optionally, the lithium transition metal oxides may include, but are not limited to, lithium cobalt oxides (such as LiCoO2), lithium nickel oxides (such as LiNiO2), lithium manganese oxides (such as LiMnO2, LiMn2O4), lithium nickel manganese oxides, and lithium nickel cobalt manganese oxides (such as LiNi). 1 / 3 Co 1 / 3Mn 1 / 3 O2 (abbreviated as NCM) 333 LiNi 0.5 Co 0.2 Mn 0.3 O2 (abbreviated as NCM) 523 LiNi 0.5 Co 0.25 Mn 0.25 O2 (abbreviated as NCM) 211 LiNi 0.6 Co 0.2 Mn 0.2 O2 (abbreviated as NCM) 622 LiNi 0.8 Co 0.1 Mn 0.1 O2 (abbreviated as NCM) 811 LiNi 0.96 Co 0.02 Mn 0.02 O2 (Ni) 96 (e.g., lithium nickel cobalt aluminum oxides, such as LiNi) 0.85 Co 0.15 Al 0.05 One or more of O2 and its modified compounds.

[0117] In some specific embodiments of this application, the positive electrode active material may include lithium phosphates with an olivine structure, such as, but not limited to, lithium iron phosphate (e.g., LiFePO4 (LFP)), lithium iron phosphate and carbon composites, lithium manganese phosphate (e.g., LiMnPO4), lithium manganese phosphate and carbon composites, lithium manganese iron phosphate, and lithium manganese iron phosphate and carbon composites.

[0118] In some specific embodiments of this application, the positive electrode active material layer may optionally include a binder, a conductive agent, and other optional additives. As an example, the conductive agent may include, but is not limited to, one or more of superconducting carbon, acetylene black, carbon black, Ketjen black, carbon dots, carbon nanotubes, Super P (SP), graphene, and carbon nanofibers. As an example, the binder may include, but is not limited to, one or more of styrene-butadiene rubber (SBR), water-based acrylic resin, polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), ethylene-vinyl acetate copolymer (EVA), polyacrylic acid (PAA), carboxymethyl cellulose (CMC), polyvinyl alcohol (PVA), and polyvinyl butyral (PVB).

[0119] [Negative electrode plate]

[0120] In a battery, the negative electrode typically includes a negative current collector and a layer of negative active material disposed on the negative current collector, the negative active material layer comprising a negative active material. The negative current collector can be a conventional metal foil or a composite current collector (for example, a composite current collector can be formed by depositing metal material on a polymer substrate). As an example, the negative current collector can be copper foil.

[0121] In some embodiments of this application, the battery of the fourth aspect of this application can be a lithium-ion battery. In this case, the specific type of negative electrode active material is not limited, and any active material known in the art that can be used for the negative electrode of a battery can be used. Those skilled in the art can flexibly select according to actual needs. As an example, the negative electrode active material may include, but is not limited to, one or more of artificial graphite, natural graphite, hard carbon, soft carbon, silicon-based materials, and tin-based materials. Optionally, silicon-based materials may include one or more of elemental silicon, silicon oxide compounds (e.g., silicon suboxide), silicon-carbon composites, silicon-nitrogen composites, and silicon alloys. Further optionally, tin-based materials may include one or more of elemental tin, tin oxide compounds, and tin alloys. The negative electrode active materials within the given range can be prepared or obtained commercially.

[0122] In some specific embodiments of this application, the negative electrode active material may include silicon-based materials, such as composite negative electrode active materials doped with silicon-based materials and carbon materials. Using silicon-based materials in the negative electrode active material layer is beneficial to further improve the energy density of the battery. Optionally, the silicon content in the negative electrode active material may be not less than 10 wt%.

[0123] In some specific embodiments of this application, the negative electrode active material layer may optionally include a binder, a conductive agent, and other optional additives. As an example, the conductive agent may include, but is not limited to, one or more of superconducting carbon, acetylene black, carbon black, Ketjen black, carbon dots, carbon nanotubes, graphene, and carbon nanofibers. As an example, the binder may include, but is not limited to, one or more of styrene-butadiene rubber (SBR), water-based acrylic resin, polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), ethylene-vinyl acetate copolymer (EVA), polyvinyl alcohol (PVA), and polyvinyl butyral (PVB). As an example, other optional additives may include, but are not limited to, thickeners and dispersants (e.g., sodium carboxymethyl cellulose CMC-Na), and PTC thermistor materials.

[0124] In some embodiments of this application, the battery of the fourth aspect of this application can be a lithium metal secondary battery, in which case its negative electrode material can be, but is not limited to, elemental lithium metal. For example, the negative electrode material can also be an alloy formed by lithium metal and various other metals or non-metals. Optionally, the metal elements can include, but are not limited to, tin (Sn), zinc (Zn), aluminum (Al), magnesium (Mg), silver (Ag), gold (Au), gallium (Ga), indium (In), and tin foil (Pt); and further optionally, the non-metal elements can include, but are not limited to, boron (B), carbon (C), and silicon (Si).

[0125] In some embodiments of this application, the battery of the fourth aspect of this application may also be a lithium metal battery without a negative electrode. In this case, the negative electrode consists only of a metal foil current collector and there is no lithium metal on its surface. During cycling, only the lithium in the positive electrode is used, and lithium metal is deposited and stripped off on the negative electrode side.

[0126] In some embodiments of this application, the separator in the battery may include, but is not limited to, a polyethylene porous membrane, a polypropylene porous membrane, a polyimide porous membrane, and a porous membrane formed by a composite of various polymers.

[0127] In some embodiments of this application, the shape of the battery in the fourth aspect of this application is not particularly limited, and those skilled in the art can flexibly choose according to actual needs, for example, it can be cylindrical, square (see reference). Figure 1 (Understanding) or other arbitrary shapes.

[0128] In some embodiments of this application, the battery may include an outer packaging for encapsulating the positive electrode, the negative electrode, the separator, and the electrolyte.

[0129] In some embodiments, the outer packaging may include a shell and a cover. The shell may include a base plate and side plates attached to the base plate, the base plate and side plates enclosing a receiving cavity. The shell has an opening communicating with the receiving cavity, and the cover can be placed over the opening to close the receiving cavity.

[0130] In some embodiments, the positive electrode, negative electrode, and separator can be formed into an electrode assembly via a winding or stacking process. The electrode assembly is encapsulated within the receiving cavity. The electrolyte can be a gel polymer electrolyte, with the electrolyte solution in the gel polymer electrolyte wetting the electrode assembly. The battery can contain one or more electrode assemblies, which can be adjusted as needed.

[0131] In some implementations, the outer packaging of the battery can be a hard shell, which can be a metal shell or a non-metal shell, such as a hard plastic shell, an aluminum shell, a steel shell, etc.

[0132] In some embodiments, the outer packaging of the battery can also be a soft pack, such as a pouch. The material of the soft pack can include plastics, such as one or more of polypropylene (PP), polybutylene terephthalate (PBT), polybutylene succinate (PBS), etc., or aluminum-plastic film, etc.

[0133] In some embodiments of this application, the battery can be either a single battery cell 1 (see reference 1) Figure 1 (Understanding), or it can be a battery module 2 composed of individual battery cells 1 (refer to) Figure 2 (Understanding) or battery pack 3 (Reference) Figure 3 understand).

[0134] In some implementations, the battery can be a battery module, and the number of individual battery cells contained in the battery module can be one or more, the specific number of which can be adjusted according to the application and capacity of the battery module. For example... Figure 2 This is battery module 2 as an example. (See reference...) Figure 2 In battery module 2, multiple battery cells 1 can be arranged sequentially along the length of battery module 2. Of course, they can also be arranged in any other manner. Furthermore, the multiple battery cells 1 can be secured with fasteners. Optionally, battery module 2 may also include a housing with a receiving space in which the multiple battery cells 1 are received.

[0135] In some embodiments, the battery modules described above can also be assembled into a battery pack, and the number of battery modules contained in the battery pack can be adjusted according to the application and capacity of the battery pack. (See reference...) Figure 3 or Figure 4 ( Figure 3 and Figure 4 As an example, a battery pack 3 may include a battery compartment and multiple battery modules 2 disposed within the battery compartment. The battery compartment may include an upper housing 4 and a lower housing 5, with the upper housing 4 covering the lower housing 5 to form a closed space for accommodating the battery modules 2. The multiple battery modules 2 may be arranged in any manner within the battery compartment.

[0136] In addition, this application also provides an electrical device comprising: a battery according to the fourth aspect of this application. The battery, such as a single cell, battery module, or battery pack, can serve as both a power source and an energy storage unit for the electrical device. The electrical device may include, but is not limited to, mobile devices (e.g., mobile phones, laptops), electric vehicles (e.g., pure electric vehicles, hybrid electric vehicles, plug-in hybrid electric vehicles, electric bicycles, electric scooters, electric golf carts, electric trucks, etc.), electric trains, ships and satellites, and energy storage systems. Reference Figure 5 To illustrate, as a specific example, the electrical device could be a vehicle. The specific type of battery can be selected based on the device's usage requirements, such as individual battery cells, battery modules, or battery packs.

[0137] As an example, the electrical device can be a pure electric vehicle, a hybrid electric vehicle, or a plug-in hybrid electric vehicle. To meet the high power and high energy density requirements of the battery, a battery pack or battery module can be used.

[0138] As another example, the device could be a mobile phone, tablet, or laptop. These devices typically require a slim and lightweight design and can use battery cells as their power source.

[0139] The following describes embodiments of this application. The embodiments described below are exemplary and are only used to explain this application, and should not be construed as limiting this application. Where specific techniques or conditions are not specified in the embodiments, they are performed according to the techniques or conditions described in the literature in this field or according to the product instructions. Reagents or instruments used, unless otherwise specified, are all conventional products that can be obtained commercially.

[0140] Example 1

[0141] (1) Preparation of positive electrode sheet

[0142] Lithium nickel cobalt manganese oxide (LiNi) is used as the positive electrode active material. 0.8 Co 0.1 Mn 0.1O2 (NCM811), conductive agent acetylene black, and binder PVDF were mixed at a mass ratio of 98:1:1. N-methylpyrrolidone (NMP) solvent was added and stirred until the system was homogeneous, yielding a positive electrode slurry (70 wt% solids content). The positive electrode slurry was then subjected to a reaction at approximately 25 mg / cm³. 2 The loading capacity was uniformly coated on both sides of the positive electrode current collector aluminum foil, air-dried at room temperature, then transferred to an oven for further drying, and then cut into 40mm×50mm rectangles to serve as the positive electrode sheet, with a positive electrode surface capacity of 3.5mAh / cm². 2 .

[0143] (2) Preparation of negative electrode sheet

[0144] A 50μm lithium foil is rolled onto a 12μm copper foil and then cut into 41mm×51mm rectangles for use as negative electrode sheets.

[0145] (3) Preparation of gel polymer electrolytes:

[0146] A 1.5M electrolyte was prepared by mixing 1.0g of the main solvent 1,2-dimethoxyethane (DME), 6.4g of the auxiliary solvent 1,1,2,2-tetrafluoroethyl-2,2,3,3-tetrafluoropropyl ether (TTE), and 1.5g of lithium salt bis(fluorosulfonyl)imide. Then, 0.9g of the polymer monomer I-12' and 16.9mg of the initiator azobisisoheptanenitrile were added (after injection and encapsulation, the electrolyte was cured at 60°C for 12h to prepare a gel polymer electrolyte).

[0147] (4) Preparation of the diaphragm

[0148] A 12μm thick polyethylene porous membrane was selected as the separator and cut into rectangles of 45mm*55mm for later use.

[0149] (5) Preparation of secondary batteries

[0150] Battery Assembly: A pre-cut positive electrode is matched with two pre-cut negative electrodes, separated by the aforementioned separator. The electrodes are then wrapped in an aluminum-plastic film bag to form a stacked dry cell. 0.3g of the prepared electrolyte is injected, and the aluminum-plastic film bag is vacuum-sealed using heat pressing. After standing at room temperature for at least 6 hours, cycle testing can begin. The rated capacity of the stacked battery prepared in this way is 140mAh.

[0151] Comparative Example 1

[0152] The difference from Example 1 is that a liquid electrolyte is used instead of a gel polymer electrolyte.

[0153] Preparation of electrolyte: 1.0 g of main solvent 1,2-dimethoxyethane (DME), 6.4 g of auxiliary solvent 1,1,2,2-tetrafluoroethyl-2,2,3,3-tetrafluoropropyl ether (TTE) and 1.5 g of lithium salt lithium difluorosulfonylimide were used to form a 1.5 M concentration electrolyte.

[0154] Comparative Example 2

[0155] The difference from Example 1 is that the types of polymer monomers added are different when preparing the gel polymer electrolyte.

[0156] (3) Preparation of gel polymer electrolyte: 1.0 g of main solvent 1,2-dimethoxyethane (DME), 6.4 g of auxiliary solvent 1,1,2,2-tetrafluoroethyl-2,2,3,3-tetrafluoropropyl ether (TTE) and 1.5 g of lithium salt lithium difluorosulfonylimide were added to form a 1.5 M concentration electrolyte. Then, 0.9 g of methyl acrylate and 16.9 mg of initiator azobisisoheptanenitrile were added.

[0157] Comparative Examples 3-5

[0158] The difference from Comparative Example 2 is that the type of the second polymerizable monomer added during the preparation of the gel polymer electrolyte is different.

[0159] The second polymerizable monomers used in Comparative Examples 3, 4, and 5 were vinylene carbonate, hexafluoroisopropyl methacrylate, and hydroxyethyl methacrylate, respectively, as detailed in Table 1.

[0160] Examples 2-5

[0161] The difference from Example 1 is that the types of polymer monomers added during the preparation of the gel polymer electrolyte are different. The polymer monomers used in Examples 2, 3, 4 and 5 are I-49', I-192', I-84' and I-108', respectively. See Table 1 for details.

[0162] Example 6

[0163] The difference from Example 1 is as follows:

[0164] (3) Preparation of gel polymer electrolyte: 1.0 g of main solvent 1,2-dimethoxyethane (DME), 6.4 g of auxiliary solvent 1,1,2,2-tetrafluoroethyl-2,2,3,3-tetrafluoropropyl ether (TTE) and 1.5 g of lithium salt lithium difluorosulfonylimide were added to form a 1.5 M concentration electrolyte. Then, 0.45 g of polymer monomer I-12', 0.45 g of polymer monomer I-108' and 20 mg of initiator azobisisoheptanenitrile were added.

[0165] Example 7

[0166] The difference from Example 1 is as follows:

[0167] (3) Preparation of gel polymer electrolyte: 1.0 g of main solvent 1,2-dimethoxyethane (DME), 6.4 g of auxiliary solvent 1,1,2,2-tetrafluoroethyl-2,2,3,3-tetrafluoropropyl ether (TTE) and 1.5 g of lithium salt lithium difluorosulfonylimide were added to form a 1.5 M concentration electrolyte. Then, 0.45 g of polymer monomer I-84', 0.45 g of polymer monomer I-192' and 20 mg of initiator azobisisoheptanenitrile were added.

[0168] Example 8

[0169] The difference from Example 1 is as follows:

[0170] (3) Preparation of gel polymer electrolyte: 1.0 g of main solvent 1,2-dimethoxyethane (DME), 6.4 g of auxiliary solvent 1,1,2,2-tetrafluoroethyl-2,2,3,3-tetrafluoropropyl ether (TTE) and 1.5 g of lithium salt lithium difluorosulfonylimide were added to form a 1.5 M concentration electrolyte. Then, 0.45 g of polymerizable monomer I-12', 0.45 g of second polymerizable monomer methyl acrylate and 20 mg of initiator azobisisoheptanenitrile were added.

[0171] Examples 9-11

[0172] The difference from Example 8 is that the type of the second polymerizable monomer added is different when preparing the gel polymer electrolyte.

[0173] The second polymerizable monomers used in Examples 9, 10, and 11 are, in order, vinylene carbonate, hexafluoroisopropyl methacrylate, and hydroxyethyl methacrylate, as detailed in Table 1.

[0174] Examples 12-18

[0175] The difference from Example 1 is that the types of polymer monomers added during the preparation of the gel polymer electrolyte are different. The polymer monomers used in Examples 12 to 18 are, in order, the polymer monomers I-60', I-125', I-137', I-149', I-173', I-205', and I-229' of polymers I-60, I-125, I-137', I-149', I-173', I-205', and I-229', respectively. See Table 1 for details.

[0176] Example 19

[0177] The difference from Example 1 is as follows:

[0178] (3) Preparation of gel polymer electrolyte: 1.0 g of main solvent 1,2-dimethoxyethane (DME), 6.4 g of auxiliary solvent 1,1,2,2-tetrafluoroethyl-2,2,3,3-tetrafluoropropyl ether (TTE) and 1.5 g of lithium salt lithium difluorosulfonylimide were added to form a 1.5 M concentration electrolyte. Then, 0.089 g of polymer monomer I-12' and 6.0 mg of initiator azobisisoheptanenitrile were added.

[0179] Example 20

[0180] The difference from Example 1 is as follows:

[0181] (3) Preparation of gel polymer electrolyte: 1.0 g of main solvent 1,2-dimethoxyethane (DME), 6.4 g of auxiliary solvent 1,1,2,2-tetrafluoroethyl-2,2,3,3-tetrafluoropropyl ether (TTE) and 1.5 g of lithium salt lithium difluorosulfonylimide were added to form a 1.5 M concentration electrolyte. Then, 0.445 g of polymer monomer I-12' and 6.0 mg of initiator azobisisoheptanenitrile were added.

[0182] Example 21

[0183] The difference from Example 1 is as follows:

[0184] (3) Preparation of gel polymer electrolyte: 1.0 g of main solvent 1,2-dimethoxyethane (DME), 6.4 g of auxiliary solvent 1,1,2,2-tetrafluoroethyl-2,2,3,3-tetrafluoropropyl ether (TTE) and 1.5 g of lithium salt lithium difluorosulfonylimide were added to form a 1.5 M concentration electrolyte. Then, 1.335 g of polymer monomer I-12' and 31.0 mg of initiator azobisisoheptanenitrile were added.

[0185] Example 22

[0186] The difference from Example 1 is as follows:

[0187] (3) Preparation of gel polymer electrolyte: 1.0 g of main solvent 1,2-dimethoxyethane (DME), 6.4 g of auxiliary solvent 1,1,2,2-tetrafluoroethyl-2,2,3,3-tetrafluoropropyl ether (TTE) and 1.5 g of lithium salt lithium difluorosulfonylimide were added to form a 1.5 M concentration electrolyte. Then, 2.225 g of polymer monomer I-12' and 31.0 mg of initiator azobisisoheptanenitrile were added.

[0188] It should be noted that the above embodiments of this application exemplarily provide several methods for preparing gel polymer electrolytes. Other gel polymer electrolytes can be prepared by referring to these exemplary methods. Based on the exemplary compound preparation methods, those skilled in the art can readily obtain specific methods for implementing each synthetic step from relevant scientific literature or standard textbooks in the field. Unless specifically indicated, commercially available or literature-known compounds are used as raw materials for synthesis. Those skilled in organic synthesis will recognize that the nature and order of the proposed synthetic steps can be modified to optimize the formation of the compounds described herein. In addition, all raw materials, reagents, etc., whose sources are not clearly identified in the preparation process are conventional products obtained through commercial purchase.

[0189] Performance testing:

[0190] 1. Characterization of the polymer matrix in the obtained gel polymer electrolyte.

[0191] The electrolyte obtained in step (3) of preparing the gel polymer electrolyte was mixed with the polymer monomer and initiator, cured at 60°C for 12 hours, then vacuum dried to remove the solvent, washed to remove the lithium salt, dissolved in an appropriate amount of good solvent, and finally filtered by sedimentation with n-hexane to obtain the polymer matrix. Combined with infrared spectroscopy (IR) and nuclear magnetic resonance (NMR, for example... 1 H or 13 C or 19 F or 31 The obtained polymer matrix was characterized by one or more of the following methods: P), mass spectrometry (MS), elemental analysis, gel permeation chromatography (GPC), and laser Raman spectroscopy (LR).

[0192] 2. Secondary battery nail penetration test

[0193] The following steps were performed at 25°C: charging to 4.3V at 0.2C, followed by constant voltage charging to 0.05C at 4.3V; penetrating the cell's geometric center with a 3mm diameter high-temperature resistant steel needle at a speed of 25mm / s, keeping the needle inside the cell, and observing the heating state at that time. Each embodiment provided five parallel test groups, and the highest temperature reached was measured by installing thermocouples 2cm away from the puncture point on the surface of each battery, and the average value of the five parallel test groups was obtained.

[0194] The polymer matrices obtained in Examples 1-22 were characterized by nuclear magnetic resonance spectroscopy (NMR, for example...). 1 HNMR and 19Characteristic functional groups in the polymer were identified by 1H NMR and infrared spectroscopy (IR), and the polymer structure was identified by elemental analysis. The characterization results showed that the polymer matrix obtained by polymerizing the monomers in Examples 1 to 22 under initiator conditions has the structure shown in general formula I or general formula II of this application.

[0195] The secondary batteries prepared in Examples 1-22 and Comparative Examples 1-5 were subjected to nail penetration tests under the same conditions. The test results are shown in Table 1.

[0196] Table 1. Differences and test results between Examples 1-22 and Comparative Examples 1-5

[0197]

[0198]

[0199] Note: The polymer monomers I-12', I-49', I-192', I-84', I-108', I-60', I-125', I-137', I-149', I-173', I-205', and I-229' used in Examples 1-22 were all obtained using the preparation method disclosed in this application; methyl acrylate CAS: 96-33-3, Maclean, purity 99%; vinylene carbonate CAS: 872-36-6, Xienen, purity 99%; hexafluoroisopropyl methacrylate CAS: 3063-94-3, Merrill, purity 99%; hydroxyethyl methacrylate CAS: 868-77-9, Aladdin Biochemical, purity 99%.

[0200] Results and conclusions:

[0201] As shown in Examples 1-22 and Comparative Examples 1-5, using polymers with cyclic phosphate ester structures in electrolytes is beneficial for improving battery thermal stability and reducing the probability of battery combustion and thermal runaway. Furthermore, as shown in Examples 1-5 and Examples 12-18, in cyclic phosphate ester polymers, compared to X1 and X2 being sulfur or imino, when X1 and X2 are oxygen, it is beneficial for improving battery thermal stability; compared to Y being sulfur or imino, when Y is alkyl or alkoxy, it is beneficial for improving battery thermal stability; as shown in Examples 2 and 12, compared to structures without fluorine substitution, when cyclic phosphate ester polymers have fluorine substitution, it is beneficial for improving battery thermal stability. Additionally, as shown in Examples 1 and 19-22, as the content of the polymer matrix in the gel polymer electrolyte increases, the thermal stability of the battery also improves.

[0202] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and not to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application, and they should all be covered within the scope of the claims and specification of this application. In particular, as long as there is no structural conflict, the various technical features mentioned in the embodiments can be combined in any way. This application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A polymer, characterized in that, The general formula of the polymer is shown in Formula I: Formula I, Where: m includes 0 or 1; n is a positive integer; X1 and X2 independently include oxygen, sulfur or imino, respectively; X3 includes oxygen or sulfur; Y includes oxygen, sulfur, imine group, and unsubstituted or halogenated C. 1~8 Alkylene, unsubstituted or halogenated -SC 1~8 Alkylene, unsubstituted or halogenated -NH-C 1~8 Alkylene, unsubstituted or halogenated C 1~8 Any one of the alkeneoxy groups; R1, R2, R3, and R4 each independently include hydrogen, fluorine, unsubstituted or halogenated C. 1~6 Any of the alkyl groups; R5 includes unsubstituted or halogenated C. 1~10 alkyl, Any one of them; R9 includes unsubstituted or halogenated C 1~10 Any one of the alkyl groups.

2. The polymer according to claim 1, characterized in that, The halogens include fluorine.

3. The polymer according to claim 2, characterized in that, X1 and X2 each independently include oxygen or sulfur; Y includes oxygen, unsubstituted or fluorine-substituted C. 1~8 Alkylene, unsubstituted or fluorinated C 1~8 Any one of the alkeneoxy groups; R1, R2, R3, and R4 each independently include hydrogen, fluorine, and an unsubstituted or fluorine-substituted C. 1~6 Any of the alkyl groups; R5 includes unsubstituted or fluorinated C. 1~10 alkyl, Any one of them; R9 includes unsubstituted or fluorinated C 1~10 alkyl.

4. The polymer according to claim 3, characterized in that, X1 and X2 each independently include oxygen; X3 includes oxygen; Y includes oxygen, unsubstituted or fluorine-substituted C. 1~8 Alkylene, unsubstituted or fluorinated C 1~8 Any one of the alkeneoxy groups.

5. The polymer according to claim 1 or 2, characterized in that, The average molecular weight is 20,000 to 60,000.

6. The polymer according to claim 1 or 2, characterized in that, R1, R2, R3, and R4 each independently include unsubstituted or fluorinated C atoms. 1~6 alkyl.

7. The polymer according to claim 1 or 2, characterized in that, The polymer monomers include cyclic phosphate compounds containing double bonds.

8. The polymer according to claim 7, characterized in that, The monomer is a cyclic phosphate compound containing double bonds.

9. The polymer according to claim 7, characterized in that, The polymer monomers include: 。 10. The polymer according to claim 1 or 2, characterized in that, The polymer includes at least one of the following compounds: 。 11. The polymer according to claim 7, characterized in that, The polymeric monomers of the polymer also include a second polymerizable compound, and the polymer has the general formula shown in Formula II: Formula II, Where: a and b are independent positive integers, and 0.5≤a / b≤4; R6 is an unsubstituted or halogenated C. 3~8 Alkyl, unsubstituted or halogenated C 3~8 Epoxy groups, unsubstituted or halogenated C 3~8 Allyl, unsubstituted or halogenated C 3~8 (Meth)acryloyl, unsubstituted or halogenated C 3~8 Any type of acrylate.

12. The polymer according to claim 11, characterized in that, The second polymerizable compound includes at least one of the polymeric monomers, oligomers, and copolymers of gel-like polymeric electrolytes.

13. The polymer according to claim 11, characterized in that, The second polymerizable compound includes methyl methacrylate, styrene, methyl acrylate, ethyl acrylate, acrylic acid, trimethylsilyl methacrylate, acrolein dimethyl acetal, acrolein diethanolamide, 2-phenoxyethyl acrylate, tridecafluoro-2-hydroxynonyl acrylate, trifluoroethyl methacrylate, acrylonitrile-1,3-sulfonyl lactone, glycidyl methacrylate, acrylamide, trifluoroethyl acrylate, (acrylateoxymethyl)dimethylmethoxysilane, cyanoethyl acrylate, hydroxyethyl acrylate, triallyl benzotriazine, hydroxypropyl acrylate, 3-(perfluoro-3-methylbutyl)-2-hydroxypropyl acrylate, 1 At least one of the following: vinyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide, 1-allyl-3-ethylimidazolium bis(trifluoromethanesulfonyl)imide, 1-allyl-1-methylpyrrolidone bis(trifluoromethanesulfonyl)imide, 1,6-di(acryloyloxy)-2,2,3,3,4,4,5,5-octafluorohexane, pentafluorophenol acrylate, vinylene carbonate, maleic anhydride, ethyl cyanoacrylate, butyl acrylate, hexafluoroisopropyl methacrylate, hexafluorobutyl methacrylate, 2-hydroxy-3-phenoxypropyl acrylate, hydroxyethyl methacrylate, and vinyl vinyl carbonate.

14. The polymer according to claim 11, characterized in that, The second polymerizable compound includes at least one of vinylene carbonate, maleic anhydride, ethyl cyanoacrylate, butyl acrylate, hexafluoroisopropyl methacrylate, hexafluorobutyl methacrylate, hydroxypropyl acrylate, 2-hydroxy-3-phenoxypropyl acrylate, hydroxyethyl methacrylate, and vinyl vinyl carbonate.

15. A method for preparing the polymer according to any one of claims 1 to 14, characterized in that, include: It enables the self-polymerization of cyclic phosphate compounds containing double bonds; or, This involves copolymerizing cyclic phosphate compounds containing double bonds with a second polymerizable compound.

16. The method according to claim 15, characterized in that, The method for preparing the cyclic phosphate compound containing double bonds includes: make and A cyclization reaction occurs, yielding the product with the general formula: Compounds; or, make and A substitution reaction occurs, yielding the general formula: and / or compounds, in: m is 0 or 1; X1' and X2' independently include hydroxyl, mercapto, or amino groups respectively; X1 and X2 independently include oxygen, sulfur, or imino groups respectively; R1, R2, R3, and R4 each independently include hydrogen, fluorine, and unsubstituted or halogenated C atoms. 1~6 Any one of the alkyl groups; R7 and R8 each independently include an unsubstituted or halogenated C. 2~11 Alkenes; Y' includes hydrogen, hydroxyl, mercapto, or amino groups; Y" includes oxygen, sulfur, or imino groups; R9 includes unsubstituted or halogenated C groups. 1~10 alkyl.

17. The method according to claim 16, characterized in that, The It includes at least one of ethylene glycol, ethylenedithiol, 2-mercaptoethanol, mercaptoethylamine, ethanolamine, ethylenediamine, 1,3-propanediol, 1,3-propanedithiol, 3-mercapto-1-propanol, 3-amino-1-propanol, 3-mercapto-1-propaneamine, and 1,3-propanediamine.

18. The method according to claim 16, characterized in that, The method for preparing the cyclic phosphate compound containing double bonds further includes: right A sulfidation reaction is carried out to obtain the general formula: Compounds; or, right and / or A sulfidation reaction is carried out to obtain the general formula: and / or Compounds.

19. The method according to claim 15, characterized in that, The cyclic phosphate compounds containing double bonds include polymer monomers of at least one of polymers I-12, I-49, I-84, I-108, and I-192.

20. The method according to claim 15, characterized in that, The self-polymerization or copolymerization is carried out under initiator conditions, wherein the initiator includes at least one of azobisisobutyronitrile, azobisisoheptanenitrile, 2,2''-azabis(2-imidazoline) dihydrochloride, 2,2'-azobisisobutylamidine dihydrochloride, benzoyl peroxide, benzoyl tert-butyl peroxide, and methyl ethyl ketone peroxide.

21. A gel polymer electrolyte, characterized in that, It includes a polymer matrix and an electrolyte, wherein the polymer matrix comprises the polymer according to any one of claims 1 to 14 or a polymer obtained by the method according to any one of claims 15 to 20.

22. The gel polymer electrolyte according to claim 21, characterized in that, The polymer matrix has a mass percentage of 0.5wt% to 25wt%.

23. The gel polymer electrolyte according to claim 21, characterized in that, The polymer matrix accounts for 5 wt% to 15 wt% of the total mass.

24. The gel polymer electrolyte according to claim 21, characterized in that, The polymer matrix comprises 5wt% to 12wt% by mass.

25. A battery, characterized in that, It includes the gel polymer electrolyte of any one of claims 21 to 24, or the polymer prepared by the method of any one of claims 15 to 20, or the polymer of any one of claims 1 to 14.

26. An electrical appliance, characterized in that, Includes the battery as described in claim 25.

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