Polymers and their use

Abstract

This application provides a polymer and its use. The polymer has at least the structural formula shown in Formula 1, where R1 is selected from substituted or unsubstituted C1-C30 alkyl groups and substituted or unsubstituted C6-C60 aryl groups; R2 is selected from substituted or unsubstituted polyether groups, substituted or unsubstituted C1-C30 alkyl groups, substituted or unsubstituted C1-C30 alkoxy groups, and *-b1-SS-b2-* groups; b1 and b2 are each independently selected from substituted or unsubstituted C2-C15 linear alkyl groups and substituted or unsubstituted C6-C60 aryl groups; and R3 is an ionic liquid group, where n≧1 and n is an integer. Due to its special molecular structure, the polymer exhibits excellent ionic conductivity at room temperature when applied to polymer electrolytes.

Description

[Technical Field]

[0001] Embodiments of the present application relate to polymers and their use, and belong to the field of energy technology. [Background technology]

[0002] In the 1990s, Sony successfully industrialized lithium-ion batteries. Over decades of development, lithium-ion batteries have become widespread in all sectors of society, including 3C electronic products, electric vehicles, energy storage, and aerospace. In current lithium-ion batteries, organic electrolytes such as ether-based and carbonate-based electrolytes are used as the conductive medium for lithium ions. However, organic electrolytes have safety issues such as being highly volatile, prone to leakage, highly flammable, and highly explosive. Furthermore, during the lithium-ion battery cycle, non-uniform deposition of lithium at the negative electrode interface causes the formation and growth of lithium dendritic crystals. These dendritic crystals penetrate the battery separator, leading to short circuits and safety problems such as thermal runaway and battery ignition / combustion.

[0003] Inorganic solid electrolytes are widely used to solve safety problems in lithium-ion batteries due to their excellent electrochemical stability, thermal stability, and mechanical strength. However, inorganic solid electrolytes have a performance drawback: they are highly brittle, making them prone to cracking during use, which increases the internal resistance of the battery and, in severe cases, causes it to fail. Furthermore, poor solid-to-solid contact interfaces between the inorganic solid electrolyte and the positive and negative electrodes of the battery also increase the internal resistance of lithium-ion batteries, resulting in a rapid decrease in the capacity and performance of the lithium-ion battery.

[0004] Polymer electrolytes were developed to overcome the shortcomings of inorganic solid electrolytes. Polymer electrolytes possess excellent processability, flexibility, and mechanical strength, compensating for the performance deficiencies of inorganic solid electrolytes, but they typically have low ionic conductivity at room temperature. [Overview of the Initiative] [Problems that the invention aims to solve]

[0005] This invention provides a polymer that, due to its special molecular structure, exhibits excellent ionic conductivity at room temperature when applied to polymer electrolytes.

[0006] This invention provides a polymer electrolyte with excellent ionic conductivity at room temperature and can be widely applied to batteries to improve their electrochemical performance.

[0007] This application provides a separator which, since it contains the above-mentioned polymer or polymer electrolyte, can improve the electrochemical performance of a battery when applied to it.

[0008] The battery according to this application contains one of the above-mentioned polymer, polymer electrolyte, and separator, and therefore exhibits excellent electrochemical performance. [Means for solving the problem]

[0009] This application provides a polymer having at least the structural formula shown in Formula 1. [ka] In formula 1, R1 is selected from substituted or unsubstituted C1-C30 alkyl groups and substituted or unsubstituted C6-C60 aryl groups. R2 is selected from substituted or unsubstituted polyethers, substituted or unsubstituted C1-C30 alkyl groups, substituted or unsubstituted C1-C30 alkoxy groups, and *-b1-SS-b2-*. b1 and b2 are each independently selected from substituted or unsubstituted C2-C15 linear alkyl groups and substituted or unsubstituted C6-C60 aryl groups. R3 is an ionic liquid group, n ≥ 1 and n is an integer.

[0010] As the above polymer, When a polymer has multiple structural formulas of formula 1, R3 is selected from the same ionic liquid group.

[0011] As the above polymer, when the polymer has a plurality of structural formulas of Formula 1, at least a) R1 in the plurality of structural formulas of Formula 1 is selected from the same group; b) R2 in the plurality of structural formulas of Formula 1 is selected from the same group; satisfies one of the following.

[0012] As the above polymer, R3 is selected from one of an imidazole-based ionic liquid group, a pyridine-based ionic liquid group, a quaternary ammonium-based ionic liquid group or a quaternary phosphonium-based ionic liquid group.

[0013] As the above polymer, R3 is selected from any one of the following groups.

Chemical formula

[0014] As the above polymer, R2 is selected from any one of the following groups.

Chemical formula

[0015] As the above polymer, at least a) R1 is a cyclic structure; b) R2 is a chain structure; satisfies one of the following.

[0016] As the above polymer, The polymer is obtained by the reaction of an iminoionic liquid with a diisocyanate compound.

[0017] This application provides a polymer electrolyte comprising a lithium salt and the above-mentioned polymer.

[0018] In the polymer electrolyte described above, the mass percentage content of lithium salt is 5% to 30%, and the mass percentage content of polymer is 70% to 95%.

[0019] This application provides a porous substrate and a separator comprising the above-mentioned polymer or polymer electrolyte installed on at least a portion of the surface of the porous substrate and / or at least a portion of the voids of the porous substrate.

[0020] This application includes the above polymer, Alternatively, it may contain the polymer electrolyte described above. Alternatively, a battery including the above-mentioned separator is provided. [Effects of the Invention]

[0021] The polymer according to this application has the structural formula shown in Formula 1, and the ionic liquid groups in the polymer can generate good interactions with the anionic groups, thereby fixing the anions and rapidly dissociating lithium ions, increasing the concentration of freely mobile lithium ions in the electrolyte, and improving the ionic conductivity and ion transport rate of the polymer electrolyte. At the same time, the structure of the polymer is relatively orderly, and the ionic liquid is easily dispersed uniformly within the polymer, which is advantageous in promoting the rapid conduction of lithium ions in the electrolyte, reducing the conduction resistance of lithium ions, and improving the electrochemical performance of the polymer electrolyte.

[0022] The polymer electrolyte relating to this application comprises the above-mentioned polymer, and the polymer electrolyte exhibits excellent ionic conductivity and mechanical strength at room temperature, and can be widely applied to batteries to improve the electrochemical performance of the battery.

[0023] Since the separator of this application contains the above-mentioned polymer or polymer electrolyte, when applied to a battery, it can improve the electrochemical performance of the battery.

[0024] The battery according to this application contains one of the above-mentioned polymer, polymer electrolyte, and separator, and therefore exhibits excellent electrochemical performance. [Brief explanation of the drawing]

[0025] [Figure 1] This is the infrared spectrum of the polymer in Example 1 of the present application. [Modes for carrying out the invention]

[0026] To clarify the purpose, technical solutions, and advantages of the embodiments of this application, the technical solutions will be described clearly and completely below with reference to the drawings of the embodiments of this application. Naturally, the embodiments described are only a part of the embodiments of this application, not all of them. All other embodiments obtained by a person skilled in the art without creative work based on the embodiments of this application are all within the scope of protection of this application.

[0027] In a first aspect, the present application provides a polymer having at least the structural formula shown in Formula 1. [ka] In Formula 1, R1 is selected from substituted or unsubstituted C1-C30 alkyl groups and substituted or unsubstituted C6-C60 aryl groups; R2 is selected from substituted or unsubstituted polyethers, substituted or unsubstituted C1-C30 alkoxy groups, substituted or unsubstituted C1-C30 alkyl groups, and *-b1-SS-b2-* groups; b1 and b2 are each independently selected from substituted or unsubstituted C2-C15 linear alkyl groups and substituted or unsubstituted aryl groups; and R3 is an ionic liquid group. n ≥ 1 and n is a positive integer.

[0028] Specifically, R1 is selected from substituted or unsubstituted C1-C30 alkyl groups (e.g., linear alkyl groups, branched alkyl groups, cyclic alkyl groups, substituted linear alkyl groups, substituted branched alkyl groups, substituted cyclic alkyl groups), and substituted or unsubstituted C6-C60 aryl groups (e.g., substituted phenyl groups, unsubstituted phenyl groups, substituted biphenyl groups, unsubstituted biphenyl groups).

[0029] R2 is selected from substituted or unsubstituted polyethers (e.g., substituted linear polyethers, unsubstituted linear polyethers), substituted or unsubstituted C1-C30 alkyls (e.g., linear alkyls, branched alkyls, cyclic alkyls, substituted linear alkyls, substituted branched alkyls, substituted cyclic alkyls), substituted or unsubstituted C1-C30 alkoxys (e.g., substituted branched alkoxys, substituted linear alkoxys, substituted cyclic alkoxys, unsubstituted linear alkoxys, unsubstituted branched alkoxys, unsubstituted cyclic alkoxys), and *-b1-SS-b2-* (where b1 and b2 are independently selected from substituted or unsubstituted C2-C15 linear alkyls and substituted or unsubstituted C6-C60 aryls, with linear alkyls or branched alkyls as examples of linear alkyls, and unsubstituted phenyls, substituted phenyls, substituted biphenyls, and unsubstituted biphenyls as examples of aryls, and * indicates the connection position to the main chain of formula 1).

[0030] This application does not particularly limit the substituents at R1 and R2, and the substituents may be substituents commonly used in the art. Exemplary substituents may be selected from substituted or unsubstituted C1-C30 alkyl groups, substituted or unsubstituted C2-C30 alkenes, substituted or unsubstituted C3-30 alkynes, esters, substituted or unsubstituted C1-C30 alkoxy groups, substituted or unsubstituted C6-C60 aryl groups, or halogens.

[0031] In R3, an ionic liquid group refers to an organic group containing both a cation and anion.

[0032] n represents the degree of polymerization, is a positive integer, and is within the range 50 ≤ n ≤ 800.

[0033] The polymer according to this application has the structural formula shown in Formula 1. The ionic liquid groups in the polymer can generate good interactions with the anionic groups, thereby fixing the anions and rapidly dissociating the lithium ions. This increases the concentration of freely mobile lithium ions in the electrolyte, improving the ionic conductivity and ion transport rate of the polymer electrolyte. At the same time, the structure of the polymer is relatively orderly, and the ionic liquid is easily dispersed uniformly within the polymer. This promotes the rapid conduction of lithium ions in the electrolyte, reduces the conduction resistance of lithium ions, and is advantageous for improving the electrochemical performance of the polymer electrolyte. Furthermore, the ionic liquid groups can improve the flame retardancy of the polymer, resulting in a polymer electrolyte containing this polymer having excellent flame retardancy, and consequently improving the safety performance of the battery.

[0034] In the polymer relating to this application, R1, R2, and R3 in the structure shown in Formula 1 may be selected from the same group or from different groups. That is, when the polymer has multiple structures of Formula 1 (when n≧2), R1 in the multiple structures of Formula 1 may be the same or different, R2 in the multiple structures of Formula 1 may be the same or different, and R3 in the multiple structures of Formula 1 may be the same or different.

[0035] In some embodiments of the present application, when the polymer has multiple structures of formula 1, R3 in the multiple structures of formula 1 is selected from the same ionic liquid group, and the same ionic liquid group is advantageous for improving the uniformity of ionic conduction, further improving the ionic conductivity of the polymer.

[0036] In some embodiments of the present invention, when the polymer has multiple structures of formula 1, R1 in the multiple structures of formula 1 is selected from the same group, and R2 in the multiple structures of formula 1 is selected from the same group, and the same group is advantageous in improving the structural uniformity of the polymer, and further improving the mechanical properties and ionic conductivity of the polymer.

[0037] In some embodiments of the present application, R3 is selected from one of an imidazole-based ionic liquid group, a pyridine-based ionic liquid group, a quaternary ammonium-based ionic liquid group or a quaternary phosphonium-based ionic liquid group.

[0038] In the present application, when the polymer containing the above ionic liquid group is applied to a polymer electrolyte, it is excellent in ionic conductivity and flame retardancy at room temperature. The ionic liquid for forming the above ionic liquid group is easily available and the price is relatively low, which helps to reduce the manufacturing cost.

[0039] Furthermore, R3 is selected from any one of the following groups.

Chemical formula

[0040] Specifically, * in the above structural formula refers to the connection position with the main chain shown in Formula 1.

[0041] R4 is selected from substituted or unsubstituted C1-C30 alkyl groups (e.g., substituted linear alkyl groups, substituted branched alkyl groups, substituted cyclic alkyl groups, unsubstituted branched alkyl groups, unsubstituted linear alkyl groups, or unsubstituted cyclic alkyl groups), and substituted or unsubstituted C1-C30 alkoxy groups (e.g., substituted linear alkoxy groups, substituted cyclic alkoxy groups, substituted branched alkoxy groups, unsubstituted cyclic alkoxy groups, unsubstituted linear alkoxy groups, or unsubstituted branched alkoxy groups). R5 is selected from substituted or unsubstituted C1-C10 alkyl groups (e.g., substituted linear alkyl groups, substituted branched alkyl groups, substituted cyclic alkyl groups, unsubstituted branched alkyl groups, unsubstituted linear alkyl groups, or unsubstituted cyclic alkyl groups).

[0042] The formation of anionic groups is obtained by the dissociation of the corresponding salts. For example, the borate tetrafluoride ion is obtained by the dissociation of lithium borate tetrafluoride, and the phosphate hexafluoride ion is obtained by the dissociation of lithium phosphate hexafluoride. The structures of each anionic group in this application are as follows. [ka]

[0043] This application does not particularly limit the substituents in R4 and R5, and the substituents may be substituents commonly used in the art. Exemplary examples, the substituents may be selected from at least one of substituted or unsubstituted C1-C30 alkyl groups, substituted or unsubstituted C2-C30 alkenes, substituted or unsubstituted C3-30 alkynes, esters, substituted or unsubstituted C1-C30 alkoxy groups, substituted or unsubstituted C6-C60 aryl groups, and halogens.

[0044] When R3 is selected from the above structural formula, it becomes possible to further improve the electrochemical performance and flame retardancy of the battery while reducing manufacturing costs.

[0045] In some embodiments of the present application, R2 is selected from, but is not limited to, the following structures: [ka]

[0046] In R2, n represents the degree of polymerization and is a positive integer between 1 and 30. The degrees of polymerization in each structural formula of this application may be the same or different, and * indicates the position where it is connected to the main chain as shown in Formula 1.

[0047] When R2 is selected from the above structural formula, the electrochemical performance of the battery can be further improved.

[0048] In some embodiments of the present application, R1 is a cyclic structure. That is, R1 is selected from substituted or unsubstituted C1-C30 cyclic alkyl groups (e.g., substituted cyclic alkyl groups and unsubstituted cyclic alkyl groups).

[0049] When R1 has a ring structure, it contributes to improving the rigidity and thermal performance of the polymer, thereby improving the mechanical and heat-resistant properties of the composite electrolyte and extending the battery's lifespan.

[0050] Furthermore, R2 has a chain-like structure. Specifically, R2 is selected from substituted or unsubstituted chain-like polyethers (e.g., substituted linear polyethers, substituted branched polyethers, unsubstituted linear polyethers, and unsubstituted branched polyethers), substituted or unsubstituted C1-C30 chain-like alkoxys (e.g., substituted branched alkoxys and substituted linear alkoxys), and *-b1-SS-b2-* (where b1 and b2 are independently selected from C2-C15 chain-like alkyls, and these alkyls are either linear or branched alkyls).

[0051] In this invention, when R2 has a chain-like structure, the conductivity between the ionic liquid structures of lithium ions can be adjusted, thereby improving the lithium ion conductivity efficiency of the polymer electrolyte.

[0052] In particular, when R1 in a polymer has a cyclic structure and R2 has a chain-like structure, the structural formula of the polymer possesses both rigidity and flexibility. This allows the polymer electrolyte to achieve both excellent mechanical performance and lithium-ion conductivity, thereby improving the electrochemical performance of the battery and extending its lifespan.

[0053] This application does not impose any special restrictions on the raw materials and manufacturing methods for the polymer. As long as the polymer satisfies the above-mentioned characteristics, the raw materials and manufacturing methods can be freely selected according to the purpose.

[0054] In some embodiments of the present application, the polymer is obtained by the reaction of an iminoionic liquid with a diisocyanate compound.

[0055] This application does not particularly limit the iminoionic liquid, and any imino-containing ionic liquid commonly used in this field may be used. The iminoionic liquid may be purchased commercially or obtained by self-production in a laboratory.

[0056] This application does not particularly limit diisocyanate compounds, and diisocyanate compounds may be compounds containing two isocyanates that are commonly used in the art. For example, diisocyanate compounds may be at least one selected from isophorone diisocyanate, diphenylmethane-4,4'-diisocyanate, terephenylenediisocyanate, 1,3-bis(isocyanatomethyl)benzene, 2,6-toluene diisocyanate, m-xylylene diisocyanate, toluene-2,4-diisocyanate, and 4,4'-diisocyanatodicyclohexylmethane.

[0057] In this invention, the iminoionic liquid reacts with the diisocyanate compound, with the iminoionic liquid being used to form R2 and R3 groups, and the diisocyanate compound being used to form the R1 group.

[0058] This invention not only provides a polymer with excellent integrated performance by manufacturing it according to the above procedure, but also demonstrates that the manufacturing method is simple and suitable for widespread dissemination and application.

[0059] This application does not particularly limit the specific reaction conditions between the iminoionic liquid and the diisocyanate compound. Generally, the amount of diisocyanate compound used should be greater than or equal to the amount of iminoionic liquid used, primarily to ensure that the imino in the iminoionic liquid undergoes a complete chemical reaction. Furthermore, a moderate excess of isocyanate can form potential chemical reaction sites in the resulting polyurea polymer electrolyte, causing chemical crosslinking with other components in the polymer electrolyte and improving the crosslinking density of the polyurea polymer electrolyte. Exemplarily, the remaining isocyanate can continue reacting with amine-containing or hydroxyl-containing compounds to further improve the crosslinking density of the polymer electrolyte, and a moderate excess of isocyanate can react with water, effectively mitigating the adverse effects of moisture on the performance of the polyurea polymer electrolyte. In some embodiments, the molar ratio of imino in the iminoionic liquid to isocyanate in the diisocyanate compound may be 1:(1.0~1.2).

[0060] In some embodiments, polymers with superior performance can be obtained when the reaction process between the iminoionic liquid and the diisocyanate compound is carried out at a temperature of 40°C to 80°C and for a duration of 30 minutes to 24 hours. A catalyst can be added to the reaction process between the iminoionic liquid and the diisocyanate compound. The catalyst may be an organotin catalyst or an alcoholamine catalyst, and the amount of catalyst used may be 0.2 to 3 mol% of the total amount of the individual components (the sum of the amounts of the iminoionic liquid and the diisocyanate compound used).

[0061] In some embodiments, an iminoionic liquid can be prepared by an addition reaction between an amino ionic liquid and a dienyl compound, as shown in Formula 2. Here, the amino group ionic liquid may be an amine-containing ionic liquid commonly used in this field, and the amino group ionic liquid may be purchased commercially or obtained by preparing it in the laboratory. Dienyl compounds may be compounds containing two enyls commonly used in this field. For example, dienyl compounds can be selected from at least one of the following: poly(ethylene glycol) diacrylate, poly(ethylene glycol) dimethyl acrylate, polyethylene glycol-block-polypropylene glycol-block-polyethylene glycol diacrylate, ethylene glycol diacrylate, triethylene glycol diacrylate, tetra(ethylene glycol) diacrylate, ethylene glycol dimethyl acrylate, poly(propylene glycol) dimethacrylate, bis(2-methacrylate)ethoxydisulfide, and diallyl disulfide. The structural formulas of some of the above-mentioned dienyl compounds are as follows. [ka] Here, in the structure described above, n represents the degree of polymerization and is a positive integer.

[0062] As shown in Equation 2, when an amino ionic liquid reacts with a dienyl compound, the dienyl compound is used to form R2, and the amino ionic liquid is used to form R3, thereby obtaining an imino ionic liquid containing R3 and R2. [ka]

[0063] Specifically, compound A1 can form an a1 group, compound A2 can form an a2 group, compound A3 can form an a3 group, compound A4 can form an a4 group, compound A5 can form an a5 group, and compound A6 can form an a6 group.

[0064] This application does not particularly limit the specific reaction conditions between the amino ionic liquid and the dienyl compound. The purpose of using a moderate excess of amine ions is primarily to ensure that the dienyl compound undergoes a complete chemical reaction with the amine. Furthermore, the molar ratio of amino groups in the amino ionic liquid to enyl in the dienyl compound may be (1.0~1.2):1. In some embodiments, a reaction process between the amino ionic liquid and the dienyl compound at a temperature of 40°C to 90°C and a time of 8 to 24 hours is advantageous for obtaining polymers with excellent integrated performance.

[0065] In a second aspect, the present application provides a polymer electrolyte comprising a lithium salt and the polymer of the first aspect of the present application.

[0066] Lithium salts are used for lithium ion conduction, polymers form the backbone of polymer electrolytes, and lithium salts are embedded within the polymer backbone.

[0067] The present invention does not particularly limit lithium salts, but lithium salts can be selected from lithium salts commonly used in the art. For example, lithium salts can be selected from at least one of lithium bis(trifluoromethanesulfonyl)imide (LiTFSI), lithium bis(trifluorosulfonyl)imide (LiFSI), lithium tetrafluoroborate (LiBF4), and lithium hexafluorophosphate (LiPF6). Since the polymer electrolyte according to the present invention contains the polymer in the first embodiment, when applied to a battery, it can improve the electrochemical performance of the battery and extend the battery's service life.

[0068] In this application, it should be understood that the lithium salt may be added either directly during the preparation of the polymer electrolyte or in the form of an electrolyte during the manufacturing of the battery.

[0069] In some embodiments, the polymer in the first embodiment can be uniformly mixed with a lithium salt and a solvent, and then the solvent can be removed to form a polymer electrolyte containing the polymer in the first embodiment and a lithium salt.

[0070] In another embodiment, the polymer electrolyte is obtained by the reaction of a starting material system comprising a lithium salt, an iminoionic liquid, and a diisocyanate compound.

[0071] Specifically, a starting material is obtained by mixing a solvent, a lithium salt, an iminoionic liquid, and a diisocyanate compound. When the starting material is reacted, the iminoionic liquid reacts with the diisocyanate compound to form a polymer having the structure of formula 1. The electrolyte formed by the lithium salt and the solvent is embedded in the polymer. When the solvent is removed by drying, a polymer electrolyte containing the lithium salt and the polymer in the first embodiment is obtained.

[0072] This application does not impose any special restrictions on the method of preparing the polymer electrolyte, and those skilled in the art can freely select a manufacturing method according to their purpose.

[0073] In some embodiments, the polymer electrolyte is obtained by forming a self-supporting film. For example, the raw material system of the polymer electrolyte may be attached to a support (such as a release film, electrode plate, or inside a battery case) and polymerization of the raw material system may be induced to obtain the polymer electrolyte. Alternatively, the polymer system may be poured onto a release film, solidified to form a film, and then peeled off. Alternatively, the polymer system may be extruded to form a film.

[0074] In some embodiments, the polymer electrolyte is A step of adding the polymer to a first solvent to obtain a first mixture, and the first mixed liquid The process involves adding a lithium salt and stirring uniformly to obtain a polymer system, then pouring the polymer system onto the surface of a release film, after which the first solvent is removed and separated from the release film. Polymer electrolytes It can be prepared by a method that includes the step of obtaining [something].

[0075] This application does not impose any special restrictions on the first solvent, and any commonly used solvent can be selected, such as N-methylpyrrolidone (NMP), acetone, methanol, and ethanol.

[0076] In some embodiments of the present invention, when the polymer electrolyte contains 5% to 30% by mass of lithium salt and 70% to 95% by mass of polymer, the polymer electrolyte exhibits superior ionic conductivity and mechanical properties at room temperature, and when applied to a battery, it can further improve the electrochemical performance of the battery and extend its service life.

[0077] In a third aspect, the present invention provides a separator comprising a porous substrate, a polymer in the first aspect, or a polymer electrolyte in the second aspect, which is installed on at least a portion of the surface of the porous substrate and / or in at least a portion of the voids of the porous substrate.

[0078] This application does not impose any special limitations on the thickness of the porous substrate; for example, it may preferably be 5 μm to 50 μm. This application also does not impose any special limitations on the pore size and porosity of the porous substrate; for example, they may preferably be 0.2 μm to 100 μm and 10% to 99%, respectively, and more preferably 0.5 μm to 50 μm and 30% to 70%, respectively.

[0079] In the separator according to this application, the polymer may be placed on a part or the entire surface of the porous substrate, or on a part or the entire void of the porous substrate, and the polymer electrolyte may be placed on a part or the entire surface of the porous substrate, or on a part or the entire void of the porous substrate.

[0080] This invention does not limit the specific installation method, and a separator can be formed by employing installation methods commonly used in the art to install a polymer or polymer electrolyte on at least a portion of the surface of a porous substrate and / or at least a portion of the voids of the porous substrate.

[0081] In some embodiments, the polymer electrolyte raw material system is porous substrateThe material may be applied to induce polymerization of the raw material system and cured to obtain a separator, or a self-forming polymer electrolyte may be compounded with a porous substrate by hot pressure or roll rolling to obtain a separator, or the polymer system may be porous substrate The material may be applied to a surface and cured to obtain a separator. The separator has a porous substrate, and the porous substrate may be any porous substrate used in conventional battery separators. For example, the porous substrate may be a film or fabric substrate formed from any of the following polymers, and the polymer may be selected from at least one of polyethylene terephthalate, polybutylene terephthalate, polymethyl methacrylate, polyacetal, polyamide, polycarbonate, polyimide, polyetheretherketone, polyethersulfone, polyphenylene ether, polyphenylene sulfide, polyethylene naphthalate, polyvinylidene fluoride, polyethylene oxide, polyacrylonitrile, tetrafluoropropene copolymer, hexafluoropropene copolymer, or at least one of copolymers of propylene, 1-butene, pentene, 1-hexene, 4-methyl-1-pentene, 1-octene, 1-decene, homogeneous polymers and their derivatives.

[0082] In some embodiments, the steps include adding the polymer to a first solvent to obtain a first mixture, and the first mixed liquid The preparation is carried out by a method comprising the steps of: adding a lithium salt and stirring uniformly to obtain a polymer system; and pouring the polymer system onto at least a portion of the surface of a porous substrate, and then removing the first solvent to obtain a separator.

[0083] This application does not impose any special restrictions on the first solvent, and it can be selected from commonly used solvents, such as N-methylpyrrolidone (NMP), acetone, methanol, and ethanol.

[0084] In some embodiments, the method for manufacturing the separator may further include a step of roll-rolling the separator obtained after drying to further strengthen the bond between the polymer electrolyte and the porous substrate.

[0085] Since the separator according to this application contains the above-mentioned polymer or polymer electrolyte, when applied to a battery, it can improve the electrochemical performance of the battery and expand the range of battery applications.

[0086] In the fourth aspect, the present application includes the polymer in the first aspect, Alternatively, it may include a polymer electrolyte in the second embodiment, Alternatively, the present invention provides a battery including a separator in a third embodiment. It should be understood that the battery according to the present invention further comprises a positive electrode plate, a negative electrode plate, and a package.

[0087] In some embodiments, a gel electrolyte, which is a combination of a polymer and an electrolyte, can be applied to the battery. Specifically, a positive electrode plate, a polymer (or separator), and a negative electrode plate are stacked and arranged to obtain an electrode assembly, the electrode assembly is placed in a package, the electrolyte is injected, and then the battery is sealed.

[0088] In another embodiment, a positive electrode plate, a polymer electrolyte (or a separator containing a polymer electrolyte), and a negative electrode plate are stacked and arranged to obtain an electrode assembly, and the electrode assembly is placed in a package and sealed to obtain a battery.

[0089] Because the battery according to this invention contains the above-mentioned polymer electrolyte, it has excellent electrochemical performance and a superior user experience, making it suitable for widespread application.

[0090] The technical measures relating to this application will be described in detail below using specific examples. [Examples]

[0091] The origins of some of the components in the examples and comparative examples are as follows. For components in the examples or comparative examples where specific experimental procedures or conditions are not specified, these components can be obtained by following the usual experimental procedures or conditions described in existing art. (1) Amino ionic liquid: (1) Both 1-aminoethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt (CAS: 1384979-21-8) and 1-aminopropyl-3-methylimidazolium tetrafluoroborate (CAS: 914770-49-3) were purchased from Qingdao Aolike New Materials Technology Co., Ltd. (2) (6-aminohexyl)triphenylphosphonium bromide bistrifluoromethylsulfoimide salt: obtained by laboratory preparation, the method of preparation is as follows. (6-aminohexyl)triphenylphosphonium bromide hydrobromide (purchased from Sigma-Aldrich) is dissolved in anhydrous ethanol (purchased from Shanghai Aladdin Biochemical Technology Co., Ltd.) and stirred until fully dissolved. Then, silver bistrifluoromethylsulfoimide (purchased from Sigma-Aldrich) is gradually added and stirring is continued until a silver bromide (AgBr) precipitate is formed. The precipitate is then removed by filtration, the anhydrous ethanol is removed by vacuum rotary evaporation, and after heating and drying, (6-aminohexyl)triphenylphosphonium bromide bistrifluoromethylsulfoimide salt can be obtained. (ii) Triethylene glycol diacrylate: Purchased from Shanghai Alading Biochemical Technology Co., Ltd. (iii) Dicyclohexylmethane 4,4'-diisocyanate: Purchased from Shanghai Alading Biochemical Technology Co., Ltd. (IV) Dibutyltin dilaurate: Purchased from Sigma-Aldrich. (5) Hexamethylene diisocyanate: Purchased from Shanghai Alading Biochemical Technology Co., Ltd. (VI) 1,4-Cyclohexanedimethanol divinyl ether: Purchased from Shanghai Malin Biochemical Technology Co., Ltd. (7) m-Xylylene diisocyanate: Purchased from Shanghai Malin Biochemical Technology Co., Ltd. (8) Polyethylene glycol diacrylate (Mn=575): Purchased from Shanghai McLin Biochemical Technology Co., Ltd. (9) 1,4-Phenylene diisocyanate: Purchased from Shanghai McLin Biochemical Technology Co., Ltd. (10) Diallyl disulfide: Purchased from Shanghai Malin Biochemical Technology Co., Ltd.

[0092] Example 1 The battery in this embodiment is manufactured by a method that includes the following steps.

[0093] 1) Preparation of polymers The process involves a first reaction between an amino ionic liquid and a dienyl compound to obtain an imino ionic liquid, The process includes a step of carrying out a second reaction with an iminoionic liquid and a diisocyanate compound to obtain a polymer, The amino ionic liquid is 1-aminoethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt, the dienyl compound is triethylene glycol diacrylate, and the diisocyanate compound is 4,4'-diphenylmethane diisocyanate. In the first reaction, the ratio of the molar content of amino groups in the amino ionic liquid to the molar content of enyl in the dienyl compound was 1:1, the temperature was 60°C, and the time was 12h. In the second reaction, the ratio of the molar content of imino in the iminoionic liquid to the molar content of isocyanate in the diisocyanate compound was 1:1, the temperature was 60°C, the time was 12h, the catalyst was dibutyltin dilaurate, and the amount of catalyst used was 0.2 mol% of the total amount of iminoionic liquid and diisocyanate compound used.

[0094] 2) Preparation of polymer electrolytes After mixing the solvent, lithium salt, and polymer from step 1), the mixture is dried to obtain a polymer electrolyte. The lithium salt is lithium hexafluorophosphate, and the solvent is NMP. The polymer electrolyte contains 10% lithium salt by mass and 90% polymer by mass.

[0095] 3) Battery manufacturing A positive electrode plate, a polymer electrolyte, and a negative electrode plate are stacked and installed to obtain an electrode assembly, the electrode assembly is placed in an aluminum plastic film and sealed to obtain a battery. The positive electrode plate includes an aluminum foil and a positive electrode active layer placed on the surface of the aluminum foil. The positive electrode active layer contains lithium cobalt oxide, a conductive agent Super P, and an adhesive PVDF. The mass ratio of lithium cobalt oxide, conductive agent, and adhesive is 96:2:2. The negative electrode plate includes a copper foil and a negative electrode active layer placed on the surface of the copper foil. The negative electrode active layer contains silicon-doped graphite, a conductive agent SuperP, and an adhesive PAA. The mass ratio of silicon-doped graphite, conductive agent, and adhesive is 95:2:3.

[0096] Example 2 The method for manufacturing the battery in this embodiment is almost the same as in Example 1, 1) Preparation of polymers Diisocyanate compounds differ in that they are hexamethylene diisocyanates.

[0097] Example 3 The method for manufacturing the battery in this embodiment is almost the same as in Example 1, 1) Preparation of polymers The amino ionic liquid differs in that it is 1-aminopropyl-3-methylimidazolium tetrafluoroborate, the dienyl compound is 1,4-cyclohexanedimethanol divinyl ether, and the diisocyanate compound is m-xylylene diisocyanate.

[0098] Example 4 The method for manufacturing the battery in this embodiment is almost the same as in Example 1, 1) Preparation of polymers The amino ionic liquid differs in that it is 1-aminopropyl-3-methylimidazolium tetrafluoroborate, the dienyl compound is polyethylene glycol diacrylate (Mn=575), and the diisocyanate compound is 1,4-phenylenediisocyanate.

[0099] Example 5 The method for manufacturing the battery in this embodiment is almost the same as in Example 1, 1) Preparation of polymers The amino ionic liquid differs in that it is 1-aminopropyl-3-methylimidazolium tetrafluoroborate, the dienyl compound is diallyl disulfide, and the diisocyanate compound is 1,4-phenylenediisocyanate.

[0100] Example 6 The method for manufacturing the battery in this embodiment is almost the same as in Example 1, 1) Preparation of polymers The amino ionic liquid is (6-aminohexyl)triphenylphosphonium bromide bistrifluoromethylsulfoimide salt, the dienyl compound is polyethylene glycol diacrylate (Mn=575), and the diisocyanate compound is 1,4-phenylenediisocyanate. In the first reaction, the ratio of the molar content of amino groups in the amino ionic liquid to the molar content of enyl groups in the dienyl compound is 1.2:1. The second reaction differs in that the ratio of the molar content of imino in the iminoionic liquid to the molar content of isocyanate in the diisocyanate compound is 1:1.2.

[0101] Example 7 The method for manufacturing the battery in this embodiment is almost the same as in Example 1, Polymer electrolytes are The process involves a first reaction between an amino ionic liquid and a dienyl compound to obtain an imino ionic liquid, The product is manufactured by a method comprising the steps of carrying out a second reaction with an iminoionic liquid, a diisocyanate compound, a lithium salt, and a solvent, followed by drying to obtain a polymer electrolyte. The amino ionic liquid is 1-aminoethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt, the dienyl compound is triethylene glycol diacrylate, and the diisocyanate compound is dicyclohexylmethane 4,4'-diisocyanate. In the first reaction, the ratio of the molar content of amino groups in the amino ionic liquid to the molar content of enyl in the dienyl compound is 1:1, the temperature is 60°C, and the time is 12h. In the second reaction, the ratio of the molar content of imino in the iminoionic liquid to the molar content of isocyanate in the diisocyanate compound was 1:1, the temperature was 60°C, the time was 12h, the catalyst was dibutyltin dilaurate, and the amount of catalyst used was 0.2 mol% of the total amount of iminoionic liquid and diisocyanate compound used. The lithium salt is lithium hexafluorophosphate, and the solvent is NMP. The difference lies in the fact that the polymer electrolyte contains 10% lithium salt by mass and 90% polymer by mass.

[0102] Example 8 The method for manufacturing the battery in this embodiment is almost the same as in Example 1, 2) Preparation of polymer electrolytes The difference lies in the fact that the polymer electrolyte contains 40% lithium salt by mass and 60% polymer by mass.

[0103] Example 9 The method for manufacturing the battery in this embodiment is almost the same as in Example 1, 2) Preparation of polymers The amino ionic liquid contains 1-aminoethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt, 1-aminopropyl-3-methylimidazolium tetrafluoroborate, and (6-aminohexyl)triphenylphosphonium bromide bistrifluoromethylsulfoimide salt, differing in that the molar ratio of 1-aminoethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt, 1-aminopropyl-3-methylimidazolium tetrafluoroborate, and (6-aminohexyl)triphenylphosphonium bromide bistrifluoromethylsulfoimide salt is 1:1:1.

[0104] Example 10 The method for manufacturing the battery in this embodiment is almost the same as in Example 1, 2) Preparation of polymers The dienyl compounds include triethylene glycol diacrylate, 1,4-cyclohexanedimethanol divinyl ether, and polyethylene glycol diacrylate (Mn=575), differing in that the molar ratio of triethylene glycol diacrylate, 1,4-cyclohexanedimethanol divinyl ether, and polyethylene glycol diacrylate is 1:1:1.

[0105] Example 11 The method for manufacturing the battery in this embodiment is almost the same as in Example 1, 2) Preparation of polymers Diisocyanate compounds differ in that they contain 1,4-phenylenediisocyanate and m-xylylenediisocyanate, with a molar ratio of 1,4-phenylenediisocyanate to m-xylylenediisocyanate being 1:1.

[0106] Comparative Example 1 The method for manufacturing the battery in this comparative example is almost the same as in Example 1, Polymer electrolytes are The product is manufactured by a method that includes the steps of mixing polyetheramine D230, hexamethylene diisocyanate, lithium salt, and solvent, reacting them at a temperature of 60°C for 12 hours, and then drying to remove the solvent to obtain a polymer electrolyte. The above reaction differs in that the ratio of the molar content of amino groups in polyetheramine D230 to the molar content of isocyanic acid in hexamethylene diisocyanate is 1.1:1.

[0107] Comparative Example 2 The method for manufacturing the battery in this comparative example is almost the same as in Example 1, Polymer electrolytes are The product is manufactured by a method that includes the steps of mixing 1-aminoethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt, dicyclohexylmethane 4,4'-diisocyanate, lithium salt, and a solvent, reacting them at a temperature of 60°C for 12 hours, and then drying to remove the solvent to obtain a polymer electrolyte. The above reaction differs in that the ratio of the molar content of the amino group in 1-aminoethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt to the molar content of isocyanate in hexamethylene diisocyanate is 1:2, the catalyst is dibutyltin dilaurate, and the amount of catalyst used is 0.2 mol% of the total amount of iminoionic liquid and diisocyanate compound used.

[0108] Comparative Example 3 The method for manufacturing the battery in this comparative example is almost the same as in Example 1, Polymer electrolytes are The product is manufactured by a method that includes mixing 1-aminoethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt, triethylene glycol diacrylate, lithium salt, and a solvent, reacting them at a temperature of 60°C for 12 hours, and then drying to remove the solvent to obtain a polymer electrolyte. The above reaction differs in that the ratio of the molar content of the amino group in 1-aminoethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt to the molar content of the vinyl in triethylene glycol diacrylate is 1:2, the catalyst is dibutyltin dilaurate, and the amount of catalyst used is 0.2 mol% of the total amount of iminoionic liquid and diisocyanate compound used.

[0109] Comparative Example 4 The method for manufacturing the battery in this comparative example is almost the same as in Example 1, 1) Preparation of polymers The first reaction is carried out by adding an amino ionic liquid, a dienyl compound, and a diisocyanate compound to the reaction vessel (the amino ionic liquid and the diisocyanate compound react preferentially to form a urea-based intermediate compound). After the catalyst is added, the enyl compound of the dienyl compound and the imino compound of the urea-based intermediate undergo a second reaction to obtain a polymer. In the first reaction, the ratio of the molar content of amino groups in the amino ionic liquid, the molar content of enyl in the dienyl compound, and the molar content of isocyanate in the diisocyanate compound is 1:1:1, the temperature is 60°C, and the time is 2 hours. The second reaction differs in that the catalyst is dibutyltin dilaurate, the amount of catalyst used is 0.2 mol% of the total amount of amino ionic liquid, dienyl compound, and diisocyanate compound used, the temperature is 60°C, and the time is 12 hours.

[0110] Performance Test The polymers, polymer electrolytes, or batteries in the examples and comparative examples were subjected to the following performance tests, and the test results are shown in Table 1.

[0111] 1. Measurement by infrared spectroscopy Infrared spectroscopy was performed on the polymer in Example 1. From Figure 1, the infrared spectrum of the polymer in Example 1 is 3308 cm⁻¹. -1 and 1642cm -1The absorption peaks at 1228 cm² are due to vibrational absorption of NH bonds and C=O bonds in urea, respectively. -1 The absorption peak at 1373 cm² is the stretching vibration absorption peak of the CN bond. -1 The absorption peak at 1453 cm² was confirmed to be due to vibrational absorption of the tertiary amine, indicating the presence of the tertiary amine in the polymer structure, and also at 1453 cm². -1 , 1506cm -1 and 1594cm -1 The absorption peak at 1537 cm is due to the absorption of stretching vibrations of the benzene ring. -1 The absorption peak at 1178 cm is due to the absorption of skeletal vibrations of the imidazole ring. -1 The absorption peak at 2860-2930 cm is due to the absorption of stretching vibrations of the imidazole ring. -1 The absorption peak in is These are the stretching vibration absorption peaks for methyl and methylene, at 1102 cm². -1 The absorption peak at was confirmed to be due to the absorption of stretching vibrations of the ether bond in the polymer structure. These findings demonstrate that a polymer having the structural formula shown in Formula 1 was successfully prepared in Example 1 of this application.

[0112] 2. Ionic conductivity at room temperature The measurements were taken according to the method specified in "Method for Measuring Ionic Conductivity of Thin Films in Power Batteries" (Industry Standard NB / T 10827-2021).

[0113] 3. Battery cycle performance The measurements were taken in accordance with the methods specified in the national standard GB / T31486-2015, "Electrical performance requirements and test methods for power storage batteries for electric vehicles."

[0114] 4. Extreme Oxygen Index The measurements were taken in accordance with the methods specified in GB / T2406.1-2008 "Part 1: Guidelines for the Measurement of Combustion Behavior of Plastics by Oxygen Index Method" and GB / T2406.2-2009 "Part 2: Room Temperature Test for the Measurement of Combustion Behavior of Plastics by Oxygen Index Method".

[0115] 5. Tensile strength test The tensile strength of the polymer electrolyte was measured according to the standard test method of ASTM D638-14, "Standard Test Method for Tensile Performance of Plastics."

[0116] [Table 1]

[0117] Table 1 confirms that the product in the embodiment of this application exhibits excellent ionic conductivity, battery capacity retention, and extreme oxygen index at room temperature, and due to its superior performance, it can be applied to a wide range of applications.

[0118] Finally, it should be noted that the above embodiments are intended to illustrate, and not limit, the technical solutions of the present application. While the present application will be described in detail with reference to the above embodiments, those skilled in the art can still modify the technical solutions described in the above embodiments or make equivalent substitutions to some or all of their technical features, and these modifications or substitutions should be understood not to deviate from the essence of the corresponding technical solutions within the scope of the technical solutions of the embodiments of the present application.

Claims

1. A polymer having at least one structural formula shown in Formula 1. 【Chemistry 1】 In formula 1, R １ These are selected from substituted or unsubstituted C1-C30 alkyl groups and substituted or unsubstituted C6-C60 aryl groups. R ２ This is selected from substituted or unsubstituted polyethers, substituted or unsubstituted C1-C30 alkyl groups, substituted or unsubstituted C1-C30 alkoxy groups, and *-b1-S-S-b2-*. b1 and b2 are each independently selected from substituted or unsubstituted C2-C15 linear alkyl groups and substituted or unsubstituted C6-C60 aryl groups. R ３ It is an ionic liquid group, n ≥ 1 and n is an integer.

2. When the polymer has multiple structural formulas of the above formula 1, the R ３ The polymer according to claim 1, which is selected from the same ionic liquid group.

3. When the polymer has multiple structural formulas of formula 1, at least a) The R in multiple structural formulas of formula 1 １ This means being selected from the same base. b) The R in multiple structural formulas of formula 1 ２ This means being selected from the same base. The polymer according to claim 1, satisfying one of the following conditions.

4. The aforementioned R ３ The polymer according to claim 1, wherein is selected from one of an imidazole-based ionic liquid group, a pyridine-based ionic liquid group, a quaternary ammonium-based ionic liquid group, or a quaternary phosphonium-based ionic liquid group.

5. The aforementioned R ３ It is selected from one of the following bases: 【Chemistry 2】 R ４ is selected from substituted or unsubstituted C1-C30 alkyl, substituted or unsubstituted C1-C30 alkoxy, R ５ is selected from substituted or unsubstituted C1-C10 alkyl, A is BF ４ － , PF ６ － , TFSI － , OTf － , DCA － or TOS － selected from, The polymer according to claim 4.

6. The aforementioned R ２ teeth, 【Transformation 3】 Choose one of the following: n is a positive integer. The polymer according to any one of claims 1 to 5.

7. at least a) The R １ It has a ring structure. b) The R ２ It has a chain-like structure. A polymer according to any one of claims 1 to 6, satisfying one of the following conditions.

8. The polymer according to any one of claims 1 to 7, obtained by the reaction of an iminoionic liquid with a diisocyanate compound.

9. A polymer electrolyte comprising a lithium salt and the polymer according to any one of claims 1 to 8.

10. The polymer electrolyte according to claim 9, wherein the mass percentage content of the lithium salt is 5% to 30% and the mass percentage content of the polymer is 70% to 95%.

11. A separator comprising a porous substrate and a polymer according to any one of claims 1 to 8 or a polymer electrolyte according to any one of claims 9 to 10, provided on at least a portion of the surface of the porous substrate and / or at least a portion of the voids of the porous substrate.

12. The polymer comprises any one of claims 1 to 8, Alternatively, it may contain the polymer electrolyte described in any one of claims 9 to 10. Alternatively, a battery comprising the separator described in claim 11.

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