Gel polymer electrolyte composition, gel polymer electrolyte, battery cell and manufacturing method therefor, battery, and electric device

Abstract

The present application discloses a gel polymer electrolyte composition, a gel polymer electrolyte, a battery cell and a manufacturing method therefor, a battery, and an electric device. The gel polymer electrolyte composition comprises a non-aqueous electrolytic solution, a polymer monomer, and an ionic liquid monomer; the polymer monomer is a polymer monomer having an ether oxygen segment and capable of performing free radical polymerization, and the weight-average molecular weight of the polymer monomer is 400 to 80,000; and the ionic liquid monomer comprises one or more of an N-containing ionic liquid, a P-containing ionic liquid, and an S-containing ionic liquid, and the terminal group of the ionic liquid is alkenyl or a (meth)acrylate group. The use of the gel polymer electrolyte composition in a battery cell enables the battery cell to have a long cycle life.

Description

Gel polymer electrolyte composition, gel polymer electrolyte, battery cell and its preparation method, battery and electrical device

[0001] Cross-references to related applications

[0002] This application claims priority to Chinese Patent Application No. 202410780586.1, filed on June 17, 2024, entitled “Gel polymer electrolyte composition, gel polymer electrolyte, battery cell and preparation method thereof, battery and power device”, the entire contents of which are incorporated herein by reference. Technical Field

[0003] This application relates to a gel polymer electrolyte composition, a gel polymer electrolyte, a battery cell and a method for preparing the same, a battery and an electrical device. Background Technology

[0004] The cycle life of a battery cell has a crucial impact on its performance. Currently, battery cells typically use non-aqueous electrolytes. However, during long-term cycling, non-aqueous electrolytes are prone to localized deficiencies or even drying out due to prolonged static placement in a specific orientation under the influence of gravity. This increases cell polarization, affecting the cell's capacity utilization and lifespan.

[0005] Summary of the Invention

[0006] This application provides a gel polymer electrolyte composition, a gel polymer electrolyte, a battery cell and a method for preparing the same, a battery and an electrical device. The gel polymer electrolyte composition, when used in a battery cell, enables the battery cell to have a long cycle life.

[0007] In a first aspect, this application provides a gel polymer electrolyte composition comprising a non-aqueous electrolyte, a polymer monomer, and an ionic liquid monomer, wherein the polymer monomer is a polymer monomer having an ether oxygen segment and capable of free radical polymerization, and the weight-average molecular weight of the polymer monomer is 400 to 80,000; the ionic liquid monomer comprises one or more of N-containing ionic liquids, P-containing ionic liquids, and S-containing ionic liquids, and the end group of the ionic liquid is an alkenyl or (meth)acrylate group.

[0008] The gel polymer electrolyte composition provided in this application includes a polymer monomer capable of free radical polymerization and an ionic liquid monomer, which polymerize to form a gel polymer electrolyte. The gel polymer electrolyte is flexible and can have good contact with the interface, thereby reducing interfacial impedance. The polymer monomer and the ionic liquid monomer polymerize to form the polymer backbone of the gel polymer electrolyte.

[0009] Ionic liquid monomers have excellent ion transport properties, and the polymer skeleton formed by their polymerization with polymer monomers can give gel polymer electrolytes good ionic conductivity without reducing mechanical properties. The polymer skeleton cations also have an attractive effect on anions in non-aqueous electrolytes, which can promote the dominance of lithium ions in ion transport, reduce concentration polarization, and avoid lithium ion depletion during charging and discharging. This is conducive to the long-term stable performance of battery cell capacity and gives battery cells a long cycle life.

[0010] The polymer monomers have a weight-average molecular weight of 400 to 80,000 and have relatively long molecular chains, which allows them to polymerize with ionic liquid monomers to form a polymer backbone that also has good flexibility.

[0011] The polymer monomers possess ether-oxygen segments that are affinity for non-aqueous electrolytes, while the ionic liquid monomers have strong dipoles. Therefore, the polymer backbone formed by the polymerization of the ionic liquid monomers and polymer monomers can completely bind the non-aqueous electrolyte within the polymer backbone network even at a low mass percentage, preventing the non-aqueous electrolyte from flowing freely. This reduces the side reactions that continuously consume active lithium at the negative electrode interface caused by unstable organic solvents and anions in the non-aqueous electrolyte. Furthermore, it facilitates the long-term stable wetting of the electrode components by the non-aqueous electrolyte, reducing the occurrence of localized drying problems, thereby improving the cycle life of the battery cells.

[0012] The polymer monomers have a weight-average molecular weight of 400 to 80,000, which can make the polymer monomers highly active and easy to undergo polymerization reactions. It can also make the polymer skeleton formed by polymerization have a suitable cross-linking density, thereby binding more non-aqueous electrolytes, and thus enabling the gel polymer electrolyte to have good ion transport properties.

[0013] Therefore, the gel polymer electrolyte composition provided in this application embodiment can be used in battery cells to enable battery cells to have a long cycle life.

[0014] In some embodiments, the polymer monomer includes one or more of the polymer monomers shown in Formula I and Formula II.

[0015] X is selected from C1-C10 alkylene or C1-C10 haloalkylene, R1 is selected from hydrogen atom or methyl, R2 is selected from hydrogen atom or methyl, and n is selected from an integer between 10 and 1000.

[0016] The polymer monomers shown in Formula I and Formula II can polymerize with ionic liquid monomers to form a cross-linked structure, which can give the gel polymer electrolyte good oxidation-reduction stability, thus helping the battery cell to have a longer cycle life.

[0017] In some embodiments, X is selected from C1-C4 alkylene groups, and / or n is selected from integers between 50 and 800.

[0018] In some embodiments, the cation of the ionic liquid monomer includes any one of the following ions with an alkenyl or (meth)acrylate end group: tetrahydropyrrole ion, quaternary ammonium ion, imidazole ion, piperidinium ion, pyridinium ion, thionium ion, and phosphonium ion.

[0019] In some embodiments, the cation of the ionic liquid monomer is composed of any one of the end groups shown in Formula 1 and any one of the cations shown in Formula 2, where * indicates a linking site.

[0020] R3 is selected from hydrogen atom or methyl group, R4, R6, R8, R9, R 10 R 12 R 15 R 17 R 18 R 20 R 21 Alkyl groups independently selected from C1-C10, R5, R7, R 11 R 13 R 14 R 16 R 19 Each is independently selected from C1-C10 alkylene groups or C1-C10 oxaalkylene groups.

[0021] In some embodiments, R4, R6, R8, R9, R 10 R 12 R 15 R 17 R 18 R 20 R 21 Alkyl groups selected independently from C1-C3.

[0022] In some embodiments, R5, R7, R 11 R 13 R 14 R 16 R 19 Each is independently selected from C2-C3 alkylene or C2-C3 oxaalkylene.

[0023] In some embodiments, the cation of the ionic liquid monomer includes any of the following:

[0024] In some embodiments, the anion of the ionic liquid monomer includes any one of the following: chloride ion, bromide ion, iodide ion, bis(trifluoromethyl)sulfonamide ion, bis(trifluoromethyl)sulfonamide ion, hexafluorophosphate, tetrafluoroborate, hexafluoroarsenate, trifluoromethanesulfonate, difluorophosphate, dioxaloborate, difluorooxaloborate, difluorodioxalophosphate, and tetrafluorooxalophosphate.

[0025] In some embodiments, the molar ratio of the ionic liquid monomer to the polymer monomer is 1:1 to 10:1.

[0026] When the molar ratio of ionic liquid monomers to polymer monomers is within the above range, the polymer skeleton formed by polymerization can have a suitable crosslinking density, thereby binding more non-aqueous electrolyte. This, in turn, can give the gel polymer electrolyte good ion transport properties, and give the battery cell a longer cycle life.

[0027] In some embodiments, the sum of the mass fractions of the polymer monomers and the ionic liquid monomers is 0.5%-20% based on the total mass of the gel polymer electrolyte composition.

[0028] When the sum of the mass fractions of the ionic liquid monomer and the polymer monomer is within the above range, the polymer skeleton formed by polymerization can bind the electrolyte, improve the interfacial stability and electrolyte wettability during long-term cycling, and also enable the gel polymer electrolyte formed by polymerization to have good ion transport properties.

[0029] In some embodiments, the gel polymer electrolyte composition further includes an initiator.

[0030] In a second aspect, this application provides a gel polymer electrolyte obtained by polymerizing the gel polymer electrolyte composition of the first aspect of this application.

[0031] Thirdly, this application provides a battery cell including a gel polymer electrolyte, which is obtained by polymerizing the gel polymer electrolyte composition of the first aspect of this application.

[0032] The battery cell includes a gel polymer electrolyte obtained by polymerizing the gel polymer electrolyte composition of the first aspect of this application, thereby having a long cycle life.

[0033] In some embodiments, the method for polymerizing the gel polymer electrolyte composition of the first aspect of this application is in-situ curing polymerization.

[0034] Fourthly, this application provides a method for preparing a battery cell, comprising the following steps:

[0035] A battery cell to be injected with electrolyte is provided. A precursor liquid is obtained by mixing the gel polymer electrolyte composition of the first aspect of this application. The obtained precursor liquid is injected into the battery cell to be injected with electrolyte. Then, the precursor liquid is treated under heating conditions to solidify and polymerize in situ inside the battery cell to form a gel polymer electrolyte, thereby obtaining the battery cell.

[0036] Fifthly, this application provides a battery, including a battery cell according to the third aspect of this application or a battery cell prepared by the preparation method according to the fourth aspect of this application.

[0037] Sixthly, this application provides an electrical device including the battery of the fifth aspect of this application.

[0038] The electrical device of this application includes the battery provided in this application, and therefore has at least the same advantages as the battery. Attached Figure Description

[0039] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments of this application will be briefly described below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on the drawings without creative effort.

[0040] Figure 1 is a schematic diagram of one embodiment of the battery cell of this application.

[0041] Figure 2 is an exploded view of one embodiment of the battery cell of this application.

[0042] Figure 3 is a schematic diagram of one embodiment of the battery module of this application.

[0043] Figure 4 is a schematic diagram of one embodiment of the battery pack of this application.

[0044] Figure 5 is an exploded view of an embodiment of the battery pack shown in Figure 4.

[0045] Figure 6 is a schematic diagram of one embodiment of an electrical device that uses the battery of this application as a power source.

[0046] The accompanying drawings are not necessarily drawn to scale.

[0047] The reference numerals in the attached diagram are explained as follows: 1. Battery pack; 2. Upper casing; 3. Lower casing; 4. Battery module; 5. Battery cell; 51. Housing; 52. Electrode assembly; 53. Cover plate. Detailed Implementation

[0048] The following detailed description, with appropriate reference to the accompanying drawings, discloses embodiments of the gel polymer electrolyte composition, gel polymer electrolyte, battery cell, preparation method thereof, battery, and power device of this application. However, unnecessary detailed descriptions may be omitted. For example, detailed descriptions of well-known matters and repetitive descriptions of practically identical structures may be omitted. This is to avoid unnecessarily lengthy descriptions and to facilitate understanding by those skilled in the art. Furthermore, the accompanying drawings and the following description are provided to enable those skilled in the art to fully understand this application and are not intended to limit the subject matter of the claims.

[0049] The "range" disclosed in this application is defined by a lower limit and an upper limit. A given range is defined by selecting a lower limit and an upper limit, which define the boundaries of a particular range. Ranges defined in this way can include or exclude endpoints and can be arbitrarily combined; that is, any lower limit can be combined with any upper limit to form a range. For example, if ranges of 60-120 and 80-110 are listed for a specific parameter, it is expected that ranges of 60-110 and 80-120 are also included. Furthermore, if minimum range values ​​of 1 and 2 are listed, and if maximum range values ​​of 3, 4, and 5 are listed, then the following ranges are all expected: 1-3, 1-4, 1-5, 2-3, 2-4, and 2-5. In this application, unless otherwise stated, the numerical range "ab" represents a shortened representation of any combination of real numbers between a and b, where a and b are real numbers. For example, the numerical range "0-5" indicates that all real numbers between "0-5" have been listed in this article; "0-5" is simply a shortened representation of these numerical combinations. Furthermore, when a parameter is stated as an integer ≥2, it is equivalent to disclosing that the parameter is, for example, an integer such as 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.

[0050] 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.

[0051] 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.

[0052] Unless otherwise specified, all steps in this application may be performed sequentially or randomly, preferably sequentially. For example, the method includes steps (a) and (b), indicating that the method may include steps (a) and (b) performed sequentially, or it may include steps (b) and (a) performed sequentially. For example, the mention that the method may also include step (c) indicates that step (c) may be added to the method in any order. For example, the method may include steps (a), (b), and (c), or it may include steps (a), (c), and (b), or it may include steps (c), (a), and (b), etc.

[0053] Unless otherwise stated, the terms used in this application have the common meanings as commonly understood by those skilled in the art.

[0054] Unless otherwise stated, the values ​​of the parameters mentioned in this application can be determined using various testing methods commonly used in the art, for example, according to the testing methods given in the embodiments of this application. Unless otherwise stated, the test temperature for each parameter is 25°C.

[0055] The battery mentioned in the embodiments of this application may include one or more battery cells as a single physical module to provide higher voltage and capacity. For example, the battery mentioned in this application may include battery cells, battery modules, or battery packs.

[0056] A battery cell is the smallest unit that makes up a battery, and it can independently perform the functions of charging and discharging. A battery cell can be cylindrical, cuboid, or other shapes, and the embodiments of this application are not limited to this. Figure 1 shows a cuboid battery cell 5 as an example.

[0057] When there are multiple battery cells, they are connected in series, parallel, or mixed via a busbar. In some embodiments, the battery can be a battery module; when there are multiple battery cells, they are arranged and fixed to form a battery module. In some embodiments, the battery can be a battery pack, which includes a housing and battery cells, with the battery cells or battery modules housed within the housing. In some embodiments, the housing can be part of the vehicle's chassis structure. For example, a portion of the housing can be at least part of the vehicle's floor, or a portion of the housing can be at least part of the vehicle's crossbeams and longitudinal beams.

[0058] In some embodiments, the battery can be an energy storage device. Energy storage devices include energy storage containers, energy storage cabinets, etc.

[0059] The battery cell includes an electrode assembly. The electrode assembly can be a wound structure or a stacked structure, and the embodiments of this application are not limited to this.

[0060] The battery cell may also include an outer packaging, which can be used to encapsulate electrode components and non-aqueous electrolyte. The outer packaging can be a rigid shell, such as a hard plastic shell, aluminum shell, or steel shell. The outer packaging can also be a flexible package, such as a pouch-type flexible package. The material of the flexible package can be plastic, such as one or more of aluminum-plastic film, polypropylene (PP), polybutylene terephthalate (PBT), and polybutylene succinate (PBS).

[0061] In some embodiments, as shown in FIG2, the outer packaging may include a housing 51 and a cover 53. The housing 51 may include a base plate and side plates connected to the base plate, the base plate and side plates enclosing a receiving cavity. The housing 51 has an opening communicating with the receiving cavity, and the cover 53 is used to cover the opening to close the receiving cavity. Electrode assemblies 52 are encapsulated in the receiving cavity. The number of electrode assemblies 52 contained in the battery cell 5 may be one or more, and can be adjusted as needed.

[0062] In some embodiments, individual battery cells can be assembled into a battery module. The number of battery cells in a battery module can be multiple, and the specific number can be adjusted according to the application and capacity of the battery module. Figure 3 is a schematic diagram of a battery module 4 as an example. As shown in Figure 3, in the battery module 4, multiple battery cells 5 can be arranged sequentially along the length of the battery module 4. Of course, they can also be arranged in any other arbitrary manner. Furthermore, the multiple battery cells 5 can be fixed in place using fasteners.

[0063] Optionally, the battery module 4 may also include a housing with a receiving space in which multiple battery cells 5 are received.

[0064] 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.

[0065] Figures 4 and 5 are schematic diagrams of a battery pack 1 as an example. As shown in Figures 4 and 5, the battery pack 1 may include a housing and multiple battery modules 4 disposed within the housing. The housing includes an upper housing 2 and a lower housing 3. The upper housing 2 covers the lower housing 3, forming a closed space for accommodating the battery modules 4. The multiple battery modules 4 can be arranged in any manner within the housing.

[0066] This application provides a gel polymer electrolyte composition, which can form a gel polymer electrolyte after polymerization.

[0067] The gel polymer electrolyte composition provided in this application includes a non-aqueous electrolyte, a polymer monomer, and an ionic liquid monomer. The polymer monomer is a polymer monomer with an ether oxygen segment that can undergo free radical polymerization, and the weight average molecular weight of the polymer monomer is 400 to 80,000; the ionic liquid monomer includes one or more of N-containing ionic liquids, P-containing ionic liquids, and S-containing ionic liquids, and the end group of the ionic liquid is an alkenyl or (meth)acrylate group.

[0068] The gel polymer electrolyte composition provided in this application includes a polymer monomer capable of free radical polymerization and an ionic liquid monomer, which polymerize to form a gel polymer electrolyte. The gel polymer electrolyte is flexible and can have good contact with the interface, thereby reducing interfacial impedance. The polymer monomer and the ionic liquid monomer polymerize to form the polymer backbone of the gel polymer electrolyte.

[0069] Ionic liquid monomers have excellent ion transport properties, and the polymer skeleton formed by their polymerization with polymer monomers can give gel polymer electrolytes good ionic conductivity without reducing mechanical properties. The polymer skeleton cations also have an attractive effect on anions in non-aqueous electrolytes, which can promote the dominance of lithium ions in ion transport, reduce concentration polarization, and avoid lithium ion depletion during charging and discharging. This is conducive to the long-term stable performance of battery cell capacity and gives battery cells a long cycle life.

[0070] The polymer monomers have a weight-average molecular weight of 400 to 80,000 and have relatively long molecular chains, which allows them to polymerize with ionic liquid monomers to form a polymer backbone that also has good flexibility.

[0071] The polymer monomers possess ether-oxygen segments that are affinity for non-aqueous electrolytes, while the ionic liquid monomers have strong dipoles. Therefore, the polymer backbone formed by the polymerization of the ionic liquid monomers and polymer monomers can completely bind the non-aqueous electrolyte within the polymer backbone network even at a low mass percentage, preventing the non-aqueous electrolyte from flowing freely. This reduces the side reactions that continuously consume active lithium at the negative electrode interface caused by unstable organic solvents and anions in the non-aqueous electrolyte. Furthermore, it facilitates the long-term stable wetting of the electrode components by the non-aqueous electrolyte, reducing the occurrence of localized drying problems, thereby improving the cycle life of the battery cells.

[0072] The polymer monomers have a weight-average molecular weight of 400 to 80,000, which can make the polymer monomers highly active and easy to undergo polymerization reactions. It can also make the polymer skeleton formed by polymerization have a suitable cross-linking density, thereby binding more non-aqueous electrolytes, and thus enabling the gel polymer electrolyte to have good ion transport properties.

[0073] Therefore, the gel polymer electrolyte composition provided in this application embodiment can be used in battery cells to enable battery cells to have a long cycle life.

[0074] The weight-average molecular weight of the polymer monomers is from 400 to 80,000, for example, it can be 400, 600, 800, 1000, 2000, 4000, 6000, 8000, 10,000, 12,000, 14,000, 16,000, 18,000, 20,000, 22,000, 24,000, 26,000, 28,000, 30,000, 32,000, 34,000, 36,000, 38,000, 40,000, 42,000, 44,000, 46,000, 48,000, 50,000, 54,000, 58,000, 62,000, 66,000, 70,000, 75,000, 80,000, or any combination of the above values.

[0075] Optionally, the weight-average molecular weight of the polymer monomers can be 4 million to 66,000, 4 million to 54,000, 4 million to 48,000, 4 million to 40,000, 4 million to 36,000, 8 million to 66,000, 8 million to 54,000, 8 million to 48,000, 8 million to 40,000, 8 million to 36,000, 2,000 to 66,000, 2,000 to 54,000, 2,000 to 48,000, 2,000 to 40,000, or 2,000 to 36,000.

[0076] When the weight-average molecular weight of the polymer monomer is within the above range, the battery cell can have a longer cycle life.

[0077] In some embodiments, the polymer monomer may include one or more of the polymer monomers shown in Formula I and Formula II. The polymer monomer shown in Formula I is a diacrylate type polymer monomer. The polymer monomer shown in Formula II is a diallylamide type polymer monomer.

[0078] X is selected from C1-C10 alkylene or C1-C10 haloalkylene, R1 is selected from hydrogen atom or methyl, R2 is selected from hydrogen atom or methyl, and n is selected from an integer between 10 and 1000.

[0079] C1-C10 alkylene groups and C1-C10 haloalkylene groups can have either a straight-chain structure or a branched structure.

[0080] The polymer monomers shown in Formula I and Formula II can polymerize with ionic liquid monomers to form a cross-linked structure, which can give the gel polymer electrolyte good oxidation-reduction stability, thus helping the battery cell to have a longer cycle life.

[0081] Optionally, X may be selected from C1-C4 alkylene groups.

[0082] Alternatively, X may be selected from C2-C4 alkylene groups.

[0083] Alternatively, X may be selected from ethylene.

[0084] Ethylene can enable the intermediate segments of polymer monomers to form a flexible glycol ether structure that is also compatible with non-aqueous electrolytes. This is beneficial for the polymer skeleton formed after polymerization to better bind the non-aqueous electrolyte and also for the gel polymer electrolyte to have good elasticity.

[0085] n is selected from an integer between 10 and 1000, for example, it can be 10, 20, 50, 100, 150, 200, 250, 300, 350, 400, 450, 500, 550, 600, 650, 700, 750, 800, 850, 900, 950, 1000, or any range of the above values.

[0086] Optionally, n can be selected from an integer between 50 and 800, an integer between 50 and 500, an integer between 50 and 400, an integer between 50 and 300, or an integer between 50 and 200.

[0087] Within the above range, the polymer monomers can have high activity, making them easy to polymerize. The polymer skeleton formed by polymerization can also have a suitable crosslinking density, thereby binding more non-aqueous electrolyte. This, in turn, can give the gel polymer electrolyte good ion transport properties, resulting in a longer cycle life for the battery cells.

[0088] In some embodiments, the cation of the ionic liquid monomer may include any one of the following ions with an alkenyl or (meth)acrylate end group: tetrahydropyrrole ion, quaternary ammonium ion, imidazole ion, piperidinium ion, pyridinium ion, thionium ion, and phosphonium ion.

[0089] In some embodiments, the cation of the ionic liquid monomer can be composed of any one of the end groups shown in Formula 1 and any one of the cations shown in Formula 2, where * indicates a linking site.

[0090] R3 is selected from hydrogen atom or methyl group, R4, R6, R8, R9, R 10 R 12 R 15 R 17 R 18 R 20 R 21 Alkyl groups independently selected from C1-C10, R5, R7, R 11 R 13 R 14 R 16 R 19Each is independently selected from C1-C10 alkylene groups or C1-C10 oxaalkylene groups.

[0091] C1-C10 alkyl, C1-C10 alkylene, and C1-C10 oxaalkylene can be straight-chain or branched.

[0092] Optionally, R4, R6, R8, R9, R 10 R 12 R 15 R 17 R 18 R 20 R 21 Each alkyl group can be independently selected from C1-C5. More preferably, R4, R6, R8, R9, R 10 R 12 R 15 R 17 R 18 R 20 R 21 Alkyl groups can be selected independently from C1-C3.

[0093] Optionally, R5, R7, R 11 R 13 R 14 R 16 R 19 It can be independently selected from C2-C5 alkylene groups or C2-C5 oxaalkylene groups. More preferably, R5, R7, R... 11 R 13 R 14 R 16 R 19 They can be independently selected from C2-C3 alkylene groups or C2-C3 oxaalkylene groups.

[0094] In some embodiments, the cation of the ionic liquid monomer may include any of the following:

[0095] The anion of the ionic liquid monomer can be an organic anion or an inorganic anion. In some embodiments, the anion of the ionic liquid monomer may include any of the following: chloride ion (Cl... - ), bromide ions (Br) - ), iodide ions (I) - ), difluorosulfonyl imide ion (FSI) - ), bis(trifluoromethyl)sulfonylimide ion (TFSI) - ), hexafluorophosphate (PF6) - ), tetrafluoroborate (BF4)- ), hexafluoroarsenate (AsF6) - ), trifluoromethanesulfonate (OTF) - ), difluorophosphate (DFP) - ), dioxalate borate (BOB) - ), difluorooxalate borate (DFOB) - ), difluorodioxazoline phosphate and tetrafluorooxazoline phosphate.

[0096] In some embodiments, the molar ratio of the ionic liquid monomer to the polymer monomer can be from 1:1 to 10:1, for example, it can be 1:1, 1.5:1, 2:1, 2.5:1, 3:1, 3.5:1, 4:1, 4.5:1, 5:1, 5.5:1, 6:1, 6.5:1, 7:1, 7.5:1, 8:1, 8.5:1, 9:1, 9.5:1, 10:1, or any range of the above values.

[0097] When the molar ratio of ionic liquid monomers to polymer monomers is within the above range, the polymer skeleton formed by polymerization can have a suitable crosslinking density, thereby binding more non-aqueous electrolyte. This, in turn, can give the gel polymer electrolyte good ion transport properties, and give the battery cell a longer cycle life.

[0098] Optionally, the molar ratio of the ionic liquid monomer to the polymer monomer can be 2:1 to 8:1, 3:1 to 7:1, or 4:1 to 6:1.

[0099] In some embodiments, based on the total mass of the gel polymer electrolyte composition, the sum of the mass fractions of the polymer monomers and the ionic liquid monomers can be 0.5%-20%, for example, it can be 0.5%, 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, 20%, or any range of the above values.

[0100] When the sum of the mass fractions of the ionic liquid monomer and the polymer monomer is within the above range, the polymer skeleton formed by polymerization can bind the electrolyte, improve the interfacial stability and electrolyte wettability during long-term cycling, and also enable the gel polymer electrolyte formed by polymerization to have good ion transport properties.

[0101] Optionally, based on the total mass of the gel polymer electrolyte composition, the sum of the mass fractions of the ionic liquid monomer and the polymer monomer can be 1%-15%, 1%-10%, or 3%-8%.

[0102] In some embodiments, the mass fraction of the non-aqueous electrolyte can be 80%-99.5% based on the total mass of the gel polymer electrolyte composition, for example, it can be 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, 99.5%, or any range of the above values.

[0103] Optionally, based on the total mass of the gel polymer electrolyte composition, the mass fraction of the non-aqueous electrolyte can be 85%-99%, 90%-99%, or 92%-97%.

[0104] In some embodiments, the gel polymer electrolyte composition may further include an initiator.

[0105] In some embodiments, the mass of the initiator can be 0.1%-10% of the total mass of the ionic liquid monomer and the polymer monomer. An appropriate amount of initiator is beneficial for the full polymerization of the polymer monomer and the ionic liquid monomer.

[0106] Optionally, the initiator may include one or more of azo initiators and peroxide initiators, for example, one or more of azobisisobutyronitrile (AIBN), azobisisoheptanenitrile (AMVN), acetyl peroxide, and hydrogen peroxide.

[0107] The non-aqueous electrolyte includes lithium salts and organic solvents. In some embodiments, the lithium salt may be one or more of lithium bis(trifluoromethyl)sulfonylimide (LiFSI), lithium hexafluorophosphate (LiPF6), lithium tetrafluoroborate (LiBF4), lithium hexafluoroarsenate (LiAsF6), lithium bis(trifluoromethyl)sulfonylimide (LiTFSI), lithium trifluoromethanesulfonate (LiOTF), lithium dioxolaneborate (LiBOB), lithium difluorooxolaneborate (LiDFOB), lithium difluorodioxolane phosphate, and lithium tetrafluorooxolane phosphate. In some embodiments, the organic solvent may be one or more of ester solvents and ether solvents.

[0108] This application also provides a gel polymer electrolyte, which is obtained by polymerizing the above-described gel polymer electrolyte composition.

[0109] This application also provides a battery cell. The battery cell includes a gel polymer electrolyte, which is obtained by polymerizing the above-described gel polymer electrolyte composition. Therefore, the battery cell provided in this application has a long cycle life.

[0110] Optionally, the polymerization method is in-situ curing polymerization.

[0111] Gel polymer electrolytes consist of a polymer backbone and a non-aqueous electrolyte bound within the polymer backbone.

[0112] The polymer backbone structure of gel polymer electrolytes can be obtained through methods such as NMR and FT-IR. For example, after disassembling a battery cell, a sample of the residual gel polymer electrolyte is taken and injected into an NMR sample tube or FT-IR sample stage for testing. The resulting spectrum is compared with a standard spectrum to determine the specific structure, such as whether it contains C=O, CO, C=C, pyrrole ions, quaternary ammonium ions, imidazole ions, piperidinium ions, pyridine ions, thionium ions, phosphonium ions, etc. A comprehensive analysis is then used to determine the type of polymer backbone structure.

[0113] The skeletal structure of the gel polymer electrolyte and the mass fraction of the bound non-aqueous electrolyte can be obtained by freeze-drying. For example, after disassembling a battery cell, a gel polymer electrolyte sample from the residual space is taken, and the sample mass m1 is weighed. This sample is then placed in a freeze dryer for freeze-drying. After freeze-drying, the residual sample mass m2 is weighed. m1-m2 represents the mass of the organic solvent in the non-aqueous electrolyte. The freeze-dried sample is then thoroughly cleaned and dried using ethyl methyl carbonate (e.g., for lithium-ion battery cells) or dimethyl glycol ether (e.g., for lithium metal battery cells or negative electrode-free lithium metal battery cells). The dried sample is weighed again, and the mass m3 represents the mass of the polymer skeleton. m2-m3 represents the mass of the lithium salt. Thus, the mass fractions of different components in the gel polymer electrolyte, such as the polymer skeleton, non-aqueous electrolyte, organic solvent, and lithium salt, can be obtained.

[0114] A single battery cell also includes a positive electrode, a negative electrode, and a separator.

[0115] The battery cells provided in the embodiments of this application may include lithium-ion battery cells, lithium metal battery cells, and lithium metal battery cells without a negative electrode. Specifically, the types of battery cells differ, as do the compositions of the negative electrode and the compositions of the non-aqueous electrolyte.

[0116] [Negative electrode plate]

[0117] First, taking a lithium-ion battery cell as an example, the negative electrode sheet may include a negative current collector and a negative electrode film layer located on at least one surface of the negative current collector. The negative electrode film layer includes a negative electrode active material, which may include one or more of carbon-based materials, silicon-based materials, and lithium alloys. Optionally, the carbon-based material may include, but is not limited to, one or more of artificial graphite and natural graphite. Optionally, the silicon-based material may include, but is not limited to, one or more of elemental silicon, silicon oxide, silicon-carbon composites, silicon-nitrogen composites, and silicon alloys.

[0118] Optionally, the negative electrode active material may include silicon-based materials, thereby enabling the battery cell to have a high energy density. However, silicon-based negative electrodes experience large volume changes and are easily broken during cycling, and consume non-aqueous electrolyte and active lithium relatively quickly. The battery cell provided in this application embodiment includes a gel polymer electrolyte obtained by polymerizing the above-mentioned gel polymer electrolyte composition. Its polymer skeleton structure can bind the non-aqueous electrolyte, thereby reducing side reactions at the negative electrode interface and reducing the consumption of non-aqueous electrolyte and active lithium.

[0119] Optionally, the negative electrode film layer may further include a negative electrode conductive agent and / or a negative electrode binder. As an example, the negative electrode conductive agent may include, but is not limited to, one or more of superconducting carbon, conductive graphite, acetylene black, carbon black, Ketjen black, carbon dots, carbon nanotubes, graphene, and carbon nanofibers; as an example, the negative electrode binder may include, but is not limited to, one or more of styrene-butadiene rubber (SBR), water-soluble unsaturated resin SR-1B, waterborne acrylic resins (e.g., polyacrylic acid PAA, polymethacrylic acid PMAA, sodium polyacrylate PAAS), polyacrylamide (PAM), polyvinyl alcohol (PVA), sodium alginate (SA), and carboxymethyl chitosan (CMCS).

[0120] Optionally, the negative electrode film layer may also include other additives. For example, other additives may include thickeners, such as sodium carboxymethyl cellulose (CMC), PTC thermistor materials, etc.

[0121] Optionally, the negative electrode current collector can be a metal foil or a composite current collector. Examples of metal foils include copper foil, copper alloy foil, nickel foil, and nickel alloy foil. The composite current collector can include a polymer base material and a metal material layer formed on at least one surface of the polymer base material. Examples of metal materials include, but are not limited to, one or more of copper, copper alloys, nickel, nickel alloys, titanium, titanium alloys, silver, and silver alloys. Examples of polymer base materials include, but are not limited to, one or more of polypropylene (PP), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polystyrene (PS), and polyethylene (PE).

[0122] In some embodiments, the organic solvent may include one or more of carbonates and carboxylic esters, such as fluorinated or unfluorinated cyclic carbonates, fluorinated or unfluorinated chain carbonates, and fluorinated or unfluorinated carboxylic esters. Cyclic carbonates may include, but are not limited to, one or more of ethylene carbonate (EC), propylene carbonate (PC), fluoroethylene carbonate (FEC), and difluoroethylene carbonate (DFEC); chain carbonates may include, but are not limited to, one or more of dimethyl carbonate (DMC), ethyl methyl carbonate (EMC), diethyl carbonate (DEC), fluoroethyl methyl carbonate, and fluorodiethyl carbonate; carboxylic esters may include, but are not limited to, one or more of ethyl formate (EF), ethyl acetate (EA), methyl acetate, ethyl fluoroformate, ethyl fluoroacetate, and methyl fluoroacetate.

[0123] Optionally, the organic solvent may include fluorinated or unfluorinated cyclic carbonates or fluorinated or unfluorinated chain carbonates, and the sum of the mass fractions of fluorinated and unfluorinated cyclic carbonates in the organic solvent is less than 50%, optionally 15%-40%, 18%-40%, or 18%-38%.

[0124] In some embodiments, the non-aqueous electrolyte may also include additives. Additives may include, but are not limited to, one or more of the following: ethylene carbonate (VC), propane sulpholactone (PS), vinyl sulfate (ES), vinyl sulfite, tris(trimethylsilane) phosphate, tris(trimethylsilane) phosphite, tris(trifluoroethyl) phosphate, tris(trifluoroethyl) phosphite, tris(trimethylsilane) borate, dimethyl maleic anhydride, butyl 1,4-diisocyanate, and lithium difluorophosphate (LiDFP).

[0125] In some embodiments, the lithium salt may include, but is not limited to, one or more of lithium bis(trifluoromethyl)sulfonylimide (LiFSI), lithium hexafluorophosphate (LiPF6), lithium tetrafluoroborate (LiBF4), lithium hexafluoroarsenate (LiAsF6), lithium bis(trifluoromethyl)sulfonylimide (LiTFSI), lithium trifluoromethanesulfonate (LiOTF), lithium dioxolaneborate (LiBOB), lithium difluorooxolaneborate (LiDFOB), lithium difluorodioxolane phosphate, and lithium tetrafluorooxolane phosphate.

[0126] Alternatively, the lithium salt may include lithium hexafluorophosphate. This lithium salt has good resistance to oxidation and reduction, which is beneficial for the long cycle life of lithium-ion battery cells.

[0127] In some embodiments, the lithium salt concentration of the non-aqueous electrolyte can be 0.5 mol / L to 1.5 mol / L, for example, 0.5 mol / L, 0.8 mol / L, 0.9 mol / L, 1 mol / L, 1.1 mol / L, 1.2 mol / L, 1.3 mol / L, 1.4 mol / L, 1.5 mol / L, or any range of the above values. Optionally, the lithium salt concentration of the non-aqueous electrolyte can be 0.8 mol / L to 1.4 mol / L, and optionally 0.9 mol / L to 1.3 mol / L.

[0128] Secondly, taking a lithium metal battery cell as an example, the negative electrode sheet may include a negative current collector and a lithium metal layer disposed on at least one surface of the negative current collector; taking a lithium metal battery cell without a negative electrode as an example, the negative electrode sheet may include a negative current collector but does not include a lithium metal layer. In some embodiments, the negative current collector may be a metal foil or a composite current collector. As examples of metal foil, copper foil, copper alloy foil, nickel foil, and nickel alloy foil may be used. The composite current collector may include a polymer material base layer and a metal material layer formed on at least one surface of the polymer material base layer. As examples, the metal material may include, but is not limited to, one or more of copper, copper alloy, nickel, nickel alloy, titanium, titanium alloy, silver, and silver alloy. As examples, the polymer material base layer may include, but is not limited to, one or more of polypropylene (PP), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polystyrene (PS), and polyethylene (PE).

[0129] Lithium metal battery cells and electrodeless lithium metal battery cells have high energy density, but lithium metal anodes experience large volume changes and are easily broken during cycling, and consume non-aqueous electrolyte and active lithium relatively quickly. The battery cell provided in this application includes a gel polymer electrolyte obtained by polymerizing the above-mentioned gel polymer electrolyte composition. Its polymer backbone structure can bind the non-aqueous electrolyte, thereby reducing side reactions at the anode interface and decreasing the consumption of non-aqueous electrolyte and active lithium.

[0130] A negative electrode-free lithium metal battery cell typically refers to a battery cell in which no negative electrode active material layer is actively formed on the negative electrode side during the battery cell manufacturing process. For example, the negative electrode active material layer is not formed at the negative electrode through processes such as coating or deposition. During the first charge, ions gain electrons on the negative electrode side and deposit on the surface of the negative electrode current collector to form a metallic phase. During discharge, the metal can transform into metal ions and return to the positive electrode, achieving cyclic charging and discharging. Compared to other battery cells, a negative electrode-free lithium metal battery cell can achieve a higher energy density due to the absence of a negative electrode active material layer. In some embodiments, to improve the performance of the battery cell, some conventional materials that can be used as negative electrode active materials, such as carbon materials, can also be placed on the negative electrode side of the negative electrode-free lithium metal battery cell. Although these materials have a certain capacity, because their content is small and they are not used as the main negative electrode active material in the battery cell, the battery cell constructed in this way can still be regarded as a negative electrode-free lithium metal battery cell. The CB value of a cathodeless lithium metal battery cell is typically very small; for example, in some embodiments, the CB value of a cathodeless lithium metal battery cell can be less than or equal to 0.1. The CB value is the capacity per unit area of ​​the negative electrode divided by the capacity per unit area of ​​the positive electrode in the battery cell. Because a cathodeless lithium metal battery cell contains little or no negative electrode active material, the capacity per unit area of ​​the negative electrode is small, resulting in a very small CB value, typically less than or equal to 0.1.

[0131] In some embodiments, the organic solvent may include ether solvents. Ether solvents may include one or more of chain ether solvents and cyclic ether solvents.

[0132] Chain ether solvents may include, but are not limited to, one or more of diethyl ether, dipropyl ether, ethylpropyl ether, methyl butyl ether, dibutyl ether, ethyl butyl ether, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol diethyl ether, ethylene glycol dipropyl ether, ethylene glycol dibutyl ether, propylene glycol dimethyl ether, propylene glycol diethyl ether, propylene glycol diethyl ether, butanediol dimethyl ether, butanediol diethyl ether, butanediol diethyl ether, and butanediol diethyl ether. Cyclic ether solvents may include, but are not limited to, one or more of tetrahydrofuran, 3-methyltetrahydrofuran, 1,3-dioxopentane, tetrahydropyran, 1,3-dioxane, and 1,4-dioxane.

[0133] Optionally, the organic solvent may include one or both of ethylene glycol dimethyl ether (DME) and propylene glycol dimethyl ether (DMP). These organic solvents exhibit good lithium salt solubility and stability at both positive and negative electrodes, which is beneficial for rapid ion conduction and stability at the positive and negative electrode interfaces.

[0134] In some embodiments, the non-aqueous electrolyte may further include a diluent. The diluent may include, but is not limited to, benzene, fluorobenzene, p-difluorobenzene, m-difluorobenzene, o-difluorobenzene, trifluorotoluene, trifluoromethoxybenzene, decafluoropentane, 1,1,2,2-tetrafluoroethyl-2,2,3,3-tetrafluoropropyl ether, 1,2-dimethoxy-1,1,2,2-tetrafluoroethane, 1,2-bis(difluoromethoxy)ethane, 1,2-bis(trifluoromethoxy)ethane, 1,2-diethoxy-1,1,2,2-tetrafluoroethane, 1,2-bis(1,1,2,2-tetrafluoroethoxy)ethane, bis(2,2,2-trifluoroethyl) ether, bis(2,2-difluoroethyl) ether, 1, One or more of the following: 1,2,3,3,3-hexafluoropropyl ethyl ether, 1H,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, and bis(1,1,2,2-tetrafluoroethyl) ether.

[0135] Optionally, the diluent includes one or both of benzene and 1,2-bis(difluoromethoxy)ethane. This type of diluent has low viscosity, low molecular weight, and high stability, which can improve the interfacial stability of the positive and negative electrodes, while simultaneously reducing the viscosity of the non-aqueous electrolyte and increasing its ionic conductivity, thereby enhancing the ion transport properties of the polymer electrolyte formed by polymerization.

[0136] In some embodiments, the non-aqueous electrolyte may simultaneously include an organic solvent and a diluent, and the mass ratio of the organic solvent to the diluent may be from 10:90 to 80:20, for example, it may be 10:90, 15:85, 20:80, 25:75, 30:70, 35:65, 40:60, 45:55, 50:50, 55:45, 60:40, 65:35, 70:30, 75:25, 80:20, or any range of the above values.

[0137] In some embodiments, the lithium salt may include, but is not limited to, one or more of lithium bis(trifluoromethyl)sulfonylimide (LiFSI), lithium hexafluorophosphate (LiPF6), lithium tetrafluoroborate (LiBF4), lithium hexafluoroarsenate (LiAsF6), lithium bis(trifluoromethyl)sulfonylimide (LiTFSI), lithium trifluoromethanesulfonate (LiOTF), lithium dioxolaneborate (LiBOB), lithium difluorooxolaneborate (LiDFOB), lithium difluorodioxolane phosphate, and lithium tetrafluorooxolane phosphate.

[0138] Optionally, the lithium salt includes lithium bisfluorosulfonylimide (LiFSI). This lithium salt can decompose on the negative electrode surface to form an inorganic fluorine-rich SEI film component, which is beneficial for the long cycle life of lithium metal battery cells and negative electrode-free lithium metal battery cells; at the same time, this lithium salt also has relatively good oxidation stability, which can support high-voltage cycling of lithium metal battery cells and negative electrode-free lithium metal battery cells.

[0139] In some embodiments, the lithium salt concentration of the non-aqueous electrolyte can be between 1 mol / L and 6 mol / L, for example, it can be 1 mol / L, 1.5 mol / L, 2 mol / L, 2.5 mol / L, 3 mol / L, 3.5 mol / L, 4 mol / L, 4.5 mol / L, 5 mol / L, 5.5 mol / L, 6 mol / L, or any range of the above values. Optionally, the lithium salt concentration of the non-aqueous electrolyte can be between 2 mol / L and 5 mol / L, or between 2 mol / L and 4 mol / L.

[0140] [Positive electrode plate]

[0141] In some embodiments, the positive electrode includes a positive current collector and a positive electrode film layer disposed on at least one surface of the positive current collector, the positive electrode film layer comprising a positive active material. For example, the positive current collector has two surfaces opposite each other in its thickness direction, and the positive electrode film layer is disposed on either or both of the two opposite surfaces of the positive current collector.

[0142] The positive electrode active material includes materials capable of lithium extraction and insertion. Optionally, the positive electrode active material may include, but is not limited to, one or more of lithium transition metal oxides, lithium-containing phosphates, and their respective modified compounds. Examples of lithium transition metal oxides may include, but are not limited to, one or more of lithium cobalt oxides, lithium nickel oxides, lithium manganese oxides, lithium nickel cobalt oxides, lithium manganese cobalt oxides, lithium nickel manganese oxides, lithium nickel cobalt manganese oxides, lithium nickel cobalt aluminum oxides, and their respective modified compounds. Examples of lithium-containing phosphates may include, but are not limited to, lithium iron phosphate, lithium iron phosphate and carbon composites, lithium manganese phosphate, lithium manganese phosphate and carbon composites, lithium manganese iron phosphate, lithium manganese iron phosphate and carbon composites, and their respective modified compounds. The modified compounds of the above-mentioned positive electrode active materials may be for doping modification and / or surface coating modification of the positive electrode active material.

[0143] In some embodiments, to further improve the energy density of a single battery cell, the positive electrode active material may include materials of the general formula Li. a Ni b Co c M d O e A fOne or more of lithium transition metal oxides and their modified compounds. 0.8≤a≤1.2, 0.5≤b<1, 0<c<1, 0<d<1, 1≤e≤2, 0≤f≤1, M includes one or more of Mn, Al, Zr, Zn, Cu, Cr, Mg, Fe, V, Ti and B, and A includes one or more of N, F, S and Cl.

[0144] In some embodiments, as an example, the positive electrode active material may include, but is not limited to, LiCoO2, LiNiO2, LiMnO2, LiMn2O4, and LiNi 1 / 3 Co 1 / 3 Mn 1 / 3 O2 (abbreviated as NCM333), LiNi 0.5 Co 0.2 Mn 0.3 O2 (abbreviated as NCM523), LiNi 0.5 Co 0.25 Mn 0.25 O2 (abbreviated as NCM211), LiNi 0.6 Co 0.2 Mn 0.2 O2 (abbreviated as NCM622), LiNi 0.8 Co 0.1 Mn 0.1 O2 (abbreviated as NCM811), LiNi 0.96 Co 0.02 Mn 0.02 O2 (abbreviated as Ni96), LiNi 0.80 Co 0.15 Al 0.05 O2, LiFePO4, LiMnPO4, and one or more of their respective modified compounds.

[0145] During the charging and discharging process, lithium (Li) undergoes insertion / extraction and consumption within a single battery cell, resulting in varying molar Li content at different discharge states. In the examples of positive electrode active materials in this application, the molar Li content represents the initial state of the material, i.e., the state before material addition. As the positive electrode active material is applied to the battery cell, the molar Li content changes after charge-discharge cycles. Similarly, in the examples of positive electrode active materials in this application, the molar O content is only a theoretical value. Lattice oxygen release causes changes in the molar O content, leading to fluctuations in the actual molar O content.

[0146] In some embodiments, the positive electrode film layer may further include a positive electrode conductive agent. As an example, the positive electrode conductive agent may include, but is not limited to, one or more of superconducting carbon, conductive graphite, acetylene black, carbon black, Ketjen black, carbon dots, carbon nanotubes, graphene, and carbon nanofibers.

[0147] In some embodiments, the positive electrode film layer may further include a positive electrode binder. As an example, the positive electrode binder may include, but is not limited to, one or more of polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), PVDF-tetrafluoroethylene-propylene terpolymer, PVDF-hexafluoropropylene-tetrafluoroethylene terpolymer, tetrafluoroethylene-hexafluoropropylene copolymer, and fluorinated acrylate resins.

[0148] In some embodiments, the positive current collector may be a metal foil or a composite current collector. An example of a metal foil is aluminum foil. The composite current collector may include a polymeric material substrate and a metal material layer formed on at least one surface of the polymeric material substrate. As an example, the metal material may include, but is not limited to, one or more of aluminum, aluminum alloys, nickel, nickel alloys, titanium, titanium alloys, silver, and silver alloys. As an example, the polymeric material substrate may include, but is not limited to, one or more of polypropylene (PP), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polystyrene (PS), and polyethylene (PE).

[0149] The positive electrode film can be formed by coating a positive electrode slurry onto a positive electrode current collector, followed by drying and cold pressing. The positive electrode slurry is typically formed by dispersing positive electrode active materials, positive electrode conductive agents, positive electrode binders, and any other components in a solvent and stirring until homogeneous. The solvent can be N-methylpyrrolidone (NMP), but is not limited to this.

[0150] [Isolation membrane]

[0151] A separator can be disposed between the positive and negative electrode plates, primarily serving to prevent internal short circuits. This application does not impose any particular limitation on the type of separator; any known porous membrane with good chemical and mechanical stability can be selected. In some embodiments, the separator material may include, but is not limited to, one or more of glass fiber, nonwoven fabric, polyethylene, polypropylene, polyvinylidene fluoride, and polyimide. The separator can be a single-layer film or a multi-layer composite film. When the separator is a multi-layer composite film, the materials of each layer may be the same or different.

[0152] This application also provides a method for preparing a battery cell. The method for preparing a battery cell includes the following steps: providing a battery cell to be injected with electrolyte; mixing the above-mentioned gel polymer electrolyte composition to obtain a precursor solution; injecting the obtained precursor solution into the battery cell to be injected with electrolyte; and then treating under heating conditions to allow the precursor solution to solidify and polymerize in situ inside the battery cell to form a gel polymer electrolyte, thereby obtaining the battery cell.

[0153] In some embodiments, the heating temperature can be 60°C-80°C.

[0154] In some embodiments, the heating time can be 6h-24h.

[0155] In some embodiments, the precursor solution can be heated during the static soaking process to allow the precursor solution to solidify and polymerize in situ inside the battery cell to form a gel polymer electrolyte.

[0156] Optionally, the precursor solution is first allowed to stand and soak at 20℃-45℃ for 2h-12h to allow the precursor solution to soak the battery cell to be injected; then it is allowed to stand and soak at 60℃-80℃ for 6h-24h to allow the precursor solution to solidify and polymerize in situ inside the battery cell to form a gel polymer electrolyte.

[0157] The preparation method of the battery cell to be injected with electrolyte is well known. In some embodiments, the positive electrode sheet, the separator, and the negative electrode sheet can be formed into an electrode assembly through a winding process and / or a stacking process. The electrode assembly is placed in an outer packaging and dried to obtain the battery cell to be injected with electrolyte.

[0158] Electrical appliances

[0159] This application also provides an electrical device, which includes the battery provided in this application embodiment. The battery can be used as the power source of the electrical device or as the energy storage unit of the electrical device. The electrical device can be, but is not limited to, mobile devices (such as mobile phones, tablets, laptops, etc.), electric vehicles (such as 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, energy storage systems, etc.

[0160] Electrical devices can choose the type of battery according to their usage needs, such as individual battery cells, battery modules, or battery packs.

[0161] Figure 6 is a schematic diagram of an example electrical device. This device is a pure electric vehicle, a hybrid electric vehicle, or a plug-in hybrid electric vehicle, etc. To meet the device's requirements for high power and high energy density, a battery pack or battery module can be used.

[0162] Another example of an electrical device could be a mobile phone, tablet, or laptop. These devices typically require a slim and lightweight design and can use a single battery cell as their power source.

[0163] Example

[0164] The following embodiments describe the disclosure of this application in more detail. These embodiments are merely illustrative, as various modifications and variations will be apparent to those skilled in the art within the scope of the disclosure of this application. Unless otherwise stated, all parts, percentages, and ratios reported in the following embodiments are based on weight, and all reagents used in the embodiments are commercially available or synthesized by conventional methods and can be used directly without further processing, and the instruments used in the embodiments are commercially available.

[0165] In the following examples and comparative examples, for the sake of simplicity, the ionic liquid monomers are numbered as follows.

[0166] This application provides an exemplary method for preparing ionic liquid monomer 6. Other ionic liquid monomers described in this application can be prepared by referring to this exemplary method. Based on the exemplary method for preparing ionic liquid monomers, 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 otherwise specified, 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 generation of the compounds described in this application.

[0167] The process described in the embodiments of this application can be monitored using any suitable method known in the art. For example, product formation can be achieved through spectroscopic means such as nuclear magnetic resonance spectroscopy (NMR, e.g.) 1 H, 13 C or 19 F) Monitoring can be performed using infrared spectroscopy (IR), spectrophotometry (e.g., UV visible), mass spectrometry (MS), or chromatographic methods such as high performance liquid chromatography (HPLC), gas chromatography (GC), gel permeation chromatography (GPC), or thin-layer chromatography (TLC).

[0168] For example, the preparation method of ionic liquid monomer 6 is as follows.

[0169] 3-Bromo-1-propanol (13.90 g, 0.1 mol) and triethylamine (11.13 g, 0.11 mol) were dissolved in 120 mL of redistilled dichloromethane under argon protection. After stirring and cooling to 0 °C, methacryloyl chloride (10.45 g, 0.1 mol) was added dropwise. After the addition was complete, the mixture was kept at this temperature for 15 min, then heated to room temperature (approximately 25 °C) and stirred for 3 h. After the reaction was complete, the reaction was quenched with ice water and then heated to room temperature (approximately 25 °C). The mixture was extracted with dichloromethane (50 mL × 3), washed with saturated brine, and then dried over anhydrous sodium sulfate. The mixture was filtered, concentrated under reduced pressure to remove the organic solvent dichloromethane, and the crude product was obtained. The crude product was then distilled under reduced pressure to obtain 16.98 g (molar yield: 82%) of colorless liquid compound 1, which was reserved for later use.

[0170] 1 H NMR (DMSO-d6, 400MHz), δ (ppm): 6.15 (m, 1H), 5.58 (m, 1H), 4.15 (m, 2H), 3.30 (m, 2H), 2.07 (m, 2H), 1.93 (s, 3H). 13 C NMR (DMSO-d6, 100MHz), δ (ppm): 165.0, 138.0, 122.9, 65.5, 33.8, 29.1, 18.4. HRMS(ESI + )m / z[M] + calcd.for C7H 11 BrO2:205.9942,found:205.9948.

[0171] N-methylimidazole (8.21 g, 0.1 mol) was dissolved in 100 mL of tetrahydrofuran under argon protection. After stirring and cooling to 0 °C, compound 1 (20.71 g, 0.1 mol) was added dropwise. After the addition was complete, the mixture was kept at this temperature for 15 min, then heated to room temperature (approximately 25 °C) and stirred for 14 h. After the reaction was complete, the mixture was concentrated under reduced pressure to remove some of the organic solvent tetrahydrofuran. The solution was filtered and dried under vacuum to obtain 26.03 g (molar yield: 90%) of solid compound 2.

[0172] 1 H NMR(DMSO-d6,400MHz), δ(ppm):9.72(s,1H),8.26(s,1H),7.97(s,1H),6.15(m,1 H),5.58(m,1H),4.15(m,2H),3.63(s,3H),1.93(s,3H),1.60(m,2H),1.30(m,2H). 13C NMR (DMSO-d6, 100MHz), δ (ppm): 165.0, 138.0, 137.5, 130.2, 122.9, 120.6, 65.5, 34.4, 33.8, 29.1, 18.4. Electrospray,MS(+ve):m / z 209.13(100% T-4 + MS(-ve): m / z 79.03 (100% Br) - ).

[0173] Compound 2 (2.89 g, 0.01 mol) and LiFSI (1.87 g, 0.01 mol) were dissolved in 10 mL of acetonitrile under argon protection and stirred at room temperature (approximately 25 °C) for 24 h. The organic solvent acetonitrile was removed by concentration under reduced pressure. Tetrahydrofuran was then added and stored at low temperature. The mixture was filtered, and the filtrate was concentrated under reduced pressure. This process was repeated until no solid precipitate was observed. The organic solvent tetrahydrofuran was removed by concentration under reduced pressure to obtain a pale yellow oily liquid. Water and dichloromethane were then added for extraction. The mixture was separated until no yellow precipitate was formed upon the addition of silver nitrate to the aqueous phase. The organic phase was dried over anhydrous sodium sulfate, filtered, and the dichloromethane was removed by concentration under reduced pressure. The mixture was then dried under vacuum to obtain 3.65 g of a pale yellow oily substance (molar yield: 90.12%), which is the ionic liquid monomer 6.

[0174] 1 H NMR(DMSO-d6,400MHz), δ(ppm):9.72(s,1H),8.26(s,1H),7.97(s,1H),6.15(m,1 H),5.58(m,1H),4.15(m,2H),3.63(s,3H),1.93(s,3H),1.60(m,2H),1.30(m,2H). 13 C NMR (DMSO-d6, 100MHz), δ (ppm): 165.0, 138.0, 137.5, 130.2, 122.9, 120.6, 65.5, 34.4, 33.8, 29.1, 18.4. 19 F NMR (DMSO-d6, 376MHz), δ (ppm): -129.8. Electrospray,MS(+ve):m / z 209.13(100%T-4 + ),MS(-ve):m / z 179.92(100% FSI - ).

[0175] In the following examples and comparative examples, the polymer monomers used are diacrylate polymers represented by Formula I. For simplicity, the polymer monomers are numbered as follows.

[0176] For the sake of simplicity, the non-aqueous electrolytes are numbered as follows in the following examples and comparative examples.

[0177] EC: Ethylene carbonate. PC: Propylene carbonate. EMC: Ethyl methyl carbonate. DMC: Dimethyl carbonate. FEC: Fluorinated ethylene carbonate. DFEC: Difluoroethylene carbonate. ES: Ethylene sulfate. VC: Ethylene carbonate. LiDFP: Lithium difluorophosphate.

[0178] Example 1

[0179] (1) Preparation of lithium-ion battery cells to be injected with electrolyte

[0180] LiNi, the positive electrode active material 0.8 Co 0.1 Mn 0.1 O2, conductive agent acetylene black, and binder PVDF are mixed at a mass ratio of 98:1:1, and then added to the solvent N-methylpyrrolidone (NMP) and stirred until the system is homogeneous, obtaining a positive electrode slurry with a solid content of approximately 70%. The positive electrode slurry is then subjected to a reaction at approximately 12.5 mg / cm³. 2 The loading amount is evenly coated on both surfaces of the positive current collector aluminum foil, dried, transferred to an oven for further drying, and then cut into 40mm×50mm rectangles as positive electrode sheets for later use.

[0181] Cut the polyethylene porous membrane into rectangles of 45mm × 55mm to serve as a release liner.

[0182] Silicon powder (anode active material), acetylene black (conductive agent), CMC (dispersant), and PAA (binder) were mixed in a mass ratio of 95:1:1:2. Water was added and the mixture was stirred until homogeneous, yielding a cathode slurry with a solid content of approximately 60%. The cathode slurry was then mixed with water at a concentration of approximately 2 mg / cm³. 2 The loading amount is evenly coated on the negative electrode current collector copper foil, dried, transferred to an oven for further drying, and then cut into rectangles of 41mm×51mm as negative electrode sheets for later use.

[0183] Take a cut positive electrode sheet and match it with two cut negative electrode sheets, separate them with the aforementioned separator, and wrap them in an aluminum-plastic film bag to form a lithium-ion battery cell to be injected with electrolyte.

[0184] (2) Preparation of non-aqueous electrolyte

[0185] Ethylene carbonate (EC), ethyl methyl carbonate (EMC), and fluoroethylene carbonate (FEC) were mixed in a mass ratio of 2:7:1 to form a mother liquor. 0.76 g of lithium hexafluorophosphate was then added to 5 ml of the mother liquor, followed by the addition of ethylene sulfate (ES) as an additive. The mixture was stirred thoroughly to form a colorless, transparent, non-aqueous electrolyte (numbered 1) with a concentration of 1 mol / L. The mass of ethylene sulfate (ES) was 0.5% of the total mass of the non-aqueous electrolyte.

[0186] (3) Preparation of finished lithium-ion battery cells

[0187] Ionic liquid monomer 1 and polymer monomer 1 are premixed at a molar ratio of 5:1. An appropriate amount is then injected into the previously prepared non-aqueous electrolyte to form a precursor solution, with the sum of the mass fractions of the ionic liquid monomer and polymer monomer in the precursor solution being 5%. Then, azobisisobutyronitrile (AIBN) initiator is added to the precursor solution and mixed thoroughly, with the initiator's mass being 0.05% of the total mass of the ionic liquid monomer and polymer monomer. 0.3g of the precursor solution is injected into the prepared lithium-ion battery cell to be injected. The cell is then vacuum-sealed in an aluminum-plastic film bag and allowed to stand at 25°C for 6 hours, followed by standing at 60°C for 12 hours to allow the ionic liquid monomer and polymer monomer to undergo a relatively thorough in-situ polymerization and solidification reaction, forming a gel polymer electrolyte, thus obtaining the finished lithium-ion battery cell. The rated capacity of the lithium-ion battery cell is 70mAh.

[0188] Comparative Example 1

[0189] (1) Preparation of lithium-ion battery cells to be injected with electrolyte

[0190] Same as Example 1.

[0191] (2) Preparation of non-aqueous electrolyte

[0192] Same as Example 1.

[0193] (3) Preparation of finished lithium-ion battery cells

[0194] 0.3g of non-aqueous electrolyte was injected into the prepared battery cell, and then the aluminum-plastic film bag was vacuum heat-sealed. After standing at 25°C for 6 hours, it was transferred to 60°C and stood for 12 hours to obtain the finished lithium-ion battery cell. The rated capacity of the lithium-ion battery cell is 70mAh.

[0195] Cyclic performance test

[0196] Take the prepared lithium-ion battery cell, set the ambient temperature to 25℃, and charge it with a constant current of 0.33C (i.e., 23mA) until the cutoff voltage of 4.2V is reached. Then, continue charging with a constant voltage of 4.2V until the current decays to 0.1C (i.e., 7mA). Then, discharge it with a constant current of 0.33C (i.e., 23mA) to 3V to obtain the first discharge capacity. Repeat the above charge-discharge cycle and record the discharge capacity after each cycle. When the discharge capacity decays to 80% of the first discharge capacity, the lithium-ion battery cell is considered to have reached the end of its lifespan. Record the number of cycles the lithium-ion battery cell has undergone at this point as the cycle life of the lithium-ion battery cell.

[0197] Table 1

[0198] The test results of Example 1 and Comparative Example 1 show that the cycle life of lithium-ion battery cells using gel polymer electrolytes is better than that of lithium-ion battery cells using non-aqueous electrolytes.

[0199] Examples 2 to 8 and Comparative Example 2

[0200] Except for the different types of ionic liquid monomers in the precursor solution, the preparation method of the lithium-ion battery cell is the same as in Example 1.

[0201] Table 2

[0202] The test results above show that the cycle life of lithium-ion battery cells varies depending on the type of ionic liquid monomer in the precursor solution. Using ionic liquid monomers with alkenyl or (meth)acrylate end groups can result in lithium-ion battery cells with better cycle life.

[0203] Examples 9 to 15 and Comparative Example 3

[0204] Except for the different types of polymer monomers in the precursor solution, the preparation method of the lithium-ion battery cells is the same as in Example 1.

[0205] Table 3

[0206] The test results above show that the cycle life of lithium-ion battery cells varies depending on the type of polymer monomer in the precursor solution. Comparative Example 3 uses polymer monomers with a weight-average molecular weight of less than 400, resulting in a polymer skeleton with poor flexibility and thus a poor cycle life for the battery cells.

[0207] Examples 16 to 17

[0208] Except for the difference in the molar ratio of ionic liquid monomer to polymer monomer in the precursor solution, the preparation method of lithium-ion battery cells is the same as in Example 1.

[0209] Table 4

[0210] The test results above show that further adjusting the molar ratio of ionic liquid monomers to polymer monomers can give lithium-ion battery cells a longer cycle life.

[0211] Example 18, Example 19, Comparative Example 4

[0212] Except for the difference in the sum of the mass fractions of ionic liquid monomers and polymer monomers in the precursor solution, the preparation method of lithium-ion battery cells is the same as in Example 1.

[0213] Table 5

[0214] The test results above show that the cycle life of lithium-ion battery cells varies depending on the sum of the mass fractions of ionic liquid monomers and polymer monomers in the precursor solution. In Comparative Example 4, the excessively high sum of the mass fractions of ionic liquid monomers and polymer monomers resulted in poor ion transport in the formed gel polymer electrolyte, which could not support the long-term cycling of the lithium-ion battery cell.

[0215] Examples 20 to 31, Comparative Example 5

[0216] Unless the type of electrolyte is different, the preparation method of the lithium-ion battery cell is the same as in Example 1.

[0217] Table 6

[0218] The test results above show that the composition of non-aqueous electrolytes affects the cycle life of lithium-ion battery cells. Lithium-ion battery cells using ester solvents have a longer cycle life.

[0219] Example 32

[0220] (1) Preparation of lithium metal battery cells to be injected with liquid electrolyte

[0221] LiNi, the positive electrode active material 0.8 Co 0.1 Mn 0.1 O2, conductive agent acetylene black, and binder PVDF are mixed at a mass ratio of 98:1:1, and then added to the solvent N-methylpyrrolidone (NMP) and stirred until the system is homogeneous, obtaining a positive electrode slurry with a solid content of approximately 70%. The positive electrode slurry is then subjected to a reaction at approximately 12.5 mg / cm³. 2 The loading amount is evenly coated on both surfaces of the positive current collector aluminum foil, dried, transferred to an oven for further drying, and then cut into 40mm×50mm rectangles as positive electrode sheets for later use.

[0222] Cut the polyethylene porous membrane into rectangles of 45mm × 55mm to serve as a release liner.

[0223] A 50μm lithium foil is rolled onto a 12μm copper foil and then cut into 41mm×51mm rectangles to serve as negative electrode sheets for later use.

[0224] Take a cut positive electrode sheet and match it with two cut negative electrode sheets, separate them with the aforementioned separator, and wrap them in an aluminum-plastic film bag to form a lithium metal battery cell to be injected with liquid.

[0225] (2) Preparation of non-aqueous electrolyte

[0226] Take the organic solvent ethylene glycol dimethyl ether (DME) and the diluent 1,2-bis(difluoromethoxy)ethane at a mass ratio of 3:7 to form a solvent stock solution; then take 2.805g of lithium bisfluorosulfonylimide (LiFSI) and add it to 5ml of the solvent stock solution, and stir thoroughly to form a colorless and transparent non-aqueous electrolyte with a concentration of 3mol / L.

[0227] (3) Preparation of finished lithium metal battery cells

[0228] Ionic liquid monomer 1 and polymer monomer 1 are premixed at a molar ratio of 5:1. An appropriate amount is then injected into the previously prepared non-aqueous electrolyte to form a precursor solution. The sum of the mass fractions of the ionic liquid monomer and polymer monomer in the precursor solution is 5%. Then, an initiator, azobisisobutyronitrile (AIBN), is added to the precursor solution and mixed thoroughly. The mass of the initiator is 0.05% of the total mass of the ionic liquid monomer and polymer monomer. 0.3g of the precursor solution is injected into the prepared lithium metal battery cell to be injected. The cell is then vacuum-sealed in an aluminum-plastic film bag and allowed to stand at 25°C for 6 hours, followed by standing at 60°C for 12 hours. This allows the ionic liquid monomer and polymer monomer to undergo a relatively thorough in-situ polymerization and solidification reaction, forming a gel polymer electrolyte, thus obtaining the finished lithium metal battery cell. The rated capacity of the lithium metal battery cell is 70mAh.

[0229] Comparative Example 6

[0230] (1) Preparation of lithium metal battery cells to be injected with liquid electrolyte

[0231] Same as Example 1.

[0232] (2) Preparation of non-aqueous electrolyte

[0233] Same as Example 1.

[0234] (3) Preparation of finished lithium metal battery cells

[0235] 0.3g of non-aqueous electrolyte was injected into the prepared battery cell, and then the aluminum-plastic film bag was vacuum heat-sealed. After standing at 25°C for 6 hours, it was transferred to 60°C and stood for 12 hours to obtain the finished lithium metal battery cell. The rated capacity of the lithium metal battery cell is 70mAh.

[0236] Cyclic performance test

[0237] Take the prepared lithium metal battery cell and set the ambient temperature to 25℃. Charge it at a constant current of 0.2C (14mA) until the cutoff voltage of 4.3V is reached. Then, continue charging at a constant voltage of 4.3V until the current decays to 0.1C (7mA). Then, discharge it at a constant current of 1C (70mA) to 2.8V to obtain the first discharge capacity. Repeat the above charge-discharge cycle and record the discharge capacity after each cycle. When the discharge capacity decays to 80% of the first discharge capacity, the lithium metal battery cell is considered to have reached the end of its lifespan. Record the number of cycles the lithium metal battery cell has undergone at this point as the cycle life of the lithium metal battery cell.

[0238] Table 7

[0239] As can be seen from the test results of Example 32 and Comparative Example 6, the cycle life of lithium metal battery cells using gel polymer electrolyte is better than that of lithium metal battery cells using non-aqueous electrolyte.

[0240] Examples 33 to 39 and Comparative Example 7

[0241] Except for the different types of ionic liquid monomers in the precursor solution, the preparation method of the lithium metal battery cell is the same as in Example 32.

[0242] Table 8

[0243] The test results above show that the cycle life of lithium metal battery cells varies depending on the type of ionic liquid monomer in the precursor solution. Using ionic liquid monomers with alkenyl or (meth)acrylate end groups can result in better cycle life for lithium metal battery cells.

[0244] Examples 40 to 46 and Comparative Example 8

[0245] Except for the different types of polymer monomers in the precursor solution, the preparation method of the lithium metal battery cell is the same as in Example 32.

[0246] Table 9

[0247] The test results above show that the cycle life of lithium metal battery cells varies depending on the type of polymer monomer in the precursor solution. Comparative Example 8 uses polymer monomers with a weight-average molecular weight of less than 400, resulting in a polymer backbone with poor flexibility and a poor cycle life for the battery cells.

[0248] Examples 47 to 48

[0249] Except for the difference in the molar ratio of ionic liquid monomer to polymer monomer in the precursor solution, the preparation method of lithium metal battery monomer is the same as in Example 32.

[0250] Table 10

[0251] The test results above show that further adjusting the molar ratio of ionic liquid monomers to polymer monomers can give lithium metal battery cells a longer cycle life.

[0252] Example 49, Example 50, Comparative Example 9

[0253] Except for the difference in the sum of the mass fractions of ionic liquid monomers and polymer monomers in the precursor solution, the preparation method of lithium metal battery cells is the same as in Example 32.

[0254] Table 11

[0255] The test results above show that the cycle life of lithium metal battery cells varies depending on the sum of the mass fractions of ionic liquid monomers and polymer monomers in the precursor solution. In Comparative Example 9, the excessively high sum of the mass fractions of ionic liquid monomers and polymer monomers resulted in poor ion transport in the formed gel polymer electrolyte, which could not support the long-term cycling of the lithium metal battery cells.

[0256] Examples 51 to 60, Comparative Example 10

[0257] Unless the type of aqueous electrolyte is different, the preparation method of the lithium metal battery cell is the same as in Example 32.

[0258] Table 12

[0259] The test results above show that the composition of non-aqueous electrolytes also affects the cycle life of lithium metal battery cells. Lithium metal battery cells using ether solvents have a longer cycle life.

[0260] It should be noted that this application is not limited to the above-described embodiments. The above embodiments are merely examples, and any embodiments with the same structure and effect as the technical concept within the scope of this application are included in the technical scope of this application. Furthermore, various modifications that can be conceived by those skilled in the art to the embodiments, and other ways of constructing by combining some of the constituent elements of the embodiments, without departing from the spirit of this application, are also included in the scope of this application.

Claims

1. A gel polymer electrolyte composition, wherein, Including non-aqueous electrolytes, polymer monomers, and ionic liquid monomers. The polymer monomer is a polymer monomer with ether oxygen segments that can undergo free radical polymerization, and the weight-average molecular weight of the polymer monomer is 400 to 80,000. The ionic liquid monomer includes one or more of N-containing ionic liquids, P-containing ionic liquids, and S-containing ionic liquids, and the end group of the ionic liquid is an alkenyl or (meth)acrylate group.

2. The gel polymer electrolyte composition according to claim 1, wherein, The polymer monomer includes one or more of the polymer monomers shown in Formula I and Formula II. X is selected from C1-C10 alkylene or C1-C10 haloalkylene, R1 is selected from hydrogen atom or methyl, R2 is selected from hydrogen atom or methyl, and n is selected from an integer between 10 and 1000.

3. The gel polymer electrolyte composition according to claim 2, wherein, X is selected from C1-C4 alkylene groups, and / or n is selected from integers between 50 and 800.

4. The gel polymer electrolyte composition according to any one of claims 1-3, wherein, The cation of the ionic liquid monomer includes any one of the following ions with an alkenyl or (meth)acrylate end group: tetrahydropyrrole ion, quaternary ammonium ion, imidazole ion, piperidinium ion, pyridinium ion, thionium ion, and phosphonium ion.

5. The gel polymer electrolyte composition according to any one of claims 1-4, wherein, The cation of the ionic liquid monomer is composed of any one of the terminal groups shown in Formula 1 and any one of the cations shown in Formula 2, where * indicates a linking site; R3 is selected from hydrogen atom or methyl group, R4, R6, R8, R9, R 10 R 12 R 15 R 17 R 18 R 20 R 21 Alkyl groups independently selected from C1-C10, R5, R7, R 11 R 13 R 14 R 16 R 19 Each is independently selected from C1-C10 alkylene groups or C1-C10 oxaalkylene groups.

6. The gel polymer electrolyte composition according to claim 5, wherein, The cation of the ionic liquid monomer satisfies at least one of the following conditions (1) to (2): (1) R4, R6, R8, R9, R 10 R 12 R 15 R 17 R 18 R 20 R 21 Alkyl groups selected independently from C1-C3; (2) R5, R7, R 11 R 13 R 14 R 16 R 19 Each is independently selected from C2-C3 alkylene or C2-C3 oxaalkylene.

7. The gel polymer electrolyte composition according to any one of claims 1-6, wherein, The cation of the ionic liquid monomer includes any one of the following:

8. The gel polymer electrolyte composition according to any one of claims 1-7, wherein the anion of the ionic liquid monomer includes any one of the following: chloride ion, bromide ion, iodide ion, bis(trifluoromethyl)sulfonylimide ion, bis(trifluoromethyl)sulfonylimide ion, hexafluorophosphate, tetrafluoroborate, hexafluoroarsenate, trifluoromethanesulfonate, difluorophosphate, bis(oxalate)borate, difluorooxalateborate, difluorobis(oxalate)phosphate, and tetrafluorooxalate phosphate.

9. The gel polymer electrolyte composition according to any one of claims 1-8, wherein, The molar ratio of the ionic liquid monomer to the polymer monomer is 1:1 to 10:1; and / or, Based on the total mass of the gel polymer electrolyte composition, the sum of the mass fractions of the polymer monomer and the ionic liquid monomer is 0.5%-20%.

10. The gel polymer electrolyte composition according to any one of claims 1-9, wherein, The gel polymer electrolyte composition also includes an initiator.

11. A gel polymer electrolyte, wherein, It is obtained by polymerizing the gel polymer electrolyte composition according to any one of claims 1-10.

12. A battery cell, wherein, The invention includes a gel polymer electrolyte, which is obtained by polymerizing the gel polymer electrolyte composition according to any one of claims 1-10.

13. The battery cell according to claim 12, wherein, The method for polymerizing the gel polymer electrolyte composition according to any one of claims 1-10 is in-situ curing polymerization.

14. A method for preparing a single battery cell, comprising the following steps: A battery cell to be injected with electrolyte is provided. A precursor solution is obtained by mixing the gel polymer electrolyte composition according to any one of claims 1-10, injecting the obtained precursor solution into the battery cell to be injected with electrolyte, and then treating it under heating conditions to solidify and polymerize the precursor solution in situ inside the battery cell to form a gel polymer electrolyte, thereby obtaining the battery cell.

15. A battery comprising a battery cell according to any one of claims 12-13 or a battery cell prepared by the preparation method according to claim 14.

16. An electrical device comprising the battery of claim 15.

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