Polymer and method of preparation, gel polymer electrolyte, battery, electric device

Abstract

The application discloses a polymer and a preparation method thereof, a gel polymer electrolyte, a battery, and an electric device. A general formula of the polymer is shown in formula (1): wherein R1 comprises a substituted or unsubstituted C1-C4 alkyl group, R2 and R3 each independently comprise an alkyl group and / or an alkoxy group with a carbon atom number less than or equal to 3, and the value of n is 200-1000. Therefore, the gel polymer electrolyte containing the polymer has a high ionic conductivity.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of batteries, in particular, to a polymer and a preparation method, a gel polymer electrolyte, a battery, and a power utilization device. BACKGROUND

[0002] In recent years, with the increasingly wide application of secondary batteries, secondary batteries are widely used in energy storage power systems such as hydroelectric, thermal, wind and solar power stations, and in many fields such as electric tools, electric bicycles, electric motorcycles, electric vehicles, military equipment, aerospace, etc. However, with the increasingly wide application of secondary batteries, the rate performance of secondary batteries has also been challenged. At present, there are still many problems to be solved in the industrial production and application of lithium ion batteries. SUMMARY

[0003] In a first aspect of the present application, a polymer is provided, the general formula of the polymer is shown in formula (1):

[0004]

[0005] wherein R1 comprises a substituted or unsubstituted C1-C4 alkyl group, R2 and R3 each independently comprise an alkyl group and / or an alkoxy group with a carbon atom number less than or equal to 3, and n is 200-1000. Thus, when metal active ions migrate, the sulfone group structure can act as a transition site during the migration of metal active ions, improving the migration efficiency, and thus the gel polymer electrolyte containing the polymer has a high ionic conductivity.

[0006] According to an embodiment of the present application, the number of carbon atoms spaced between adjacent sulfone groups is less than or equal to 4. Thus, the distance between adjacent sulfone groups is closer, and the migration efficiency of metal active ions is higher, which can improve the migration rate of metal active ions in the gel polymer electrolyte containing the polymer.

[0007] According to an embodiment of the present application, the number of carbon atoms spaced between adjacent sulfone groups is 1 or 2. Thus, the distance between adjacent sulfone groups is closer, and the migration efficiency of metal active ions between adjacent sulfone groups is higher.

[0008] According to an embodiment of the present application, the content of sulfone groups in the polymer is 20%-80%. Thus, the content of sulfone groups in the polymer is high, which can provide more transition sites for the migration of metal ions, thereby further improving the migration rate of metal active ions in the gel polymer electrolyte containing the polymer.

[0009] According to an embodiment of the present application, the content of sulfone groups in the polymer is 60%-80%. Thus, the content of sulfone groups in the polymer is high, which can provide more transition sites for the migration of metal ions.

[0010] According to an embodiment of the present application, the carbon atom of the alkoxy group is connected to the sulfur atom of the sulfone group. Thus, the oxidation resistance of the gel polymer electrolyte containing the polymer can be improved.

[0011] According to an embodiment of the present application, the number of carbon atoms between the oxygen atom of the alkoxy group and the sulfur atom of the adjacent sulfone group is less than or equal to 4. Thus, the oxygen atom between the alkoxy groups can act as a transition site when the metal active ion is transferred between the adjacent sulfone groups, and the transfer rate of the metal active ion in the gel polymer electrolyte containing the polymer can be further improved.

[0012] According to an embodiment of the present application, the number of carbon atoms between the oxygen atom of the alkoxy group and the sulfur atom of the adjacent sulfone group is 1 or 2. Thus, the distance between the oxygen atom between the alkoxy groups and the sulfone group is closer, and the transfer efficiency of the metal active ion between the alkoxy oxygen atom and the sulfone group is higher.

[0013] According to an embodiment of the present application, the polymer comprises at least one of the following:

[0014]

[0015]

[0016]

[0017]

[0018] Thus, the ionic conductivity of the gel polymer electrolyte containing the polymer can be further improved.

[0019] According to an embodiment of the present application, the number average molecular weight of the polymer is 40000-80000. Thus, the polymer has good liquid binding capacity for the electrolyte, and the ionic conductivity and liquid content of the gel polymer electrolyte containing the polymer can be improved.

[0020] According to an embodiment of the present application, the number average molecular weight of the polymer is 55000-65000. Thus, the polymer has good liquid binding capacity for the electrolyte.

[0021] According to an embodiment of the present application, the polymer dispersibility index of the polymer is 1.5-2.5. Thus, the molecular weight uniformity of the polymer is high, the internal structure consistency is high, and the transfer efficiency of the metal active ion between the adjacent sulfone groups is high.

[0022] According to an embodiment of the present application, the polymer dispersibility index of the polymer is 1.7-2.2. Thus, the transfer efficiency of the metal active ion between the adjacent sulfone groups is high,

[0023] In a second aspect of this application, a method for preparing a polymer is proposed, comprising: adding a monomer and an initiator to a solvent and subjecting the mixture to heat treatment to obtain the polymer, wherein the monomer comprises a sulfone-substituted alkane containing an unsaturated bond, the alkane comprising substituted or unsubstituted C1-C4 alkanes, and the unsaturated bond comprising at least one of a double bond and a triple bond. Thus, a polymer that can effectively improve the ionic conductivity of gel polymer electrolytes can be obtained through a relatively simple synthetic method.

[0024] According to embodiments of this application, the alkane comprises at least two sulfone groups, and the number of carbon atoms separating adjacent sulfone substituents is less than or equal to 4. This allows for an increase in the sulfone content of the obtained polymer.

[0025] According to embodiments of this application, the alkane further comprises an ether bond, wherein the number of carbon atoms separating the oxygen atom of the ether bond from the sulfur atom of the adjacent sulfone group is less than or equal to 4. This can further improve the ionic conductivity of the gel polymer electrolyte containing the obtained polymer.

[0026] According to embodiments of this application, the initiator includes at least one selected from azobisisobutyronitrile, 2,2”-azabis(2-imidazoline) dihydrochloride, 2,2'-azobisisobutyranin dihydrochloride, benzoyl peroxide, benzoyl tert-butyl peroxide, and methyl ethyl ketone peroxide. This can improve the polymer yield.

[0027] In a third aspect, this application proposes a gel polymer electrolyte comprising a polymer matrix, said polymer matrix comprising the aforementioned polymer; and / or a polymer prepared using the aforementioned method. Thus, the gel polymer electrolyte possesses all the features and advantages of the aforementioned polymer and the aforementioned method, which will not be elaborated further here.

[0028] According to embodiments of this application, the electrolyte comprises a plasticizer and a metal salt, wherein the plasticizer comprises a sulfone plasticizer. This improves the ionic conductivity of the gel polymer electrolyte.

[0029] According to embodiments of this application, the sulfone plasticizer includes at least one selected from sulfolane, dimethyl sulfone, ethyl methyl sulfone, ethyl isopropyl sulfone, and 3-methylcyclosulfone. This can further improve the ionic conductivity of the gel polymer electrolyte.

[0030] According to embodiments of this application, the sulfone plasticizer includes sulfolane. This can further improve the ionic conductivity of the gel polymer electrolyte.

[0031] According to embodiments of this application, the mass fraction of the polymer matrix in the gel polymer electrolyte is 10%-80%. This improves the mechanical strength of the gel polymer electrolyte.

[0032] According to embodiments of this application, the mass fraction of the plasticizer in the gel polymer electrolyte is 20%-60%. This improves the ionic conductivity of the gel polymer electrolyte and reduces costs.

[0033] According to embodiments of this application, the mass fraction of the metal salt in the gel polymer electrolyte is 5%-30%. This reduces the cost of the gel polymer electrolyte.

[0034] In a fourth aspect, this application proposes a battery comprising the aforementioned gel polymer electrolyte. Thus, the battery possesses all the features and advantages of the aforementioned gel polymer electrolyte, and exhibits superior rate performance and low-temperature cycling performance.

[0035] In a fifth aspect, this application proposes an electrical device comprising the aforementioned gel polymer electrolyte and / or the aforementioned battery. Thus, the electrical device possesses all the features and advantages of the aforementioned gel polymer electrolyte and battery, which will not be repeated here. Attached Figure Description

[0036] The above and / or additional aspects and advantages of this application will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0037] Figure 1 A schematic diagram of the structure of a battery according to an embodiment of this application is shown;

[0038] Figure 2 A schematic diagram of a battery according to an embodiment of this application is shown;

[0039] Figure 3 yes Figure 2 An exploded view of a battery according to an embodiment of this application is shown;

[0040] Figure 4 A schematic diagram of a battery module according to an embodiment of this application is shown;

[0041] Figure 5 A schematic diagram of a battery pack according to one embodiment of this application is shown;

[0042] Figure 6 yes Figure 5 An exploded view of a battery pack according to an embodiment of this application is shown;

[0043] Figure 7A schematic diagram of an electrical device in which a battery is used as a power source according to an embodiment of this application is shown.

[0044] Explanation of reference numerals in the attached figures:

[0045] Battery pack 1, upper casing 2, lower casing 3, battery module 4, battery 5.

[0046] Positive electrode 10, positive current collector 11, positive active material layer 12, negative electrode 20, negative current collector 21, negative active material layer 22, separator 30, gel polymer electrolyte 40, shell 51, electrode assembly 52, top cover assembly 53. Detailed Implementation

[0047] The embodiments of this application are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application.

[0048] In the description of this application, it should be understood that the terms "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0049] In the description of this application, "A and / or B" can include any of the cases of A alone, B alone, or A and B, where A and B are merely examples and can be any technical feature connected by "and / or" in this application.

[0050] In the description of this application, "multiple" means two or more.

[0051] Unless otherwise stated, all technical terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains. All patents and publications referenced in this application are incorporated herein by reference in their entirety. The terms "comprising" or "including" are open-ended expressions, meaning they include the contents specified in this application but do not exclude other contents.

[0052] In the description of this application, all figures disclosed herein, whether or not the words "approximately" or "about" are used, are approximate values. Each figure may vary by less than 10% or by a difference that is considered reasonable by one of the art, such as 1%, 2%, 3%, 4%, or 5%.

[0053] Taking lithium-ion batteries as an example, the rate charge / discharge performance of a battery is an important indicator of its capacity retention under rapid charge / discharge conditions. The rate charge / discharge performance of a battery depends on the lithium-ion migration rate in the active material, the ionic conductivity of lithium-ions in the electrolyte, and the ionic migration rate of lithium-ions at the electrode-electrolyte interface. The ionic conductivity of lithium-ions in the electrolyte and the ionic migration rate of lithium-ions at the electrode-electrolyte interface are closely related to the composition and properties of the electrolyte within the battery.

[0054] Electrolytes include at least one of organic liquid electrolytes, solid polymer electrolytes, and gel polymer electrolytes. Gel polymer electrolytes are semi-solid electrolytes that mix liquid and solid. The polymer molecules in gel polymer electrolytes exhibit a cross-linked spatial network structure, with liquid plasticizers filling the pores. Lithium salts are dissolved in the polymer and plasticizer, where both the polymer matrix and the plasticizer are continuous phases. Replacing or partially replacing organic liquid electrolytes with gel polymer electrolytes can effectively reduce production safety problems such as electrode corrosion and oxidative combustion caused by leakage of organic liquid electrolytes.

[0055] In this application, lithium salt is used as an example, and the active metal ion of lithium salt is Li. + Li + When dissolved in plasticizers, solvation occurs, thereby affecting the Li + A solvated outer shell forms on the surface, while the lithium salt anions hardly undergo solvation, thus making Li... + The solvation effect of Li limited the Li + The migration speed is also affected. Furthermore, due to the high viscosity of the gel polymer electrolyte, the transfer mode of solvated metal active ions between plasticizers is a jump-like transfer, resulting in greater resistance to lithium ion migration between the positive electrode 10 and the negative electrode 20. Ultimately, the room temperature ionic conductivity of the gel polymer electrolyte is only a fraction or even a few tens of times that of organic liquid electrolytes, leading to poor high-rate charge / discharge performance and low-temperature performance of batteries using gel polymer electrolytes.

[0056] In this application, a polymer containing a sulfone group structure is used as the polymer matrix of the gel polymer electrolyte. When metal active ions migrate between the positive electrode 10 and the negative electrode 20, the sulfone group structure can serve as a transition site during the migration process, providing a closer contact site for the hopping transport of metal active ions. This constructs a rapid transport channel for metal active ions, allowing solvated metal active ions to coordinate and bind with the sulfone group after detaching from the plasticizer, and then undergo solvation again after the sulfone group transition to participate in subsequent transport. By using a polymer containing a sulfone group structure as the polymer matrix of the gel polymer electrolyte, the ionic conductivity of the gel polymer electrolyte is effectively improved, thereby enhancing the rate performance and low-temperature cycling performance of the battery containing this gel polymer electrolyte.

[0057] As an example, the active metal ions may include at least one of lithium ions, sodium ions, and magnesium ions.

[0058] The batteries disclosed in this application can be used, but are not limited to, in electrical devices such as vehicles, ships, or aircraft. Power systems incorporating the batteries and electrical devices disclosed in this application can be used.

[0059] This application provides an electrical device that uses batteries and / or batteries as a power source. The electrical device includes, but is not limited to, mobile phones, tablets, laptops, electric toys, power tools, electric vehicles, electric cars, ships, and spacecraft. Electric toys can include stationary or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys. Spacecraft can include airplanes, rockets, space shuttles, and spacecraft.

[0060] It should be understood that the technical solutions described in the embodiments of this application are not limited to the batteries and electrical devices described above, but can also be applied to all electrical devices that use batteries. However, for the sake of brevity, the following embodiments are all illustrated using electric vehicles as examples.

[0061] In a first aspect of this application, a polymer is proposed, the polymer having the general formula shown in formula (1):

[0062]

[0063] R1 comprises substituted or unsubstituted C1-C4 alkyl groups, and R2 and R3 each independently comprise alkyl groups with 3 or fewer carbon atoms and / or alkoxy groups. The gel polymer electrolyte containing this polymer can provide a rapid transport channel for the transfer of metal active ions, effectively improving the ionic conductivity of the gel polymer electrolyte and enhancing the rate performance and low-temperature cycling performance of batteries containing this gel polymer electrolyte.

[0064] As an example, R2 may include at least one of methyl, ethyl, propyl, methoxy, ethoxy, and propoxy.

[0065] As an example, R3 may include at least one of methyl, ethyl, propyl, methoxy, ethoxy, and propoxy.

[0066] As an example, R1 may include at least one of substituted or unsubstituted methyl, substituted or unsubstituted ethyl, substituted or unsubstituted n-propyl, substituted or unsubstituted isopropyl, substituted or unsubstituted n-butyl, substituted or unsubstituted sec-butyl, substituted or unsubstituted isobutyl, and substituted or unsubstituted tert-butyl.

[0067] In some embodiments, R1 comprises a substituted or unsubstituted C1-C4 alkyl group, and the substituents of R1 may include sulfone groups.

[0068] By selecting R1 groups substituted with sulfone groups, the sulfone content in the polymer can be effectively increased. A higher sulfone content in the polymer can provide more transition sites for the transfer of metal active ions, thereby effectively improving the ionic conductivity of the gel polymer electrolyte containing this polymer.

[0069] In some embodiments, the number of carbon atoms between adjacent sulfone groups is less than or equal to 4; alternatively, the number of carbon atoms between adjacent sulfone groups is 1 or 2.

[0070] As an example, the R1 group separating adjacent sulfone groups can be a substituted or unsubstituted C1-C4 alkyl group, meaning the number of carbon atoms between adjacent sulfone groups can be 1, 2, 3, or 4. When the number of carbon atoms between adjacent sulfone groups is less than or equal to 4, the spacing between them is shorter. Compared to two sulfone groups located at the para position on the benzene ring, adjacent sulfone groups exhibit less steric hindrance and better molecular chain flexibility, providing faster lithium-ion transport speeds. After detaching from the solvation, the active metal ions, after binding with the sulfone groups, can further transfer between sulfone groups through adjacent sulfone groups. After detaching from the sulfone groups, the active metal ions can participate in subsequent transport through ion solvation. The transfer of active metal ions between adjacent sulfone groups is achieved through reversible coordination bonds, resulting in high transport efficiency and effectively improving the ionic conductivity of the gel polymer electrolyte.

[0071] In some embodiments, the position of the sulfone group can be adjusted according to the structure of the polymer. As long as the total number of carbon atoms between adjacent sulfone groups is less than or equal to 4, that is, as long as the sum of the number of main chain carbon atoms and the number of branch chain carbon atoms between adjacent sulfone groups is less than or equal to 4, the transfer efficiency of metal active ions between adjacent sulfone groups can be improved, and the ionic conductivity of the gel polymer electrolyte can be effectively improved.

[0072] As an example, both adjacent sulfone groups can be located on the main chain of the polymer; or, one of the two adjacent sulfone groups can be located on the main chain of the polymer, and the other sulfone group can be located on a side chain of the polymer; or, both adjacent sulfone groups can be located on a side chain of the polymer.

[0073] As an example, adjacent sulfone groups can be spaced between substituted or unsubstituted C1-C4 alkyl groups. Compared to benzene rings, substituted or unsubstituted C1-C4 alkyl groups have less steric hindrance, resulting in less resistance to the transfer of metal active ions between adjacent sulfone groups.

[0074] In some embodiments, the sulfone content in the polymer can be 20%-80%, and optionally, the sulfone content in the polymer can be 60%-80%.

[0075] As an example, the sulfone content in the polymer can be 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, or 80%.

[0076] The sulfone content in a polymer refers to the percentage of the total mass of the polymer containing sulfone groups (O=S=O structure).

[0077] As an example, the sulfone content in a polymer can be determined using infrared spectroscopy. For instance, a standard solution is first prepared using a sulfone-based substance with a known sulfone content, and the absorbance of the standard solution is measured. A standard curve is then plotted based on the relationship between absorbance and content. Next, the absorbance of the sample to be tested is measured, and the sulfone content of the sample is obtained from the standard curve. Specifically, the method for testing sulfone content is as follows: First, polymers with different sulfone contents are synthesized. Then, 1g of each polymer with different sulfone contents is dissolved in 15ml of acetonitrile solvent to prepare standard solutions. Infrared spectroscopy is used to obtain different absorption peak intensities, and a linear standard curve is plotted based on the relationship between peak intensity and sulfone content. Then, polymers with unknown sulfone contents are subjected to infrared spectroscopy following the same procedure. The obtained absorption peak intensities are then input into the standard curve, and the sulfone content is calculated by comparison.

[0078] When the sulfone content in the polymer is 20%-80%, the polymer can provide more jumping sites for metal active ions, which significantly improves the ionic conductivity of the gel polymer electrolyte containing this polymer; moreover, the viscosity and rigidity of the gel polymer electrolyte containing this polymer are moderate, resulting in a high ionic conductivity of the gel polymer electrolyte.

[0079] In some embodiments, the carbon atom of the alkoxy group is bonded to the sulfur atom of the sulfone group.

[0080] As an example, when R2 and / or R3 include alkoxy groups with 3 or fewer carbon atoms, the carbon atom of the alkoxy group is bonded to the sulfur atom on the sulfone group, meaning the oxygen atom of the alkoxy group is not directly bonded to the sulfur atom of the adjacent sulfone group. Due to the low strength of the SO bond and poor oxidation resistance, when the oxygen atom of the alkoxy group is directly bonded to the sulfur atom of the adjacent sulfone group, the polymer's oxidation resistance is also poor. Furthermore, because the surface of the positive electrode is highly oxidizing, during cycling, the highly oxidizing positive electrode will cause electrochemical side reactions on the surface of the gel polymer electrolyte, resulting in a high battery volume expansion rate, a significant increase in internal impedance, and a significant decrease in capacity retention.

[0081] In some embodiments, the number of carbon atoms between the oxygen atom of the alkoxy group and the sulfur atom of the adjacent sulfone group is less than or equal to 4; alternatively, the number of carbon atoms between the oxygen atom of the alkoxy group and the sulfur atom of the adjacent sulfone group is 1 or 2.

[0082] As an example, when R2 and / or R3 include an alkoxy group with 3 or fewer carbon atoms, the number of carbon atoms separating the oxygen atom of the alkoxy group from the sulfur atom of the adjacent sulfone group can be 1, 2, 3, or 4. When the number of carbon atoms separating the oxygen atom of the alkoxy group from the sulfur atom of the adjacent sulfone group is 4 or fewer, the spacing between the oxygen atoms of the sulfone group and the alkoxy group is shorter. The oxygen atoms between the alkoxy groups can serve as transition sites for the transfer of metal active ions between adjacent sulfone groups, improving the transfer efficiency of metal active ions and thus increasing the ionic conductivity of the gel polymer electrolyte.

[0083] In some embodiments, the polymer may include at least one of the following:

[0084]

[0085]

[0086]

[0087]

[0088] In some embodiments, when the degree of polymerization n of the polymer is 200-1000, the number-average molecular weight of the polymer can be 40,000-80,000, and optionally, the number-average molecular weight of the polymer can be 55,000-65,000. When the molecular weight of the polymer is 40,000-80,000, the polymer has good liquid binding ability. When this polymer is used as the polymer matrix of the gel polymer electrolyte, the polymer matrix has good capacity to accommodate the electrolyte, which is beneficial to improving the migration number of metal active ions. At the same time, the viscosity of the gel polymer electrolyte containing this polymer is moderate, which can improve the ionic conductivity of the gel polymer electrolyte.

[0089] As an example, the number average molecular weight of the polymer can be 40,000, 42,000, 45,000, 48,000, 50,000, 52,000, 55,000, 58,000, 60,000, 62,000, 65,000, 68,000, 70,000, 72,000, 75,000, 78,000, or 80,000.

[0090] Number average molecular weight measures the molecular weight of a polymer based on its number fraction. Numerically, number average molecular weight is equal to the molecular weight of each component of the polymer multiplied by the mole fraction of the corresponding component.

[0091] As an example, polymer solutions exhibit the same colligative properties as ideal solutions at extremely low concentrations. The number-average molecular weight of the polymer can be tested based on the boiling point colligative property of the solution, i.e., using the boiling point elevation method. When a non-volatile polymer is added to a pure solvent to form a polymer solution, the vapor pressure of the solution decreases, resulting in a higher boiling point and a lower freezing point compared to the pure solvent. Specifically, this can be calculated using the following formula:

[0092]

[0093] Among them, △T b =T2-T1, where T1 is the boiling point of the pure solvent and T2 is the boiling point of the polymer solution; M n is the number-average molecular weight of the polymer; c is the concentration of the polymer solution; K b This is a characteristic constant of the pure solvent, which can be measured by the boiling point rise of a compound with a known molecular weight.

[0094] In some embodiments, the dispersibility index of the polymer can be 1.5-2.5, and optionally, the dispersibility index of the polymer can be 1.7-2.2. Specifically, the dispersibility index of the polymer can be 1.5, 1.6, 1.7, 1.8, 1.9, 2.0, 2.1, 2.2, 2.3, 2.4, or 2.5. When the dispersibility index of the polymer is 1.5-2.5, the polymer has a narrow molecular weight distribution and a high degree of uniformity in its internal structure. When metal active ions are transported within the polymer, there are more closely spaced sulfone groups that can serve as transition sites, resulting in higher transport efficiency.

[0095] The polymer dispersity index (PDI) describes the molecular weight distribution of a polymer. It is the ratio of the polymer's weight-average molecular weight to its number-average molecular weight, and a PDI value greater than 1. A higher PDI indicates a wider molecular weight distribution, while a lower PDI indicates a narrower molecular weight distribution.

[0096] As an example, the polymer dispersibility index (PDI) of a polymer can be tested using gel permeation chromatography (GPC). GPC, also known as volume exclusion chromatography, separates polymer molecules based on their different volumes. Specifically, the column is first calibrated using a standard substance with a known molecular weight, and a standard curve is plotted between the eluent volume and the molecular weight. When an unknown sample enters the column, the eluent volume is measured and compared with the standard curve to calculate the current molecular weight of the sample. By recording the molecular weight and its distribution at each moment, the PDI can be calculated.

[0097] In a second aspect of this application, a method for preparing a polymer is proposed, comprising: adding a monomer and an initiator to a solvent and subjecting the solvent to heat treatment to obtain a polymer, wherein the monomer comprises a sulfone-substituted alkane containing an unsaturated bond, the alkane comprising substituted or unsubstituted C1-C4 alkanes, and the unsaturated bond comprising at least one of a double bond and a triple bond. The above preparation method can relatively easily obtain a polymer that can effectively improve the ionic conductivity of the gel polymer electrolyte.

[0098] As an example, a monomer is a small molecule that can be covalently linked with the same or other molecules to form a polymer.

[0099] As an example, substituted or unsubstituted C1-C4 alkanes may include at least one of substituted or unsubstituted methane, substituted or unsubstituted ethane, substituted or unsubstituted n-propane, substituted or unsubstituted isopropane, substituted or unsubstituted n-butane, substituted or unsubstituted sec-butane, substituted or unsubstituted isobutane, and substituted or unsubstituted tert-butane.

[0100] According to embodiments of this application, the alkane comprises at least two sulfone groups, wherein the number of carbon atoms between adjacent sulfone substituents is less than or equal to 4.

[0101] As an example, an alkane may include two sulfone substituents, and when the alkane is a substituted or unsubstituted C1-C4 alkane, the number of carbon atoms between adjacent sulfone groups may be 1, 2, 3 or 4.

[0102] As an example, the monomer may include at least one of bis(vinyl sulfonyl)methane, bis(vinyl sulfonyl)ethane, 1,3-bis(vinyl sulfonyl)-2-propanol, 2,2'-[methylenebissulfonyl]diethanol, 1,4-bis(vinyl sulfonyl)butane, vinyl sulfone, bis(vinyl sulfonyl)propane, 2,2'-sulfonyldiethanol, 1,3'-bis(chloroethyl sulfonyl)propanol, and 1,3'-bis(hydroxyethyl sulfonyl)propanol.

[0103] In some embodiments, the alkane further includes an ether bond, wherein the number of carbon atoms between the oxygen atom of the ether bond and the sulfur atom of the adjacent sulfone group is less than or equal to 4.

[0104] As an example, the number of carbon atoms separating the oxygen atom of the ether bond from the sulfur atom of the adjacent sulfone group can be 1, 2, 3, or 4.

[0105] As an example, alkanes containing ether bonds can include alkoxy groups.

[0106] In some embodiments, the initiator may include at least one of azobisisobutyronitrile, 2,2”-azabis(2-imidazoline) dihydrochloride, 2,2'-azobisisobutyranin dihydrochloride, benzoyl peroxide, benzoyl tert-butyl peroxide, and methyl ethyl ketone peroxide.

[0107] Initiators, also known as free radical initiators, are a class of compounds that are easily decomposed into free radicals (i.e., primary free radicals) when heated. They can be used to initiate free radical polymerization and copolymerization reactions of olefin and diene monomers, as well as crosslinking and curing of unsaturated polyesters and polymer crosslinking reactions.

[0108] As an example, the temperature for heat treatment can be between 40°C and 80°C. For instance, the temperature for heat treatment can be 40°C, 45°C, 50°C, 55°C, 60°C, 65°C, 70°C, 75°C, or 80°C.

[0109] As an example, the solvent for polymerization reactions may include tetrahydrofuran (THF).

[0110] In some specific embodiments, the polymer of formula I-1 can be prepared by referring to the route of reaction formula I-1:

[0111]

[0112] Specifically, bis(ethylene sulfonyl)methane and azobisisobutyronitrile (AIBN) were placed in a single-necked flask. The flask was then placed in liquid nitrogen to solidify the reactants, and a vacuum was maintained for a period of time. The reactants were then melted and argon gas was introduced. This process was repeated several times. Finally, the reactants were heated and stirred at 70°C for a period of time. After the reaction was complete, the product was added dropwise to n-hexane to precipitate, resulting in a solid precipitate. This solid product, polymer I-1, was obtained by filtration.

[0113] In some specific embodiments, the polymer of formula I-2 can be prepared by referring to the route of reaction formula I-2:

[0114]

[0115] Reaction I-2,

[0116] Specifically, sodium hydride and anhydrous THF were placed in a three-necked flask under argon protection. The reactants were cooled to 0°C, and a tetrahydrofuran solution of 2,2'-[methylenebissulfonyl]diethanol was added dropwise. After the addition was complete, the reaction mixture was stirred at 0°C. The tetrahydrofuran solution of 2,2'-[methylenebissulfonyl]diethanol was added dropwise again, and the mixture was stirred at room temperature after the addition was complete. Finally, the reaction mixture was stirred at 70°C for a period of time. After the reaction was complete, the THF was removed by concentration under reduced pressure. The product was then added dropwise to n-hexane to precipitate, resulting in a solid precipitate. This solid product, polymer I-2, was obtained by filtration.

[0117] In some specific embodiments, the polymer of formula I-5 can be prepared by referring to the route of reaction formula I-5:

[0118]

[0119] It should be noted that the relevant parameters in the above-described method for preparing polymers can refer to some or all of the technical features in the foregoing embodiments. The parts of the method for preparing polymers that are not described in the relevant embodiments can also refer to the foregoing embodiments and related figures, and will not be repeated here.

[0120] The description of the various embodiments above tends to emphasize the differences between the various embodiments. The similarities or similarities between them can be referred to, and for the sake of brevity, they will not be repeated here.

[0121] In a third aspect, this application provides a gel polymer electrolyte comprising a polymer matrix, the polymer matrix comprising the aforementioned polymer; and / or a polymer prepared using the aforementioned method. Thus, the gel polymer electrolyte possesses all the features and advantages of the aforementioned polymer and the aforementioned method, which will not be elaborated further here.

[0122] In some embodiments, the electrolyte includes a plasticizer and a metal salt, and the plasticizer includes sulfone plasticizers.

[0123] As an example, the plasticizer can be a liquid plasticizer. The conduction of metal active ions in the gel polymer electrolyte is mainly through conduction in the liquid-phase plasticizer. The liquid plasticizer acts as a solvent in the electrolyte, thereby helping to improve the ionic conductivity of the gel polymer electrolyte.

[0124] As an example, sulfone plasticizers contain sulfone groups, which can coordinate with active metal ions. The active metal ions can be transferred between adjacent sulfone groups in the plasticizer, and also between the sulfone groups in the plasticizer and the sulfone groups in the polymer matrix, thereby effectively improving the transfer rate of active metal ions.

[0125] In some embodiments, sulfone plasticizers may include at least one of sulfolane, dimethyl sulfone, ethyl methyl sulfone, ethyl isopropyl sulfone, and 3-methylcyclosulfone.

[0126] As an example, sulfone plasticizers such as sulfolane (SL), dimethyl sulfone (DMS), ethyl methyl sulfone (EMS), ethyl isopropyl sulfone (EiPS), and 3-methylcyclosulfone (MSL) can provide more sulfone groups to the electrolyte, thereby improving the transfer of active metal ions.

[0127] In some embodiments, sulfone plasticizers may include sulfolane. Sulfolane possesses high metal salt solubility and high oxidation stability. Furthermore, sulfolane has a relatively limited conformation, exhibiting faster Li-curing behavior compared to chain-structured sulfone plasticizers such as ethyl methyl sulfone. + Ligand exchange rate can effectively improve the cycle performance and rate performance of batteries.

[0128] A conformation refers to a different, temporary, and variable spatial structure formed by the free rotation of an atom (group) around a C-C single bond in a molecule. Different conformations can interconvert, and among various conformations, the one with the lowest potential energy and the most stable conformation is the dominant conformation.

[0129] In some embodiments, the mass fraction of the polymer matrix in the gel polymer electrolyte is 10%-80%.

[0130] As an example, the mass fraction of the polymer matrix in the gel polymer electrolyte can be 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, or 80%.

[0131] When the mass fraction of polymer matrix in gel polymer electrolyte is 10%-80%, gel polymer electrolyte has superior mechanical strength and can reduce the occurrence of explosion when encountering abnormal use conditions such as impact, crushing and puncture. Gel polymer electrolyte has good bendability and stretchability and can be used to prepare batteries of various shapes, such as flexible batteries.

[0132] In some embodiments, the mass fraction of plasticizer in the gel polymer electrolyte is 20%-60%.

[0133] As an example, the mass fraction of plasticizer in the gel polymer electrolyte can be 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, or 60%.

[0134] When the mass fraction of plasticizer in the gel polymer electrolyte is less than 20%, the amount of metal salt that can be dissolved in the gel polymer electrolyte is too small, resulting in a significant decrease in the transfer number of metal active ions. The efficiency of charge transfer between the positive electrode 10 and the negative electrode 20 is low, which in turn leads to excessive accumulation of anions on the surface of the positive electrode 10, creating a concentration gradient between the positive electrode 10 and the negative electrode 20. This causes concentration polarization in the ion battery, resulting in a large overpotential and limiting the improvement of battery energy density and power density. When the mass fraction of plasticizer in the gel polymer electrolyte is greater than 60%, the amount of metal salt added in the gel polymer electrolyte needs to be reduced accordingly, which leads to excessive plasticizer. The plasticizer cannot provide capacity during the charge and discharge cycle of the battery, which in turn reduces the volumetric energy density of the battery.

[0135] In some embodiments, the mass fraction of the metal salt in the gel polymer electrolyte is 5%-30%.

[0136] As an example, the mass fraction of metal salt in the gel polymer electrolyte can be 5%, 8%, 10%, 15%, 20%, 25%, or 30%.

[0137] As an example, the metal salt in the electrolyte may include lithium salts, which may include at least one of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium perchlorate, lithium hexafluoroarsenate, lithium bis(fluorosulfonyl)imide, lithium bis(trifluoromethanesulfonyl)imide, lithium trifluoromethanesulfonate, lithium difluorooxalate borate, lithium dioxalate borate, lithium difluorophosphate, lithium difluorodioxalate phosphate, and lithium tetrafluorooxalate phosphate.

[0138] In a fourth aspect, this application proposes a battery comprising the aforementioned gel polymer electrolyte. Thus, the battery possesses all the features and advantages of the aforementioned gel polymer electrolyte, and exhibits superior rate performance and low-temperature cycling performance. Typically, the battery comprises a positive electrode 10, a negative electrode 20, an electrolyte, and a separator 30. The electrolyte may include the aforementioned gel polymer electrolyte 40. During battery charging and discharging, active ions repeatedly insert and extract between the positive electrode 10 and the negative electrode 20. The electrolyte acts as a conductor of ions between the positive electrode 10 and the negative electrode 20. The separator 30 is disposed between the positive electrode 10 and the negative electrode 20, primarily serving to prevent short circuits between the positive and negative electrodes while allowing ions to pass through.

[0139] In the embodiments of this application, battery 5 can be a metal battery.

[0140] As an example, battery 5 can be a sodium metal battery, a lithium metal battery, etc.

[0141] In some embodiments, reference Figure 3The electrode assembly 52 can be a wound structure. The positive electrode 10 and the negative electrode 20 are wound to form a wound structure.

[0142] In some embodiments, the electrode assembly 52 has a stacked structure.

[0143] As an example, multiple positive electrode plates 10 and multiple negative electrode plates 20 can be set, and multiple positive electrode plates 10 and multiple negative electrode plates 20 can be stacked alternately.

[0144] As an example, multiple positive electrode plates 10 can be provided, and multiple negative electrode plates 20 can be folded to form multiple stacked folded segments, with a positive electrode plate 10 sandwiched between adjacent folded segments.

[0145] As an example, both the positive electrode 10 and the negative electrode 20 are folded to form multiple stacked folded segments.

[0146] In some embodiments, the separator 30 is disposed between the positive electrode 10 and the negative electrode 20, mainly to prevent short circuit between the positive and negative electrodes, while allowing ions to pass through.

[0147] As an example, multiple separators 30 can be provided, each disposed between any adjacent positive electrode 10 or negative electrode 20.

[0148] As an example, the separator 30 can be continuously arranged between any adjacent positive electrode 10 or negative electrode 20 by folding or rolling.

[0149] In some embodiments, the electrode assembly may be cylindrical, flat, or polygonal, etc.

[0150] In some embodiments, the electrode assembly has tabs that allow current to be drawn from the electrode assembly. The tabs include a positive tab and a negative tab.

[0151] In some embodiments, the positive electrode 10 may include a positive current collector 11 and a positive active material layer 12 disposed on at least one side surface of the positive current collector 11.

[0152] As an example, the positive current collector 11 has two surfaces opposite each other in its own thickness direction, and the positive active material layer 12 is disposed on either or both of the two opposite surfaces of the positive current collector 11.

[0153] As an example, the positive electrode current collector 11 can be a metal foil, a foamed metal, or a composite current collector. For example, as a metal foil, it can be aluminum or stainless steel with a silver surface treatment, stainless steel, copper, aluminum, nickel, carbon electrode, carbon, nickel, or titanium, etc. The composite current collector can include a polymer material base layer and a metal layer. The foamed metal can be foamed nickel, foamed copper, foamed aluminum, foamed alloy, or foamed carbon, etc. The composite current collector can be formed by forming a metal material (aluminum, aluminum alloy, nickel, nickel alloy, titanium, titanium alloy, silver and silver alloy, etc.) on a polymer material substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0154] As an example, the positive electrode active material layer may include at least one of optional doped lithium cobalt oxide, optional doped lithium manganese oxide, optional doped nickel-cobalt ternary material, and optional doped lithium iron phosphate.

[0155] In some embodiments, the negative electrode 20 may include a negative electrode current collector 21, which may be a metal foil, a foamed metal, or a composite current collector. For example, as a metal foil, it may be aluminum or stainless steel with a silver surface treatment, stainless steel, copper, aluminum, nickel, carbon electrode, carbon, nickel, or titanium, etc. The foamed metal may be foamed nickel, foamed copper, foamed aluminum, foamed alloy, or foamed carbon, etc. The composite current collector may include a polymer material base layer and a metal layer, and the composite current collector may be formed by depositing a metal material (copper, copper alloy, nickel, nickel alloy, titanium, titanium alloy, silver and silver alloy, etc.) on a polymer material substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0156] In some embodiments, the negative electrode 20 may be a rolled metal foil or a metal powder coated with an inert layer on the current collector.

[0157] In some embodiments, the negative electrode current collector 21 can be a composite current collector. For example, the composite current collector may include at least one of carbon cloth, carbon film, carbonaceous material, porous current collector, alloy-modified current collector, lithium-loving modified current collector, and sodium-loving modified current collector.

[0158] As an example, silicon-based materials may include at least one of elemental silicon, silicon oxide, silicon-carbon composite, silicon-nitrogen composite, and silicon alloy materials. Tin-based materials may include at least one of elemental tin, tin oxide, and tin alloy materials.

[0159] This application does not impose any particular restrictions on the type of separator 30; any porous separator with good chemical and mechanical stability can be selected.

[0160] As an example, the main material of the separator 30 may include at least one of glass fiber, non-woven fabric, polyethylene, polypropylene, ceramic, and polyvinylidene fluoride. The number of layers in the separator 30 is not particularly limited; the separator 30 can be a single-layer film or a multi-layer composite film. When the separator 30 is a multi-layer composite film, the materials of each layer are not particularly limited; the materials of each layer can be the same or different. The separator 30 can be a separate component located between the positive electrode 10 and the negative electrode 20, or it can be attached to the surface of the positive electrode and / or the negative electrode.

[0161] As an example, this application does not impose any particular limitation on the shape of the battery; it can be cylindrical, square, or any other arbitrary shape. For example, Figure 2 This is a square-structured battery 5 as an example. Specifically, refer to... Figure 3 The outer packaging of battery 5 may include a housing 51 and a top cover assembly 53. The housing 51 may include a base plate and side plates connected to the base plate, the base plate and side plates forming a receiving cavity. The housing 51 has an opening communicating with the receiving cavity, and the top cover assembly 53 can be placed over the opening to close the receiving cavity.

[0162] As an example, the positive electrode 10, the negative electrode 20, and the separator 30 can be formed into an electrode assembly 52 by a winding process or a stacking process. The electrode assembly 52 is encapsulated within a receiving cavity, and the gel polymer electrolyte wets the electrode assembly 52. ​​The battery 5 may contain one or more electrode assemblies 52, which can be selected by those skilled in the art according to specific practical needs.

[0163] As an example, batteries can be assembled into battery modules, and the number of batteries contained in a battery module can be one or more, the specific number of which can be selected by those skilled in the art according to the application and capacity of the battery module. Figure 4 This is battery module 4, used as an example. (See reference...) Figure 4 In battery module 4, multiple batteries 5 can be arranged sequentially along the length of battery module 4. Of course, they can also be arranged in any other manner. Furthermore, the multiple batteries 5 can be fixed in place by fasteners. Battery module 4 may also include a housing with a receiving space in which the multiple batteries 5 are received.

[0164] As an example, the battery modules described above can also be assembled into a battery pack. The number of battery modules contained in the battery pack can be one or more, and the specific number can be selected by those skilled in the art according to the application and capacity of the battery pack. Figure 5 and Figure 6 This is battery pack 1 as an example. (See reference...) Figure 5 and Figure 6The battery pack 1 may include a battery box and multiple battery modules 4 disposed within the battery box. The battery box includes an upper body 2 and a lower body 3, with the upper body 2 covering the lower body 3 to form a closed space for accommodating the battery modules 4. The multiple battery modules 4 can be arranged in any manner within the battery box.

[0165] In a fifth aspect, this application proposes an electrical device comprising the aforementioned gel polymer electrolyte and / or the aforementioned battery. Thus, the electrical device possesses all the features and advantages of the aforementioned gel polymer electrolyte and battery, which will not be repeated here.

[0166] Batteries, battery modules, or battery packs can serve as power sources for electrical devices or as energy storage units for those devices. Electrical devices can include, but are not limited to, mobile devices (e.g., mobile phones, laptops), electric vehicles (e.g., pure electric vehicles, hybrid electric vehicles, plug-in hybrid electric vehicles, electric bicycles, electric scooters, electric golf carts, electric trucks), electric trains, ships and satellites, energy storage systems, etc. The type of battery, battery module, or battery pack can be selected based on the device's usage requirements.

[0167] As an example, Figure 7 This is an example of an electrical device. The device could be a pure electric vehicle, a hybrid electric vehicle, or a plug-in hybrid electric vehicle. To meet the device's requirements for high battery power and high energy density, a battery pack or battery module can be used.

[0168] As an example, electrical devices could also be mobile phones, tablets, laptops, etc. These devices typically require a slim and lightweight design and can use batteries as their power source.

[0169] The following specific embodiments illustrate the solution of this application. It should be noted that these embodiments are for illustrative purposes only and should not be considered as limiting the scope of this application. Where specific techniques or conditions are not specified in the embodiments, they are performed according to the techniques or conditions described in the literature in this field or according to the product instructions. Reagents or instruments whose manufacturers are not specified are all conventional products that can be obtained commercially.

[0170] Example 1

[0171] The polymer shown in Formula I-1:

[0172] 1.5 g of bis(ethylene sulfonyl)methane and 32 mg of azobisisobutyronitrile (AIBN) in 25 mL were placed in a single-necked flask. The flask was then placed in liquid nitrogen to allow the reactants to solidify. A vacuum was maintained for 10 min using an oil pump. The reactants were then melted and argon gas was introduced. This process was repeated four times. Finally, the flask was placed in an oil bath and the reactants were heated and stirred at 70 °C for 20 h. After the reaction was complete, the product was added dropwise to 20 mL of n-hexane to precipitate, resulting in a solid precipitate. The solid product, polymer I-1, was obtained by filtration.

[0173] The polymerization reaction is shown in reaction formula I-1.

[0174]

[0175] Preparation of the positive electrode sheet:

[0176] Lithium nickel cobalt manganese oxide (NMC), acetylene black (conductive agent), and polyvinylidene fluoride (PVDF) (binder) were mixed at a mass ratio of 98:1:1. N-methylpyrrolidone (NMP) solvent was added and the mixture was stirred until homogeneous to obtain a positive electrode slurry. The positive electrode slurry was uniformly coated on both sides of a positive electrode current collector aluminum foil, air-dried at room temperature, and then transferred to an oven for further drying. The resulting slurry was then cut into 40mm × 50mm rectangles to form the positive electrode sheet, with an areal capacity of 3.5 mAh / cm². 2 .

[0177] Preparation of negative electrode sheet:

[0178] A 50μm lithium foil is rolled onto a 12μm copper foil and then cut into 41mm×51mm rectangles for use as negative electrode sheets.

[0179] Preparation of gel polymer electrolytes:

[0180] Accurately weigh 10g of the aforementioned polymer, dissolve it in 150ml of acetonitrile solvent, and heat and stir for 24h to ensure the polymer is fully dispersed and dissolved. Then, cast it onto a glass plate and transfer it to a vacuum drying oven at 120℃ for 24h. After the solvent has completely evaporated, cool it down, remove it, and cut it into rectangular polymer matrix membranes of 43mm × 53mm. Then, immerse the cut polymer matrix membranes in 10mL of a 4M lithium bis(fluorosulfonyl)imide sulfolane (SL) solution to allow them to swell fully, thus obtaining a gel polymer electrolyte membrane.

[0181] Battery Assembly: One pre-cut positive electrode sheet is matched with two pre-cut negative electrode sheets. A gel polymer electrolyte membrane is placed between the positive and negative electrode sheets to isolate them. The assembly is then wrapped in an aluminum-plastic film bag to form a stacked battery cell. The aluminum-plastic film bag is vacuum-sealed using heat sealing. After standing at room temperature for at least 6 hours, cycle testing can begin. The rated capacity of the stacked battery is 140mAh.

[0182] Example 2

[0183] Example 2 is consistent with Example 1, except that the polymer shown in Formula I-5 is synthesized and used as the polymer matrix, wherein bis(ethylene sulfone)methane is replaced with bis(ethylene sulfone)ethane during polymer synthesis.

[0184] The polymerization reaction is shown in reaction formula I-5.

[0185]

[0186] Example 3

[0187] Example 3 is consistent with Example 1, except that the polymer shown in Formula I-29 is synthesized and used as the polymer matrix, wherein bis(ethylene sulfonyl)methane is replaced with 1,4-bis(ethylene sulfonyl)butane (CAS: 3088-17-3) during polymer synthesis.

[0188] Example 4

[0189] Example 4 was consistent with Example 1, except that the polymer shown in Formula I-2 was synthesized and used as the polymer matrix. Specifically, 0.172 g of sodium hydride (NaH, 60%) and 20 mL of anhydrous THF were placed in a 50 mL three-necked flask under argon protection. The reactants were cooled to 0 °C using an ice-water bath. 1.0 g of a tetrahydrofuran solution of 2,2'-[methylenebissulfonyl]diethanol (5 mL) was added dropwise. After the addition was complete, the mixture was stirred at 0 °C for 1 h. Another 1.0 g of a tetrahydrofuran solution of 2,2'-[methylenebissulfonyl]diethanol (5 mL) was added dropwise. After the addition was complete, the mixture was brought back to room temperature and stirred for 1 h. Finally, the three-necked flask was placed in an oil bath and the reactants were stirred at 70 °C for 10 h. After the reaction was complete, the THF was removed by concentration under reduced pressure. The product was then added dropwise to 20 mL of n-hexane to precipitate, resulting in a solid precipitate. The solid product, polymer I-2, was obtained by filtration.

[0190] The polymerization reaction is shown in reaction formula I-2.

[0191]

[0192] Reaction formula I-2.

[0193] Example 5

[0194] Example 5 is consistent with Example 1, except that dimethyl sulfone (DMS) is used as a plasticizer.

[0195] Example 6

[0196] Example 6 is consistent with Example 1, except that ethyl methyl sulfone (EMS) is used as the plasticizer.

[0197] Example 7

[0198] Example 7 is consistent with Example 1, except that ethyl isopropyl sulfone (EiPS) is used as the plasticizer.

[0199] Comparative Example 1

[0200] Comparative Example 1 is consistent with Example 1, except that the structure of the polymer is as follows:

[0201] The CAS number is 25608-63-3, and the manufacturer is McLean.

[0202] Comparative Example 2

[0203] Comparative Example 2 is consistent with Example 1, except that the polymer structure is as follows:

[0204] The CAS number is 25135-51-7, and the manufacturer is McLean.

[0205] The ionic conductivity of the gel polymer electrolytes in Examples 1-7 and Comparative Examples 1-2 was tested, and the results are shown in Table 1.

[0206] The ionic conductivity was tested using the AC impedance method. Specifically, a 1.6 cm diameter gel polymer electrolyte was placed in a stainless steel fixture to construct a blocked cell with a stainless steel / gel polymer electrolyte / stainless steel structure. The impedance of the blocked cell was measured using an electrochemical workstation, employing the formula: σ = L / SR. b The ionic conductivity of the gel polymer electrolyte was calculated, where σ is the ionic conductivity of the gel polymer electrolyte, L is the thickness of the gel polymer electrolyte, S is the area of ​​the gel polymer electrolyte, and R... b The impedance of the gel polymer electrolyte at room temperature

[0207] The cycle performance, low-temperature cycle performance, and rate performance of the batteries in Examples 1-7 and Comparative Examples 1-2 were tested, and the test results are shown in Table 1:

[0208] Cyclic performance testing method: The ambient temperature was set to 25℃, and charge-discharge cycles were performed using a charge rate of 0.5C (i.e., 70mA) and a discharge rate of 0.5C (i.e., 70mA). The charging cut-off voltage was set to 4.3V, and the discharging cut-off voltage was set to 2.8V. When the discharge capacity decayed to 80% of the first discharge capacity, the battery life was considered to have ended, and the number of cycles at this point was recorded.

[0209] Test method for rate performance: The ambient temperature was set to 25℃. Three charge-discharge cycles were performed using a 0.2C charging rate (28mA) and a 0.5C discharging rate (70mA). The charging cutoff voltage was set to 4.3V, and the discharging cutoff voltage was set to 2.8V. Then, while maintaining the 0.2C charging rate, the discharging rate was increased to 4C. After the cycle stabilized, the discharge capacity under the 4C high-rate condition was recorded.

[0210] Low-temperature cycling performance testing method: Set the ambient temperature to -30℃ (for example, the battery can be placed in a low-temperature oven), and perform charge-discharge cycles using a charge rate of 0.2C (i.e., 28mA) and a discharge rate of 0.2C (i.e., 28mA). The charging cutoff voltage is set to 4.3V, and the discharging cutoff voltage is set to 2.8V. After the cycle stabilizes, record the discharge capacity under the low-temperature condition of -30℃.

[0211] Table 1

[0212]

[0213]

[0214] In Example 1, 1.23 g of solid product was obtained, with a product yield of 82%; in Example 4, 0.94 g of solid product was obtained, with a product yield of 47%.

[0215] Elemental analysis of the polymer in Example 1 yielded the following calculated values: C, 30.29; H, 5.08; O, 32.28; S, 32.35. Analyzed values ​​were: C, 31.02; H, 5.21; O, 31.58; S, 32.19. The obtained polymer was subjected to number-average molecular weight analysis, yielding a molecular weight of 38,000 and a polymer dispersibility index of 1.9.

[0216] Elemental analysis of the polymer in Example 2 yielded the following calculated values: C, 33.95; H, 5.70; O, 30.15; S, 30.21. Analytical values ​​were: C, 33.65; H, 5.98; O, 31.45; S, 28.92. The obtained polymer was subjected to number-average molecular weight analysis, yielding a molecular weight of 35,000 and a polymer dispersibility index of 1.7.

[0217] Elemental analysis of the polymer in Example 4 yielded the following calculated values: C, 28.03; H, 4.70; O, 37.34; S, 29.93. Analytical values ​​were: C, 29.02; H, 4.51; O, 38.58; S, 27.89. The number-average molecular weight of the obtained polymer was determined to be 31,000, and the polymer dispersibility index was 2.0.

[0218] In the description of this specification, references to terms such as "one embodiment," "another embodiment," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment is included in at least one embodiment of this application. The illustrative expressions of the above terms in this specification do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in a suitable manner in any one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of those different embodiments or examples.

[0219] Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of this application.

Claims

1. A gel polymer electrolyte, characterized in that, It includes a polymer matrix and an electrolyte, wherein the polymer matrix comprises a polymer having the general formula shown in formula (1): Equation (1), Wherein, R1 includes a substituted or unsubstituted C1-C4 alkyl group, R2 includes an alkyl group with 3 or more carbon atoms and R3 includes an alkoxy group with 3 or more carbon atoms, or R2 includes an alkoxy group with 3 or more carbon atoms and R3 includes an alkyl group with 3 or more carbon atoms, the value of n is 200-1000, and the carbon atom of the alkoxy group is attached to the sulfur atom on the sulfone group.

2. The gel polymer electrolyte according to claim 1, characterized in that, The number of carbon atoms between adjacent sulfone groups is less than or equal to 4.

3. The gel polymer electrolyte according to claim 1, characterized in that, The number of carbon atoms separating adjacent sulfone groups is 1 or 2.

4. The gel polymer electrolyte according to any one of claims 1-3, characterized in that, The polymer contains 20%-80% sulfone groups.

5. The gel polymer electrolyte according to any one of claims 1-3, characterized in that, The polymer contains 60%-80% sulfone groups.

6. The gel polymer electrolyte according to any one of claims 1-3, characterized in that, The number of carbon atoms separating the oxygen atom of the alkoxy group from the sulfur atom of the adjacent sulfone group is less than or equal to 4.

7. The gel polymer electrolyte according to any one of claims 1-3, characterized in that, The number of carbon atoms separating the oxygen atom of the alkoxy group from the sulfur atom of the adjacent sulfone group is 1 or 2.

8. The gel polymer electrolyte according to any one of claims 1-3, characterized in that, The polymer includes at least one of the following: 。 9. The gel polymer electrolyte according to any one of claims 1-3, characterized in that, The number average molecular weight of the polymer is 40,000-80,000.

10. The gel polymer electrolyte according to any one of claims 1-3, characterized in that, The number-average molecular weight of the polymer is 55,000-65,000.

11. The gel polymer electrolyte according to any one of claims 1-3, characterized in that, The polymer has a polymer dispersibility index of 1.5-2.

5.

12. The gel polymer electrolyte according to any one of claims 1-3, characterized in that, The polymer has a polymer dispersibility index of 1.7-2.

2.

13. The gel polymer electrolyte according to any one of claims 1-3, characterized in that, The electrolyte includes plasticizers and metal salts, and the plasticizers include sulfone plasticizers.

14. The gel polymer electrolyte according to claim 13, characterized in that, The sulfone plasticizers include at least one of sulfolane, dimethyl sulfone, ethyl methyl sulfone, ethyl isopropyl sulfone, and 3-methylcyclosulfone.

15. The gel polymer electrolyte according to claim 13, characterized in that, The sulfone plasticizers include sulfolane.

16. The gel polymer electrolyte according to any one of claims 1-3, characterized in that, The polymer matrix in the gel polymer electrolyte has a mass fraction of 10%-80%.

17. The gel polymer electrolyte according to claim 13, characterized in that, The mass fraction of the plasticizer in the gel polymer electrolyte is 20%-60%.

18. The gel polymer electrolyte according to claim 13, characterized in that, The mass fraction of the metal salt in the gel polymer electrolyte is 5%-30%.

19. A battery, characterized in that, Includes the gel polymer electrolyte according to any one of claims 1-18.

20. An electrical appliance, characterized in that, Includes the gel polymer electrolyte according to any one of claims 1-18, and / or the battery according to claim 19.

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