Battery cells, batteries and power consuming devices

Abstract

A battery cell, a battery, and a power consumption device, the battery cell comprising a negative plate having a length a in a first direction, the negative plate having a first end and a second end, and a gel polymer electrolyte located at least between the positive and negative plates, wherein when the capacity of the battery cell is 90% or less of the nominal capacity of the battery cell, a first region is present in the negative plate, the distance between the first end and a point farthest from the first end in the first region is (I), a second region is present in the negative plate, the area of ​​the second region is the same or approximately the same as the area of ​​the first region, the distance between the second end and a point farthest from the second end in the second region is (I), in a temperature range of 25°C-180°C, the heat loss of the negative plate located in the first region is m, the heat loss of the negative plate located in the second region is n, and m / n is 50% or more.

Description

[Technical Field]

[0001] The present disclosure relates to the field of batteries, and more particularly to battery cells, batteries and power consuming devices. [Background technology]

[0002] In recent years, as the application range of secondary batteries has become increasingly broad, secondary batteries have been widely used in energy storage power systems such as hydroelectric power plants, thermal power plants, wind power plants, and solar power plants, as well as in multiple fields such as power tools, electric bicycles, electric motorcycles, electric vehicles, military equipment, and aerospace. However, as the application range of secondary batteries has become increasingly broad, serious challenges have also been raised regarding the cycle performance of secondary batteries. Currently, lithium-ion batteries still have many problems to be solved at the industrial production and application levels. Summary of the Invention

[0003] According to a first aspect of the present application, the present application provides a battery cell, the battery cell including an electrode assembly, the electrode assembly including a positive electrode plate and a negative electrode plate, the negative electrode plate having a length of a in a first direction, the negative electrode plate having a first end and a second end, the direction from the first end to the second end being the same as the first direction, and a gel polymer electrolyte located at least between the positive electrode plate and the negative electrode plate, wherein when the capacity of the battery cell is 90% or less of a nominal capacity of the battery cell, the negative electrode plate has an area of

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[0004] According to the examples of the present application, the m / n is 70% or more, which means that the difference in the electrolyte content between the upper and lower ends of the negative electrode plate is relatively small, and the electrolyte has relatively high permeability into the negative electrode plate, resulting in a battery cell with relatively excellent cycle performance.

[0005] According to an embodiment of the present application, there is a first angle between the first direction and the second direction, and the first angle is 70°-90°, so that the battery cells can be installed almost vertically or directly vertically to the ground, optimizing the arrangement of the battery cells and improving space utilization.

[0006] According to an embodiment of the present application, the first angle is 85°-90°, which allows the battery cells to be installed almost vertically or directly vertically to the ground, thereby optimizing the battery cell arrangement and improving space utilization.

[0007] According to an embodiment of the present application, the gel polymer electrolyte includes a polymer substrate obtained by polymerizing a polymer monomer, the polymer monomer including a first monomer and a second monomer, and the first monomer including at least two cross-linking moieties, such that the first monomer can not only initiate the polymerization reaction of the second monomer but also cross-link the polymer chains formed by polymerizing a plurality of second monomers, thereby improving the elasticity of the polymer substrate.

[0008] According to the embodiment of the present application, the cross-linking moiety includes at least one of a double bond, a triple bond, and a cyclic ether, which can enhance the cross-linking effect of the first monomer and further improve the elasticity of the polymer substrate.

[0009] According to an embodiment of the present application, the first monomer comprises at least one of an acrylic acid-based monomer and an acrylate-based monomer, which can improve the crosslinking state of the polymer substrate.

[0010] According to an embodiment of the present application, the first monomer is selected from the group consisting of: the acrylic acid-based monomer including at least one of acrylic acid, methacrylic acid, methyl methacrylate, butyl methacrylate, methyl acrylate, ethyl acrylate, hydroxyethyl acrylate, hydroxyethyl methacrylate, butyl acrylate, isodecyl acrylate, isooctyl acrylate, lauryl acrylate, isobornyl acrylate, isobornyl methacrylate, and ethoxyethoxyethyl acrylate; and the acrylate-based monomer is selected from the group consisting of cyanoacrylate, caprolactone acrylate, 2-phenoxyethyl acrylate, tetrahydrofuryl acrylate, ethoxytetrahydrofuran acrylate, and cyclohexane. Trimethylolpropane acrylate, 2-carboxyethyl acrylate, cyclohexyl acrylate, ethylene glycol diacrylate, ethylene glycol dimethacrylate, propylene glycol dimethacrylate, diethylene glycol diacrylate, diethylene glycol dimethacrylate, triethylene glycol diacrylate, triethylene glycol dimethacrylate, tetraethylene glycol diacrylate, tetraethylene glycol dimethacrylate, 1,4-butanediol diacrylate, 1,4-butanediol dimethacrylate, 1,3-butanediol diacrylate, 1,3-butanediol dimethacrylate, 1,6-hexanediol diacrylate, 1,6-Hexanediol dimethacrylate, dipropylene glycol diacrylate, dipropylene glycol dimethacrylate, tripropylene glycol diacrylate, tripropylene glycol dimethacrylate, neopentyl glycol diacrylate, neopentyl glycol dimethacrylate, 2(propoxylated) neopentyl glycol diacrylate, ethylene glycol diacrylate oligomer, ethylene glycol dimethacrylate oligomer, propylene glycol dimethacrylate oligomer, cyclohexyl acrylate oligomer, methoxypolyethylene glycol acrylate and at least one of the following conditions is satisfied: at least one of the following is included: acrylate, ethoxylated trimethylolpropane triacrylate, trimethylolpropane trimethacrylate, methoxyethylene glycol methacrylate oligomer, pentaerythritol triacrylate, propoxylated glycerin triacrylate, tris(2-hydroxyethyl)isocyanuric acid triacrylate, bis(trimethylolpropane)tetraacrylate, pentaerythritol tetraacrylate, 4(ethoxy)pentaerythritol tetraacrylate, and dipentaerythritol hexaacrylate. This further improves the crosslinking state of the polymer substrate, thereby improving the elasticity of the polymer substrate.

[0011] According to an embodiment of the present application, the second monomer includes at least one of a carbonate-based monomer, a sulfate-based monomer, a sulfonate-based monomer, a phosphate-based monomer, a carboxylate-based monomer, a sulfone-based monomer, an amide-based monomer, a nitrile-based monomer, and an ether-based monomer, which can improve the strength of the polymer substrate.

[0012] According to an embodiment of the present application, the second monomer is selected from the group consisting of: a condition in which the carbonate-based monomer includes at least one of vinylene carbonate, vinyl ethylene carbonate, ethylene carbonate, propylene carbonate, butylene carbonate, fluoroethylene carbonate, and chloroethylene carbonate; a condition in which the sulfate-based monomer includes at least one of vinyl vinyl sulfite, vinyl sulfite, 4-methyl vinyl sulfate, and 4-ethyl vinyl sulfate; a condition in which the sulfonate-based monomer includes at least one of 1,3-propene sultone, 1,3-propane sultone, 1,4-butane sultone, and methane disulfonic acid methylene ring ester; and a condition in which the phosphate-based monomer includes at least one of dimethyl vinyl phosphate, diethyl vinyl phosphate, diethyl propenyl phosphate, diethyl butenyl phosphate, diethyl 1-buten-2-yl phosphonate, diethyl ethynyl phosphate, vinyl trifluoromethyl phosphate, and vinyl-1-trifluoroethenyl phosphate. The polymer substrate satisfies one or more of the following conditions: the carboxylic acid ester monomer includes at least one of methyl vinyl sulfone, ethyl vinyl sulfone, cyclobutene sulfone, sulfolane, and ethylene sulfoxide; the amide monomer includes acrylamide; the nitrile monomer includes at least one of acrylonitrile, succinonitrile, glutaronitrile, and adiponitrile; and the ether monomer includes at least one of 1,3-dioxolane, ethylene oxide, 1,2-propylene oxide, 4-methyl-1,3-dioxolane, tetrahydrofuran, 2-methyltetrahydrofuran, 1,4-dioxane, ethylene glycol dimethyl ether, ethylene glycol diglycidyl ether, and triethylene glycol divinyl ether. This can further improve the strength of the polymer substrate.

[0013] In the embodiment of the present application, the mass of the electrolyte is c, the mass of the polymer substrate is b, and c / (c+b) is 60%-97%, so that the content of the electrolyte in the battery cell is relatively high, which can further improve the cycle performance of the battery cell.

[0014] According to the embodiment of the present application, the ratio c / (c+b) is 80%-95%, which can further improve the cycle performance of the battery cell.

[0015] According to an embodiment of the present application, the battery further includes a case, which is used to package the electrode assembly and the gel polymer electrolyte, and when the state of charge of the battery cell is less than 5%, the volume of the electrode assembly is V1, the volume of the battery case is V2, and V1 / V2 is less than or equal to 92%, thereby improving the structural stability and usage reliability of the battery cell.

[0016] According to an embodiment of the present application, the negative electrode plate includes a negative electrode current collector and a negative electrode active material layer disposed on at least one surface of the negative electrode current collector, the negative electrode active material layer including a negative electrode active material, the negative electrode active material including at least one of natural graphite, artificial graphite, soft carbon, hard carbon, a silicon-based material, a tin-based material, and lithium titanate, thereby improving the energy density of the negative electrode plate.

[0017] According to an embodiment of the present application, the negative electrode active material satisfies one or more of the following conditions: the silicon-based material includes at least one of silicon elemental, silicon oxide, silicon carbon composite, silicon nitrogen composite, and silicon alloy material; and the tin-based material includes at least one of tin elemental, tin oxide, and tin alloy material, thereby improving the energy density of the negative electrode plate.

[0018] According to a second aspect of the present application, the present application provides a battery including the battery cell described above, whereby the battery has all the features and advantages of the battery cell described above, which will not be further described herein.

[0019] According to a third aspect of the present application, the present application provides a power consuming device, comprising a battery cell as described above and / or a battery as described above, whereby the power consuming device has all the features and advantages of the battery cell and battery as described above, which will not be further described herein. [Brief explanation of the drawings]

[0020] The above and / or additional aspects and advantages of the present application will become apparent and readily understood from the following description of exemplary embodiments in conjunction with the drawings, in which: [Figure 1] 1 is a structural schematic diagram of a battery cell according to an embodiment of the present application; [Figure 2] FIG. 2 is a structural schematic diagram of a negative electrode plate according to an embodiment of the present application. [Figure 3] 1 is a schematic diagram of a battery cell according to one embodiment of the present application; [Figure 4] FIG. 4 is an exploded view of the battery cell shown in FIG. 3 according to an embodiment of the present application. [Figure 5] 1 is a schematic diagram of a battery module according to an embodiment of the present application; [Figure 6] 1 is a schematic diagram of a battery pack according to one embodiment of the present application. [Figure 7] FIG. 7 is an exploded view of the battery pack shown in FIG. 6 according to an embodiment of the present application. [Figure 8] 1 is a schematic diagram of a battery-powered power consuming device according to one embodiment of the present application; DETAILED DESCRIPTION OF THE INVENTION

[0021] The following describes in detail the embodiments of the present application, and examples of the embodiments are shown in the drawings, where the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the drawings are merely illustrative and are for the purpose of interpreting the present application, and should not be understood as limitations on the present application.

[0022] In describing the present application, it should be understood that the orientations or positional relationships indicated by terms such as "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," etc. are orientations or positional relationships shown based on the drawings, and are merely for the convenience and simplification of the description of the present application, and do not indicate or imply that the referred-to devices or elements must have a specific orientation or be configured and operated in a specific orientation, and therefore should not be understood as limitations on the present application.

[0023] In the description of this application, "A and / or B" may include any one of the cases of A alone, B alone, and A and B, where A and B are used only as examples, and it may be any technical feature connected using "and / or" in this application.

[0024] In the context of this application, "plurality" means two or more.

[0025] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. All patents and publications pertaining to this application are incorporated herein by reference in their entirety. The terms "comprises" or "comprises" are open-ended, i.e., include the content explicitly stated in this application but do not exclude the content of other aspects.

[0026] In the description of this application, regardless of whether terms such as "about" or "approximately" are used, all numbers disclosed herein are approximate values. The numerical values ​​of each number may vary by up to 10%, or by a difference that would be considered reasonable by a person skilled in the art, such as 1%, 2%, 3%, 4%, or 5%.

[0027] In the description of this application, when A and B are both numerical values, A being the same as B means that A and B are completely the same, and A being almost the same as B means that there is a difference between A and B of 10% or less, or a difference that a person skilled in the art would consider reasonable, for example, 1%, 2%, 3%, 4%, or 5%.

[0028] In this application, taking a metal battery using a liquid electrolyte as an example, when the battery cell 5 is charged, metal active ions are desorbed from the positive electrode active material, diffuse through the electrolyte, migrate to the surface of the negative electrode plate 20, and are absorbed into the negative electrode active material. When the battery cell 5 is discharged, the metal active ions are desorbed from the negative electrode active material, diffuse through the electrolyte, migrate to the surface of the positive electrode plate 10, and are absorbed into the positive electrode active material. During the charge and discharge process, the negative electrode active material expands in volume due to the absorption of the metal active ions, and contracts in volume due to the desorption of the metal active ions. Furthermore, the negative electrode active material continuously undergoes volume changes during the charge and discharge cycles of the battery cell 5.

[0029] In some embodiments, using a negative electrode active material, such as a silicon-based negative electrode active material, that exhibits a relatively large volume expansion during charge / discharge cycling, the negative electrode plate 20 containing the silicon-based negative electrode material has a minimum volume c1 when the battery cell 5 is in a fully discharged state, and a maximum volume c2 when the battery cell 5 is in a fully charged state. The negative electrode plate 20 containing the silicon-based negative electrode material can have a volume change rate c2 / c1 of 300% or more during charge / discharge cycling. The negative electrode plate 20 exhibits a large volume effect during charge / discharge cycling. During charging of the battery cell 5, the expansion force inside the battery cell 5 increases as the volume of the negative electrode plate 20 increases, and the electrolyte inside the negative electrode plate 20 is gradually pushed out along one side of the negative electrode plate 20. For example, if the battery cell 5 is vertically placed on the ground, during charging of the battery cell 5, the electrolyte inside the negative electrode plate 20 will gradually be extruded along the upper region of the negative electrode plate 20 and accumulate in the expansion space previously left inside the battery cell 5. During discharging of the battery cell 5, the extruded electrolyte cannot return to the negative electrode plate 20 in a timely manner, thereby reducing the wettability of the electrolyte in the upper region of the negative electrode plate 20 and ultimately causing lithium deposition. In the early stages of lithium deposition, the lithium nuclei and the negative electrode plate still maintain good contact, and the deposited metallic lithium continues to grow into lithium dendrites. During subsequent cycles, the tops of the lithium dendrites become inactive and become elemental lithium that cannot participate in charge and discharge cycles, which significantly affects the cycle life and capacity of the battery cell.

[0030] Fully charged refers to a state in which the state of charge of a battery cell 5 is 100%, but of course, fully charged may refer to cases in which the state of charge of a battery cell 5 is other numerical values, for example, a state in which the state of charge is greater than 90%, and this application is not limited thereto. Fully discharged refers to a state in which the state of charge of a battery cell 5 is 0%, but of course, fully discharged may refer to cases in which the state of charge of a battery cell 5 is other numerical values, for example, a state in which the state of charge is less than 5%, and this application is not limited thereto.

[0031] The nominal capacity of a battery cell refers to the capacity exhibited when a fully charged battery cell is discharged at a 1C rate at room temperature, where the current corresponding to a 1C rate discharge is the current required to completely discharge the battery cell in one hour.

[0032] In this application, by replacing the liquid electrolyte with a gel polymer electrolyte, the occupancy effect of the polymer substrate in the gel polymer electrolyte is utilized to effectively alleviate the problem that the electrolyte inside the battery cell is pushed out when it expands under internal pressure, which further deteriorates the wettability of the negative electrode plate and significantly reduces the cycle performance of the battery cell.

[0033] In some embodiments, after the electrode assembly is placed in the battery cell case, an electrolyte solution containing a polymer monomer is injected into the battery cell, so that the interior of the battery cell 5 is infiltrated with the electrolyte solution containing the polymer monomer, and the curing reaction of the polymer monomer is initiated by external conditions, such as heat treatment, to form a polymer matrix, thereby ensuring that the interior of the battery cell 5 is filled with a gel polymer electrolyte 40 consisting of the polymer matrix and the electrolyte solution. Compared to liquid electrolytes, the polymer matrix has higher elasticity and pressure-resistance capacity, and can bounce back to its original state as much as possible after bearing pressure.

[0034] In the present application, a gel polymer electrolyte is formed between the positive and negative electrodes by curing in situ, and has a relatively high elasticity, thereby replacing the liquid electrolyte with a polymer matrix. Furthermore, when the negative electrode plate 20 expands during the charge-discharge cycle of the battery cell 5, the polymer matrix can effectively relieve the pressure caused by the expansion of the negative electrode plate 20. Furthermore, the electrolyte is less likely to be extruded from the upper region of the negative electrode plate 20. The electrolyte has a relatively high infiltration ability into the upper region of the negative electrode plate 20 throughout the charge-discharge cycle, maintaining ion channels in the upper region of the negative electrode plate 20 and effectively inhibiting the growth of lithium dendrites on the surface of the negative electrode plate 20, thereby effectively improving the cycle performance of the battery cell 5.

[0035] The battery cells disclosed in the embodiments of the present application can be used in, but are not limited to, power consumption devices such as vehicles, ships, and aircraft, etc. The battery cells, batteries, etc. disclosed in the present application can be used to configure the power supply system of the power consumption device.

[0036] An embodiment of the present application provides a power consuming device that uses a battery cell and / or a battery as a power source, and the power consuming device may be, but is not limited to, a mobile phone, a tablet, a laptop, an electric toy, an electric tool, a battery vehicle, an electric car, a steamship, a spacecraft, etc. Here, the electric toy may include a stationary or mobile electric toy, such as a game console, an electric car toy, an electric steamship toy, and an electric plane toy, and the spacecraft may include an airplane, a rocket, a spacecraft, a spaceship, etc.

[0037] It should be understood that the technical solutions described in the embodiments of the present application are not limited to the application to the battery cells and power consumption devices described above, but can also be applied to all batteries including battery cells and power consumption devices that use batteries. However, for the sake of simplicity, the following embodiments will all be described using electric vehicles as examples.

[0038] According to a first aspect of the present application, with reference to FIGS. 1 and 2, the present application provides a battery cell 5, comprising an electrode assembly, the electrode assembly including a positive electrode plate 10 and a negative electrode plate 20, the negative electrode plate 20 having a length a in a first direction, the negative electrode plate 20 having a first end 201 and a second end 202, the direction from the first end 201 to the second end 202 being the same as the first direction, and a gel polymer electrolyte 40 located between the positive electrode plate 10 and the negative electrode plate 20, wherein when the capacity of the battery cell 5 is 90% or less of the nominal capacity of the battery cell 5, the negative electrode plate 20 has an area of

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[0039] In some embodiments, a gel polymer electrolyte is cured in situ between the positive and negative electrodes to form a gel polymer electrolyte with high elasticity. This allows the polymer matrix to effectively relieve the pressure caused by the expansion of the negative electrode plate 20. Furthermore, the electrolyte is less likely to be extruded from one side of the negative electrode plate 20. The electrolyte has a relatively high permeability to the negative electrode plate 20 throughout the entire charge-discharge cycle. The electrolyte contents of the negative electrode plate 20 in the first region 203 and the negative electrode plate 20 in the second region 204 are both relatively high. When the capacity of the battery cell 5 is 90% or less of the nominal capacity of the battery cell 5, i.e., when the battery cell 5 has undergone multiple charge-discharge cycles, the difference in the electrolyte content between the region near the first end 201 and the region near the second end 202 of the negative electrode plate 20 is relatively small. Specifically, the electrolyte vaporizes and desorbs from the negative electrode plate 20 within the temperature range of 25°C to 180°C. Therefore, by testing the heat loss of the negative electrode plate 20 in a specific region within the temperature range of 25°C to 180°C, the electrolyte content in the corresponding region can be directly expressed.

[0040] For example, when testing the heat loss of the negative electrode plate 20 in the temperature range of 25°C to 180°C, the negative electrode plate 20 may be gradually heated from 25°C to 180°C until the electrolyte is completely evaporated.

[0041] In the embodiment of the present application, the second direction may be parallel to a plane on which the battery cells 5 are arranged, for example, the second direction may be parallel to the ground.

[0042] In some embodiments, a first angle exists between the first direction and the second direction, and the first angle may be 70°-90°. Optionally, the first angle may be 85°-90°. The battery cells may be installed approximately perpendicular to the ground or directly perpendicular to the ground, which can optimize the arrangement of the battery cells and improve space utilization. Specifically, when the angle between the first direction and the second direction is 90°, the battery cells are installed perpendicular to the ground.

[0043] In the embodiments of the present application, the battery cells 5 may be metal batteries. In some embodiments, the battery cells 5 may be sodium metal batteries, lithium metal batteries, etc.

[0044] In some embodiments, the electrode assembly is a wound structure. The positive electrode plate 10 and the negative electrode plate 20 are wound to form a wound structure.

[0045] In some embodiments, the electrode assembly is a laminate structure.

[0046] For example, a plurality of positive electrode plates 10 and a plurality of negative electrode plates 20 may be installed, and the plurality of positive electrode plates 10 and the plurality of negative electrode plates 20 may be installed in an alternating stack.

[0047] For example, multiple positive electrode plates 10 may be installed, and the negative electrode plates 20 may be folded to form multiple folded segments that are stacked and installed, with one positive electrode plate 10 sandwiched between adjacent folded segments.

[0048] For example, both the positive electrode plate 10 and the negative electrode plate 20 are folded to form a plurality of folded segments that are arranged in a stack.

[0049] In some embodiments, the separator 30 is disposed between the positive electrode plate 10 and the negative electrode plate 20, and serves mainly to prevent short-circuiting between the positive and negative electrodes, while allowing active ions to pass through.

[0050] For example, a plurality of separators 30 may be provided, each disposed between any adjacent positive electrode plates 10 or negative electrode plates 20 .

[0051] For example, the separator 30 may be disposed continuously or may be disposed between any adjacent positive electrode plates 10 or negative electrode plates 20 in a folded or wound manner.

[0052] In some embodiments, the electrode assembly may have a cylindrical, flattened, or polygonal prism shape.

[0053] In some embodiments, the electrode assembly is provided with tabs through which current can be drawn from the electrode assembly, including a positive electrode tab and a negative electrode tab.

[0054] In some embodiments, the positive electrode plate 10 may include a positive electrode current collector 11 and a positive electrode active material layer 12 disposed on at least one surface of the positive electrode current collector 11 .

[0055] For example, the positive electrode current collector 11 has two surfaces facing each other in the thickness direction thereof, and the positive electrode active material layer 12 is disposed on one or both of the two facing surfaces of the positive electrode current collector 11.

[0056] For example, the positive electrode current collector 11 may be a metal foil sheet, a metal foam, or a composite current collector. For example, the metal foil sheet may be silver-surface-treated aluminum or stainless steel, stainless steel, copper, aluminum, nickel, a carbon electrode, carbon, nickel, or titanium. The composite current collector may include a polymeric material base layer and a metal layer. The metal foam may be nickel foam, copper foam, aluminum foam, alloy foam, or carbon foam. The composite current collector may be formed by forming a metal material (such as aluminum, aluminum alloy, nickel, nickel alloy, titanium, titanium alloy, silver, or silver alloy) on a polymeric material substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, or polyethylene).

[0057] In some embodiments, the negative electrode plate 20 may include a negative electrode current collector 21, which may be a metal foil sheet, a metal foam, or a composite current collector. For example, the metal foil sheet may be silver-finished aluminum or stainless steel, stainless steel, copper, aluminum, nickel, a carbon electrode, carbon, nickel, or titanium. The metal foam may be nickel foam, copper foam, aluminum foam, alloy foam, or carbon foam. The composite current collector may include a polymeric material substrate and a metal layer. The composite current collector may be formed by forming a metal material (such as copper, copper alloy, nickel, nickel alloy, titanium, titanium alloy, silver, or silver alloy) on a polymeric material substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, or polyethylene).

[0058] In some embodiments, negative electrode plate 20 may be rolled from a metal foil or coated with a passivation layer of metal powder applied to a current collector.

[0059] In some embodiments, anode current collector 21 may be a composite current collector, for example, the composite current collector may include at least one of a carbon cloth, a carbon film, a carbonaceous, a porous current collector, an alloy-modified current collector, a lithium-affinity-modified current collector, and a sodium-affinity-modified current collector.

[0060] In some embodiments, the negative electrode plate 20 may include a negative electrode current collector 21 and a negative electrode active material layer 22 disposed on at least one surface of the negative electrode current collector 21. The negative electrode active material layer 22 may include a negative electrode active material. The negative electrode active material may be a high gram capacity material, for example, the negative electrode active material may include at least one of natural graphite, artificial graphite, soft carbon, hard carbon, a silicon-based material, a tin-based material, and lithium titanate.

[0061] By way of example, the silicon-based material may include at least one of elemental silicon, silicon oxide, silicon carbon composite, silicon nitrogen composite, and silicon alloy material, and the tin-based material may include at least one of elemental tin, tin oxide, and tin alloy material.

[0062] The present application does not particularly limit the type of separator 30, and any porous structure separator with good chemical stability and mechanical stability may be selected.

[0063] For example, the main material of the separator 30 may include at least one of glass fiber, nonwoven fabric, polyethylene, polypropylene, ceramic, and polyvinylidene fluoride. The separator 30 may be a single-layer film or a multi-layer composite film, without any particular limitations. When the separator 30 is a multi-layer composite film, the materials of each layer may be the same or different, without any particular limitations. The separator 30 may be a single member located between the positive electrode plate 10 and the negative electrode plate 20, or may be attached to the surfaces of the positive and negative electrodes.

[0064] In some embodiments, when the capacity of the battery cell 5 is less than 90% of the nominal capacity of the battery cell 5, the battery cell has already undergone multiple charge / discharge cycles, and the negative electrode plate 20 accordingly undergoes multiple reciprocating volume expansions and contractions, and the electrolyte inside the battery cell 5 undergoes multiple pressure extrusions and refluxes.

[0065] In some embodiments, the first direction may be parallel to a predetermined surface of the battery cell, for example, the first direction may be parallel to the large surface of the battery cell, and in this case, there may be a first angle of 70°-90° between the first direction and the second direction, i.e., there may be an angle of 70°-90° between the large surface of the battery cell 5 and the ground. Here, taking a wound battery cell as an example, the two sides with the largest area are called large sides, and the other two sides are called narrow sides.

[0066] In some embodiments, the shape of the first region 203 is not particularly limited, and the distance between the farthest point from the first end 201 in the first region and the first end 201 is

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[0067] In some embodiments, the shape of the second region 204 is not particularly limited, and the distance between the point in the second region 204 farthest from the second end 202 and the second segment 202 is

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[0068] In some embodiments, the areas of the first region 203 and the second region 204 are the same or approximately the same, for example, when a is greater than 50 mm, the areas of the first region 203 and the second region 204 are

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[0069] For example, a differential scanning calorimeter (DSC) sampling device may be used, and specifically, a disk with a diameter of 5 mm may be obtained by a mechanical die punching method.

[0070] For example, a thermogravimetric analyzer may be used, specifically, a differential thermal-thermogravimetric analyzer may be used to measure the heat loss in the 25°C-180°C range of the negative electrode plate 20 in the first region 203 and the negative electrode plate 20 in the second region 204.

[0071] In some embodiments, m / n may be 70% or greater. A larger m / n value indicates a smaller difference in electrolyte content between the region near the first end 201 and the region near the second end 202 of the negative electrode plate 20, and when the battery cell is placed vertically on the ground, the wettability of the upper and lower regions of the negative electrode plate 20 will be approximately the same.

[0072] For example, m / n may be 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95%, 96%, or 97%. As can be appreciated, limited by the battery cell's fill factor, the electrolyte content of negative plate 20 in first region 203 may be less than the electrolyte content of negative plate 20 in second region 204, i.e., m / n may be greater than or equal to 50% and less than 100%.

[0073] In some embodiments, the gel polymer electrolyte comprises a polymer substrate, the polymer substrate being obtained by polymerizing a polymer monomer, the polymer monomer comprising a first monomer and a second monomer, the first monomer comprising at least two cross-linking moieties.

[0074] For example, a first monomer can act as a cross-linking agent, and a second monomer can be polymerized to form a polymer chain. Because the first monomer contains at least two cross-linking moieties, the first monomer can not only initiate the polymerization reaction of the second monomer, but also cross-link the polymer chains formed by polymerizing multiple second monomers. That is, the first monomer can be a component of the polymer chain, or it can connect multiple polymer chains as a connecting structure.

[0075] For example, the first monomer may include two cross-linking sites, and the first monomer having double cross-linking sites can effectively improve the cross-linking state of the polymer substrate and effectively enhance the elasticity of the polymer substrate, further improving the elasticity of the gel polymer electrolyte when subjected to pressure, and further reducing the extrusion of the electrolyte in the negative electrode plate 20 under pressure.

[0076] In some embodiments, the crosslinking moiety may include at least one of a double bond, a triple bond, and a cyclic ether.

[0077] In some embodiments, the first monomer may include at least one of an acrylic acid-based monomer, an acrylate-based monomer.

[0078] By way of example, the acrylic acid-based monomer may include at least one of acrylic acid, methacrylic acid, methyl methacrylate, butyl methacrylate, methyl acrylate, ethyl acrylate, hydroxyethyl acrylate, hydroxyethyl methacrylate, butyl acrylate, isodecyl acrylate, isooctyl acrylate, lauryl acrylate, isobornyl acrylate, isobornyl methacrylate, and ethoxyethoxyethyl acrylate.

[0079] Examples of the acrylate monomer include cyanoacrylate, caprolactone acrylate, 2-phenoxyethyl acrylate, tetrahydrofuryl acrylate, ethoxytetrahydrofuran acrylate, cyclotrimethylolpropane acrylate, 2-carboxyethyl acrylate, cyclohexyl acrylate, ethylene glycol diacrylate, ethylene glycol dimethacrylate, propylene glycol dimethacrylate, diethylene glycol diacrylate, diethylene glycol dimethacrylate, triethylene glycol diacrylate, triethylene glycol dimethacrylate, tetraethylene glycol diacrylate, tetraethylene glycol dimethacrylate, 1,4-butanediol diacrylate, 1,4-butanediol dimethacrylate, 1,3-butanediol diacrylate, 1,3-butanediol dimethacrylate, 1,6-hexanediol diacrylate, 1,6-hexanediol dimethacrylate, dipropylene glycol diacrylate, dipropylene glycol dimethacrylate The copolymer may comprise at least one of the following copolymers: acrylate, tripropylene glycol diacrylate, tripropylene glycol dimethacrylate, neopentyl glycol diacrylate, neopentyl glycol dimethacrylate, 2(propoxylated) neopentyl glycol diacrylate, ethylene glycol diacrylate oligomer, ethylene glycol dimethacrylate oligomer, propylene glycol dimethacrylate oligomer, cyclohexyl acrylate oligomer, methoxypolyethylene glycol acrylate, ethoxylated trimethylolpropane triacrylate, trimethylolpropane trimethacrylate, methoxyethylene glycol methacrylate oligomer, pentaerythritol triacrylate, propoxylated glycerin triacrylate, tris(2-hydroxyethyl)isocyanuric acid triacrylate, bis(trimethylolpropane)tetraacrylate, pentaerythritol tetraacrylate, 4(ethoxy)pentaerythritol tetraacrylate, and dipentaerythritol hexaacrylate.

[0080] By way of example, an oligomer refers to a polymer having a number average molecular weight of less than 10,000, and can be obtained by an oligomerization reaction.

[0081] In some examples, the second monomer may include at least one of a carbonate-based monomer, a sulfate-based monomer, a sulfonate-based monomer, a phosphate-based monomer, a carboxylate-based monomer, a sulfone-based monomer, an amide-based monomer, a nitrile-based monomer, and an ether-based monomer.

[0082] In some embodiments, the carbonate-based monomer may include at least one of vinylene carbonate, vinyl ethylene carbonate, ethylene carbonate, propylene carbonate, butylene carbonate, fluoroethylene carbonate, and chloroethylene carbonate; the sulfate-based monomer may include at least one of vinyl vinyl sulfite, vinyl sulfite, 4-methyl vinyl sulfate, and 4-ethyl vinyl sulfate; the sulfonate-based monomer may include at least one of 1,3-propene sultone, 1,3-propane sultone, 1,4-butane sultone, and methane disulfonic acid methylene ring ester; and the phosphate-based monomer may include at least one of dimethyl vinyl phosphate, diethyl vinyl phosphate, diethyl propenyl phosphate, diethyl butenyl phosphate, diethyl 1-buten-2-yl phosphonate, diethyl ethynyl phosphate, vinyl trifluoromethyl phosphate, and vinyl-1-trifluoroethenyl phosphate. The carboxylic acid ester-based monomer may include at least one of methyl vinyl sulfone, ethyl vinyl sulfone, cyclobutene sulfone, sulfolane, and ethylene sulfoxide. The amide-based monomer may include acrylamide. The nitrile-based monomer may include at least one of acrylonitrile, succinonitrile, glutaronitrile, and adiponitrile. The ether-based monomer may include at least one of 1,3-dioxolane, ethylene oxide, 1,2-propylene oxide, 4-methyl-1,3-dioxolane, tetrahydrofuran, 2-methyltetrahydrofuran, 1,4-dioxane, ethylene glycol dimethyl ether, ethylene glycol diglycidyl ether, and triethylene glycol divinyl ether.

[0083] In some embodiments, the mass of the electrolyte is c, the mass of the polymer substrate is b, and c / (c+b) can be 60%-97%. Optionally, c / (c+b) can be 80%-95%.

[0084] The use of a gel polymer electrolyte effectively reduces the problem of uneven electrolyte distribution on the negative electrode plate during the later stages of battery cell use, allowing for better cycle performance with a smaller amount of electrolyte, improving the volumetric energy density of the battery cell, and reducing the occurrence of lithium precipitation. The use of a larger amount of electrolyte allows for better cycle performance with a reduced occurrence of lithium precipitation.

[0085] As examples, c / (c+b) may be 60%, 61%, 62%, 63%, 64%, 65%, 66%, 67%, 68%, 69%, 70%, 71%, 72%, 73%, 74%, 75%, 76%, 77%, 78%, 79%, 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, or 97%.

[0086] In some embodiments, the electrolyte in the gel polymer electrolyte may include a solvent and an inorganic salt.

[0087] By way of example, the solvent in the electrolyte may include at least one of ethyl methyl carbonate, diethyl carbonate, dimethyl carbonate, dipropyl carbonate, methyl propyl carbonate, ethyl propyl carbonate, methyl formate, methyl acetate, ethyl acetate, propyl acetate, methyl propionate, ethyl propionate, propyl propionate, methyl butyrate, ethyl butyrate, 1,4-butyrolactone, dimethyl sulfone, ethyl methyl sulfone, and diethyl sulfone.

[0088] By way of example, the inorganic salt in the electrolyte may include at least one of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium perchlorate, lithium hexafluoroarsenate, lithium bis(fluorosulfonyl)imide, lithium bis(trifluoromethanesulfonyl)imide, lithium trifluoromethylsulfonate, lithium difluorophosphate, lithium difluoro(oxalato)borate, lithium bis(oxalato)borate, lithium difluorobis(oxalato)phosphate, and lithium tetrafluoro(oxalato)phosphate.

[0089] In some embodiments, the battery further includes a case, the case being used to package the electrode assembly and the gel polymer electrolyte, and when the state of charge of the battery cell is less than 5%, the volume of the electrode assembly is V1, the volume of the battery case is V2, and V1 / V2 is less than or equal to 92%.

[0090] By making the volume of the case larger than the volume of the electrode assembly, expansion space for the negative electrode plate 20 can be left inside the battery cell case, reducing expansion deformation of the case due to expansion of the negative electrode plate until the structure is deactivated. By replacing the liquid electrolyte with a gel polymer electrolyte portion, it is possible to effectively reduce the occurrence of the phenomenon in which the electrolyte in the negative electrode plate is extruded under pressure and then deposited in the expansion space left inside the battery cell 5.

[0091] For example, if V1 / V2 is greater than 92%, the expansion space of the battery cell left in the case is too small, and the volume change of the negative electrode plate during the charging and discharging process is directly reflected on the layer surface of the battery cell, which makes it very likely that defects such as swelling of the battery cell will occur.

[0092] For example, the case of the battery cell 5 is used to package components such as the electrode assembly and the electrolyte, etc. The case may be a steel housing, an aluminum housing, a plastic housing (e.g., polypropylene), a composite metal housing (e.g., a copper-aluminum composite case), an aluminum-plastic film, etc.

[0093] For example, the structure of the gel polymer electrolyte is relatively flexible and highly unlikely to explode when subjected to abnormal usage conditions such as overcharging / overdischarging, impact, rolling, and puncture, and can be used to manufacture batteries of various shapes.

[0094] For example, the battery cells may be cylindrical battery cells, prismatic battery cells, pouch battery cells, or other shaped battery cells, and the prismatic battery cells include prismatic case battery cells, blade-shaped battery cells, and polygonal prismatic batteries. The polygonal prismatic batteries may be hexagonal prismatic batteries, etc., and the present application is not particularly limited thereto.

[0095] According to a second aspect of the present application, the present application provides a battery including the aforementioned battery cell 5, whereby the battery has all the features and advantages of the aforementioned battery cell 5, which will not be further described herein.

[0096] A typical battery includes a positive electrode plate 10, a negative electrode plate 20, an electrolyte, and a separator 30. The electrolyte may include the aforementioned gel polymer electrolyte 40. During charging and discharging of the battery, active ions shuttle between the positive electrode plate 10 and the negative electrode plate 20, absorbing and desorbing them. The electrolyte serves to conduct ions between the positive electrode plate 10 and the negative electrode plate 20. The separator 30 is disposed between the positive electrode plate 10 and the negative electrode plate 20 and serves mainly to prevent short-circuiting between the positive and negative electrodes while allowing the active ions to pass through.

[0097] For example, the present application does not particularly limit the shape of the battery, which may be cylindrical, square, or any other shape. For example, FIG. 3 shows an example of a rectangular battery cell 5. Specifically, referring to FIG. 4, the exterior body of the battery cell 5 may include a case 51 and a top cover assembly 53. Here, the case 51 may include a bottom plate and side plates connected to the bottom plate, and the bottom plate and side plates form a surrounding storage cavity. The case 51 has an opening communicating with the storage cavity, and the top cover assembly 53 can be installed to cover the opening to seal the storage cavity.

[0098] For example, the positive electrode plate 10, the negative electrode plate 20, and the separator 30 may be wound or stacked to form an electrode assembly 52. ​​The electrode assembly 52 is packaged in a receiving cavity, and a gel polymer electrolyte fills the internal space of the electrode assembly 52. ​​The number of electrode assemblies 52 included in the battery cell 5 may be one or more, and can be selected by those skilled in the art according to specific actual needs.

[0099] For example, batteries may be assembled into a battery module, and the number of batteries included in the battery module may be one or more, with the specific number being selectable by those skilled in the art depending on the application and capacity of the battery module. FIG. 5 shows an example battery module 4. Referring to FIG. 5, in the battery module 4, a plurality of battery cells 5 may be arranged in sequence along the longitudinal direction of the battery module 4. Of course, any other arrangement may also be used. The plurality of battery cells 5 may also be fastened by fasteners. The battery module 4 may further include a housing having an accommodating space, and the plurality of battery cells 5 are accommodated in the accommodating space.

[0100] For example, the battery modules may be assembled into a battery pack. The battery pack may include one or more battery modules, and the specific number may be selected by those skilled in the art depending on the application and capacity of the battery pack. FIGS. 6 and 7 show an example battery pack 1. Referring to FIGS. 6 and 7, the battery pack 1 may include a battery box and a plurality of battery modules 4 installed in the battery box. The battery box includes an upper housing 2 and a lower housing 3, and the upper housing 2 can be fitted with a lid on the lower housing 3 to form a sealed space for accommodating the battery modules 4. The plurality of battery modules 4 may be arranged in the battery box in any manner.

[0101] According to a third aspect of the present application, the present application provides a power consuming device, comprising a battery cell 5 as described above and / or a battery as described above, whereby the power consuming device has all the features and advantages of the battery cell and battery as described above, which will not be further described herein.

[0102] The battery, battery module, or battery pack may be used as a power source for a power consuming device or as an energy storage unit for the power consuming device. The power consuming device may include, but is not limited to, mobile devices (e.g., mobile phones, laptops, etc.), electric vehicles (e.g., pure electric vehicles, hybrid electric vehicles, plug-in hybrid electric vehicles, electric bicycles, electric scooters, electric golf carts, electric trucks, etc.), electric trains, ships and satellites, energy storage systems, etc. The power consuming device can select a battery, battery module, or battery pack depending on its usage needs.

[0103] For example, Figure 8 illustrates an exemplary power consuming device, such as a pure electric vehicle, a hybrid electric vehicle, or a plug-in hybrid electric vehicle, which may employ a battery pack or battery module to meet the demand for high battery power and high energy density.

[0104] As another example, the power consuming device may be a mobile phone, a tablet computer, a laptop computer, etc. These devices are generally required to be thin and may employ a battery as a power source.

[0105] The present invention will be described and illustrated by specific examples below. The following examples are merely for the purpose of illustrating the present invention and should not be construed as limiting the scope of the present invention. Unless specific techniques or conditions are specified in the examples, they are carried out in accordance with the techniques or conditions described in the literature in the field or in accordance with the product instructions. Unless the manufacturers of the reagents or equipment used are specified, they are all commercially available products.

[0106] Example 1 Positive electrode plate manufacturing: Cathode active material LiNi 0.5 Co 0.2 Mn 0.3 O2, conductive agent carbon black (SuperP), and adhesive polyvinylidene fluoride (PVDF) were uniformly mixed in a mass ratio of 91.6:1.8:6.6 in a solvent N-methylpyrrolidone (NMP) to prepare a positive electrode slurry. The prepared positive electrode slurry was applied to one surface of an aluminum foil current collector at a coating density of 17.66 mg / cm. 2 After drying in an oven, the same weight of positive electrode slurry was applied to the other side of the current collector, which was then dried and cold-pressed to obtain a positive electrode plate.

[0107] Negative electrode plate manufacturing: The negative electrode active material graphite, conductive agent carbon black (SuperP), adhesive styrene butadiene rubber (SBR), and thickener carboxymethyl cellulose sodium (CMC-Na) were mixed in a mass ratio of 95.4:1.5:2.5:0.6 in an appropriate amount of solvent deionized water with sufficient stirring to form a uniform negative electrode slurry. The negative electrode slurry was then uniformly applied to one surface of a copper foil current collector at an application area density of 11.3 mg / cm. 2 After drying in an oven, the same weight of the positive electrode slurry was applied to the other side of the current collector, which was then dried and cold-pressed to obtain a negative electrode plate.

[0108] Battery Assembly: The separator, positive electrode plate, and negative electrode plate are arranged in the order of positive electrode plate, separator, negative electrode plate, and separator, and after the winding process, they are hot pressed at 80°C and 1 MPa pressure, and the size of the electrode assembly is 143*84*25mm (i.e., V1=300.3cm 3 ) and then through tab welding, case insertion, and top cover welding processes, the hard case dry battery core without liquid injection is assembled, where the internal size of the hard case is 145*88*26mm (i.e., V2=331.76cm 3 ) and V1 / V2 is 90.51%. Ethylene carbonate (EC) and ethyl methyl carbonate (EMC) were mixed in a volume ratio of 3:7 to obtain an organic solvent. Lithium hexafluorophosphate (LiPF6) was then dissolved in the organic solvent to obtain electrolyte solution A, where the LiPF6 concentration was 1 mol / L. Next, a gel electrolyte was prepared by mixing electrolyte solution A with a first monomer (ethylene glycol diacrylate oligomer, molecular weight 400), a second monomer (vinyl ethylene carbonate), and an initiator (azobisisobutyronitrile) in a weight ratio of 10:10:79.8:0.2. 110 g of the gel electrolyte was poured into a battery core. The battery core was then evacuated to -20 kPa and held for 10 minutes. After leaving the battery at room temperature for 24 hours, the battery core was charged to 4.0 V at 3 A at 45 °C to form the gel polymer electrolyte. The battery core was then discharged to 2.8 V at 3 A at room temperature to form the gel polymer electrolyte, and a battery was obtained.

[0109] Example 2 Example 2 is identical to Example 1, with the difference being that the first monomer in Example 2 is triethylene glycol diacrylate.

[0110] Example 3 Example 3 is identical to Example 1, except that the first monomer in Example 3 is ethoxylated trimethylolpropane triacrylate.

[0111] Example 4 Example 4 is identical to Example 1, with the difference being that the first monomer in Example 4 is pentaerythritol tetraacrylate.

[0112] Example 5 Example 5 is identical to Example 1, except that the second monomer in Example 5 is diethylpropenyl phosphate.

[0113] Example 6 Example 6 is identical to Example 1, except that the second monomer in Example 6 is triethylene glycol divinyl ether.

[0114] Example 7 Example 7 is identical to Example 1, except that the second monomer in Example 7 is ethyl vinyl sulfone.

[0115] Comparative Example 1 Comparative Example 1 is identical to Example 1, except that a liquid electrolyte is used in Comparative Example 1. Specifically, ethylene carbonate (EC) and ethyl methyl carbonate (EMC) are mixed in a volume ratio of 3:7 to obtain an organic solvent, and then lithium hexafluorophosphate (LiPF6) is dissolved in the organic solvent to obtain an electrolyte, where the concentration of LiPF6 is 1 mol / L. The amount of electrolyte injected is 110 g.

[0116] Comparative Example 2 Comparative Example 2 is identical to Comparative Example 1, except that the injection amount in Comparative Example 2 is 120 g.

[0117] The following tests were carried out on the batteries of Examples 1 to 7 and Comparative Examples 1 and 2, and the test results are shown in Table 1.

[0118] Number of cycles at 90% capacity retention: The battery is cycled once at a 0.33C rate of the design capacity, and the actual capacity C0 is measured, which determines the nominal capacity of the battery. Then, a charge / discharge cycle is performed at a rate of 1C, and the capacity retention C per cycle is calculated. n Record and C n When / C0=90%, the cycle number p is recorded, i.e., the corresponding cycle number at 90% capacity retention.

[0119] Cycle life test: The battery is cycled at a rate of 0.33C of the design capacity, and the actual capacity C0 is measured, which determines the nominal capacity of the battery. Then, a charge / discharge cycle is performed at a rate of 1C, and the capacity developed per cycle C0 is measured. n Record and C n When / C0=80%, the number of cycles q is recorded, i.e., the cycle life of the battery.

[0120] Negative electrode plate heat loss test: When the battery reached 90% capacity retention, the battery was disassembled under the condition that the battery was in a 0% SOC state. The outermost negative electrode plate of the electrode assembly was removed, and small 5mm diameter discs were punched out from the first and second regions of the same electrode plate. The samples were placed on the test sample stand, and the first and second regions were tested using two identical devices (Netzsch synchronous thermal analyzer STA-STA449F3). The test procedure was to heat up to 70°C at a rate of 5°C / min and hold at 70°C for 30 minutes, recording the mass loss (m) in the first region and the mass loss (n) in the second region throughout the process.

[0121] [Table 1]

[0122] In the description of this specification, the reference words "in one embodiment," "in another embodiment," and the like mean that the specific features, structures, materials, or characteristics described in connection with this embodiment are included in at least one embodiment of the present application. In this specification, general expressions using such terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any appropriate manner in any one or more embodiments or examples. Furthermore, if not inconsistent, those skilled in the art may combine and combine different embodiments or examples and features of different embodiments or examples described herein.

[0123] In the description of this specification, the terms "first" and "second" are for descriptive purposes only and should not be understood as indicating or implying the relative importance or the number of technical features being indicated. Although the embodiments of the present application have been shown and described above, it should be understood that the above embodiments are illustrative and should not be understood as limiting the present application, and those skilled in the art may make changes, modifications, substitutions and variations to the above embodiments within the scope of the present application. [Explanation of symbols]

[0124] 1 battery pack, 2 upper housing, 3 lower housing, 4 battery module, 5 battery cell, 10 positive electrode plate, 11 positive electrode current collector, 12 positive electrode active material layer, 20 negative electrode plate, 21 negative electrode current collector, 22 negative electrode active material layer, 30 separator, 40 gel polymer electrolyte, 51 case, 52 electrode assembly, 53 top cover assembly, 201 first end, 202 second end, 203 first region, 204 second region.

Claims

1. A battery cell, an electrode assembly including a positive electrode plate and a negative electrode plate, the negative electrode plate having a length a in a first direction, the negative electrode plate having a first end and a second end, the direction from the first end to the second end being the same as the first direction; a gel polymer electrolyte located between at least the positive electrode plate and the negative electrode plate; Here, when the capacity of the battery cell is 90% or less of the nominal capacity of the battery cell, the area of ​​the negative electrode plate is [Equation 1] a first region is present, and the distance between the first edge and a point in the first region farthest from the first edge is: [Equation 2] A second region is present in the negative electrode plate, the area of ​​the second region is the same as or approximately the same as the area of ​​the first region, and the distance between the second end and a point in the second region farthest from the second end is: [Equation 3] and In a temperature range of 25°C to 180°C, the amount of heat loss of the negative electrode plate located in the first region is m, the amount of heat loss of the negative electrode plate located in the second region is n, and m / n is 50% or more.

2. 2. The battery cell according to claim 1, wherein the m / n is 70%-100%.

3. 3. The battery cell according to claim 1, wherein a first angle exists between the first direction and the second direction, and the first angle is between 70° and 90°.

4. 4. The battery cell of claim 1, wherein the gel polymer electrolyte comprises a polymer substrate and an electrolytic solution, the polymer substrate being obtained by polymerizing a polymer monomer, the polymer monomer comprising a first monomer and a second monomer, and the first monomer comprising at least two cross-linking moieties.

5. The battery cell according to claim 4 , wherein the cross-linked moiety includes at least one of a double bond, a triple bond, and a cyclic ether.

6. The battery cell according to claim 4 or 5, wherein the first monomer includes at least one of an acrylic acid-based monomer and an acrylate-based monomer.

7. The first monomer is the acrylic acid-based monomer includes at least one of acrylic acid, methacrylic acid, methyl methacrylate, butyl methacrylate, methyl acrylate, ethyl acrylate, hydroxyethyl acrylate, hydroxyethyl methacrylate, butyl acrylate, isodecyl acrylate, isooctyl acrylate, lauryl acrylate, isobornyl acrylate, isobornyl methacrylate, and ethoxyethoxyethyl acrylate; Examples of the acrylate monomer include cyanoacrylate, caprolactone acrylate, 2-phenoxyethyl acrylate, tetrahydrofuryl acrylate, ethoxytetrahydrofuran acrylate, cyclotrimethylolpropane acrylate, 2-carboxyethyl acrylate, cyclohexyl acrylate, ethylene glycol diacrylate, ethylene glycol dimethacrylate, propylene glycol dimethacrylate, diethylene glycol diacrylate, diethylene glycol dimethacrylate, triethylene glycol diacrylate, triethylene glycol dimethacrylate, tetraethylene glycol diacrylate, tetraethylene glycol dimethacrylate, 1,4-butanediol diacrylate, 1,4-butanediol dimethacrylate, 1,3-butanediol diacrylate, 1,3-butanediol dimethacrylate, 1,6-hexanediol diacrylate, 1,6-hexanediol dimethacrylate, dipropylene glycol diacrylate, dipropylene glycol dimethacrylate, and tripropylene glycol.

7. The battery cell of claim 6, wherein the polymerizable monomers satisfy one or more of the following conditions: at least one of trimethylolpropane triacrylate, tripropylene glycol dimethacrylate, neopentyl glycol diacrylate, neopentyl glycol dimethacrylate, 2(propoxylated) neopentyl glycol diacrylate, ethylene glycol diacrylate oligomer, ethylene glycol dimethacrylate oligomer, propylene glycol dimethacrylate oligomer, cyclohexyl acrylate oligomer, methoxypolyethylene glycol acrylate, ethoxylated trimethylolpropane triacrylate, trimethylolpropane trimethacrylate, methoxyethylene glycol methacrylate oligomer, pentaerythritol triacrylate, propoxylated glycerin triacrylate, tris(2-hydroxyethyl)isocyanuric acid triacrylate, bis(trimethylolpropane)tetraacrylate, pentaerythritol tetraacrylate, 4(ethoxy)pentaerythritol tetraacrylate, and dipentaerythritol hexaacrylate.

8. 8. The battery cell according to claim 4, wherein the second monomer includes at least one of a carbonate-based monomer, a sulfate-based monomer, a sulfonate-based monomer, a phosphate-based monomer, a carboxylic acid ester-based monomer, a sulfone-based monomer, an amide-based monomer, a nitrile-based monomer, and an ether-based monomer.

9. The second monomer is the carbonate-based monomer includes at least one of vinylene carbonate, vinylethylene carbonate, ethylene carbonate, propylene carbonate, butylene carbonate, fluoroethylene carbonate, and chloroethylene carbonate; the sulfate ester monomer includes at least one of vinyl vinyl sulfite, vinyl sulfite, 4-methyl vinyl sulfate, and 4-ethyl vinyl sulfate; the sulfonate ester monomer contains at least one of 1,3-propene sultone, 1,3-propane sultone, 1,4-butane sultone, and methanedisulfonic acid methylene ring ester; the phosphate ester monomer includes at least one of dimethyl vinyl phosphate, diethyl vinyl phosphate, diethyl propenyl phosphate, diethyl butenyl phosphate, diethyl 1-buten-2-ylphosphonate, diethyl ethynyl phosphate, vinyl trifluoromethyl phosphate, vinyl-1-trifluoroethyl phosphate, diethyl fluorovinyl phosphate, and 1-trifluoropropenylethyl phosphate; the carboxylic acid ester monomer contains vinyl acetate; the sulfone-based monomer includes at least one of methyl vinyl sulfone, ethyl vinyl sulfone, cyclobutene sulfone, sulfolane, and ethylene sulfoxide; the amide-based monomer contains acrylamide; The nitrile monomer includes at least one of acrylonitrile, succinonitrile, glutaronitrile, and adiponitrile; The battery cell according to claim 8, wherein the ether-based monomer contains at least one of 1,3-dioxolane, ethylene oxide, 1,2-propylene oxide, 4-methyl-1,3-dioxolane, tetrahydrofuran, 2-methyltetrahydrofuran, 1,4-dioxane, ethylene glycol dimethyl ether, ethylene glycol diglycidyl ether, and triethylene glycol divinyl ether.

10. 10. The battery cell according to claim 4, wherein the mass of the electrolyte is c, the mass of the polymer substrate is b, and c / (c+b) is 60%-97%.

11. The battery cell according to claim 10, wherein c / (c+b) is 80%-95%.

12. The battery further includes a case, the case being used to package the electrode assembly and the gel polymer electrolyte, and when the state of charge of the battery cell is less than 5%, the volume of the electrode assembly is V １ and the volume of the battery case is V ２ and V １ / V ２ The battery cell according to claim 1 , wherein the % of the total charge is 92% or less.

13. 13. The battery cell of claim 1, wherein the negative electrode plate includes a negative electrode current collector and a negative electrode active material layer located on at least one side of the negative electrode current collector, the negative electrode active material layer including a negative electrode active material, the negative electrode active material including at least one of natural graphite, artificial graphite, soft carbon, hard carbon, a silicon-based material, a tin-based material, and lithium titanate.

14. The negative electrode active material is the silicon-based material includes at least one of silicon elemental material, silicon oxide, silicon carbon composite, silicon nitrogen composite, and silicon alloy material; The battery cell according to claim 13 , wherein the tin-based material satisfies one or more of the following conditions: the tin-based material includes at least one of elemental tin, tin oxide, and tin alloy material.

15. A battery comprising the battery cell of any one of claims 1 to 14.

16. 16. A power consuming device comprising a battery cell according to any one of claims 1 to 14 and / or a battery according to claim 15.

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