Battery, battery module and battery pack

Abstract

The invention discloses a battery, a battery module and a battery pack, and relates to the technical field of batteries, the battery comprises a shell, a cover plate, a battery cell and an insulating film, the distance L from the outer edge, facing the second end, of a reference electrode plate to the outer edge, facing the second end, of the battery cell, the thickness D1 of the insulating film and the elastic modulus E of a diaphragm are adjusted, and the elastic modulus E of the diaphragm is adjusted; the insulating film, the diaphragm and the electrode plate are matched, so that the insulating film and the cover plate are matched, the spacing distance between the insulating film and the cover plate is in a proper range, and the insulating property between the battery cell and the shell is ensured; the spacing distance between the insulating film and the cover plate can avoid the phenomenon that the insulating film is welded through and melted in the welding process due to the fact that the spacing distance between the insulating film and the cover plate is small. The battery module and the battery pack apply the battery and have the beneficial effects of the battery pack.

Description

[0001] This application is a divisional application of the patent application No. 202510408549.2, with the application date of April 2, 2025, and the invention name of "Battery and battery module and battery pack". TECHNICAL FIELD

[0002] The present application relates to the technical field of batteries, in particular to a battery and a battery module and a battery pack. BACKGROUND

[0003] The laminated battery is a kind of lithium ion battery, which assembles the positive electrode sheet, the diaphragm and the negative electrode sheet in order to form a laminated battery cell with a multi-layer structure. Compared with the traditional winding type battery, the laminated battery has higher space utilization and more uniform current distribution, which is suitable for high energy density and high power application scenarios, such as electric vehicles and energy storage systems.

[0004] The diaphragm plays a key role in the laminated battery. In the assembly process of the laminated battery, the diaphragm is usually arranged between the positive electrode sheet and the negative electrode sheet to prevent direct contact between the two and cause short circuit, and the diaphragm is usually wound on the outside of the positive electrode sheet and the negative electrode sheet to prevent the positive electrode sheet and the negative electrode sheet from directly contacting the battery shell.

[0005] The diaphragm wound on the outside of the positive electrode sheet and the negative electrode sheet usually has an insulating tape attached to the end of the diaphragm to make the diaphragm winding compact. However, in different application scenarios, the end of the diaphragm of each battery cell (i.e. the end position of the diaphragm winding) may be distributed on different surfaces. Due to the compact structure of the part of the diaphragm end with the insulating tape and the relatively loose area without the insulating tape, this difference will cause the diaphragm on one side of the battery to have a difference in flatness, which will affect the subsequent coating of the insulating layer. SUMMARY

[0006] The purpose of the present application is to provide a battery and a battery module and a battery pack, which match the insulating film, the diaphragm and the electrode sheet to reduce the influence of the diaphragm on the coating of the insulating film, so as to solve the problem that the diaphragm of the existing battery has a difference in flatness and easily affects the coating of the insulating film.

[0007] In order to achieve the above-mentioned purpose, the technical scheme adopted by the present application is as follows:

[0008] A battery comprises:

[0009] A housing having a first end and a second end arranged oppositely in a first direction, and the housing is provided with a containing cavity, and the first end is provided with an opening communicating the containing cavity with the external environment;

[0010] A cover plate connected to the opening to isolate the containing cavity from the external environment;

[0011] The battery cell comprises a separator and a plurality of electrode sheets, wherein the plurality of electrode sheets are arranged in a stack, and the stacking direction of the plurality of electrode sheets is perpendicular to the first direction to form a discontinuous stack structure; the separator is arranged between two adjacent electrode sheets and covers the outside of the stack structure; and the separator has an end, which is fixed to one side of the battery cell facing the first end.

[0012] An insulating film is arranged on the outside of the battery cell and extends towards the first end, and the insulating film is provided with a notch facing the cover plate to avoid the side of the battery cell provided with the end; and

[0013] In the first direction, the electrode sheet in the outermost layer and close to the second end is taken as a reference electrode sheet, the distance from the outer edge of the reference electrode sheet facing the second end to the outer edge of the battery cell facing the second end is L, the thickness of the insulating film is D1, and the elastic modulus of the separator is E, and the above parameters satisfy:

[0014] 250≤(D1×E) / L≤3000,

[0015] And the distance L satisfies: 3≤L≤200μm, the thickness D1 of the insulating film satisfies: 50≤D1≤150μm, and the elastic modulus E of the separator satisfies: 200≤E≤2000Mpa.

[0016] Based on the above-mentioned battery, the application further provides a battery module, which comprises at least two batteries as described above, and the two batteries are connected in series or in parallel.

[0017] Based on the above-mentioned battery module, the application further provides a battery pack, which comprises a shell and at least two battery modules as described above, and the two battery modules are arranged in the shell and are electrically connected.

[0018] Compared with the prior art, the battery, the battery module and the battery pack provided by the application have the following advantages:

[0019] The battery and the battery pack can match the insulating film, the separator and the electrode sheet by adjusting the distance L from the outer edge of the reference electrode sheet toward the second end to the outer edge of the electrode core toward the second end, the thickness D1 of the insulating film, and the elastic modulus E of the separator, so that the insulating film and the cover plate are matched, the interval distance between the insulating film and the cover plate is in a proper interval, the insulation performance between the electrode core and the shell is ensured, and when the cover plate and the shell are welded, the interval distance between the insulating film and the cover plate can avoid the phenomenon that the insulating film is melted and welded through during welding due to the small interval distance between the insulating film and the cover plate. The battery module and the battery pack of the application apply the above battery and have the beneficial effects of the above battery. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 is a schematic view of the battery in embodiment 1 of the application;

[0021] Figure 2 is a schematic view of the shell in embodiment 1 of the application;

[0022] Figure 3 is a top view of the battery in embodiment 1 of the application;

[0023] Figure 4 is a sectional view of A-A in Figure 3

[0024] Figure 5 is an enlarged view of B in Figure 4

[0025] Figure 6 is an enlarged view of C in Figure 4

[0026] Figure 7 is a schematic view of the stacking structure in embodiment 1 of the application, in which the stacking direction is perpendicular to the first direction;

[0027] Figure 8 is a schematic view of the stacking structure in embodiment 1 of the application, in which the stacking direction is parallel to the first direction;

[0028] Figure 9 is a schematic view of the battery pack in embodiment 2 of the application;

[0029] Figure 10 is a schematic view of the shell in embodiment 2 of the application;

[0030] Figure 11 is a top view of the battery pack in embodiment 2 of the application;

[0031] Figure 12 is a sectional view of D-D in Figure 11

[0032] ​​​​Figure 13 is Figure 12 is an enlarged view of E in FIG. 4;

[0033] Figure 14 is Figure 12 is an enlarged view of F in FIG. 4;

[0034] Figure 15 is a schematic view of a battery pack in which the fixing member is at the rear side in Embodiment 2 of the present application;

[0035] Figure 16 is a schematic view of a battery pack in which the fixing member is at the front side in Embodiment 2 of the present application.

[0036] In the drawings: 100, battery; X, first direction; Y, second direction; Z, third direction; 1, housing; 1a, first end; 1b, second end; 1c, accommodation cavity; 2, cover plate; 3, opening; 4, battery cell; 4a, separator; 4b, electrode sheet; 4b1, positive electrode sheet; 4b2, negative electrode sheet; 5, fixing member; 6, insulating film; 6a, notch; 7, insulating member; 8, barrier member. DETAILED DESCRIPTION

[0037] The specific embodiments of the present application will be further described in conjunction with the drawings and examples. The following examples are used to illustrate the present application, but are not used to limit the scope of the present application.

[0038] In the description of the present application, it is to be understood that when an element is referred to as being "on" or "fixed on" another element, it can be directly on the other element or indirectly on the other element with an intervening element. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or indirectly connected to the other element through an intervening element. The terms "mounting", "connected", and "connected" should be interpreted broadly, for example, can be fixed connection, can also be detachable connection, or integrally connected; can be mechanical connection, can also be electrical connection; can be directly connected, can also be indirectly connected through an intermediate medium, can be the internal communication of two elements or the interaction relationship between two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0039] In the description of the present application, it is to be understood that the orientation or position relationship indicated by the terms "height", "upper", "lower", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like in the present application are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and are not intended to indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0040] In the description of the present application, it should be understood that the terms "first", "second" used in the present application are only for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features defined as "first", "second" can be explicitly or implicitly included one or more of the features.

[0041] Embodiment 1

[0042] With reference to Figures 1-8 The present embodiment provides a battery 100, comprising a shell 1 and a cover plate 2, wherein the shell 1 has a first end 1a and a second end 1b arranged opposite in the length direction, the shell 1 is provided with an opening 3 at the first end 1a, and the shell 1 is provided with a containing cavity 1c, the containing cavity 1c is communicated with the external environment through the opening 3; the cover plate 2 is connected to the opening 3 to isolate the containing cavity 1c from the external environment.

[0043] In the present embodiment, the shell 1 has a first direction X, a second direction Y and a third direction Z perpendicular to each other, wherein the direction of the first end 1a and the second end 1b is the first direction X of the shell 1, i.e. the length direction; the direction of the long side of the opening 3 is the second direction Y of the shell 1, i.e. the left-right direction, and the direction of the short side of the opening 3 is the third direction Z of the shell 1, i.e. the front-back direction.

[0044] The containing cavity 1c is provided with an electrode sheet 4, and the electrode sheet 4 comprises a diaphragm 4a and a plurality of electrode sheets 4b, wherein the plurality of electrode sheets 4b are stacked to form a stacked structure, and the diaphragm 4a is arranged between adjacent two electrode sheets 4b and covers the outside of the stacked structure.

[0045] It can be understood that the electrode sheet 4b of the battery 100 usually comprises two kinds of electrode sheets with opposite polarities, i.e. positive electrode sheet 4b1 and negative electrode sheet 4b2, and the electrode assembly of the battery 100 works by moving metal ions between the positive electrode sheet 4b1 and the negative electrode sheet 4b2. The cycle process of the electrode sheet is the process that the metal ions move from the positive electrode sheet 4b1 to the negative electrode sheet 4b2 and then move from the negative electrode sheet 4b2 to the positive electrode sheet 4b1. Figure 4 In the electrode sheet 4 of the present embodiment, the positive electrode sheet 4b1 and the negative electrode sheet 4b2 are alternately stacked in sequence, i.e. the positive electrode sheet 4b1 and the negative electrode sheet 4b2 are stacked in the order of negative electrode sheet 4b2-positive electrode sheet 4b1-negative electrode sheet 4b2-positive electrode sheet 4b1-negative electrode sheet 4b2, thereby forming a stacked structure, and the negative electrode sheet 4b2 is at the outermost layer of the stacked structure.

[0046] It should be noted that the battery cell 4 of the present embodiment 1 is a stacked battery cell, for example, in the case where the battery cell 4 is a stacked battery cell, a plurality of electrode sheets 4b are stacked to form a discontinuous stacked structure, i.e., any two adjacent positive electrode sheets 4b1 are a discontinuous structure and / or any two adjacent negative electrode sheets 4b2 are a discontinuous structure.

[0047] It can be understood that the shell 1 is used to encapsulate the battery cell and other components such as electrolyte. The shell 1 can be various shapes and various sizes, such as a cuboid, a hexagonal prism, etc. The shape of the shell 1 can be determined according to the specific shape and size of the battery cell. The material of the shell 1 can be various, including but not limited to copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc.

[0048] In each battery cell 4, the separator 4a is arranged between the adjacent two electrode sheets 4b, and is wrapped to the outside of the stacked structure to wrap the outermost electrode sheet 4b. Taking the stacked battery cell as an example, during the assembly process of the battery cell 4, the positive electrode sheet 4b1, the separator 4a and the negative electrode sheet 4b2 are sequentially stacked, wherein the upper surface and the lower surface of the electrode sheet 4b are distinguished by the stacking direction of the electrode sheet 4b, the separator 4a is arranged between the positive electrode sheet 4b1 and the negative electrode sheet 4b2, covering the upper surface and the lower surface of the positive electrode sheet 4b1 and the negative electrode sheet 4b2, thereby separating the adjacent positive electrode sheet 4b1 and the negative electrode sheet 4b2, avoiding direct contact between the adjacent positive electrode sheet 4b1 and the negative electrode sheet 4b2, and the separator 4a is usually a continuous thin film that extends from the inside of the stacked structure to the outside of the stacked structure and wraps the outside of the stacked structure, thereby separating the electrode sheet 4b from the shell 1.

[0049] It should be noted that the separator 4a of the battery 100 is usually a porous insulating material, and the main function is to isolate the positive electrode sheet 4b1 and the negative electrode sheet 4b2 and allow lithium ions to pass through. The separator 4a usually has a tail end (i.e., the end position of the winding of the separator 4a), and the tail end is connected with a fixing member 5 to tension the separator 4a. For example, in some batteries 100, the tail end of the separator 4a is connected with an insulating tape as the fixing member 5, one end of the insulating tape is bonded to the tail end of the separator 4a, and the other end is bonded to other positions of the separator 4a. By pulling the insulating tape, the separator 4a can be tensioned, thereby tightly wrapping the stacked structure.

[0050] Affected by the wrapping method of the separator 4a, the specification size of the separator 4a, the specification size of the battery cell 4, etc., the tail end of the separator 4a of different battery cells 4 can be distributed on different sides of the battery cell 4. For example, in the battery 100 of the present embodiment 1, the tail end of the separator 4a is fixed to one side of the battery cell 4 facing the first end la.

[0051] An insulating film 6 is usually provided between the battery cell 4 and the shell 1 to separate the battery 100 group and the shell 1, and to ensure the safety, reliability and performance stability of the battery 100. Referring toFigure 4 With the example of the laminated battery cell, the insulating film 6 covers the side of the battery cell 4 facing the second end 1b, and the insulating film 6 extends towards the first end 1a to cover the outer circumferential side of the battery cell 4, thereby isolating the battery cell 4 and the shell 1; and the insulating film 6 is provided with a notch 6a facing the cover plate 2 to avoid the side of the battery cell 4 provided with the tail end, so that the insulating film 6 is arranged outside the side provided with the tail end and does not enter the side provided with the tail end, so as not to affect the connection of the battery cell 4 and the pole of the cover plate 2.

[0052] It can be understood that the diaphragm 4a and the insulating film 6 are arranged in the accommodating cavity 1c, and the cooperation between the two will affect the assembly of the battery cell 4 in the shell 1, and further affect the performance of the battery 100.

[0053] In some batteries 100, the cooperation between the diaphragm 4a and the insulating film 6 can be adjusted so that they match each other, for example, in the first direction X, taking the electrode sheet 4b at the outermost layer and close to the second end 1b as a reference electrode sheet, the distance from the outer edge of the reference electrode sheet facing the second end 1b to the outer edge of the battery cell 4 facing the second end 1b is L, the thickness of the insulating film 6 is D1, the elastic modulus of the diaphragm 4a is E, and the above parameters satisfy:

[0054] 250≤(D1×E) / L≤5000. (1)

[0055] For example, the ratio of the distance L from the outer edge of the reference electrode sheet facing the second end 1b to the outer edge of the battery cell 4 facing the second end 1b, the thickness D1 of the insulating film 6, and the elastic modulus E of the diaphragm 4a based on the relationship (1) can be one of 250, 350, 450, 550, 650, 750, 850, 950, 1000, 1500, 2000, 2500, 3000, 3500, 4000, 4500, and 5000.

[0056] It can be understood that the distance L from the outer edge of the reference electrode sheet towards the second end 1b to the outer edge of the battery cell 4 towards the second end 1b, the thickness D1 of the insulating film 6, and the elastic modulus E of the diaphragm 4a reflect the matching structure of the insulating film 6 and the diaphragm 4a. If the distance L from the outer edge of the reference electrode sheet towards the second end 1b to the outer edge of the battery cell 4 towards the second end 1b, the thickness D1 of the insulating film 6, and the elastic modulus E of the diaphragm 4a are too small based on the relationship (1), the insulating film 6 is prone to be welded and melted during the welding process of the shell 1 and the cover plate 2. If the distance L from the outer edge of the reference electrode sheet towards the second end 1b to the outer edge of the battery cell 4 towards the second end 1b, the thickness D1 of the insulating film 6, and the elastic modulus E of the diaphragm 4a are too large based on the relationship (1), the gap between the insulating film 6 and the cover plate 2 is too large, which affects the insulation performance of the battery 100. When the distance L from the outer edge of the reference electrode sheet towards the second end 1b to the outer edge of the battery cell 4 towards the second end 1b, the thickness D1 of the insulating film 6, and the elastic modulus E of the diaphragm 4a satisfy the above relationship (1), the insulating film 6, the diaphragm 4a and the electrode sheet 4b can be matched, so that the insulating film 6 and the cover plate 2 are matched and matched, and the interval distance between the insulating film 6 and the cover plate 2 is within a suitable interval. In this way, the insulation performance between the battery cell 4 and the shell 1 can be ensured, and during the welding of the cover plate 2 and the shell 1, the interval distance between the insulating film 6 and the cover plate 2 can avoid the phenomenon that the insulating film 6 is welded and melted during the welding process due to the small interval distance between the insulating film 6 and the cover plate 2.

[0057] It should be noted that the outermost electrode sheet 4b refers to the electrode sheet 4b that is located at the outermost side in the stacking direction of the electrode sheet 4b in the stacked structure. Referring to Figure 4 In the case where the stacked structure of the battery cell 4 is stacked along the third direction Z, the electrode sheet 4b located at the outermost layer and close to the second end 1b is the negative electrode sheet 4b2 located at the frontmost side and the negative electrode sheet 4b2 located at the rearmost side. Referring to Figure 8 In the case where the stacked structure of the battery cell 4 is stacked along the first direction X, the electrode sheet 4b located at the outermost layer and close to the second end 1b is the negative electrode sheet 4b2 located at the lowermost side.

[0058] It should be noted that the distance L from the side of the reference electrode sheet towards the second end 1b to the side of the corresponding battery cell 4 towards the second end 1b is the thickness of the diaphragm 4a arranged on the side of the reference electrode sheet towards the second end 1b. Of course, in different structures of the battery 100, the diaphragm 4a can be a single-layer structure or a multi-layer structure, so the thickness of the diaphragm 4a is usually the product of the thickness of a single-layer diaphragm and the number of layers of the diaphragm.

[0059] To verify that the structural parameters of the battery 100 provided in this embodiment 1 satisfy the above relationship (1) when the distance L from the outer edge of the reference electrode sheet toward the second end 1b to the outer edge of the battery cell 4 toward the second end 1b, the thickness D1 of the insulating film 6, and the elastic modulus E of the separator 4a match, the insulating film 6 of the battery 100 of this embodiment 1 can ensure good insulation performance and is not easily melted by welding compared to other batteries 100. This embodiment 1 conducted 9 groups of tests, as shown in the following Table 1:

[0060] In Table 1, Test Examples 1 to 9 are tests based on the structure of the battery 100 of this embodiment 1, i.e., the batteries 100 of Test Examples 1 to 15, whose distance L, thickness D1 of the insulating film 6, and elastic modulus E of the separator 4a satisfy the matching relationship of the above relationship (1). Comparative Examples 1 to 4 are other battery structures, i.e., the distance L, thickness D1 of the insulating film, and elastic modulus E of the separator of Comparative Examples 1 to 4 do not satisfy the matching relationship of the above relationship (1).

[0061] The separator welding penetration test method is as follows: according to Table 1, different thicknesses of the insulating film and different elastic moduli of the separator are selected to assemble into a battery cell. Then, the battery cell is placed in a shell, and the cover plate and the shell are welded together using laser welding technology. During welding, the welding power is maintained at 2000W, and the welding speed is set to 50mm / s. After the welding operation is completed, the battery is disassembled, and whether the insulating film is penetrated by welding is checked.

[0062] The insulation performance test method is as follows: according to Table 1, different thicknesses of the insulating film and different elastic moduli of the separator are selected to assemble into a battery cell. Then, the battery cell is placed in a shell, and the cover plate and the shell are sealed by laser welding technology, electrolyte is injected, and formation treatment is performed to finally make a battery. The positive electrode material of the battery is lithium iron phosphate. First, the battery is charged to 3.25V at a current of 1 / 3C, and after standing for 10 minutes, it is discharged to 2.5V at a current of 1 / 3C. After standing for 1 hour, the open circuit voltage is measured and recorded, marked as V1. Then, repeat the above charging and discharging process, stand for 10 minutes, and perform 500 cycles. After completing the cycle, stand for 50 minutes, and measure and record the open circuit voltage again, marked as V2. Finally, calculate the voltage difference after the battery cycle according to the formula ΔV = V1-V2.

[0063] Table 1

[0064]

[0065]

[0066] As shown in Table 1, when the distance L from the outer edge of the reference electrode sheet toward the second end 1b to the outer edge of the battery cell 4 toward the second end 1b, the thickness D1 of the insulating film 6, and the elastic modulus E of the separator 4a satisfy the matching relationship of the above relationship (1), the insulating film 6 not only ensures excellent insulation performance between the battery cell 4 and the case 1, but also does not melt due to welding during welding of the cover plate 2 and the case 1. When the distance L from the outer edge of the reference electrode sheet toward the second end 1b to the outer edge of the battery cell 4 toward the second end 1b, the thickness D1 of the insulating film 6, and the elastic modulus E of the separator 4a do not satisfy the matching relationship of the above relationship (1), the battery can have problems of melting of the insulating film 6 or insufficient insulation performance between the battery cell 1 and the case 1.

[0067] For example, in the present embodiment 1, the distance L from the outer edge of the reference electrode sheet toward the second end 1b to the outer edge of the battery cell 4 toward the second end 1b can satisfy: 3 ≤ L ≤ 200 μm, for example, the distance L can be one of 3 μm, 4 μm, 5 μm, 6 μm, 7 μm, 8 μm, 9 μm, 10 μm, 20 μm, 30 μm, 40 μm, 50 μm, 60 μm, 70 μm, 80 μm, 90 μm, 100 μm, 110 μm, 120 μm, 130 μm, 140 μm, 150 μm, 160 μm, 170 μm, 180 μm, 190 μm, 200 μm.

[0068] For example, in the present embodiment 1, the thickness D1 of the insulating film can satisfy: 50 ≤ D1 ≤ 150 μm, for example, the thickness D1 of the insulating film can be one of 50 μm, 60 μm, 70 μm, 80 μm, 90 μm, 100 μm, 110 μm, 120 μm, 130 μm, 140 μm, 150 μm.

[0069] For example, in the present embodiment 1, the elastic modulus E of the separator 4a can satisfy: 200 ≤ E ≤ 2000 Mpa, for example, the elastic modulus E of the separator 4a can be one of 200 Mpa, 300 Mpa, 400 Mpa, 500 Mpa, 600 Mpa, 700 Mpa, 800 Mpa, 900 Mpa, 1000 Mpa, 1100 Mpa, 1200 Mpa, 1300 Mpa, 1400 Mpa, 1500 Mpa, 1600 Mpa, 1700 Mpa, 1800 Mpa, 1900 Mpa, 2000 Mpa.

[0070] It can be understood that a large amount of heat is generated when the cover plate 2 is welded, and if the insulating film 6 is too close to the cover plate 2, the heat generated by the welding of the cover plate 2 is easy to be transmitted to the insulating film 6, causing the insulating film 6 to shrink due to heat, which is easy to cause the battery cell to be exposed from the insulating film 6, resulting in the risk of the battery cell being overlapped with the shell 1. Therefore, there is usually a certain interval distance between the insulating film 6 and the cover plate 2, that is, there is a certain interval distance between the side of the insulating film 6 facing the cover plate 2 and the side of the cover plate 2 facing the battery cell 4 in the first direction X. In this embodiment, the interval distance is defined as the shortest vertical distance h1 between the insulating film 8 and the cover plate 2 in the first direction X. For example, in the partial battery 100, the shortest vertical distance h1 between the insulating film 8 and the cover plate 2 in the first direction X can satisfy: 0.5≤h1≤5mm, for example, h1 can be one of 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1mm, 1.5mm, 2mm, 2.5mm, 3mm, 3.5mm, 4mm, 4.5mm, 5mm.

[0071] Of course, when the interval distance between the insulating film 6 and the cover plate 2 satisfies h1, the interval distance between the insulating film 6 and the cover plate 2 is more suitable for the battery cell 4, so in this case, taking the electrode sheet 4b in the outermost layer and close to the second end 1b as a reference electrode sheet 4b, the distance L from the outer edge of the reference electrode sheet 4b facing the second end 1b to the outer edge of the battery cell 4 facing the second end 1b, the thickness D1 of the insulating film 6, and the elastic modulus E of the diaphragm 4a can also satisfy:

[0072] 250≤(D1×E) / L≤4000……(2)

[0073] For example, the ratio of the distance L from the outer edge of the reference electrode sheet 4b facing the second end 1b to the outer edge of the battery cell 4 facing the second end 1b, the thickness D1 of the insulating film 6, and the elastic modulus E of the diaphragm 4a based on the relationship (2) can be one of 250, 350, 450, 550, 650, 750, 850, 950, 1000, 1500, 2000, 2500, 3000, 3500, 4000.

[0074] It should be noted that the battery cell 4 arranged in the accommodating cavity 1c has various arrangements, for example, the stacking direction of the plurality of electrode sheets 4b can be parallel to the first direction X. Referring to Figures 1-6 、 Figure 8In the case where the stacking direction of the plurality of electrode sheets 4b is parallel to the first direction X, the parallel stacking of the plurality of electrode sheets 4b can make the insulating film 6 and the separator 4a more easily flat during the stacking process, make the battery cell 4 more easily put into the accommodation cavity 1c, and reduce the degree of folding of the separator near the second end 1b. Therefore, in this case, the distance L from the outer edge of the reference electrode sheet 4b toward the second end 1b to the outer edge of the battery cell 4 toward the second end 1b, the thickness D1 of the insulating film 6, and the elastic modulus E of the separator 4a can satisfy the following relationship:

[0075] 250≤(D1×E) / L≤3000... (3)

[0076] For example, the ratio of the distance L from the outer edge of the reference electrode sheet 4b toward the second end 1b to the outer edge of the battery cell 4 toward the second end 1b, the thickness D1 of the insulating film 6, and the elastic modulus E of the separator 4a can be one of 250, 350, 450, 550, 650, 750, 850, 950, 1000, 1500, 2000, 2500, and 3000 based on the relationship (3).

[0077] Of course, the stacking direction of the plurality of electrode sheets 4b can also be perpendicular to the first direction X. The reference electrode sheet 4b can be the electrode sheet 4b that is the outermost layer and is closest to the second end 1b. Figures 1-6 、 Figure 7 In the case where the stacking direction of the plurality of electrode sheets 4b is perpendicular to the first direction X, the perpendicular stacking of the plurality of electrode sheets 4b can make the insulating film 6 and the separator 4a more evenly stressed during the stacking process, reduce the local stress concentration of the insulating film 6 and the separator 4a, and reduce the size of the housing 1 in the second direction Y or the third direction Z, thereby reducing the welding length of the housing 1 and the cover plate 2, and improving the welding yield of the housing 1 and the cover plate 2. Therefore, in this case, the distance L from the outer edge of the reference electrode sheet 4b toward the second end 1b to the outer edge of the battery cell 4 toward the second end 1b, the thickness D1 of the insulating film 6, and the elastic modulus E of the separator 4a can satisfy the following relationship:

[0078] 1200≤(D1×E) / L≤5000... (4)

[0079] For example, the ratio of the distance L from the outer edge of the reference electrode sheet 4b toward the second end 1b to the outer edge of the battery cell 4 toward the second end 1b, the thickness D1 of the insulating film 6, and the elastic modulus E of the separator 4a can be one of 1200, 1300, 1400, 1500, 2000, 2500, 3000, 3500, 4000, 4500, and 5000 based on the relationship (4).

[0080] The reference electrode sheet 4b can be the electrode sheet 4b that is the outermost layer and is closest to the second end 1b. Figures 1-8In some embodiments, an insulating member 7 is arranged between the cell 4 and the cover plate 2 to isolate the electrical connection components in the housing 1 from the cover plate 2, thereby reducing the risk of short circuit. The insulating member 7 can be made of plastic, rubber, or the like. The thickness of the insulating member 7 can affect its insulating performance. In some embodiments, the thickness D2 of the insulating member 7 can satisfy 0.5≤D2≤5mm. For example, the thickness D2 of the insulating member 7 can be 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1mm, 1.5mm, 2mm, 2.5mm, 3mm, 3.5mm, 4mm, 4.5mm, or 5mm.

[0081] The thickness D2 of the insulating member 7 can satisfy 0.5≤D2≤5mm, which can ensure the insulating performance of the insulating member 7, thereby improving the insulation effect between the cell 4 and the cover plate 2 and increasing the spacing distance between the insulating film 6 and the cover plate 2. In this case, the distance L from the outer edge of the reference electrode tab 4b toward the second end 1b to the outer edge of the cell 4 toward the second end 1b, the thickness D1 of the insulating film 6, and the elastic modulus E of the separator 4a can satisfy:

[0082] 250≤(D1×E) / L≤2500. (5)

[0083] For example, the ratio of the distance L from the outer edge of the reference electrode tab 4b toward the second end 1b to the outer edge of the cell 4 toward the second end 1b, the thickness D1 of the insulating film 6, and the elastic modulus E of the separator 4a can be 250, 350, 450, 550, 650, 750, 850, 950, 1000, 1500, 2000, or 2500.

[0084] Reference Figures 1-8 In some embodiments, a barrier member 8 is arranged between the cell 4 and the housing 1 to isolate the housing 1 from the cell 4, thereby reducing the risk of short circuit. The barrier member 8 can be arranged between the side of the cell 4 facing the second end 1b and the housing 1 and can be made of plastic, rubber, or the like.

[0085] It can be understood that the thickness of the barrier member 8 can affect its insulating performance. In some embodiments, the thickness D3 of the barrier member 8 can satisfy 0.5≤D3≤3mm. For example, the thickness D3 of the barrier member 8 can be 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1mm, 1.5mm, 2mm, 2.5mm, or 3mm.

[0086] The thickness D3 of the barrier piece 8 satisfies 0.5≤D3≤3mm, which can ensure the insulation performance of the barrier piece 8 and ensure that the barrier piece 8 can support the battery cell 4 and reduce the influence of the R corner of the shell 1 on the battery cell 4. In this case, the distance L from the outer edge of the reference electrode sheet 4b toward the second end 1b to the outer edge of the battery cell 4 toward the second end 1b, the thickness D1 of the insulation film 6, and the elastic modulus E of the diaphragm 4a can also satisfy:

[0087] 1800≤(D1×E) / L≤2500……(6)

[0088] For example, the ratio of the distance L from the outer edge of the reference electrode sheet 4b toward the second end 1b to the outer edge of the battery cell 4 toward the second end 1b, the thickness D1 of the insulation film 6, and the elastic modulus E of the diaphragm 4a based on the relationship (6) can be one of 1800, 1900, 2000, 2100, 2200, 2300, 2400, and 2500.

[0089] Based on the above-mentioned battery 100, the present embodiment 1 further provides a battery module, which comprises at least two of any one of the above-mentioned batteries 100, and the two batteries are connected in series or in parallel to achieve electrical connection.

[0090] Based on the above-mentioned battery module, the present embodiment 1 further provides a battery pack, which comprises a shell and at least two of the above-mentioned battery modules, and the two battery modules are arranged in the shell and are electrically connected.

[0091] Embodiment 2

[0092] Reference Figures 9-16 The present embodiment 2 provides a battery 100, which comprises a shell 1 and a cover plate 2, wherein the shell 1 has a first end 1a and a second end 1b arranged opposite in the length direction, the shell 1 is provided with an opening 3 at the first end 1a, and the shell 1 is provided with a containing cavity 1c; the cover plate 2 is connected to the opening 3 to isolate the containing cavity 1c from the external environment.

[0093] In the present embodiment 2, the shell 1 has a first direction X, a second direction Y, and a third direction Z perpendicular to each other, wherein the direction of the first end 1a and the second end 1b is the first direction X of the shell 1, i.e. the length direction; the direction of the long side of the opening 3 is the second direction Y of the shell 1, i.e. the left-right direction, and the direction of the short side of the opening 3 is the third direction Z of the shell 1, i.e. the front-back direction.

[0094] The accommodating cavity 1c is provided with an electrode assembly. In this embodiment 2, the electrode assembly includes two electrode cores 4, each of which includes a diaphragm 4a and a plurality of electrode sheets 4b, wherein the plurality of electrode sheets 4b are stacked to form a stacked structure, and two adjacent electrode cores are arranged along the stacking direction of the stacked structure.

[0095] It can be understood that the electrode sheet 4b of the battery generally includes two kinds of electrode sheets with opposite polarities, i.e., a positive electrode sheet 4b1 and a negative electrode sheet 4b2, and the electrode assembly of the battery works by moving metal ions between the positive electrode sheet 4b1 and the negative electrode sheet 4b2. The cycle process of the electrode core is the process of moving the metal ions from the positive electrode sheet 4b1 to the negative electrode sheet 4b2 and then from the negative electrode sheet 4b2 to the positive electrode sheet 4b1. Referring to Figures 9-16 In the electrode core 4 of this embodiment 2, the positive electrode sheet 4b1 and the negative electrode sheet 4b2 are alternately and sequentially stacked, i.e., the positive electrode sheet 4b1 and the negative electrode sheet 4b2 are sequentially stacked in the order of negative electrode sheet 4b2-positive electrode sheet 4b1-negative electrode sheet 4b2-positive electrode sheet 4b1-negative electrode sheet 4b2, thereby forming a stacked structure, and the negative electrode sheet 4b2 is at the outermost layer of the stacked structure.

[0096] It should be noted that the electrode core 4 of this embodiment 2 is a stacked electrode core, and the shell 1 is used to package the electrode core and electrolyte and other components. The shell 1 can be of various shapes and sizes, such as a cuboid, a hexagonal prism, etc., and the shape of the shell 1 can be determined according to the specific shape and size of the electrode core. The material of the shell 1 can be various, including but not limited to copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc.

[0097] In each electrode core 4, the diaphragm 4a is arranged between two adjacent electrode sheets 4b and is wound on the outside of the stacked structure along the stacking direction of the electrode sheet 4b to cover the outermost electrode sheet 4b. Specifically, during the assembly of the battery 100, the positive electrode sheet 4b1, the diaphragm 4a, and the negative electrode sheet 4b2 will be sequentially stacked, wherein the upper surface and the lower surface of the electrode sheet 4b are distinguished according to the stacking direction of the electrode sheet 4b, the diaphragm 4a is arranged between the positive electrode sheet 4b1 and the negative electrode sheet 4b2, covering the upper surface and the lower surface of the positive electrode sheet 4b1 and the negative electrode sheet 4b2, thereby separating the adjacent positive electrode sheet 4b1 and the negative electrode sheet 4b2, avoiding direct contact between the adjacent positive electrode sheet 4b1 and the negative electrode sheet 4b2, and the diaphragm 4a is usually a continuous and thin film that extends from the inside of the stacked structure to the outside of the stacked structure and covers the outside of the stacked structure, thereby separating the electrode sheet 4b from the shell 1.

[0098] It should be noted that the separator 4a of the battery is usually a porous insulating material, and its main function is to isolate the positive electrode sheet 4b1 and the negative electrode sheet 4b2 and allow lithium ions to pass through. The end of the separator 4a (i.e. the end position of the winding of the separator 4a) usually needs to be connected to the fixing member 5 to tension the separator 4a. For example, in some batteries, the end of the separator 4a is connected to an insulating tape as the fixing member 5, one end of the insulating tape is bonded to the end of the separator 4a, and the other end is bonded to another position of the separator 4a. By pulling the insulating tape, the separator 4a can be tensioned to tightly wrap the layer structure.

[0099] An insulating film 6, such as an insulating film, is usually provided between the battery 100 and the housing 1 to separate the battery 100 and the housing 1, and to ensure the safety, reliability and performance stability of the battery. Referring to Figures 9-16 , the insulating film 6 wraps the side of the two battery cells facing the second end 1b, and the insulating film 6 extends towards the first end 1a to wrap the outer peripheral side of the two battery cells, thereby isolating the battery cells and the housing 1; and the insulating film 6 is arranged outside the end side of the two battery cells facing the first end 1a and does not enter the end side of the two battery cells facing the first end 1a, so as not to affect the connection of the pole of the battery 100 and the cover plate 2.

[0100] It can be understood that the separator 4a of each battery cell of the battery 100 has its own end, and under the cooperation of the fixing member 5, the tension of the end of the separator 4a is usually better than that of other positions of the separator 4a. In this way, in the case that the ends of the separators 4a of the two battery cells are arranged on different sides of the layer structure, the flatness of the separator 4a on one side of the same battery 100 will be different. For this purpose, referring to Figures 9-16 , in the case that the ends of the separators 4a of the two battery cells are arranged on different sides of the layer structure, and in the case that the end of the separator 4a of one battery cell is fixed to the side of the battery cell 4 facing the first end 1a, the battery 100 of the present embodiment 2 takes the electrode sheet 4b closest to the outer peripheral side of the housing 1 as the reference electrode sheet in the first direction X, the distance from the outer edge of the reference electrode sheet facing the second end 1b to the outer edge of the battery cell 4 facing the second end 1b is L, the thickness of the insulating film 6 is D1, and the elastic modulus of the separator 4a is E. Then the above parameters satisfy:

[0101] 250≤(D1×E) / L≤4000. ……(7)

[0102] For example, the ratio of the distance L from the outer edge of the reference electrode tab toward the second end 1b to the outer edge of the battery cell 4 toward the second end 1b, the thickness D1 of the insulating film 6, and the elastic modulus E of the separator 4a can be one of 250, 350, 450, 550, 650, 750, 850, 950, 1000, 1500, 2000, 2500, 3000, 3500, 4000, 4500, and 5000 based on the relationship of formula (7).

[0103] It can be understood that the distance L from the outer edge of the reference electrode tab toward the second end 1b to the outer edge of the battery cell 4 toward the second end 1b, the thickness D1 of the insulating film 6, and the elastic modulus E of the separator 4a reflect the matching structure of the insulating film 6 and the separator 4a. If the distance L from the outer edge of the reference electrode tab toward the second end 1b to the outer edge of the battery cell 4 toward the second end 1b, the thickness D1 of the insulating film 6, and the elastic modulus E of the separator 4a are too small based on the relationship of formula (7), the insulating film 6 is prone to be welded and melted during the welding of the shell 1 and the cover plate 2. If the distance L from the outer edge of the reference electrode tab toward the second end 1b to the outer edge of the battery cell 4 toward the second end 1b, the thickness D1 of the insulating film 6, and the elastic modulus E of the separator 4a are too large based on the relationship of formula (7), the gap between the insulating film 6 and the cover plate 2 is prone to be too large, which affects the insulation performance of the battery. When the distance L from the outer edge of the reference electrode tab toward the second end 1b to the outer edge of the battery cell 4 toward the second end 1b, the thickness D1 of the insulating film 6, and the elastic modulus E of the separator 4a satisfy the above relationship of formula (7), the insulating film 6, the separator 4a, and the electrode tab 4b are matched, so that the insulating film 6 and the cover plate 2 are matched and matched, and the interval distance between the insulating film 6 and the cover plate 2 is within a proper interval. In this way, the insulation performance between the battery cell 4 and the shell 1 is ensured, and during the welding of the cover plate 2 and the shell 1, the interval distance between the insulating film 6 and the cover plate 2 can avoid the phenomenon that the insulating film 6 is welded and melted during the welding process due to the small interval distance between the insulating film 6 and the cover plate 2.

[0104] It should be noted that in the battery 100, the two battery cells 4 are arranged along the stacking direction of the stacking structure, so in the battery 100 of the present embodiment 2, the electrode tab 4b in the outermost layer and close to the outer peripheral side of the shell 1 is the negative electrode tab 4b2 in the frontmost side in the battery cell 4 on the front side, and the negative electrode tab 4b2 in the rearmost side in the battery cell 4 on the rear side.

[0105] It should be noted that the distance L between the outer edge of the reference electrode sheet facing the second end 1b and the outer edge of the battery cell 4 facing the second end 1b is the thickness of the separator 4a disposed on the side of the reference electrode sheet 4b facing the second end 1b. Of course, in different battery structures, the separator 4a can be a single-layer structure or a multi-layer structure. Therefore, the thickness of the separator 4a is generally the product of the thickness of the single-layer separator and the number of separator layers.

[0106] It should be noted that, while the tail end of the diaphragm 4a of one battery cell is fixed to the side of the battery cell 4 facing the first end 1a, there are multiple possibilities for arranging the tail end of the diaphragm 4a of the other battery cell of the present battery 100. For example, the tail end of the diaphragm 4a of one battery cell 4 is arranged on the side of the battery cell facing the second end 1b, or, in the arrangement direction of the two battery cells 4, the tail end of the diaphragm 4a of one battery cell 4 is arranged on either side of the battery cells 4 in the arrangement direction, that is, the tail end of the diaphragm 4a of one battery cell 4 is arranged on the opposite side of two adjacent battery cells, or, the tail end of the diaphragm 4a of one battery cell 4 is arranged on the side of the battery cell facing the outer periphery of the housing 1. Below, this embodiment 2 describes the two arrangements respectively.

[0107] refer to Figures 9-16 ,exist Figure 12 In the cell group shown, the cell 4 on the front side is the first cell, and the cell 4 on the rear side is the second cell. When the tail end of the diaphragm 4a of a cell is arranged on the side of the cell facing the second end 1b, that is, the tail end of the diaphragm 4a of the first cell is arranged on the lower side of the stacked structure, and the tail end of the diaphragm 4a of the second cell is arranged on the upper side of the stacked structure, at this time, the fixing part 5 of the second cell is also arranged on the upper side, the diaphragm 4a is relatively tight on the upper side of the second cell, and relatively loose on the lower side, rear side and front side of the second cell, and the insulating film 6 covers the lower side and rear side of the second cell. In this case, in the first direction X, the electrode sheet 4b in the outermost layer and close to the outer peripheral side of the shell 1 is the reference electrode sheet, the distance from the outer edge of the reference electrode sheet facing the second end 1b to the outer edge of the cell 4 facing the second end 1b is L, the thickness of the insulating film 6 is D1, and the elastic modulus of the diaphragm 4a is E, then the above parameters meet:

[0108] 250≤(D1×E) / L≤3000. ……(8)

[0109] For example, the ratio of the distance L from the outer edge of the reference electrode sheet toward the second end 1b to the outer edge of the battery cell 4 toward the second end 1b, the thickness D1 of the insulating film 6, and the elastic modulus E of the diaphragm 4a based on the relationship (8) can be one of 250, 350, 450, 550, 650, 750, 850, 950, 1000, 1500, 2000, 2500, and 3000.

[0110] Reference Figures 9-16 In the case where the end of the separator 4a of one battery cell 4 is arranged on either side of the battery cell 4 in the arrangement direction, there are cases where the end of the separator 4a of one battery cell is arranged on the side of the battery cell facing the outer periphery of the case 1, i.e., the end of the separator 4a of the first battery cell is arranged on the lower side of the stacked structure, and the end of the separator 4a of the second battery cell is arranged on the rear side of the stacked structure, and cases where the end of the separator 4a of one battery cell is arranged on the opposite side of the adjacent two battery cells, i.e., the end of the separator 4a of the first battery cell is arranged on the lower side of the stacked structure, and the end of the separator 4a of the second battery cell is arranged on the front side of the stacked structure.

[0111] In both cases, the fixing member 5 of the second battery cell is arranged on the rear side or the front side, and accordingly, the separator 4a is tight on the rear side or the front side of the second battery cell and loose on the other side of the second battery cell, and the insulating film 6 covers the lower side and the rear side of the second battery cell, so that in the cooperation of the second battery cell and the insulating film 6, the adhesion of the insulating film 6 to the second battery cell is easier on the side of the second battery cell where the constraint of the separator 4a is weaker, and thus, in the first direction X, with the electrode tab 4b on the outermost layer and close to the outer periphery of the case 1 as the reference electrode tab, the distance from the outer edge of the reference electrode tab toward the second end 1b to the outer edge of the battery cell 4 toward the second end 1b is L, the thickness of the insulating film 6 is D1, and the elastic modulus of the separator 4a is E, the above parameters satisfy:

[0112] 250≤(D1×E) / L≤3000.... (9)

[0113] For example, the ratio of the distance L from the outer edge of the reference electrode tab toward the second end 1b to the outer edge of the battery cell 4 toward the second end 1b, the thickness D1 of the insulating film 6, and the elastic modulus E of the separator 4a based on the relationship (9) can be one of 250, 350, 450, 550, 650, 750, 850, 950, 1000, 1500, 2000, 2500, and 3000.

[0114] It should be noted that, in the battery 100 of the present embodiment 2, two adjacent battery cells are arranged along the stacking direction of the stacked structure, i.e., two adjacent battery cells are arranged along the front-rear direction, and the separator 4a of the present embodiment 2 is arranged between two adjacent electrode sheets 4b and is wound outside the stacked structure along the stacking direction of the electrode sheets 4b, i.e., the separator 4a of the present embodiment 2 is wound outside the stacked structure along the front-rear direction. Therefore, even in the case where the end of the separator 4a of a battery cell is arranged on the side surface of the battery cell facing the outer circumferential side of the shell 1, the end of the separator 4a of the battery cell will only be arranged toward the rear side of the shell 1, and will not be arranged toward the left side or the right side of the shell 1. Of course, in other battery structures, if two adjacent battery cells are arranged along the left-right direction, the end of the separator 4a of the battery cell will be arranged toward the left side or the right side of the shell 1, and will not be arranged toward the front side or the rear side of the shell 1.

[0115] It can be understood that the thickness of the separator 4a will affect its rigidity. The thicker the separator 4a, the higher the rigidity, the greater the resilience when the separator 4a is bent, and it is difficult to closely fit the electrode sheet 4b. In addition, when the thickness of the separator 4a is large, the separator 4a is prone to wrinkles during winding, resulting in a loose winding structure. Of course, the thickness of the separator 4a will also increase its insulation performance to avoid the overlap of the battery cell 4 and the shell 1. Considering the insulation cooperation between the shell 1 and the battery cell 4, the thickness of the separator 4a wound on the stacked structure needs to be controlled. For example, in the arrangement direction of the two battery cells 4, at least one battery cell 4 satisfies: the distance between the outer edge of the electrode sheet 4b close to the shell 1 and the outer edge of the corresponding battery cell 4 is S1, and the distance between the outer edge of the electrode sheet 4b close to the adjacent side of the two battery cells 4 and the outer edge of the corresponding battery cell 4 is S2, and S1>S2, i.e., the thickness of the separator 4a on the front side of the first battery cell is greater than the thickness of the separator 4a on the rear side of the first battery cell, and the thickness of the separator 4a on the rear side of the second battery cell is greater than the thickness of the separator 4a on the front side of the second battery cell, to ensure good insulation performance between the shell 1 and the battery cell 4.

[0116] Of course, in the above case, the distance S1 between the outer edge of the electrode sheet 4b close to the shell 1 and the outer edge of the corresponding battery cell 4, and the distance S2 between the outer edge of the electrode sheet 4b close to the adjacent side of the two battery cells 4 and the outer edge of the corresponding battery cell 4 will affect the assembly cooperation of the separator 4a and the electrode sheet 4b, so the mutual cooperation between the insulating film 6 and the separator 4a needs to be adjusted accordingly. For example, in the first direction X, taking the electrode sheet 4b in the outermost layer and close to the outer circumferential side of the shell 1 as a reference electrode sheet, the distance from the outer edge of the reference electrode sheet toward the second end 1b to the outer edge of the battery cell 4 toward the second end 1b is L, the thickness of the insulating film 6 is D1, and the elastic modulus of the separator 4a is E. The above parameters can satisfy:

[0117] 800≤(D1×E) / L≤3500. (10)

[0118] For example, the ratio of the distance L from the outer edge of the reference electrode tab 4b toward the second end 1b to the outer edge of the electrode core 4 toward the second end 1b, the thickness D1 of the insulating film 6, and the elastic modulus E of the separator 4a can be one of 800, 850, 900, 950, 1000, 1500, 2000, 2500, 3000, and 3500 based on the ratio of the relationship (10).

[0119] In summary, the battery 100 of the present embodiment can match the insulating film 6, the separator 4a, and the electrode tab 4b by adjusting the distance L from the outer edge of the reference electrode tab 4b toward the second end 1b to the outer edge of the electrode core 4 toward the second end 1b, the thickness D1 of the insulating film 6, and the elastic modulus E of the separator 4a, so that the insulating film 6 and the cover plate 2 form a matching fit, and the spacing distance between the insulating film 6 and the cover plate 2 is within a suitable range. In this way, the insulating performance between the electrode core 4 and the shell 1 can be ensured, and when the cover plate 2 and the shell 1 are welded, the spacing distance between the insulating film 6 and the cover plate 2 can avoid the phenomenon that the insulating film 6 is melted and welded through during welding due to the small spacing distance between the insulating film 6 and the cover plate 2. The battery module and the battery pack of the present application use the above-mentioned battery 100 and have the beneficial effects of the above-mentioned battery 100.

[0120] The above description is only the preferred embodiments of the present application, and it should be noted that those skilled in the art can make several improvements and replacements without departing from the technical principles of the present application, and these improvements and replacements should also be considered as the protection scope of the present application.

Claims

1. A battery, characterized in that: include: a housing having a first end and a second end opposite to each other in a first direction, wherein the housing is provided with a receiving cavity, and the first end is provided with an opening connecting the receiving cavity with the external environment; a cover plate connected to the opening to isolate the accommodating cavity from the external environment; A battery cell comprising a separator and a plurality of electrode sheets, wherein the plurality of electrode sheets are stacked and the stacking direction of the plurality of electrode sheets is perpendicular to the first direction to form a non-continuous stacking structure; the separator is disposed between two adjacent electrode sheets and covers the outer side of the stacking structure; and the separator has a tail end, which is fixed to the side of the battery cell facing the first end; an insulating film covering the outer side of the battery cell and extending toward the first end, wherein the insulating film is provided with a notch toward the cover plate to avoid the side of the battery cell provided with the tail end; and In the first direction, the electrode sheet in the outermost layer and close to the second end is used as the reference electrode sheet, the distance from the outer edge of the reference electrode sheet facing the second end to the outer edge of the battery cell facing the second end is L, the thickness of the insulating film is D1, and the elastic modulus of the diaphragm is E, then the above parameters satisfy: 250≤(D1×E) / L≤3000, Furthermore, the distance L satisfies: 3≤L≤200 μm, the thickness D1 of the insulating film satisfies: 50≤D1≤150 μm, and the elastic modulus E of the diaphragm satisfies: 200≤E≤2000 MPa.

2. The battery according to claim 1, characterized in that In the first direction, the shortest vertical distance between the insulating film and the cover plate is h1, 0.5≤h1≤5mm, and the distance L, the insulating film thickness D1, and the diaphragm elastic modulus E satisfy: 250≤(D1×E) / L≤4000.

3. The battery according to claim 1, characterized in that An insulating member is provided between the battery cell and the cover plate, and the thickness of the insulating member is D2, and the thickness D2 of the insulating member satisfies: 0.5≤D2≤5mm, and the distance L, the thickness D1 of the insulating film, and the elastic modulus E of the diaphragm satisfy: 250≤(D1×E) / L≤2500.

4. The battery according to claim 1, characterized in that The battery further comprises: A barrier is provided between the side of the battery cell facing the second end and the shell, and the thickness of the barrier is D3, and the thickness D3 of the barrier satisfies: 0.5≤D3≤3mm, and the distance L, the thickness D1 of the insulating film, and the elastic modulus E of the diaphragm satisfy: 1800≤(D1×E) / L≤2500.

5. The battery according to claim 1, characterized in that The number of the battery cells is at least two, the two battery cells are disposed in the accommodating cavity, and the two adjacent battery cells are arranged in a direction perpendicular to the first direction; and the tail ends of the two battery cells are disposed on different sides of the stacked structure, and the tail end of at least one battery cell is fixed to a side of the battery cell facing the first end; and In the first direction, the electrode sheet in the outermost layer and close to the outer peripheral side of the shell is used as the reference electrode sheet, the distance from the outer edge of the reference electrode sheet facing the second end to the outer edge of the battery cell facing the second end is L, the thickness of the insulating film is D1, and the elastic modulus of the diaphragm is E, then the above parameters satisfy: 250≤(D1×E) / L≤4000.

6. The battery according to claim 5, characterized in that The tail end of one of the battery cells is arranged on the side of the battery cell facing the second end, and the distance L, the thickness D1 of the insulating film, and the elastic modulus E of the diaphragm satisfy: 250≤(D1×E) / L≤3000.

7. The battery according to claim 5, characterized in that In the arrangement direction of the two battery cells, the tail end of one battery cell is arranged on any side of the battery cell in the arrangement direction, and the distance L, the thickness D1 of the insulating film, and the elastic modulus E of the diaphragm satisfy: 250≤(D1×E) / L≤3500.

8. The battery according to claim 5, characterized in that In the arrangement direction of the two battery cells, at least one of the battery cells meets the following requirements: The distance between the outer edge of the electrode sheet close to one side of the shell and the outer edge of the corresponding battery cell is S1, the distance between the outer edge of the electrode sheet close to the adjacent side of two battery cells and the outer edge of the corresponding battery cell is S2, and S1>S2; and The distance L, the insulating film thickness D1, and the diaphragm elastic modulus E satisfy: 800≤(D1×E) / L≤3500.

9. A battery module, characterized in that: The method comprises at least two batteries according to any one of claims 1 to 4, wherein the two batteries are electrically connected in series or in parallel.

10. A battery pack, characterized in that: The invention comprises a housing and at least two battery modules according to claim 9, wherein the two battery modules are arranged in the housing and are electrically connected.

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