A battery and a battery module, a battery pack

Abstract

The application discloses a battery and a battery module and a battery pack, and relates to the technical field of batteries, which comprises a shell, a cover plate, a battery cell and an insulating film. By adjusting the distance L from the outer edge of the reference electrode sheet towards the second end to the outer edge of the battery cell towards the second end, the thickness D1 of the insulating film and the elastic modulus E of the diaphragm, the insulating film, the diaphragm and the electrode sheet are matched, so that the insulating film and the cover plate form a matching fit, and the interval distance between the insulating film and the cover plate is within a suitable interval, the insulation performance between the battery cell 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 welded and melted in the welding process due to the small interval distance between the insulating film and the cover plate. The battery module and the battery pack apply the above battery and have the beneficial effects of the above battery pack.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of batteries, in particular to a battery and a battery module and a battery pack. BACKGROUND

[0002] A laminated battery is a kind of lithium ion battery, which assembles positive electrode sheets, separators and negative electrode sheets in sequence to form a laminated cell with a multi-layer structure. Compared with traditional wound batteries, laminated batteries have higher space utilization and more uniform current distribution, and are suitable for high energy density and high power application scenarios such as electric vehicles and energy storage systems.

[0003] The separator plays a key role in the laminated battery. In the assembly process of the laminated battery, the separator 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 separator 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.

[0004] The separator 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 separator to make the separator winding compact. However, in different application scenarios, the end of the separator of each cell (i.e. the end position of the separator winding) may be distributed on different surfaces. Due to the compact structure of the part of the separator end where the insulating tape is attached and the relatively loose area where the insulating tape is not attached, this difference will cause the flatness difference of the separator on one side of the battery, which will further affect the subsequent coating of the insulating layer. SUMMARY

[0005] 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 separator and the electrode sheet to reduce the influence of the separator on the coating of the insulating film, so as to solve the problem that the flatness difference of the separator of the existing battery easily affects the coating of the insulating film.

[0006] In order to achieve the above-mentioned purpose, the present application adopts the following technical solutions:

[0007] A battery comprises:

[0008] 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;

[0009] A cover plate connected to the opening to isolate the containing cavity from the external environment;

[0010] An electrode sheet, comprising a separator and a plurality of electrode sheets, wherein the plurality of electrode sheets are arranged in layers to form a discontinuous laminated structure; the separator is arranged between two adjacent electrode sheets and coated to the outside of the laminated structure; and the separator has an end, which is fixed to one side of the electrode sheet facing the first end;

[0011] An insulating film, covering the outer side of the battery cell and extending towards the first end, has a notch facing the cover plate to avoid the side of the battery cell with the terminal end; and...

[0012] In the first direction, taking the outermost electrode sheet as the reference electrode sheet, the distance from the outer edge of the reference electrode sheet towards the second end to the outer edge of the cell towards the second end is L, the thickness of the insulating film is D1, and the elastic modulus of the separator is E. Then the above parameters satisfy:

[0013] 250≤(D1×E) / L≤5000.

[0014] Based on the aforementioned battery, this application also provides a battery module comprising at least two of the aforementioned batteries, wherein the two batteries are electrically connected by being connected in series or in parallel.

[0015] Based on the above-mentioned battery module, this application also provides a battery pack, which includes a housing and at least two of the aforementioned battery modules, wherein the two battery modules are disposed within the housing and are electrically connected.

[0016] Compared with the prior art, the battery, battery module, and battery pack of this invention have the following advantages:

[0017] This battery and battery pack, by adjusting the distance L from the outer edge of the reference electrode sheet facing the second end to the outer edge of the cell facing the second end, the thickness D1 of the insulating film, and the elastic modulus E of the separator, can match the insulating film, separator, and electrode sheet. This allows the insulating film to form a matching fit with the cover plate, and keeps the spacing between the insulating film and the cover plate within a suitable range. This ensures the insulation performance between the cell and the casing. Furthermore, during the welding of the cover plate and the casing, the spacing between the insulating film and the cover plate prevents the insulating film from being welded through and melting during the welding process due to a small spacing. The battery module and battery pack of this application use the above-described battery and have the beneficial effects of the above-described battery. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the battery in Embodiment 1 of the present invention;

[0019] Figure 2 This is a schematic diagram of the shell in Embodiment 1 of the present invention;

[0020] Figure 3 This is a top view of the battery in Embodiment 1 of the present invention;

[0021] Figure 4 yes Figure 3A cross-sectional schematic diagram of AA in the middle;

[0022] Figure 5 yes Figure 4 Enlarged view of B in the middle;

[0023] Figure 6 yes Figure 4 Enlarged view of C in the middle;

[0024] Figure 7 This is a schematic diagram of a stacked structure in Embodiment 1 of the present invention, in which the stacking direction is perpendicular to the first direction;

[0025] Figure 8 This is a schematic diagram of a stacked structure in Embodiment 1 of the present invention, in which the stacking direction is parallel to the first direction;

[0026] Figure 9 This is a schematic diagram of the battery pack in Embodiment 2 of the present invention;

[0027] Figure 10 This is a schematic diagram of the shell in Embodiment 2 of the present invention;

[0028] Figure 11 This is a top view of the battery pack in Embodiment 2 of the present invention;

[0029] Figure 12 yes Figure 11 A cross-sectional schematic diagram of DD;

[0030] Figure 13 yes Figure 12 Enlarged view of E in the middle;

[0031] Figure 14 yes Figure 12 Enlarged view of F in the middle;

[0032] Figure 15 This is a schematic diagram of the battery pack with the fixing member located on the rear side in Embodiment 2 of the present invention;

[0033] Figure 16 This is a schematic diagram of the battery pack with the fixing member on the front side in Embodiment 2 of the present invention.

[0034] In the diagram, 100 represents the battery; X represents the first direction; Y represents the second direction; Z represents the third direction; 1 represents the casing; 1a represents the first end; 1b represents the second end; 1c represents the receiving cavity; 2 represents the cover plate; 3 represents the opening; 4 represents the battery cell; 4a represents the separator; 4b represents the electrode plate; 4b1 represents the positive electrode plate; 4b2 represents the negative electrode plate; 5 represents the fixing component; 6 represents the insulating film; 6a represents the notch; 7 represents the insulating component; and 8 represents the barrier component. Detailed Implementation

[0035] The specific embodiments of the present invention will be described in further detail below with reference to the accompanying drawings and examples. The following examples are for illustrative purposes only and are not intended to limit the scope of the invention.

[0036] In the description of this invention, it should be understood that when an element is referred to as being "fixed to" or "set on" another element, it can be directly on or indirectly on that other element. When an element is referred to as being "connected to" another element, it can be directly connected to or indirectly connected to that other element. The terms "mounted," "connected," and "attached" should be interpreted broadly, for example, referring to a fixed connection, a detachable connection, or an integral connection; a mechanical connection or an electrical connection; a direct connection or an indirect connection through an intermediate medium; or a connection within two elements or an interaction between two elements. Those skilled in the art will understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0037] In the description of this invention, it should be understood that the terms "height," "upper," "lower," "vertical," "horizontal," "top," "bottom," "inner," and "outer" used in this invention to indicate orientation or positional relationships are based on the orientation or positional relationships shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0038] In the description of this invention, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature.

[0039] Example 1

[0040] refer to Figures 1-8 This embodiment provides a battery 100, including a housing 1 and a cover plate 2. The housing 1 has a first end 1a and a second end 1b arranged opposite to each other in the length direction. The housing 1 has an opening 3 at the first end 1a and a receiving cavity 1c is provided inside the housing 1. The receiving cavity 1c communicates with the external environment through the opening 3. The cover plate 2 is connected to the opening 3 so that the receiving cavity 1c is isolated from the external environment.

[0041] In this embodiment, the housing 1 has a first direction X, a second direction Y, and a third direction Z that are perpendicular to each other. The first direction X of the housing 1 is the direction where the first end 1a and the second end 1b are located, which is the length direction. The second direction Y of the housing 1 is the direction where the long side of the opening 3 is located, which is the left-right direction. The third direction Z of the housing 1 is the direction where the short side of the opening 3 is located, which is the front-back direction.

[0042] A battery cell 4 is disposed in the cavity 1c. Each battery cell 4 includes a diaphragm 4a and multiple electrode plates 4b. The multiple electrode plates 4b are stacked to form a stacked structure. The diaphragm 4a is disposed between two adjacent electrode plates 4b and covers the outside of the stacked structure.

[0043] Understandably, the electrode plate 4b of battery 100 typically includes two types of electrodes with opposite polarities: a positive electrode plate 4b1 and a negative electrode plate 4b2. The electrode assembly of battery 100 operates by the movement of metal ions between the positive electrode plate 4b1 and the negative electrode plate 4b2. The cell's cycling process is the process of metal ions moving from the positive electrode plate 4b1 to the negative electrode plate 4b2, and then from the negative electrode plate 4b2 to the positive electrode plate 4b1. (Reference) Figure 4 In the battery cell 4 of this embodiment, the positive electrode 4b1 and the negative electrode 4b2 are stacked alternately in sequence, that is, the positive electrode 4b1 and the negative electrode 4b2 are stacked in the order of negative electrode 4b2-positive electrode 4b1-negative electrode 4b2-positive electrode 4b1-negative electrode 4b2, thereby forming a stacked structure, and the negative electrode 4b2 is located in the outermost layer of the stacked structure.

[0044] It should be noted that the battery cell 4 in this embodiment 1 is a laminated battery cell. For example, when the battery cell 4 is a laminated battery cell, multiple electrode plates 4b are stacked to form a discontinuous stacked structure, that is, any two adjacent positive electrode plates 4b1 are discontinuous and / or any two adjacent negative electrode plates 4b2 are discontinuous.

[0045] Understandably, the housing 1 is used to encapsulate components such as the battery cell and electrolyte. The housing 1 can have various shapes and sizes, such as cuboids or hexagonal prisms, and its shape can be determined based on the specific shape and size of the battery cell. The housing 1 can be made of various materials, including but not limited to copper, iron, aluminum, stainless steel, aluminum alloy, and plastic.

[0046] In each cell 4, a separator 4a is disposed between two adjacent electrode plates 4b and covers the outer side of the stacked structure to cover the outermost electrode plate 4b. Taking a stacked cell as an example, during the assembly of the cell 4, the positive electrode plate 4b1, separator 4a, and negative electrode plate 4b2 are stacked sequentially. The upper and lower surfaces of the electrode plates 4b are distinguished by the stacking direction of the electrode plates 4b. The separator 4a is disposed between the positive electrode plate 4b1 and the negative electrode plate 4b2, covering the upper and lower surfaces of the positive electrode plate 4b1 and the negative electrode plate 4b2, thereby separating adjacent positive electrode plates 4b1 and negative electrode plates 4b2 and preventing them from directly contacting each other. Furthermore, the separator 4a is usually a continuously extending thin film that extends from the inside of the stacked structure to the outside of the stacked structure and covers the outer side of the stacked structure, thereby separating the electrode plates 4b from the housing 1.

[0047] It is important to note that the separator 4a of the battery 100 is typically a porous insulating material, whose main function is to isolate the positive electrode 4b1 and the negative electrode 4b2 while allowing lithium ions to pass through. The separator 4a usually has a terminal end (i.e., the end position of the separator 4a winding), and a fixing member 5 is connected to the terminal end to keep the separator 4a taut. For example, in some batteries 100, an insulating tape is connected to the terminal end of the separator 4a as a fixing member 5. One end of the insulating tape is adhered to the terminal end of the separator 4a, and the other end is adhered to other positions on the separator 4a. By pulling the insulating tape in, the separator 4a can be taut, thereby firmly covering the laminated structure.

[0048] Due to factors such as the coating method of the separator 4a, the specifications and dimensions of the separator 4a, and the specifications and dimensions of the battery cell 4, the ends 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 this embodiment 1, the ends of the separator 4a are fixed to the side of the battery cell 4 facing the first end 1a.

[0049] An insulating film 6 is typically provided between the battery cell 4 and the casing 1 to separate the battery pack 100 from the casing 1, ensuring the safety, reliability, and performance stability of the battery 100. (Reference) Figure 4 Taking a laminated battery cell as an example, the insulating film 6 covers the side of the battery cell 4 facing the second end 1b, and extends towards the first end 1a to cover the outer periphery of the battery cell 4, thereby isolating the battery cell 4 from the housing 1; in addition, the insulating film 6 is provided with a notch 6a facing the cover plate 2 to avoid the side of the battery cell 4 with the end, so that the insulating film 6 is placed outside the side with the end and will not enter the side with the end, so as not to affect the connection between the battery cell 4 and the terminal of the cover plate 2.

[0050] It is understandable that the separator 4a and the insulating film 6 are both arranged in the receiving cavity 1c. The cooperation between the two will affect the assembly of the cell 4 in the housing 1, and thus affect the performance of the battery 100.

[0051] In some batteries 100, the fit between the separator 4a and the insulating film 6 can be adjusted to make them match each other. For example, in the first direction X, the electrode sheet 4b located on the outermost layer and close to the second end 1b is used as the reference electrode sheet. The distance from the outer edge of the reference electrode sheet towards the second end 1b to the outer edge of the cell 4 towards 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:

[0052] 250≤(D1×E) / L≤5000. …… (1)

[0053] 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 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 (1) can be one of the following values: 250, 350, 450, 550, 650, 750, 850, 950, 1000, 1500, 2000, 2500, 3000, 3500, 4000, 4500, and 5000.

[0054] It is understandable that the distance L from the outer edge of the reference electrode sheet towards the second end 1b to the outer edge of the cell 4 towards the second end 1b, the thickness D1 of the insulating film 6, and the elastic modulus E of the separator 4a reflect the mating structure of the insulating film 6 and the separator 4a. If the values ​​of the three parameters L from the outer edge of the reference electrode sheet towards the second end 1b to the outer edge of the cell 4 towards 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 (1), it is easy to cause the insulating film 6 to melt and burn through during the welding process between the shell 1 and the cover plate 2. If the values ​​of the three parameters L from the outer edge of the reference electrode sheet towards the second end 1b to the outer edge of the cell 4 towards 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 (1), it is easy to cause the gap between the insulating film 6 and the cover plate 2 to be too large, affecting 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 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 form a matching fit, and the spacing between the insulating film 6 and the cover plate 2 is within a suitable range. In this way, the insulation performance between the cell 4 and the shell 1 can be guaranteed. Furthermore, when the cover plate 2 and the shell 1 are welded, the spacing between the insulating film 6 and the cover plate 2 can avoid the phenomenon that the insulating film 6 is welded through and melted during the welding process due to the small spacing between the insulating film 6 and the cover plate 2.

[0055] It should be noted that the outermost electrode 4b refers to the electrode 4b located on the outermost side of the stacked structure along the stacking direction of the electrode 4b. (Reference) Figure 4 In the case where the cell 4 is stacked along the third direction Z, the outermost electrode 4b closest to the second end 1b is the foremost negative electrode 4b2 and the last negative electrode 4b2. (Reference) Figure 8 In the case where the cell 4 is stacked along the first direction X, the electrode 4b that is on the outermost layer and close to the second end 1b is the negative electrode 4b2 that is on the bottom.

[0056] It should be noted that the distance L from the side of the reference electrode sheet facing the second end 1b to the side of the corresponding cell 4 facing the second end 1b is the thickness of the separator 4a arranged on the side of the reference electrode sheet facing the second end 1b. Of course, in different battery 100 structures, the separator 4a can be a single-layer structure or a multi-layer structure, so the thickness of the separator 4a is usually the product of the thickness of a single-layer separator and the number of separator layers.

[0057] To verify that the structural parameters of the battery 100 provided in this embodiment 1 satisfy the above relationship (1), that is, when the distance L from the outer edge of the reference electrode sheet 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 are matched, compared with other batteries 100, the insulating film 6 of the battery 100 in this embodiment 1 can ensure good insulation performance and is not easily melted due to welding, this embodiment 1 conducted 9 sets of tests, as shown in Table 1 below:

[0058] In Table 1, Test Examples 1 to 9 are based on the battery 100 of Example 1 of this embodiment, i.e., the batteries 100 of Test Examples 1 to 15, have a distance L, an insulating film thickness D1, and a separator elastic modulus E that satisfy the matching relationship of Equation (1) above. Comparative Examples 1 to 4 are other battery structures, i.e., the distance L, insulating film thickness D1, and separator elastic modulus E of Comparative Examples 1 to 4 do not satisfy the matching relationship of Equation (1) above.

[0059] The method for testing diaphragm weld penetration is as follows: Based on Table 1, insulating films of different thicknesses and diaphragms of different elastic moduli are selected and assembled into battery cells. Subsequently, the battery cells are placed into the casing, and the cover plate is welded to the casing using laser welding technology. During the welding process, 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 to check whether the insulating film shows signs of weld penetration.

[0060] The insulation performance test method is as follows: Insulating films of different thicknesses and separators of different elastic moduli are selected according to Table 1 and assembled into battery cells. Subsequently, the battery cells are placed into the casing, and the cover plate is sealed to the casing using laser welding technology. Electrolyte is injected, and formation treatment is performed to finally produce the battery. The positive electrode material of the battery is lithium iron phosphate. First, the battery is charged to 3.25V at 1 / 3C current, allowed to stand for 10 minutes, and then discharged to 2.5V at 1 / 3C current. After standing for 1 hour, its open-circuit voltage is measured and recorded, marked as V1. Then, the above charging and discharging process is repeated, and after standing for 10 minutes, 500 cycles are performed. After completing the cycles, the battery is allowed to stand for 50 minutes, and the open-circuit voltage is measured and recorded again, marked as V2. Finally, the voltage difference after battery cycles is calculated according to the formula ΔV = V1 - V2.

[0061] Table 1

[0062]

[0063]

[0064] As shown in Table 1, when the distance L from the outer edge of the reference electrode sheet towards the second end 1b to the outer edge of the cell 4 towards 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 formula (1), the insulating film 6 not only ensures excellent insulation performance between the cell 4 and the shell 1, but also prevents the insulating film 6 from melting during the welding process between the cover plate 2 and the shell 1. However, when the distance L from the outer edge of the reference electrode sheet towards the second end 1b to the outer edge of the cell 4 towards 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 formula (1), the battery may experience problems such as the melting of the insulating film 6 or insufficient insulation performance between the cell 1 and the shell 1.

[0065] For example, in this 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 cell 4 toward the second end 1b can satisfy: 3≤L≤200μm. For instance, the distance L can be one of the following dimensions: 3μm, 4μm, 5μm, 6μm, 7μm, 8μm, 9μm, 10μm, 20μm, 30μm, 40μm, 50μm, 60μm, 70μm, 80μm, 90μm, 100μm, 110μm, 120μm, 130μm, 140μm, 150μm, 160μm, 170μm, 180μm, 190μm, and 200μm.

[0066] For example, in this embodiment 1, the insulation film thickness D1 can satisfy: 50≤D1≤150μm. For instance, the insulation film thickness D1 can be one of the following dimensions: 50μm, 60μm, 70μm, 80μm, 90μm, 100μm, 110μm, 120μm, 130μm, 140μm, and 150μm.

[0067] For example, in this embodiment 1, the elastic modulus E of the diaphragm 4a can satisfy: 200≤E≤2000MPa. For instance, the elastic modulus E of the diaphragm 4a can be one of 200MPa, 300MPa, 400MPa, 500MPa, 600MPa, 700MPa, 800MPa, 900MPa, 1000MPa, 1100MPa, 1200MPa, 1300MPa, 1400MPa, 1500MPa, 1600MPa, 1700MPa, 1800MPa, 1900MPa, and 2000MPa.

[0068] It is understandable that a lot of heat will be generated when the cover plate 2 is welded. If the insulating film 6 is too close to the cover plate 2, the heat generated by the welding of the cover plate 2 can easily be transferred to the insulating film 6, causing the insulating film 6 to shrink due to heat. This can easily cause the battery cell to be exposed from the insulating film 6, resulting in the risk of overlap between the battery cell and the housing 1. Therefore, there is usually a certain gap between the insulating film 6 and the cover plate 2. That is, there is a certain gap 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 1, this gap 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 a portion of the 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 instance, h1 can be one of the following dimensions: 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1mm, 1.5mm, 2mm, 2.5mm, 3mm, 3.5mm, 4mm, 4.5mm, and 5mm.

[0069] Of course, when the distance between the insulating film 6 and the cover plate 2 satisfies h1, the distance between the insulating film 6 and the cover plate 2 is more compatible with the battery cell 4. Therefore, in this case, the electrode sheet 4b located on the outermost layer and close to the second end 1b is taken as the reference electrode sheet 4b. 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 can also be satisfied.

[0070] 250≤(D1×E) / L≤4000. ……(2)

[0071] 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 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 (2) can be one of the following values: 250, 350, 450, 550, 650, 750, 850, 950, 1000, 1500, 2000, 2500, 3000, 3500, and 4000.

[0072] It should be noted that the battery cell 4 disposed within the receiving cavity 1c can be arranged in various ways. For example, the stacking direction of multiple electrode sheets 4b can be parallel to the first direction X. (See reference) Figures 1-6 , Figure 8 When the stacking direction of multiple electrode sheets 4b is parallel to the first direction X, the parallel stacking of multiple electrode sheets 4b makes it easier for the insulating film 6 and the separator 4a to remain flat during the stacking process, allowing the battery cell 4 to be placed into the receiving cavity 1c more conveniently, and reducing the degree of wrinkling of the separator near the second end 1b. Therefore, in this case, the electrode sheet 4b that is on the outermost layer and close to the second end 1b is taken as the reference electrode sheet 4b. 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 separator 4a can also be satisfied.

[0073] 250≤(D1×E) / L≤3000. ……(3)

[0074] 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 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 (3) can be one of the following values: 250, 350, 450, 550, 650, 750, 850, 950, 1000, 1500, 2000, 2500, and 3000.

[0075] Of course, the stacking direction of the multiple electrode sheets 4b can also be perpendicular to the first direction X. (See reference) Figures 1-6 , Figure 7 When the stacking direction of multiple electrode sheets 4b is perpendicular to the first direction X, the perpendicular stacking of multiple electrode sheets 4b can make the insulating film 6 and the separator 4a more uniformly 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 between the housing 1 and the cover plate 2 and improving the welding yield between the housing 1 and the cover plate 2. Therefore, in this case, the electrode sheet 4b that is on the outermost layer and close to the second end 1b is taken as the reference electrode sheet 4b. The distance L from the outer edge of the reference electrode sheet towards the second end 1b to the outer edge of the cell 4 towards the second end 1b, the thickness D1 of the insulating film 6, and the elastic modulus E of the separator 4a can also be satisfied.

[0076] 1200≤(D1×E) / L≤5000. ……(4)

[0077] 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 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 (4) can be one of the following values: 1200, 1300, 1400, 1500, 2000, 2500, 3000, 3500, 4000, 4500, and 5000.

[0078] refer to Figures 1-8 In some batteries 100, an insulating element 7 is provided between the cell 4 and the cover plate 2 to isolate the electrical connection components inside the housing 1 from the cover plate 2, thereby reducing the risk of short circuits. The material of the insulating element 7 typically includes plastic, rubber, etc. As the thickness of the insulating element 7 changes, its insulation performance will be affected accordingly. As an example of this embodiment 1, the thickness of the insulating element 7 is D2, and the thickness D2 of the insulating element 7 can satisfy: 0.5≤D2≤5mm. Exemplarily, D2 can be one of the following dimensions: 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1mm, 1.5mm, 2mm, 2.5mm, 3mm, 3.5mm, 4mm, 4.5mm, and 5mm.

[0079] The thickness D2 of the insulating component 7 satisfies: 0.5≤D2≤5mm, which ensures the insulation performance of the insulating component 7, thereby improving the insulation effect between the battery cell 4 and the cover plate 2, and increasing the spacing between the insulating film 6 and the cover plate 2. In this case, the electrode plate 4b located on the outermost layer and close to the second end 1b is taken as the reference electrode plate 4b. The distance L from the outer edge of the reference electrode plate 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 can also satisfy the following:

[0080] 250≤(D1×E) / L≤2500. …… (5)

[0081] 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 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 (5) can be one of the following values: 250, 350, 450, 550, 650, 750, 850, 950, 1000, 1500, 2000, and 2500.

[0082] refer to Figures 1-8In some batteries 100, a barrier 8 is also provided between the cell 4 and the casing 1 to isolate the casing 1 and the cell 4, thereby reducing the risk of short circuit. The barrier 8 is located between the side of the cell 4 facing the second end 1b and the casing 1, and its material may include plastic, rubber, etc.

[0083] It is understandable that the insulation performance of the barrier element 8 will be affected as the thickness of the barrier element 8 changes. As an example of this embodiment 1, the thickness of the barrier element 8 is D3, and the thickness D3 of the barrier element 8 can satisfy: 0.5≤D3≤3mm. Exemplarily, D3 can be one of the dimensions of 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1mm, 1.5mm, 2mm, 2.5mm, and 3mm.

[0084] The thickness D3 of the barrier 8 satisfies: 0.5≤D3≤3mm, which ensures the insulation performance of the barrier 8 and ensures that the barrier 8 can support the battery cell 4, reducing the influence of the R angle of the housing 1 on the battery cell 4. In this case, the electrode plate 4b located on the outermost layer and close to the second end 1b is taken as the reference electrode plate 4b. The distance L from the outer edge of the reference electrode plate 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 separator 4a can also be satisfied.

[0085] 1800≤(D1×E) / L≤2500. …… (6)

[0086] 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 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 (6) can be one of the following values: 1800, 1900, 2000, 2100, 2200, 2300, 2400, and 2500.

[0087] Based on the aforementioned battery 100, this embodiment 1 also provides a battery module, which includes at least two of the aforementioned batteries 100, and the two batteries are electrically connected by being connected in series or in parallel.

[0088] Based on the above-mentioned battery module, this embodiment 1 also provides a battery pack, which includes a housing and at least two of the aforementioned battery modules, the two battery modules being disposed inside the housing and electrically connected to each other.

[0089] Example 2

[0090] refer to Figures 9-16This embodiment 2 provides a battery 100, including a housing 1 and a cover plate 2. The housing 1 has a first end 1a and a second end 1b arranged opposite to each other in the length direction. The housing 1 has an opening 3 at the first end 1a and a receiving cavity 1c is provided inside the housing 1. The cover plate 2 is connected to the opening 3 so that the receiving cavity 1c is isolated from the external environment.

[0091] In this embodiment 2, the shell 1 has a first direction X, a second direction Y and a third direction Z that are perpendicular to each other. The first direction X of the shell 1 is the direction where the first end 1a and the second end 1b are located, which is the length direction; the second direction Y of the shell 1 is the direction where the long side of the opening 3 is located, which is the left-right direction; and the third direction Z of the shell 1 is the direction where the short side of the opening 3 is located, which is the front-back direction.

[0092] A battery cell assembly is disposed within the cavity 1c. In this embodiment 2, the battery cell assembly includes two battery cells 4, each battery cell 4 including a diaphragm 4a and multiple electrode plates 4b, wherein the multiple electrode plates 4b are stacked to form a stacked structure, and adjacent battery cells are arranged along the stacking direction of the stacked structure.

[0093] Understandably, the battery electrode 4b typically includes two types of electrodes with opposite polarities: a positive electrode 4b1 and a negative electrode 4b2. The battery electrode assembly functions by the movement of metal ions between the positive electrode 4b1 and the negative electrode 4b2. The cell's cycling process involves metal ions moving from the positive electrode 4b1 to the negative electrode 4b2, and then from the negative electrode 4b2 back to the positive electrode 4b1. (Reference) Figures 9-16 In the battery cell 4 of this embodiment 2, the positive electrode 4b1 and the negative electrode 4b2 are stacked alternately in sequence, that is, the positive electrode 4b1 and the negative electrode 4b2 are stacked in the order of negative electrode 4b2-positive electrode 4b1-negative electrode 4b2-positive electrode 4b1-negative electrode 4b2, thereby forming a stacked structure, and the negative electrode 4b2 is located in the outermost layer of the stacked structure.

[0094] It should be noted that the battery cell 4 in this embodiment 2 is a laminated battery cell, and the housing 1 is used to encapsulate the battery cell and electrolyte components. The housing 1 can have various shapes and sizes, such as cuboid, hexagonal prism, etc., and the shape of the housing 1 can be determined according to the specific shape and size of the battery cell. The material of the housing 1 can be various, including but not limited to copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc.

[0095] In each cell 4, a separator 4a is disposed between two adjacent electrode plates 4b and is wound around the outside of the stacked structure along the stacking direction of the electrode plates 4b to cover the outermost electrode plate 4b. Specifically, during the assembly of the battery 100, the positive electrode plate 4b1, separator 4a, and negative electrode plate 4b2 are stacked sequentially. The upper and lower surfaces of the electrode plates 4b are distinguished by the stacking direction of the electrode plates 4b. The separator 4a is disposed between the positive electrode plate 4b1 and the negative electrode plate 4b2, covering the upper and lower surfaces of the positive electrode plate 4b1 and the negative electrode plate 4b2, thereby separating adjacent positive electrode plates 4b1 and negative electrode plates 4b2 and preventing them from directly contacting each other. Furthermore, the separator 4a is usually a continuously extending 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 plates 4b from the casing 1.

[0096] It is important to note that the battery separator 4a is typically a porous insulating material. Its main function is to isolate the positive electrode 4b1 and the negative electrode 4b2 while allowing lithium ions to pass through. The end of the separator 4a (i.e., the end position of the separator 4a winding) usually needs to be connected to a fixing element 5 to keep the separator 4a taut. For example, in some batteries, the end of the separator 4a is connected to an insulating tape as a fixing element 5. One end of the insulating tape is adhered to the end of the separator 4a, and the other end is adhered to other positions on the separator 4a. By pulling the insulating tape in, the separator 4a can be taut, thereby firmly covering the laminated structure.

[0097] An insulating film 6 is typically provided between the battery 100 and the casing 1 to separate the battery 100 and the casing 1, ensuring the battery's safety, reliability, and performance stability. (Reference) Figures 9-16 The insulating film 6 covers the side of the two cells facing the second end 1b and extends towards the first end 1a to cover the outer periphery of the two cells, thereby isolating the cells from the casing 1. Furthermore, the insulating film 6 is disposed outside the end side of the two cells facing the first end 1a and will not enter the end side of the two cells facing the first end 1a, so as not to affect the connection between the battery 100 and the terminal post of the cover plate 2.

[0098] Understandably, each cell of battery 100 has its own end of separator 4a. With the cooperation of the fixing member 5, the tension of the end of separator 4a is usually greater than the tension of other parts of separator 4a. Therefore, when the end of separator 4a of two cells is located on different sides of the stacked structure, the flatness of separator 4a on one side of the same battery 100 will differ. For this reason, refer to... Figures 9-16When the ends of the separators 4a of the two cells are arranged on different sides of the stacked structure, and when the end of the separator 4a of one cell is fixed to the side of the cell 4 facing the first end 1a, in the first direction X of the battery 100 of this embodiment, taking the electrode sheet 4b located on the outermost layer and close to the outer periphery of the casing 1 as 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 separator 4a is E, then the above parameters satisfy:

[0099] 250≤(D1×E) / L≤4000. …… (7)

[0100] 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 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 (7) can be one of the following values: 250, 350, 450, 550, 650, 750, 850, 950, 1000, 1500, 2000, 2500, 3000, 3500, 4000, 4500, and 5000.

[0101] It is understandable that the distance L from the outer edge of the reference electrode sheet towards the second end 1b to the outer edge of the cell 4 towards the second end 1b, the thickness D1 of the insulating film 6, and the elastic modulus E of the separator 4a reflect the mating structure of the insulating film 6 and the separator 4a. If the values ​​of the three parameters L from the outer edge of the reference electrode sheet towards the second end 1b to the outer edge of the cell 4 towards 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 (7), it is easy for the insulating film 6 to melt and burn through during the welding process between the shell 1 and the cover plate 2. If the values ​​of the three parameters L from the outer edge of the reference electrode sheet towards the second end 1b to the outer edge of the cell 4 towards 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 (7), it is easy for the gap between the insulating film 6 and the cover plate 2 to be too large, which will affect the insulation performance of the battery. When the distance L from the outer edge of the reference electrode sheet towards the second end 1b to the outer edge of the 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 (7), 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 form a matching fit, and the spacing between the insulating film 6 and the cover plate 2 is within a suitable range. In this way, the insulation performance between the cell 4 and the shell 1 can be guaranteed. Furthermore, when the cover plate 2 and the shell 1 are welded, the spacing between the insulating film 6 and the cover plate 2 can avoid the phenomenon that the insulating film 6 is welded through and melted during the welding process due to the small spacing between the insulating film 6 and the cover plate 2.

[0102] It should be noted that in this battery 100, the two cells 4 are arranged along the stacking direction of the stacked structure. Therefore, in the battery 100 of this embodiment 2, the electrode plate 4b located on the outermost layer and close to the outer periphery of the shell 1 is: the negative electrode plate 4b2 located on the front side of the cell 4, and the negative electrode plate 4b2 located on the rear side of the cell 4.

[0103] It should be noted that the distance L 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 the thickness of the separator 4a arranged 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, so the thickness of the separator 4a is usually the product of the thickness of a single-layer separator and the number of separator layers.

[0104] It should be noted that when the end of the separator 4a of one cell is fixed to the side of the cell 4 facing the first end 1a, there are multiple possibilities for the arrangement of the end of the separator 4a of the other cell in this battery 100. For example, the end of the separator 4a of one cell 4 can be arranged on the side of the cell facing the second end 1b, or, in the arrangement direction of the two cells 4, the end of the separator 4a of one cell 4 can be arranged on any side of the cell 4 in the arrangement direction, that is, the end of the separator 4a of one cell 4 can be arranged on the opposite side of two adjacent cells, or, the end of the separator 4a of one cell 4 can be arranged on the side of the cell facing the outer periphery of the casing 1. The two arrangements will be described below in this embodiment 2.

[0105] refer to Figures 9-16 ,exist Figure 12 In the battery cell assembly shown, the battery cell 4 located on the front side is designated as the first battery cell, and the battery cell 4 located on the rear side is designated as the second battery cell. When the end of the separator 4a of one battery cell is positioned on the side facing the second end 1b, i.e., the end of the separator 4a of the first battery cell is positioned on the lower side of the stacked structure, and the end of the separator 4a of the second battery cell is positioned on the upper side of the stacked structure, the fixing member 5 of the second battery cell is also positioned on the upper side. The separator 4a is relatively compact on the upper side of the second battery cell, and relatively loose on the lower, rear, and front sides of the second battery cell. The insulating film 6 covers the lower and rear sides of the second battery cell. In this case, in the first direction X, taking the electrode plate 4b located on the outermost layer and close to the outer periphery of the housing 1 as the reference electrode plate, the distance from the outer edge of the reference electrode plate 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:

[0106] 250≤(D1×E) / L≤3000. …… (8)

[0107] 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 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 the following values: 250, 350, 450, 550, 650, 750, 850, 950, 1000, 1500, 2000, 2500, and 3000.

[0108] refer to Figures 9-16 In cases where the end of the separator 4a of a battery cell 4 is located on any side of the battery cell 4 in the arrangement direction, there is a case where the end of the separator 4a of a battery cell is located on the side of the battery cell facing the outer periphery of the housing 1, that is, the end of the separator 4a of the first battery cell is located on the lower side of the stacked structure and the end of the separator 4a of the second battery cell is located on the rear side of the stacked structure. There is also a case where the end of the separator 4a of a battery cell is located on the opposite sides of two adjacent battery cells, that is, the end of the separator 4a of the first battery cell is located on the lower side of the stacked structure and the end of the separator 4a of the second battery cell is located on the front side of the stacked structure.

[0109] In both cases, the fixing member 5 of the second battery cell is located on the rear side or the front side. Correspondingly, the diaphragm 4a is relatively tight on the rear or front side of the second battery cell, and relatively loose on the other sides of the second battery cell. Furthermore, the insulating film 6 covers the lower and rear sides of the second battery cell. Therefore, in the cooperation between the second battery cell and the insulating film 6, the constraint force of the diaphragm 4a on only one side of the second battery cell is relatively weak, and the insulating film 6 is easier to bond with the second battery cell. In this way, in the first direction X, taking the electrode plate 4b located on the outermost layer and close to the outer periphery of the shell 1 as the reference electrode plate, the distance from the outer edge of the reference electrode plate towards the second end 1b to the outer edge of the battery cell 4 towards 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 satisfy:

[0110] 250≤(D1×E) / L≤3000. …… (9)

[0111] 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 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 (9) can be one of the following values: 250, 350, 450, 550, 650, 750, 850, 950, 1000, 1500, 2000, 2500, and 3000.

[0112] It should be noted that, in the battery 100 of this embodiment 2, adjacent cells are arranged along the stacking direction of the laminated structure, that is, adjacent cells are arranged along the front-to-back direction. Furthermore, the separator 4a of this embodiment 2 is disposed between two adjacent electrode plates 4b and is wound around the outside of the laminated structure along the stacking direction of the electrode plates 4b, that is, the separator 4a of this embodiment 2 is wound around the outside of the laminated structure along the front-to-back direction. Therefore, even if the end of the separator 4a of a cell is located on the side of the cell facing the outer periphery of the housing 1, the end of the separator 4a of that cell will only face the rear side of the housing 1, and will not face the left or right side of the housing 1. Of course, in other battery structures, if adjacent cells are arranged along the left-to-right direction, the end of the separator 4a of that cell will face the left or right side of the housing 1, and will not face the front or rear side of the housing 1.

[0113] Understandably, the thickness of the diaphragm 4a affects its rigidity. A thicker diaphragm 4a has higher rigidity, and the rebound force generated when the diaphragm 4a is bent is greater, making it difficult to fit tightly against the electrode sheet 4b. Furthermore, when the diaphragm 4a is thicker, it is more prone to wrinkles during the winding process, resulting in a looser winding structure. Of course, the thickness of the diaphragm 4a also increases its insulation performance, preventing the cell 4 from overlapping with the casing 1. Considering the insulation between the housing 1 and the battery cell 4, the thickness of the diaphragm 4a wound in 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 following: the distance between the outer edge of the electrode plate 4b on the side closer to the housing 1 and the outer edge of the corresponding battery cell 4 is S1, and the distance between the outer edge of the electrode plate 4b on the adjacent side of the two battery cells 4 and the outer edge of the corresponding battery cell 4 is S2, and S1 > S2. That is, the thickness of the diaphragm 4a on the front side of the first battery cell is greater than the thickness of the diaphragm 4a on the rear side of the first battery cell, and the thickness of the diaphragm 4a on the rear side of the second battery cell is greater than the thickness of the diaphragm 4a on the front side of the second battery cell, so as to ensure good insulation performance between the housing 1 and the battery cell 4.

[0114] Of course, in the above situation, the distance S1 between the outer edge of the electrode plate 4b near the shell 1 and the corresponding outer edge of the battery cell 4, and the distance S2 between the outer edge of the electrode plate 4b near the adjacent side of the two battery cells 4 and the corresponding outer edge of the battery cell 4, will affect the assembly and fit between the diaphragm 4a and the electrode plate 4b. Therefore, the fit between the insulating film 6 and the diaphragm 4a needs to be adjusted accordingly. For example, in the first direction X, taking the electrode plate 4b located on the outermost layer and close to the outer periphery of the shell 1 as the reference electrode plate, the distance from the outer edge of the reference electrode plate 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 diaphragm 4a is E. Then the above parameters can be satisfied:

[0115] 800≤(D1×E) / L≤3500. ……(10)

[0116] 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 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 (10) can be one of the following values: 800, 850, 900, 950, 1000, 1500, 2000, 2500, 3000, and 3500.

[0117] In summary, the battery 100 of this embodiment, by adjusting the distance L from the outer edge of the reference electrode sheet 4b towards the second end 1b to the outer edge of the cell 4 towards the second end 1b, the thickness D1 of the insulating film 6, and the elastic modulus E of the separator 4a, can make the insulating film 6, the separator 4a, and the electrode sheet 4b match, thereby making the insulating film 6 and the cover plate 2 fit together and keeping the spacing between the insulating film 6 and the cover plate 2 within a suitable range. This ensures the insulation performance between the cell 4 and the casing 1. Furthermore, during the welding of the cover plate 2 and the casing 1, the spacing between the insulating film 6 and the cover plate 2 can prevent the insulating film 6 from being welded through and melting during the welding process due to a small spacing. The battery module and battery pack of this application use the above-described battery 100 and have the beneficial effects of the battery 100.

[0118] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and substitutions can be made without departing from the technical principles of the present invention, and these improvements and substitutions should also be considered within the scope of protection of the present invention.

Claims

1. A battery, characterized by, The battery comprises: 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 an external environment; a cover plate connected to the opening to isolate the containing cavity from the external environment; an electric core comprising a diaphragm and a plurality of electrode sheets, wherein the plurality of electrode sheets are arranged in a stack to form a discontinuous stack structure; the diaphragm is arranged between two adjacent electrode sheets and covers the outside of the stack structure; and the diaphragm has an end, which is fixed to one side of the electric core facing the first end; an insulating film covering the outside of the electric core and extending towards the first end, and the insulating film is provided with a notch facing the cover plate to avoid the side of the electric core provided with the end; and In the first direction, taking the electrode sheet at the outermost layer and close to the second end as a reference electrode sheet, the distance from the outer edge of the reference electrode sheet towards the second end to the outer edge of the electrode sheet towards the second end is L, in units of μm, the thickness of the insulating film is d, in units of μm, the elastic modulus of the separator is E, in units of MPa, and the above parameters satisfy: 0.5 < L / d < 2.5, 0.5 < d / E < 2.

5. , units of μm, the elastic modulus of the separator is E, units of MPa, and the above parameters satisfy: 0.5 < L / d < 2.5, 0.5 < d / E < 2.

5. 250≤( ×E) / L≤5000。 2. The battery of claim 1, wherein, In the first direction, the shortest vertical distance between the insulating film and the cover plate is 0.5 ≤ ≤ 5 mm, and the distance L, the insulating film thickness , and the diaphragm elastic modulus E satisfy: 250≤( ×E) / L≤4000。 3. The battery of claim 1, wherein, The stacking direction of the plurality of electrode sheets is perpendicular to the first direction, and the distance L and the thickness of the insulating film are... The elastic modulus E of the diaphragm satisfies: 250≤( ×E) / L≤3000。 4. The battery of claim 1, wherein, The stacking direction of the plurality of electrode sheets is parallel to the first direction, and the distance L and the thickness of the insulating film are... The elastic modulus E of the diaphragm satisfies: 1200≤( ×E) / L≤5000。 5. The battery of claim 1, wherein, An insulating member is arranged between the battery cell and the cover plate, and the thickness of the insulating member is , and the thickness of the insulating member satisfies: 0.5≤ ≤5mm, and the distance L, the thickness of the insulating film , and the elastic modulus E of the diaphragm satisfy: 250 ≤ (E x E) / L ≤ 2500. 250 ≤ (E x E) / L ≤ 2500.

6. The battery of claim 1, wherein, the battery further comprises: A barrier is disposed between the side of the battery cell facing the second end and the housing, and the thickness of the barrier is [missing information]. And the thickness of the barrier element Satisfy: 0.5≤ ≤3mm, and the distance L and the thickness of the insulating film The elastic modulus E of the diaphragm satisfies: 1800≤( ×E) / L≤2500。 7. The battery of claim 1, wherein, The distance L satisfies: 3 ≤ L ≤ 200 μm; and / or, the insulating film thickness satisfies: 50 ≤ thickness ≤ 150 μm. satisfies: 50 ≤ thickness ≤ 150 μm. satisfies: 50 ≤ thickness ≤ 150 μm. And / or, the diaphragm elastic modulus E satisfies: 200≤E≤ ≤2000 Mpa.

8. The battery of claim 1, wherein, the number of the electric core is at least two, and two electric cores are arranged in the containing cavity, and two adjacent electric cores are arranged in a direction perpendicular to the first direction; and the ends of the two electric cores are arranged on different sides of the stack structure, and the end of at least one electric core is fixed to one side of the electric core facing the first end; and In the first direction, the electrode sheet located on the outermost layer and close to the outer periphery of the housing is used as a reference electrode sheet. The distance from the outer edge of the reference electrode sheet towards the second end to the outer edge of the cell towards the second end is L, and the thickness of the insulating film is... If the elastic modulus of the diaphragm is E, then the above parameters satisfy: 250≤( ×E) / L≤4000。 9. The battery of claim 8, wherein, The end portion 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 of the insulating film t, and the elastic modulus E of the separator satisfy the following relationships: E satisfies the following relationships: 250≤( ×E) / L≤3000。 10. The battery of claim 8, wherein, In the arrangement direction of the two battery cells, the end portion of one battery cell is arranged on either side of the battery cell in the arrangement direction, and the distance L, the thickness of the insulating film, and the elastic modulus E of the separator satisfy: the elastic modulus E of the separator satisfy: 250≤( ×E) / L≤3500。 11. The battery of claim 8, wherein, in the arrangement direction of the two electric cores, at least one electric core satisfies: 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 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 , and > ; and The distance L, the insulating film thickness The distance L, the insulating film thickness The distance L, the insulating film thickness 12. A battery module, characterized by the battery comprises at least two batteries as claimed in any one of claims 1-7, and the two batteries are connected in series or in parallel to realize electrical connection.

13. A battery pack, characterized by the battery module comprises a shell and at least two batteries as claimed in claim 12, and the two battery modules are arranged in the shell and electrically connected.

Images