Battery cell shell, battery cell, battery pack and electronic device

Abstract

The utility model provides a battery cell shell, which comprises a shell body, a battery cell, a battery cell and a battery cell, the cover plate is covered in the opening, the shell is provided with a circle of step structure at the opening, the cover plate is supported on the step structure, a first part, deviating from the electrode assembly, of the cover plate is welded with the shell, and a circle of first gap is formed between a second part, located between the first part and the step structure, of the cover plate and the side wall of the opening. The utility model aims to provide a battery cell shell, a battery cell, a battery pack and an electronic device, so as to at least improve the optimal rate of the battery cell.

Description

Technical Field

[0001] This utility model relates to a battery cell casing, a battery cell, a battery pack, and an electronic device. Background Technology

[0002] Batteries are widely used in electronic devices such as mobile phones, laptops, electric vehicles, electric cars, electric airplanes, electric ships, electric toy cars, electric toy ships, electric toy airplanes, and power tools. Commonly used batteries include nickel-cadmium batteries, nickel-metal hydride batteries, lithium-ion batteries, and rechargeable alkaline zinc-manganese batteries. Among these, lithium-ion batteries have become the mainstream power battery for new energy vehicles due to their advantages such as high specific energy, high specific power, long lifespan, and low cost. Utility Model Content

[0003] In view of the problems existing in the related technologies, the purpose of this utility model is to provide a battery cell casing, a battery cell, a battery pack and an electronic device, so as to at least improve the efficiency of the battery cell.

[0004] To achieve the above objectives, the present invention provides a battery cell housing, comprising: a housing for accommodating an electrode assembly and having an opening; a cover plate covering the opening, wherein the housing has a stepped structure at the opening, the cover plate is supported on the stepped structure, a first portion of the cover plate opposite to the electrode assembly is welded to the housing, and a second portion of the cover plate located between the first portion and the stepped structure has a first gap between it and the sidewall of the opening.

[0005] In some embodiments, the housing includes a bottom wall opposite to the opening and a first side wall, a second side wall, a third side wall, and a fourth side wall that surround the bottom wall and the opening and are connected in sequence. The first side wall is opposite to the third side wall, and the second side wall is opposite to the fourth side wall. The first side wall and the third side wall have a first dimension along the length direction from the second side wall to the fourth side wall, and the second side wall and the fourth side wall have a second dimension along the width direction from the first side wall to the third side wall. The first dimension is larger than the second dimension. A first gap is located between the cover plate and the first side wall, the second side wall, the third side wall, and the fourth side wall. A stepped structure is located on the first side wall, the second side wall, the third side wall, and the fourth side wall.

[0006] In some embodiments, when projected along the direction from the cover plate to the electrode assembly, the first gap falls entirely on the stepped structure.

[0007] In some embodiments, the bottom surface of the cover plate facing the electrode assembly is flush with the support surface of the stepped structure supporting the cover plate.

[0008] In some embodiments, the cover plate further includes a third portion located between the stepped structure and the electrode assembly, the third portion having a second gap between it and the housing.

[0009] In some embodiments, the support surface of the stepped structure support cover is parallel to the top surface of the cover away from the electrode assembly.

[0010] In some embodiments, the support surface of the stepped structure support cover plate is inclined toward the electrode assembly in the direction from the cover plate toward the electrode assembly.

[0011] Embodiments of this application also provide a battery cell, comprising: a battery cell housing according to any of the above, a cover plate covering the housing and defining a receiving cavity therebetween; and an electrode assembly housed within the receiving cavity.

[0012] Embodiments of this application also provide a battery pack including the aforementioned battery cells.

[0013] Embodiments of this application also provide an electronic device including the battery pack described above.

[0014] The beneficial technical effects of this utility model are as follows:

[0015] The embodiments of this application, by setting a first gap between the cover plate and the sidewall of the opening, can avoid interference between the cover plate and the housing when the cover plate is placed in the opening. This allows for dimensional manufacturing tolerances when obtaining the corresponding design of the cover plate and housing using appropriate molds and stamping processes, improving manufacturability, reducing equipment requirements, and simultaneously reducing assembly difficulty and increasing the yield of the battery cells. By setting a stepped structure around the opening to support the cover plate, light leakage during laser welding of the cover plate and housing can be prevented from damaging the internal structure of the battery cell, thus avoiding a reduction in the safety performance of the battery cell. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 An electronic device according to an embodiment of this application is shown.

[0018] Figure 2 A cross-sectional view of the battery cell casing according to the first embodiment of this application is shown, taken along a plane parallel to the height and length directions of the battery cell.

[0019] Figure 3 A cross-sectional view of the battery cell casing according to the first embodiment of this application is shown, taken along a plane parallel to the height direction and width (thickness) direction of the battery cell.

[0020] Figure 4A cross-sectional view of the battery cell casing according to the first embodiment of this application is shown, taken along a plane parallel to the height and length directions of the battery cell.

[0021] Figure 5 A cross-sectional view of the battery cell casing according to the second embodiment of this application is shown, taken along a plane parallel to the height and length directions of the battery cell.

[0022] Figure 6 A cross-sectional view of the battery cell casing according to the second embodiment of this application is shown, taken along a plane parallel to the height direction and width (thickness) direction of the battery cell.

[0023] Figure 7 A cross-sectional view of the battery cell casing according to the third embodiment of this application is shown, taken along a plane parallel to the height and length directions of the battery cell.

[0024] Figure 8 A cross-sectional view of the battery cell casing according to the third embodiment of this application is shown, taken along a plane parallel to the height direction and width (thickness) direction of the battery cell. Detailed Implementation

[0025] To better understand the spirit of the embodiments of this application, the following description is based on some preferred embodiments of this application.

[0026] Embodiments of this application will be described in detail below. Throughout this specification, identical or similar components and components having identical or similar functions are indicated by similar reference numerals. The embodiments described herein with reference to the accompanying drawings are illustrative and diagrammatic in nature and are intended to provide a basic understanding of this application. The embodiments of this application should not be construed as limiting this application.

[0027] As used herein, the terms “approximately,” “generally,” “substantially,” and “about” are used to describe and indicate minor variations. When used in conjunction with an event or situation, these terms may refer to examples in which the event or situation occurred precisely or in examples in which the event or situation occurred very approximately.

[0028] In this specification, unless otherwise specified or limited, relative terms such as “central,” “longitudinal,” “lateral,” “front,” “rear,” “right,” “left,” “inner,” “outer,” “lower,” “higher,” “horizontal,” “vertical,” “above,” “below,” “above,” “below,” “top,” “bottom,” and their derivatives (e.g., “horizontally,” “downward,” “upward,” etc.) should be interpreted as referring to the directions described in the discussion or depicted in the accompanying drawings. These relative terms are used for descriptive convenience only and do not require that this application be constructed or operated in a particular orientation.

[0029] For ease of description, "first," "second," "third," etc., can be used in this article to distinguish different components of a figure or a series of figures. "First," "second," "third," etc., are not intended to describe the corresponding components.

[0030] Currently, the design of the casing and top cover of prismatic batteries in the industry generally involves a transition fit on the long side and a clearance fit on the short side. Before welding, the relative positions of the casing and top cover are only fixed by a step on the short side, with no step structure on the long side. Considering the dimensional fluctuations and tolerances during the machining process, the transition fit on the long side can lead to poor manufacturability during the assembly of some top covers and casings, increasing the difficulty and reducing the yield rate. Furthermore, when greater force is used to insert the top cover into the casing due to manufacturing tolerances, it can cause casing deformation, with the long side of the top cover being more prone to deformation. This creates a gap between the top cover and the casing on the long side, which can easily cause light leakage during laser welding of the casing and top cover. This can damage the Mylar film encasing the electrode components inside the cell and the separator located between the positive and negative electrode plates, creating a safety risk.

[0031] This utility model provides an electronic device 1000. For ease of explanation, the following embodiments use a vehicle as an example to illustrate the electronic device 1000. See also... Figure 1The vehicle has a battery pack 1002 installed inside, which can be located at the bottom, front, or rear of the vehicle body 1001. The battery pack 1002 can be used to power the vehicle; for example, it can serve as the vehicle's operating power source. The working part of the electronic device 1000 is electrically connected to the battery pack 1002 to obtain electrical power. The vehicle can be a gasoline-powered vehicle, a natural gas-powered vehicle, or a new energy vehicle. New energy vehicles can be pure electric vehicles, hybrid electric vehicles, or range-extended electric vehicles, but are not limited thereto. The working part is the vehicle body, and the battery pack 1002 is located at the bottom of the vehicle body, providing electrical power for the vehicle's movement or the operation of its internal electrical components. However, in some other embodiments, the electronic device 1000 can also be a mobile phone, portable device, laptop, ship, spacecraft, electric toy, and power tool, etc. Spacecraft include airplanes, rockets, space shuttles, and spacecraft, etc.; the working part can obtain electrical energy from the battery pack 1002 and perform corresponding functions, such as a fan blade rotation unit or a vacuum cleaner's suction unit. Electric toys include stationary or mobile electric toys, such as game consoles, electric car toys, electric boat toys, and electric airplane toys, etc.; power tools include metal cutting power tools, grinding power tools, assembly power tools, and railway power tools, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete vibrators, and electric planers, etc. This application does not impose any special limitations on the aforementioned electronic device 1000.

[0032] Figure 2 A cross-sectional view of the battery cell housing 100 according to the first embodiment of this application is shown, taken along a plane parallel to the height and length directions of the battery cell, wherein the cover plate 20 and the housing 10 are not welded. Figure 3 A cross-sectional view of the battery cell housing 100 according to the first embodiment of this application is shown, taken along a plane parallel to the height direction and width (thickness) direction of the battery cell, wherein the cover plate 20 and the housing 10 are not welded. Figure 4 A cross-sectional view of the battery cell housing 100 according to the first embodiment of this application is shown, taken along a plane parallel to the height and length directions of the battery cell, wherein the cover plate 20 and the housing 10 have been welded.

[0033] Figure 5 A cross-sectional view of the battery cell housing 100 according to the second embodiment of this application is shown, taken along a plane parallel to the height and length directions of the battery cell, wherein the cover plate 20 and the housing 10 are not welded. Figure 6 A cross-sectional view of the battery cell housing 100 according to the second embodiment of this application is shown, taken along a plane parallel to the height direction and width (thickness) direction of the battery cell, wherein the cover plate 20 and the housing 10 are not welded.

[0034] Figure 7A cross-sectional view of the battery cell housing 100 according to the third embodiment of this application is shown, taken along a plane parallel to the height and length directions of the battery cell, wherein the cover plate 20 and the housing 10 are not welded. Figure 8 A cross-sectional view of the battery cell housing 100 according to the third embodiment of this application is shown, taken along a plane parallel to the height direction and width (thickness) direction of the battery cell, wherein the cover plate 20 and the housing 10 are not welded.

[0035] The battery cell in this embodiment is, for example, a prismatic battery. The battery cell includes a battery casing 100 and an electrode assembly. The battery casing 100 includes a housing 10 and a cover / top cover (aluminum sheet) 20 that covers the opening 12 of the housing 10 and defines a receiving cavity for the housing 10. The housing 10 includes a bottom wall 30 opposite to the opening 12 and a first side wall 31, a second side wall 32, a third side wall 33, and a fourth side wall 34 that surround the bottom wall 30 and the opening 12 and are sequentially connected. The first side wall 31 is opposite to the third side wall 33, and the second side wall 32 and the fourth side wall 34 are opposite to each other. Along the length direction from the second side wall 32 to the fourth side wall 34, the first side wall 31 and the third side wall 33 have a first dimension (C + the wall thickness of the two housings 10). Along the width direction from the first side wall 31 to the third side wall 33, the second side wall 32 and the fourth side wall 34 have a second dimension (c + the wall thickness of the two housings 10). The first dimension is larger than the second dimension. In other words, the first sidewall 31 and the third sidewall 33 are the long sides of the prismatic battery, and the second sidewall 32 and the fourth sidewall 34 are the short sides of the prismatic battery. The aforementioned dimension C is the distance between the second sidewall 32 and the fourth sidewall 34, and the aforementioned dimension c is the distance between the first sidewall 31 and the third sidewall 33. The wall thickness of the casing 10 ranges from 0.2 mm to 3 mm.

[0036] The housing cavity accommodates the electrode assembly, electrolyte, and other necessary battery components. Specifically, the size of the housing 10 can be determined based on the specific size and number of the electrode assembly. The housing 10 can be made of various materials, such as copper, iron, aluminum, steel, or aluminum alloy. To prevent the cell housing 100 from rusting during long-term use, a rust-preventive material such as metallic nickel can be plated onto the surface of the housing 10.

[0037] In the first to third embodiments, the housing 10 has a stepped structure 14 at the opening 12, and the cover plate 20 is supported on the stepped structure 14. The first portion 21 of the cover plate 20, facing away from the electrode assembly, is welded to the housing 10. The second portion 22 of the cover plate 20, located between the first portion 21 and the stepped structure 14, has a first gap 41 between it and the sidewall of the opening 12. Before the housing 10 and the cover plate 20 are welded, the first gap 41 is also located between the first portion 21 of the cover plate 20 and the sidewall of the opening 12. By setting a first gap 41 between the cover plate 20 and the sidewall of the opening 12, the embodiments of this application can avoid interference between the cover plate 20 and the housing 10 when it is placed in the opening 12. This allows for dimensional manufacturing tolerances when obtaining the corresponding designed cover plate 20 and housing 10 using appropriate molds and stamping processes, improving manufacturability, reducing equipment requirements, reducing assembly difficulty, and improving the yield of the battery cells. By setting a stepped structure 14 around the support cover plate 20 in the opening 12, light leakage during laser welding of the cover plate 20 and the housing 10 is prevented from damaging the separator and Mylar membrane inside the cell, thus avoiding a reduction in the safety performance of the cell.

[0038] In the first to third embodiments, the first gap 41 is located between the cover plate 20 and the first sidewall 31, the second sidewall 32, the third sidewall 33, and the fourth sidewall 34, and the stepped structure 14 is located on the first sidewall 31, the second sidewall 32, the third sidewall 33, and the fourth sidewall 34. In embodiments where the cell is a prismatic battery, the four sides (including the long and short sides) of the cover plate 20 and the housing 10 are clearance fits to prevent the cover plate 20 from interfering with the housing 10 at the edges and deforming, especially to prevent the cover plate 20 from deforming in the length direction. The difficulty of assembling the cover plate 20 and the housing 10 before welding is reduced, no need for equipment to increase the external force, reduce equipment costs, improve manufacturability, and improve the yield of the cell. Furthermore, while the first gap 41 exists on all four sidewalls of the cover plate 20 and the housing 10, the stepped structure 14 is used to block the laser during the welding of the cover plate 20 and the housing 10. Projected along the direction from the cover plate 20 to the electrode assembly, the first gap 41 falls entirely on the stepped structure 14. The first gap 41 is completely blocked and covered by the stepped structure 14 to prevent damage and loss of function of the internal structural components of the battery cell caused by laser runaway and light leakage, thereby improving the safety performance of the battery cell.

[0039] In the first to third embodiments, see, for example, see Figure 2 Let A be the distance between the second sidewall 32 and the fourth sidewall 34 at opening 12, and let σ3 be the difference between A and C. Figure 2 The sum of the dimensions of the stepped structures 14 on the left and right sides along the length direction, σ3, has a range of values, for example, >0.05mm.

[0040] In the first to third embodiments, see, for example, continuing to see Figure 2The length of the cover plate 20 is B. The difference σ1 between A and B is the sum of the length-direction dimensions of the first gaps 41 on the left and right sides between the cover plate 20 and the second side wall 32 and the fourth side wall 34. The value range of σ1 is, for example, >0.05mm and σ1<σ3.

[0041] In the first to third embodiments, see, for example, continuing to see Figure 2 The thickness (height) of the cover plate 20 is D, and the value of D is, for example, 0.5mm. <D<3mm。

[0042] In the first to third embodiments, see, for example, see Figure 3 The distance between the first sidewall 31 and the third sidewall 33 at opening 12 is a, and the difference σ4 between a and c is... Figure 3 The sum of the dimensions of the stepped structures 14 on the left and right sides along the width direction, σ4, has a range of values, for example, >0.5mm.

[0043] In the first to third embodiments, see, for example, continuing to see Figure 3 The width of the cover plate 20 is b. The difference σ2 between a and b is the sum of the width-direction dimensions of the first gaps 41 on the left and right sides between the cover plate 20 and the first side wall 31 and the third side wall 33. The value range of σ2 is, for example, >0.5mm and σ2<σ4.

[0044] After the cover plate 20 and the housing 10 are welded in the first to third embodiments, from the appearance of the battery cell, the first gap 41 between the cover plate 20 and the housing 10 is filled by the molten pool of the cover plate 20 and the housing 10. However, for example, after metallographic cutting, the first gap 41, which is closed by the molten pool below the molten pool, can be observed on the cross-section. Figure 4 As shown. In Figure 4 In the middle, the maximum height of the first gap 41 is ≥0.3mm, and this maximum value is less than the aforementioned dimension D; along the opposite direction of the length, the first gap 41 is in Figure 4 The maximum value of the dimension at one location on the left or right side (i.e., the maximum gap) is ≥0.025mm, which is 1 / 2 of the aforementioned dimension σ1; the first gap 41 is in Figure 4 The cross-sectional area at one location on the left or right side of the center is ≥0.01mm. 2 .

[0045] The difference between the first embodiment and the second and third embodiments is that the bottom surface of the cover plate 20 facing the electrode assembly is flush with the supporting surface of the step structure 14 supporting the cover plate 20. In the first embodiment, the cover plate 20 no longer extends into the cell, and the cover plate 20 occupies less height space, thereby reducing the total height of the cell and the size of the cell.

[0046] In the second and third embodiments, the cover plate 20 further includes a third portion 23 located between the stepped structure 14 and the electrode assembly, with a second gap 42 between the third portion 23 and the housing 10. The third portion 23 facilitates the positioning of the cover plate 20 and the housing 10, while the second gap 42 prevents interference between the cover plate 20 and the housing 10. In the second and third embodiments, the third portion 23 of the cover plate 20 may be a hollow structure, i.e., it can accommodate other structures of the cover plate assembly, so that the third portion 23 can also provide the benefit of assisting in the positioning of the cover plate 20 without changing the height of the battery cell.

[0047] In the second embodiment, the supporting surface of the stepped structure 14 supporting the cover plate 20 is parallel to the top surface of the cover plate 20 facing away from the electrode assembly, and the stepped structure 14 may have a right-angled shape. In the third embodiment, the supporting surface of the stepped structure 14 supporting the cover plate 20 is inclined towards the electrode assembly in the direction from the cover plate 20 to the electrode assembly, and the shape of the second part 22 of the cover plate 20 matches the supporting surface, which can facilitate the positioning of the cover plate 20 in the housing 10. The stepped structure is not limited to a right-angled shape, but may also be triangular or other shapes.

[0048] The above description is merely a preferred embodiment of this utility model and is not intended to limit the utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A battery cell casing, characterized in that, include: A housing for accommodating the electrode assembly, and having an opening; A cover plate is placed over the opening. The housing has a stepped structure at the opening, the cover plate is supported on the stepped structure, a first portion of the cover plate opposite to the electrode assembly is welded to the housing, and a second portion of the cover plate located between the first portion and the stepped structure has a first gap between it and the sidewall of the opening.

2. The battery cell casing according to claim 1, characterized in that, The housing includes a bottom wall opposite the opening and a first side wall, a second side wall, a third side wall, and a fourth side wall that surround the bottom wall and the opening and are connected in sequence. The first side wall is opposite to the third side wall, and the second side wall is opposite to the fourth side wall. Along the length direction from the second sidewall to the fourth sidewall, the first sidewall and the third sidewall have a first dimension. Along the width direction from the first sidewall to the third sidewall, the second sidewall and the fourth sidewall have a second dimension, wherein the first dimension is larger than the second dimension. The first gap is located between the cover plate and the first side wall, the second side wall, the third side wall, and the fourth side wall, and the stepped structure is located on the first side wall, the second side wall, the third side wall, and the fourth side wall.

3. The battery cell casing according to claim 1, characterized in that, Projected along the direction from the cover plate to the electrode assembly, the first gap falls entirely on the stepped structure.

4. The battery cell casing according to claim 1, characterized in that, The bottom surface of the cover plate facing the electrode assembly is flush with the supporting surface of the step structure that supports the cover plate.

5. The battery cell casing according to claim 1, characterized in that, The cover plate also includes a third portion located between the stepped structure and the electrode assembly, the third portion having a second gap between it and the housing.

6. The battery cell casing according to claim 1, characterized in that, The stepped structure supports the cover plate on a surface parallel to the top surface of the cover plate away from the electrode assembly.

7. The battery cell casing according to claim 1, characterized in that, The stepped structure supports the cover plate, with the support surface inclined toward the electrode assembly in the direction from the cover plate toward the electrode assembly.

8. A battery cell, characterized in that, include: The cell housing as described in any one of claims 1-7, wherein the cover plate covers the housing and defines a receiving cavity with the housing; The electrode assembly is housed within the receiving cavity.

9. A battery pack, characterized in that, Includes the battery cell as described in claim 8.

10. An electronic device, characterized in that, Includes the battery pack as described in claim 9.

Images