Cover plate assembly, battery cell, battery pack and electronic device

Abstract

The utility model provides a cover plate assembly, which is used for covering a shell containing an electrode assembly, and comprises a first cover plate, a pole penetrating through the first cover plate, and a second cover plate surrounding and separably sleeved on the peripheral side wall of the first cover plate, the switching piece is welded to the pole, the welding position is located on the side, away from the pole, of the switching piece, and the switching piece is provided with a first part exceeding the peripheral side wall of the first cover plate in the radial direction of the pole and away from the first direction of the pole so as to be used for being welded to a tab of the electrode assembly. The utility model aims to provide a cover plate assembly, a battery cell, a battery pack and an electronic device, so as to at least improve the safety of the battery cell.

Description

Technical Field

[0001] This utility model relates to a cover plate assembly, 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 cover plate assembly, a battery cell, a battery pack and an electronic device, so as to at least improve the safety of the battery cell.

[0004] To achieve the above objectives, the present invention provides a cover plate assembly for covering a housing containing an electrode assembly. The cover plate assembly includes: a first cover plate, an electrode post passing through the first cover plate, a second cover plate surrounding and detachably sleeved on the outer peripheral sidewall of the first cover plate; and an adapter piece welded to the electrode post, the welding position being on the side of the adapter piece opposite to the electrode post. The adapter piece has a first portion extending beyond the outer peripheral sidewall of the first cover plate along the radial direction of the electrode post and in a first direction opposite to the electrode post, for welding to the tabs of the electrode assembly.

[0005] In some embodiments, the surface of the first portion facing away from the electrode assembly forms an area for welding with the tab.

[0006] In some embodiments, the edge of the first cover plate opposite to the adapter plate has a recess, and the second cover plate has a flange resting on the recess, the flange being welded to the recess.

[0007] In some embodiments, the countersunk platform and the flange engage with each other.

[0008] In some embodiments, the weld marks formed by the countersunk and flange welding are located on the side opposite to the electrode assembly.

[0009] In some embodiments, the cover assembly further includes: a first lower plastic surrounding the electrode post and located between the first cover and the electrode post; and a second lower plastic attached to the electrode assembly-facing surface of the second cover and surrounding the first lower plastic, the inner diameter of the second lower plastic being larger than the outer diameter of the first cover.

[0010] In some embodiments, the first lower plastic and the second lower plastic are radially separated along the pole post.

[0011] Embodiments of this application also provide a battery cell, comprising: a housing; a cover assembly of any of the above, the cover assembly covering the housing and defining a receiving cavity with the housing; and an electrode assembly housed within the receiving cavity, wherein the tabs of the electrode assembly are welded to a first portion of an adapter piece.

[0012] Embodiments of this application also provide a battery pack, including any of the cells described above.

[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] Since the cover plate assembly of the embodiments of this application is divided into a first cover plate and a second cover plate, and the welding position of the adapter piece and the electrode post is on the side of the adapter piece away from the electrode post, compared with the prior art embodiment of welding from the outside of the electrode post, it is not necessary to thin the electrode post in advance. While ensuring the welding effect, the electrode post will not be welded through during welding, avoiding the risk of electrolyte leakage, and thus preventing corrosion caused by leaked electrolyte, thereby improving the safety 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 A schematic diagram of a prior art electrode assembly connected to an electrode post via an adapter plate is shown.

[0018] Figure 2 A schematic diagram is shown when the electronic device according to an embodiment of this application is a vehicle.

[0019] Figure 3 An exploded view of a cover plate assembly according to an embodiment of this application is shown.

[0020] Figure 4 A top view of a cover plate assembly according to an embodiment of this application is shown, as well as a cross-sectional view taken along line AA of the top view.

[0021] Figure 5 It shows Figure 4 An enlarged view of region B in the cross-sectional view.

[0022] Figure 6 It shows Figure 4 An enlarged view of region E of the cross-sectional view.

[0023] Figure 7 A top view of the first cover plate assembly and a cross-sectional view taken along the CC line of the top view are shown.

[0024] Figure 8 An exploded view of the first cover plate assembly is shown.

[0025] Figure 9 A perspective view of the second cover plate is shown.

[0026] Figure 10 A top view of the second cover plate and a cross-sectional view taken along line DD of the top view are shown.

[0027] Figure 11 A schematic diagram showing the connection between the electrode assembly and the first cover plate assembly according to an embodiment of this application is provided. Detailed Implementation

[0028] To better understand the spirit of the embodiments of this application, the following description is based on some preferred embodiments of this application.

[0029] 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.

[0030] 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.

[0031] 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.

[0032] 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.

[0033] See Figure 1 In existing battery cell technology, the adapter plate 1 is first connected to the tab 3 of the electrode assembly 2 via through-welding. Then, a cover plate assembly 4 is placed on top, and the electrode post of the cover plate assembly 4 is welded to the adapter plate 1 from above. The electrode post needs to be pre-drilled to form a blind hole to reduce the thickness at the welding position, allowing the bottom of the blind hole (the thinned base plate of the electrode post) to be welded to the adapter plate 1 via through-welding. During the welding process, it is easy to weld through the base plate of the electrode post, causing electrolyte leakage from the weld-through point and resulting in corrosion.

[0034] 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 2 The 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.

[0035] The battery cell, for example, is a prismatic battery, comprising: a casing; a cover assembly 150 covering the casing and defining a receiving cavity within the casing; and an electrode assembly 120 housed within the receiving cavity. The casing includes a bottom wall and side walls surrounding the bottom wall, and the receiving cavity houses the electrode assembly 120, electrolyte, and other necessary battery components. Specifically, the size of the casing can be determined based on the specific size and number of the electrode assembly 120. The casing can be made of various materials, such as copper, iron, aluminum, steel, or aluminum alloy. To prevent the battery casing from rusting during long-term use, a rust-resistant material such as metallic nickel can be plated onto the surface of the casing.

[0036] Figure 3 An exploded view of a cover plate assembly 150 according to an embodiment of this application is shown. Figure 4 A top view of a cover plate assembly 150 according to an embodiment of this application, and a cross-sectional view taken along line AA of the top view are shown. Figure 5 It shows Figure 4 An enlarged view of region B in the cross-sectional view. Figure 6 It shows Figure 4 A magnified view of region E in the cross-sectional view. Figure 7 A top view of the first cover plate assembly 110 and a cross-sectional view taken along the CC line of the top view are shown. Figure 8 An exploded view of the first cover plate assembly 110 is shown, in which Figure 7 and Figure 8 The lower plastic 50 of the first cover assembly 110 is not shown. Figure 9 A perspective view of the second cover plate 20 is shown. Figure 10 A top view of the second cover plate 20 and a cross-sectional view taken along line DD of the top view are shown.

[0037] The cover plate assembly 150 includes two first cover plate assemblies 110 (the polarities of the poles of the two first cover plate assemblies 110 are opposite), a second cover plate 20 (the second cover plate 20 is a sheet of light aluminum) surrounding the two first cover plate assemblies 110, a second lower plastic 60 attached to the lower surface (the surface facing the electrode assembly 120) of the second cover plate 20, and a pressure relief structure 24 disposed on the second cover plate 20. The first cover plate assembly 110 includes a first cover plate 10, the second cover plate 20 being detachably fitted around and onto the outer peripheral sidewall of the first cover plate 10; a pole 30 passing through the first cover plate 10; an upper plastic 90 held by the outer flange 32 of the pole 30 and the first cover plate 10; a first lower plastic 50 held by the inner flange 34 of the pole 30 and the first cover plate 10; and a sealing member 92 disposed between the columnar portion 36 of the pole 30, the inner flange 34, and the first cover plate 10 to provide a seal.

[0038] Figure 11A schematic diagram of the electrode assembly 120 connected to the first cover plate assembly 110 via an adapter piece 40 according to an embodiment of this application is shown. First, the adapter piece 40 and the electrode post 30 of the first cover plate assembly 110 are welded together (e.g., by laser welding) from the surface of the adapter piece 40 opposite to the first cover plate assembly 110. Then, the welded adapter piece 40 and the first cover plate assembly 110 are placed on the electrode assembly 120, along the radial direction of the electrode post 30 and away from the first direction of the electrode post 30 (radial outward of the electrode post 30). The adapter piece 40 has a first portion 41 extending beyond the outer peripheral sidewall of the first cover plate 10. The electrode tab 122 of the electrode assembly 120 is welded to the first portion 41 of the adapter piece 40. Finally, the second cover plate 20 and the second lower plastic 60 attached to the lower surface of the second cover plate 20 are used to cover the housing containing the electrode assembly 120. The first cover plate 10 and the second cover plate 20 are welded together by laser welding to complete the cell assembly. Since the cover plate assembly 50 of the embodiments of this application is divided into a first cover plate 10 and a second cover plate 20, and the welding position of the adapter piece 40 and the electrode post 30 is on the side of the adapter piece 40 away from the electrode post 30, compared with the prior art embodiment of welding from the outside of the electrode post, it is not necessary to thin the electrode post 30 in advance. While ensuring the welding effect, the electrode post 30 will not be welded through during welding, avoiding the risk of electrolyte leakage, and thus preventing corrosion caused by leaked electrolyte, thereby improving the safety of the battery cell.

[0039] The electrode tab 122 is welded to the area on the surface of the first part 41 away from the electrode assembly 120, which saves space compared to the embodiment in which the electrode tab 122 is welded to the lower surface of the first part 41, thus saving the space required to fold and flatten the electrode tab.

[0040] See Figure 6 The first cover plate 10 has a recessed edge 12 on the side opposite to the adapter piece 40. The second cover plate 20 has a flange 22 on the hole wall for mating with the first cover plate 10, which rests on the recessed edge 12. The flange 22 is welded to the recessed edge 12. The recessed edge of the flange 22 facilitates the mating of the first cover plate 10 and the second cover plate 20 when the second cover plate 20 is finally closed on the housing. Furthermore, the recessed edge 12 and the flange 22 interlock to achieve precise alignment of the first cover plate 10 and the second cover plate 20. The weld mark formed by the welding of the recessed edge 12 and the flange 22 is located on the side opposite to the electrode assembly 120. The weld mark does not protrude downward from the bottom surface of the first cover plate 10 and the second cover plate 20. Therefore, the weld mark formed by the welding of the first cover plate 10 and the second cover plate 20 will not affect the electrode assembly 120. For example, if welding slag falls off the weld mark due to vibration or other reasons, the welding slag will not fall into the cell and puncture the components inside the cell.

[0041] A first lower plastic insert 50 surrounds the electrode post 30 and is located between the first cover plate 10 and the electrode post 30. A second lower plastic insert 60 is attached (e.g., by heat fusion or adhesive) to the surface of the second cover plate 20 facing the electrode assembly 120 and surrounds the first lower plastic insert 50. The inner diameter of the second lower plastic insert 60 is larger than the outer diameter of the first cover plate 10. When the second lower plastic insert 60 is finally closed with the second cover plate 20, it will not interfere with the first cover plate 10. The first lower plastic insert 50 and the second lower plastic insert 60 are radially spaced along the electrode post 30, thus there is a fitting clearance between the first lower plastic insert 50 and the second lower plastic insert 60 to ensure that they do not interfere with each other during installation.

[0042] 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 cover assembly for covering a housing containing an electrode assembly, characterized in that, The cover plate assembly includes: A first cover plate, a pole passing through the first cover plate, and a second cover plate that surrounds and is detachably fitted onto the outer peripheral sidewall of the first cover plate; An adapter piece is welded to the electrode post, with the welding position on the side of the adapter piece opposite to the electrode post. Wherein, along the radial direction of the pole post and in a first direction away from the pole post, the adapter piece has a first portion extending beyond the outer peripheral sidewall of the first cover plate for welding to the tab of the electrode assembly.

2. The cover plate assembly according to claim 1, characterized in that, The surface of the first portion facing away from the electrode assembly forms an area for welding with the tab.

3. The cover plate assembly according to claim 1, characterized in that, The first cover plate has a recessed edge on the side opposite to the adapter piece, and the second cover plate has a flange that rests on the recessed edge and is welded to the recessed edge.

4. The cover plate assembly according to claim 3, characterized in that, The recessed platform and the flange are interlocked.

5. The cover plate assembly according to claim 3, characterized in that, The weld mark formed by welding the countersunk platform and the flange is located on the side opposite to the electrode assembly.

6. The cover plate assembly according to claim 1, characterized in that, Also includes: A first plastic layer surrounds the pole post and is located between the first cover plate and the pole post; A second lower plastic is attached to the surface of the second cover plate facing the electrode assembly and surrounds the first lower plastic, wherein the inner diameter of the second lower plastic is larger than the outer diameter of the first cover plate.

7. The cover plate assembly according to claim 6, characterized in that, The first lower plastic and the second lower plastic are radially separated along the pole post.

8. A battery cell, characterized in that, include: case; The cover assembly as described in any one of claims 1-7, the cover assembly covering the housing and defining a receiving cavity with the housing; An electrode assembly is housed within the receiving cavity, and the tabs of the electrode assembly are welded to the first portion of the adapter piece.

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.

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