Battery cell and electric equipment
By adding an additional venting path to the cell cover, the problem of insulating tape clogging the venting holes was solved, enabling effective exhaust of gas inside the cell and improving the liquid injection efficiency.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- SVOLT ENERGY TECHNOLOGY CO LTD
- Filing Date
- 2026-03-11
- Publication Date
- 2026-05-08
AI Technical Summary
In existing battery cell structures, the insulating tape on the electrode surface and the vent holes are prone to physical interference, resulting in incomplete venting and causing the battery cell to bulge.
An additional venting path is added to the cover plate. By connecting the liquid outlet and the liquid injection tank, a venting notch and a venting gap are set to form a new venting path (venting gap - venting notch - liquid outlet - liquid injection tank - liquid injection hole) to facilitate gas discharge.
This avoids the bulging problem caused by incomplete venting of the battery cell, improves the liquid injection efficiency and gas venting effect, and ensures the internal air pressure balance of the battery cell.
Smart Images
Figure CN122000415A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of battery technology, and in particular to a battery cell and an electrical device. Background Technology
[0002] In the battery manufacturing process, the pre-charging stage and the baking stage before electrolyte filling are key processes to ensure battery performance and safety. Among them, the pre-charging process is the core link for the first charging activation of the battery cell. During this process, the electrolyte and electrode materials undergo an interfacial reaction, which inevitably generates trace amounts of gas. The baking process before electrolyte filling aims to remove moisture from the inside of the battery cell (including components such as the electrode assembly and casing) to prevent moisture from reacting with the electrolyte to generate harmful gases that affect battery performance. During this baking process, trace amounts of residual organic matter inside the battery cell and the evaporation of moisture will also generate a certain amount of gas.
[0003] To effectively expel the gas generated during the aforementioned processes, existing battery cell structures typically include electrolyte drainage holes beneath the plastic under the cover plate as venting ports. These holes guide the gas inside the cell to the outside, preventing gas accumulation and pressure buildup. However, during cell assembly, the electrode assembly surfaces are usually covered with insulating tape to secure the electrode assembly structure and prevent short circuits between the electrode assembly and metal components such as the casing and cover plate. However, the tape is prone to misalignment, wrinkles, or over-covering, causing physical interference between the tape and the electrolyte drainage holes beneath the cover plate. This blockage of the venting ports leads to incomplete gas expulsion and cell bulging. Summary of the Invention
[0004] The purpose of this application is to provide a battery cell and an electrical device that solves the problem that existing battery cell structures typically have electrolyte drainage holes under the plastic cover as venting holes to guide the gas inside the battery cell to the outside. However, the insulating tape on the electrode surface and the venting holes are prone to physical interference, which can block the venting holes and cause the battery cell to bulge due to incomplete venting.
[0005] According to a first aspect of this application, a battery cell is provided. The cover plate has a thickness direction. The battery cell includes a cover plate and a housing. The cover plate includes a cover plate body and a first plastic part. The first plastic part is connected to one side of the cover plate body in the thickness direction. Along the thickness direction, the first plastic part and the cover plate body are projected onto a plane perpendicular to the thickness direction. The projected outline of the first plastic part falls completely within the projected outline range of the cover plate body. The cover plate body has a through-hole for liquid injection. The first plastic part includes an outlet groove and an injection groove that are connected to each other. The injection groove is correspondingly connected to the injection hole. The first bottom wall of the injection groove has an injection guide hole. The housing is connected to the cover plate body at a portion corresponding to the outer edge of its projected outline and forms an exhaust gap with the outlet groove. The side wall of the outlet groove has an exhaust notch that communicates with the exhaust gap.
[0006] In any of the above technical solutions, a venting groove is further provided on the side of the cover plate body facing the first plastic part. One end of the venting groove extends to the injection groove and the other end extends to the outlet groove to connect the injection groove and the outlet groove.
[0007] In any of the above technical solutions, the second bottom wall of the liquid outlet tank is provided with a liquid outlet.
[0008] In any of the above technical solutions, the cover plate further includes a length direction that is perpendicular to the thickness direction, the liquid outlet groove and the liquid injection groove are respectively disposed at opposite ends of the first plastic part in the length direction, and the venting groove extends along the length direction.
[0009] In any of the above technical solutions, the cover plate further satisfies: S1 / S2=0.15~0.3, S1 is the cross-sectional area of the vent groove perpendicular to the length direction, and S2 is the cross-sectional area of the injection hole, wherein the cutting direction of the cross section is perpendicular to the thickness direction.
[0010] In any of the above technical solutions, the cover plate further includes a width direction and a thickness direction, wherein the length direction, the width direction, and the thickness direction are mutually perpendicular; the venting groove is a rectangular groove, and the injection hole is a circular hole; S1 = m × n, where m is the dimension of the venting groove in the thickness direction, and n is the dimension of the venting groove in the width direction; S2 = π × r 2 r is the radius of the injection hole.
[0011] In any of the above technical solutions, further, the cross-sectional area of the venting notch perpendicular to the length direction is greater than the cross-sectional area of the injection hole.
[0012] In any of the above technical solutions, the cover plate further has a thickness direction perpendicular to the length direction; the exhaust notch is opened on one side of the side wall in the length direction, and the side of the exhaust notch facing the cover plate body is open; in the thickness direction, the distance between the exhaust notch and the second bottom wall is >3mm.
[0013] In any of the above technical solutions, the central region of the first bottom wall is positioned directly opposite the injection hole, the central region of the first bottom wall is a solid structure, and the number of injection guide holes is multiple, with the multiple injection guide holes arranged circumferentially along the solid structure.
[0014] A second aspect of this application provides an electrical device including a battery cell as described above.
[0015] The battery cell of this application includes a cover plate and a housing. The cover plate includes a cover plate body and a first plastic part, which is connected to one side of the cover plate body. The cover plate body has a liquid injection hole that penetrates through it. The first plastic part includes a liquid outlet groove and a liquid injection groove that are connected to each other. The liquid injection groove is connected to the liquid injection hole. The first bottom wall of the liquid injection groove has a liquid guide hole that penetrates through it. The housing is connected to the outer edge of the cover plate body and forms an exhaust gap with the liquid outlet groove. The side wall of the liquid outlet groove has an exhaust notch that communicates with the exhaust gap.
[0016] The cover plate of this application adds an additional venting path to the existing venting path (injection guide hole - injection tank - injection hole), that is, connecting the outlet tank and the injection tank, and opening an venting notch on the side wall of the outlet tank that communicates with the venting gap, thereby connecting the venting gap and the outlet tank, thus forming a new additional venting path (venting gap - venting notch - outlet tank - injection tank - injection hole). With this configuration, when the injection guide hole is blocked, the gas inside the cell can pass through the venting gap - venting notch - outlet tank - injection tank - injection hole, thus avoiding the problem of incomplete venting of the cell causing cell swelling. On the other hand, when a vacuum is drawn during the injection process, because the injection tank and the inside of the cell are connected by the additional venting path, the gas pressure inside the injection tank and the cell is close to the same, making it less likely for the electrode assembly to block the injection guide hole, thus facilitating venting.
[0017] To make the above-mentioned objectives, features and advantages of this application more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description
[0018] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.
[0019] Figure 1 A schematic diagram of the overall exploded structure of a battery cell according to an embodiment of this application is shown; Figure 2 A schematic diagram of the cover plate body according to an embodiment of this application is shown; Figure 3 A schematic diagram of the structure of a first plastic part according to an embodiment of this application is shown; Figure 4 Show Figure 1 Top view; Figure 5 Show Figure 4 A schematic diagram of the AA cross-sectional structure; Figure 6 Show Figure 3 Another structural diagram from another perspective; Figure 7 Show Figure 2 Top view.
[0020] Icons: 100-Cover plate body; 110-Injection hole; 120-Ventilation groove; 200-First plastic part; 210-Outlet groove; 211-Ventilation notch; 212-Second bottom wall; 213-Outlet; 220-Injection groove; 221-First bottom wall; 222-Injection guide hole; X-Length direction; Y-Width direction; Z-Thickness direction. Detailed Implementation
[0021] The following detailed embodiments are provided to help the reader gain a comprehensive understanding of the methods, apparatus, and / or systems described herein. However, various changes, modifications, and equivalents of the methods, apparatus, and / or systems described herein will be apparent after understanding the disclosure of this application. For example, the order of operations described herein is merely illustrative and is not limited to the order set forth herein; changes that will be apparent after understanding the disclosure of this application are possible, except for operations that must occur in a specific order. Furthermore, for clarity and brevity, descriptions of features known in the art may be omitted.
[0022] The features described herein may be implemented in different forms and should not be construed as being limited to the examples described herein. Rather, the examples described herein have been provided merely to illustrate some of the many feasible ways of implementing the methods, apparatus, and / or systems described herein that will be apparent upon understanding the disclosure of this application.
[0023] Throughout the specification, when an element (such as a layer, region, or substrate) is described as being "on" another element, "connected to" another element, "bonded to" another element, "on" another element, or "covering" another element, it may be directly "on" another element, "connected to" another element, "bonded to" another element, "on" another element, or "covering" another element, or there may be one or more other elements in between. In contrast, when an element is described as being "directly on" another element, "directly connected to" another element, "directly bonded to" another element, "directly on" another element, or "directly covering" another element, there may be no other elements in between.
[0024] As used herein, the term “and / or” includes any one of the relevant items listed and any combination of any two or more items.
[0025] Although terms such as “first,” “second,” and “third” may be used herein to describe individual components, assemblies, regions, layers, or parts, these components, assemblies, regions, layers, or parts are not limited by these terms. Rather, these terms are used only to distinguish one component, assembly, region, layer, or part from another. Therefore, without departing from the teachings of the examples described herein, the first component, assembly, region, layer, or part referred to as the second component, assembly, region, layer, or part may also be referred to as the second component, assembly, region, layer, or part.
[0026] For ease of description, spatial relation terms such as “above,” “upper,” “below,” and “lower” are used herein to describe the relationship between one element and another, as shown in the accompanying drawings. Such spatial relation terms are intended to include not only the orientation depicted in the drawings but also different orientations of the device during use or operation. For example, if the device in the drawings is flipped, an element described as being “above” or “upper” relative to another element will subsequently be “below” or “lower” relative to that other element. Therefore, the term “above” includes both “above” and “below” orientations depending on the spatial orientation of the device. The device may also be positioned in other ways (e.g., rotated 90 degrees or in other orientations), and the spatial relation terms used herein will be interpreted accordingly.
[0027] The terminology used herein is for the purpose of describing various examples only and is not intended to limit this disclosure. Unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. The terms “comprising,” “including,” and “having” enumerate the stated features, quantities, operations, components, elements, and / or combinations thereof, but do not exclude the presence or addition of one or more other features, quantities, operations, components, elements, and / or combinations thereof.
[0028] Variations in the shapes shown in the accompanying drawings may occur due to manufacturing techniques and / or tolerances. Therefore, the examples described herein are not limited to the specific shapes shown in the accompanying drawings, but include changes in shape that may occur during manufacturing.
[0029] The features of the examples described herein can be combined in various ways that will be apparent upon understanding the disclosure of this application. Furthermore, although the examples described herein have a wide variety of constructions, other constructions are possible, as will be apparent upon understanding the disclosure of this application.
[0030] The first aspect of this application provides a battery cell that solves the problem that existing battery cell structures typically have electrolyte drainage holes under the plastic cover as venting holes to guide gas inside the cell to the outside. However, the insulating tape on the electrode surface easily interferes with the venting holes, thus blocking them and causing incomplete venting and cell bulging. See below for reference. Figures 1 to 7 The cover plate described according to some embodiments of this application is further illustrated. Additionally, for ease of description, the cover plate will hereinafter be described as having a length direction X, a width direction Y, and a thickness direction that are perpendicular to each other.
[0031] like Figure 1 , Figure 3 , Figure 5 and Figure 6 As shown, the battery cell of this application includes a cover plate and a housing. The cover plate includes a cover plate body 100 and a first plastic part 200. The first plastic part 200 is connected to one side of the cover plate body 100, and the outer edge of the first plastic part 200 is disposed on the inner side of the outer edge of the cover plate body 100 (that is, along the thickness direction Z, the projection of the first plastic part 200 and the cover plate body 100 onto a plane perpendicular to the thickness direction Z, the projection outline of the first plastic part 200 completely falls within the projection outline range of the cover plate body 100); the cover plate body 100 has a through-hole injection hole 110, and the first plastic part 200 includes an outlet groove 210 and an injection groove 220 that are connected to each other. The injection groove 220 is correspondingly connected to the injection hole 110, and the first bottom wall 221 of the injection groove 220 has an injection guide hole 222 that extends through it; as Figure 5 and Figure 6As shown, the housing is connected to the outer edge of the cover plate body 100 corresponding to its projected outline (the housing is not shown in the figure), and an exhaust gap is formed between it and the liquid outlet 210. The side wall of the liquid outlet 210 is provided with an exhaust notch 211 that communicates with the exhaust gap.
[0032] With this configuration, the cover plate of this application adds an additional venting path to the original venting path (injection guide hole 222-injection tank 220-injection hole 110), that is, connecting the outlet tank 210 and the injection tank 220, and opening an venting notch 211 on the side wall of the outlet tank 210 to connect the venting gap and the outlet tank 210, thereby forming a new additional venting path (venting gap-venting notch 211-outlet tank 210-injection tank 220-injection hole 110). With this configuration, when the injection guide hole 222 is blocked, the gas inside the cell can pass through the venting gap-venting notch 211-outlet tank 210-injection tank 220-injection hole 110, so as to avoid the problem of cell swelling caused by incomplete venting of the cell. On the other hand, when the liquid injection process is vacuumed, since the liquid injection tank 220 and the inside of the cell are connected by an additional exhaust path, the gas pressure inside the liquid injection tank 220 and the inside of the cell are close to the same, and the electrode group is less likely to block the liquid injection guide hole 222, thus facilitating exhaust.
[0033] In the embodiments of this application, in order to facilitate the manufacture of the cover plate and avoid increasing the volume, as an example, such as Figure 1 , Figure 2 and Figure 5 As shown, a venting groove 120 is provided on the side of the cover plate body 100 facing the first plastic part 200. One end of the venting groove 120 extends to the injection groove 220 and the other end extends to the outlet groove 210 to connect the injection groove 220 and the outlet groove 210. The second bottom wall 212 of the outlet groove 210 is provided with an outlet 213 that penetrates through itself.
[0034] This design ensures that when the liquid injection guide hole 222 is blocked, the gas inside the cell can pass through the venting gap-venting notch 211-liquid outlet 210-venting channel 120-liquid injection channel 220-liquid injection hole 110, thus preventing the cell from bulging due to incomplete venting. Furthermore, it allows for pressure balance between the inside and outside of the cell before sealing.
[0035] Furthermore, in the embodiments of this application, during the cell electrolyte injection process, when the conductive holes on the upper surface of the electrode assembly are blocked, the electrolyte can flow out from the venting groove 120-injection groove 220-outlet 213 and venting notch 211, thus avoiding the risk of electrolyte overflow. Simultaneously, during the cell electrolyte injection process, if the conductive holes on the upper surface of the electrode assembly are blocked without the new venting path of this application, incomplete venting inside the cell will occur, affecting the injection volume and consequently reducing the efficiency of electrolyte injection and increasing the injection time. With the addition of the new venting path in this application, the gas inside the cell can pass through the venting gap-venting notch 211-outlet groove 210-venting groove 120-injection groove 220-injection hole 110, ensuring complete venting inside the cell and thus not affecting the injection volume, thereby increasing the injection efficiency.
[0036] In the embodiments of this application, such as Figure 2 and Figure 3 As shown, the liquid outlet 210 and the liquid injection 220 are respectively located at opposite ends of the first plastic part 200 along the length direction X, and the venting groove 120 extends along the length direction X. With this arrangement, both the liquid outlet 210 and the liquid injection 220 are located at the ends, and the venting, injection, and liquid outlet related structures are arranged in an orderly manner along the length direction X. The overall structural layout is neat and avoids complex processing procedures caused by structural intersections.
[0037] In the embodiments of this application, the cover plate satisfies: S1 / S2 = 0.15~0.3, where S1 is the cross-sectional area of the vent groove 120 perpendicular to the length direction X, and S2 is the cross-sectional area of the injection hole 110, wherein the cross-sectional direction is perpendicular to the thickness direction Z. With this configuration, if S1 / S2 < 0.15, the flow capacity of the vent groove 120 is insufficient, reducing venting efficiency. If S1 / S2 > 0.3, it will affect the structural strength of the cover plate body 100. The vent groove 120 is a rectangular groove, and the injection hole 110 is a circular hole. Figure 5 and Figure 7 As shown, S1 = m × n, where m is the dimension of the exhaust groove 120 in the thickness direction Z, and n is the dimension of the exhaust groove 120 in the width direction Y; as Figure 4 As shown, S2=π×r 2 r is the radius of the injection hole 110.
[0038] The specific implementation data is as follows: 1. With an injection hole r=3mm and an vent groove width n=1.5mm, measure whether the cell thickness (17.5±0.2mm) and cover plate flatness (≤0.2) meet the requirements under different vent groove depths m:
[0039] II. With an injection hole r=2.5mm and an venting groove width n=1.5mm, measure whether the cell thickness (16.5±0.2mm) and the flatness of the cover plate (≤0.2) meet the requirements under different venting groove depths m:
[0040] 3. With an injection hole r=2mm and an venting groove width n=1mm, measure whether the cell thickness (15±0.2mm) and cover plate flatness (≤0.2) meet the requirements under different venting groove depths m:
[0041] As can be seen from the above, when S1 / S2 is in the range of 0.15 to 0.3, the cell thickness and the flatness of the cover plate body simultaneously meet the practical requirements.
[0042] In the embodiments of this application, the cross-sectional area of the venting notch 211 perpendicular to the length direction X is greater than the cross-sectional area of the injection hole 110. With this configuration, if the cross-sectional area of the venting notch 211 perpendicular to the length direction X is less than or equal to the cross-sectional area of the injection hole 110, the venting efficiency will be reduced.
[0043] As an example, such as Figure 3 As shown, the venting notch 211 is formed on one side of the sidewall in the length direction X, and the side of the venting notch 211 facing the cover plate body 100 is open. In the thickness direction Z, the distance between the venting notch 211 and the second bottom wall 212 is >3mm. If the distance between the venting notch 211 and the second bottom wall 212 is ≤3mm, it will affect the hot-melt bonding of the insulating film on the outer side of the sidewall.
[0044] Additionally, in the embodiments of this application, such as Figure 3 As shown, the middle region of the first bottom wall 221 is positioned directly opposite the injection hole 110. In order to prevent the electrolyte from impacting the electrode assembly and causing damage to the electrode sheets during the cell injection process, the middle region of the first bottom wall 221 in this application is a solid region, and multiple injection guide holes 222 are provided around the solid region.
[0045] In summary, the cover plate of this application adds an additional venting path to the original venting path (injection guide hole 222-injection tank 220-injection hole 110), that is, connecting the outlet tank 210 and the injection tank 220, and opening an venting notch 211 on the side wall of the outlet tank 210 to connect the venting gap and the outlet tank 210, thereby forming a new additional venting path (venting gap-venting notch 211-outlet tank 210-injection tank 220-injection hole 110). With this configuration, when the injection guide hole 222 is blocked, the gas inside the cell can pass through the venting gap-venting notch 211-outlet tank 210-injection tank 220-injection hole 110, so as to avoid the problem of cell swelling caused by incomplete venting of the cell. On the other hand, when the liquid injection process is vacuumed, since the liquid injection tank 220 and the inside of the cell are connected by an additional exhaust path, the gas pressure inside the liquid injection tank 220 and the inside of the cell are close to the same, and the electrode group is less likely to block the liquid injection guide hole 222, thus facilitating exhaust.
[0046] According to a second aspect of this application, an electrical device is provided, including the battery cell as described above.
[0047] Finally, it should be noted that the above-described embodiments are merely specific implementations of this application, used to illustrate the technical solutions of this application, and not to limit them. The protection scope of this application is not limited thereto. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that any person skilled in the art can still modify or easily conceive of changes to the technical solutions described in the foregoing embodiments within the scope of the technology disclosed in this application, or make equivalent substitutions for some of the technical features. Such modifications, changes, or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application, and should all be covered within the protection scope of this application.
Claims
1. A battery cell, characterized in that, The battery cell includes a cover plate and a housing. The cover plate has a thickness direction and includes a cover plate body and a first plastic part. The first plastic part is connected to one side of the cover plate body in the thickness direction. Along the thickness direction, the first plastic part and the cover plate body are projected onto a plane perpendicular to the thickness direction. The projection outline of the first plastic part falls completely within the projection outline range of the cover plate body. The cover plate body has a through-hole for liquid injection. The first plastic part includes an outlet groove and an injection groove that are connected to each other. The injection groove is connected to the injection hole. The first bottom wall of the injection groove has an injection guide hole. The housing is connected to the outer edge of the cover plate body corresponding to its projected outline, and an exhaust gap is formed between the housing and the liquid outlet groove. The side wall of the liquid outlet groove is provided with an exhaust notch that communicates with the exhaust gap.
2. The battery cell according to claim 1, characterized in that, The cover plate body has an exhaust groove on the side facing the first plastic part. One end of the exhaust groove extends to the injection groove and the other end extends to the outlet groove to connect the injection groove and the outlet groove.
3. The battery cell according to claim 2, characterized in that, The second bottom wall of the liquid outlet tank has a liquid outlet.
4. The battery cell according to claim 3, characterized in that, The cover plate also has a length direction, which is perpendicular to the thickness direction. The liquid outlet groove and the liquid injection groove are respectively disposed at opposite ends of the first plastic part in the length direction, and the venting groove extends along the length direction.
5. The battery cell according to claim 4, characterized in that, The cover plate satisfies: S1 / S2=0.15~0.3, where S1 is the cross-sectional area of the vent groove perpendicular to the length direction, and S2 is the cross-sectional area of the injection hole, wherein the cross-sectional direction is perpendicular to the thickness direction.
6. The battery cell according to claim 5, characterized in that, The cover plate also has a width direction, and the length direction, the width direction and the thickness direction are perpendicular to each other; The venting groove is a rectangular groove, and the injection hole is a round hole; S1 = m × n, where m is the dimension of the exhaust groove in the thickness direction and n is the dimension of the exhaust groove in the width direction; S2 = π × r 2 r is the radius of the injection hole.
7. The battery cell according to claim 4, characterized in that, The cross-sectional area of the venting notch perpendicular to the length direction is greater than the cross-sectional area of the injection hole.
8. The battery cell according to claim 4, characterized in that, The vent is formed on one side of the sidewall in the length direction, and the side of the vent facing the cover body is open. In the thickness direction, the distance between the vent and the second bottom wall is >3mm.
9. The battery cell according to any one of claims 1-8, characterized in that, The central region of the first bottom wall is positioned directly opposite the injection hole. The central region of the first bottom wall is a solid structure. There are multiple injection guide holes, which are arranged circumferentially along the solid structure.
10. An electrical appliance, characterized in that, Includes the battery cell as described in any one of claims 1-9.