Battery cell and battery cell housing

Abstract

The application provides a shell of an electric core and the electric core. The shell of the electric core comprises a sleeve, a first end plate arranged at an upper end of the sleeve, and a second end plate arranged at a lower end of the sleeve. The sleeve, the first end plate and the second end plate enclose a containing cavity. The sleeve comprises a reinforcing area and a pressure relief area distributed on the reinforcing area, and the thickness of the pressure relief area is smaller than the thickness of the reinforcing area. Alternatively, the sleeve, the first end plate and the second end plate enclose the containing cavity, the sleeve comprises a reinforcing part and a pressure relief part, the strength of the material of the reinforcing part is greater than or equal to the strength of the material of the pressure relief part, and the reinforcing part and the pressure relief part are sealingly connected. The technical scheme of the application can effectively solve the problem of low strength of the shell of the electric core in the related art.

Description

[0001] This application claims priority to the invention patent with application number 202111015620.9, application date August 31, 2021, entitled "Processing method of battery electrode sheet, battery module and electrode sheet". Technical Field

[0002] This invention relates to the field of batteries, and more specifically, to a battery cell casing and a battery cell. Background Technology

[0003] With the development of new energy sources, power batteries, as an environmentally friendly energy source, have received widespread attention from users. The main structure of a power battery is the cell, which currently generally consists of a casing and an internal core. The core is encapsulated within the casing, which also contains electrolyte to ensure the cell functions properly. During operation, the cell continuously generates gas, causing the casing to expand. If the casing is not strong enough, it can easily rupture due to the gas expansion, leading to electrolyte leakage and affecting the safety of the battery pack. However, using high-strength materials for the entire casing would increase the cost of the cell. Summary of the Invention

[0004] The main objective of this invention is to provide a battery cell casing and a battery cell to solve the problem of low casing strength in related technologies.

[0005] To achieve the above objectives, according to one aspect of the present invention, a housing for a battery cell is provided, comprising: a sleeve; a first end plate disposed at the upper end of the sleeve; and a second end plate disposed at the lower end of the sleeve; wherein the sleeve, the first end plate, and the second end plate form a receiving cavity, the sleeve including a reinforcing region and a pressure relief region distributed on the reinforcing region, the thickness of the pressure relief region being less than the thickness of the reinforcing region; or, the sleeve, the first end plate, and the second end plate form a receiving cavity, the sleeve including a reinforcing portion and a pressure relief portion, the strength of the material of the reinforcing portion being greater than or equal to the strength of the material of the pressure relief portion, and the reinforcing portion and the pressure relief portion being sealed together.

[0006] Furthermore, when the sleeve includes a reinforcing zone and a pressure relief zone, the ratio of the thickness of the pressure relief zone to the thickness of the reinforcing zone is greater than or equal to 0.1 and less than 1.

[0007] Furthermore, in the case where the sleeve includes a reinforcing zone and a pressure relief zone, there are multiple pressure relief zones, which are located near the upper and lower ends of the sleeve.

[0008] Furthermore, multiple pressure relief zones near the upper end of the sleeve are spaced apart in the circumferential direction of the sleeve, with the same spacing between two adjacent pressure relief zones; multiple pressure relief zones near the lower end of the sleeve are spaced apart in the circumferential direction of the sleeve, with the same spacing between two adjacent pressure relief zones.

[0009] Furthermore, in cases where the sleeve includes a reinforcing zone and a pressure relief zone, the sleeve is made of a non-metallic insulating material.

[0010] Furthermore, the sleeve is made of fiber-reinforced material.

[0011] Furthermore, in the case where the sleeve includes a reinforcing zone and a pressure relief zone, the sleeve includes a sleeve body and a first edging disposed at the upper end of the sleeve body, the upper surface of the first end plate abuts against the lower surface of the first edging, and the first edging is sealed to the first end plate; the sleeve also includes a second edging disposed at the lower end of the sleeve body, the lower surface of the second end plate abuts against the upper surface of the second edging, and the second edging is sealed to the second end plate.

[0012] Furthermore, in cases where the sleeve includes a reinforcing zone and a pressure relief zone, a second through hole is provided on the first end plate.

[0013] Furthermore, in cases where the sleeve includes a reinforcing zone and a pressure relief zone, a third through hole is provided on the second end plate.

[0014] According to another aspect of the present invention, a battery cell is provided, comprising: a housing, the housing being the aforementioned housing; and a core disposed within a receiving cavity of the housing.

[0015] Furthermore, the core includes a first connecting terminal and a second connecting terminal, the first connecting terminal being electrically connected to the first end plate of the housing, and the second connecting terminal being electrically connected to the second end plate of the housing.

[0016] Applying the technical solution of this invention, the battery cell casing includes a reinforcing region and a weak region distributed on the reinforcing region. The reinforcing region enhances the overall strength of the battery cell, preventing it from rupturing after expansion. The weak region is thinner, making it easier to deform during battery cell expansion, thus preventing the entire battery cell casing from bursting and achieving a pressure relief effect. This design reduces the risk of the battery cell casing bursting, improving battery cell safety. Furthermore, it allows for the use of thinner materials to process the pressure relief region, reducing the production cost of the battery cell casing and consequently lowering the overall production cost of the battery cell. Attached Figure Description

[0017] The accompanying drawings, which form part of this application, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0018] Figure 1 A longitudinal sectional view of an embodiment of the casing of a battery cell according to the present invention is shown;

[0019] Figure 2 It shows Figure 1 An enlarged structural diagram of point A on the outer shell;

[0020] Figure 3 It shows Figure 1 An enlarged structural diagram of point B on the outer shell;

[0021] Figure 4 It shows Figure 1 A top view of the outer shell;

[0022] Figure 5 It shows Figure 1 A bottom view of the outer shell;

[0023] Figure 6 It shows Figure 1 The front view of the shell; and

[0024] Figure 7 A longitudinal cross-sectional structural schematic diagram of an embodiment of the battery cell according to the present invention is shown.

[0025] The above figures include the following reference numerals:

[0026] 20. Positive electrode plate; 21. Positive electrode tab; 30. Negative electrode plate; 31. Negative electrode tab; 40. Diaphragm; 50. First connecting terminal; 60. Second connecting terminal; 70. Sleeve; 71. Reinforcing area; 72. Pressure relief area; 73. Sleeve body; 74. First edging; 75. Second edging; 80. First end plate; 81. First through hole; 90. Second end plate; 91. Second through hole. Detailed Implementation

[0027] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the present invention or its application or use. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0028] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0029] Unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps set forth in these embodiments do not limit the scope of the invention. It should also be understood that, for ease of description, the dimensions of the various parts shown in the drawings are not drawn to actual scale. Techniques, methods, and devices known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and devices should be considered part of the specification. In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters in the following figures denote similar items; therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.

[0030] like Figure 1 and Figure 6 As shown, the outer casing of the battery cell in this embodiment includes: a sleeve 70, a first end plate 80, and a second end plate 90. The first end plate 80 is disposed at the upper end of the sleeve 70; the second end plate 90 is disposed at the lower end of the sleeve 70; the sleeve 70, the first end plate 80, and the second end plate 90 form a receiving cavity. The sleeve 70 includes a reinforcing region 71 and a pressure relief region 72 distributed on the reinforcing region 71, the thickness of the pressure relief region 72 being less than the thickness of the reinforcing region 71.

[0031] Applying the technical solution of this embodiment, the battery cell casing includes a reinforcing region 71 and a pressure-relief region 72 distributed on the reinforcing region 71. The reinforcing region 71 can improve the overall strength of the battery cell and prevent it from cracking after expansion. The thinner weak region is easier to deform when the battery cell expands, preventing the entire battery cell casing from bursting and achieving a pressure-relief effect. The above-mentioned arrangement reduces the risk of the battery cell casing bursting and improves the safety of the battery cell. On the other hand, a thinner material can be used to process the pressure-relief region 72, reducing the production cost of the battery cell casing and thus reducing the production cost of the battery cell.

[0032] Of course, in other embodiments not shown in the figures, the sleeve 70 of the battery cell casing may also include a reinforcing portion and a pressure-relieving portion, such that the strength of the reinforcing portion is greater than or equal to the strength of the pressure-relieving portion, and the reinforcing portion and the pressure-relieving portion are sealed together. The aforementioned reinforcing portion can improve the overall strength of the battery cell casing, and the pressure-relieving portion is used to deform when the battery cell expands, thereby reducing the probability of the battery cell casing bursting.

[0033] like Figure 6As shown, in this embodiment, the ratio of the thickness of the pressure relief region 72 to the thickness of the reinforcing region 71 is greater than or equal to 0.1 and less than 1. In the above structure, if the thickness of the pressure relief region 72 is too small, it will easily lead to insufficient strength of the pressure relief region 72, and the outer casing of the battery cell will easily burst. If the thickness of the pressure relief region 72 is too large, it will affect the deformation effect of the pressure relief region 72 and increase the probability of the outer casing of the battery cell bursting.

[0034] like Figure 6 As shown, in this embodiment, the pressure relief zone 72 includes multiple zones, and the multiple pressure relief zones 72 are disposed near the upper end and lower end of the sleeve 70.

[0035] Specifically, such as Figure 6 As shown, in this embodiment, multiple pressure relief zones 72 near the upper end of the sleeve 70 are spaced apart in the circumferential direction of the sleeve 70, with the same spacing between adjacent pressure relief zones 72; multiple pressure relief zones 72 near the lower end of the sleeve 70 are also spaced apart in the circumferential direction of the sleeve 70, with the same spacing between adjacent pressure relief zones 72. In the above structure, since the main body of the sleeve 70 is close to the core, increased strength is required, so the reinforcing zone 71 is located in the middle of the sleeve 70. The first connecting terminal is located inside the upper end of the sleeve 70, and the second connecting terminal is located inside the lower end of the sleeve 70. Since the strength requirements for this part of the sleeve 70 are lower, the pressure relief zones 72 with smaller thickness can be located here. This arrangement ensures the deformation capability of the pressure relief zones 72 while reducing the production cost of the battery cell casing.

[0036] like Figure 6 As shown, in this embodiment, when the sleeve 70 includes a reinforcing region 71 and a pressure relief region 72, the sleeve 70 is made of a non-metallic insulating material. More preferably, the sleeve 70 is made of a fiber-reinforced material. Fiber-reinforced materials are lightweight and have high strength, making them suitable as materials for processing battery sleeves.

[0037] like Figures 1 to 7 As shown, in this embodiment, the sleeve 70 includes a sleeve body 73 and a first edge 74 disposed at the upper end of the sleeve body 73. The upper surface of the first end plate 80 abuts against the lower surface of the first edge 74 (e.g., Figure 2 As shown), the first edge 74 is sealed to the first end plate 80; the sleeve 70 also includes a second edge 75 disposed at the lower end of the sleeve body 73, and the lower surface of the second end plate 90 abuts against the upper surface of the second edge 75 (as shown). Figure 3As shown in the diagram, the second edge 75 is sealed to the second end plate 90. In the above structure, the upper end of the sleeve body 73 is provided with a first edge 74, which overlaps with the first end plate 80. This arrangement increases the sealing area between the sleeve 70 and the first end plate 80, resulting in a better sealing effect for the battery cell casing. Correspondingly, the second edge 75 at the lower end of the sleeve body 73 also increases the sealing area between the sleeve 70 and the second end plate 90.

[0038] It should also be noted that, such as Figure 4 As shown, in this embodiment, a first through hole 81 is provided on the first end plate 80, such as... Figure 5 As shown, a second through hole 91 is provided on the second end plate 90. In the above structure, after the core is installed inside the housing, the core and the housing form a battery cell. When it is necessary to add electrolyte into the battery cell, the second through hole 91 can be immersed in the electrolyte, and a vacuum degree can be increased from the first through hole 81 through a negative pressure device to draw the electrolyte into the housing. After the battery cell is formed and vented, the first through hole 81 is sealed. The above structure facilitates the addition of electrolyte into the battery cell.

[0039] like Figure 7 As shown, this application also provides a battery cell, an embodiment of which includes a housing and a core. The housing is the aforementioned housing; the core is disposed within a receiving cavity of the housing. In the above structure, since the housing of this application has the advantages of high safety and low production cost, the battery cell having it also possesses the aforementioned advantages.

[0040] like Figure 7 As shown, in this embodiment, the winding core includes a first connecting terminal 50 and a second connecting terminal 60. The first connecting terminal 50 is electrically connected to the first end plate 80 of the outer casing, and the second connecting terminal 60 is electrically connected to the second end plate 90 of the outer casing. Specifically, the first end plate 80 is provided with a first mounting hole. During installation, the first connecting terminal 50 is inserted into the first mounting hole, and the first connecting terminal 50 is electrically and sealingly connected to the first end plate 80. The circumferential edge of the first end plate 80 is sealed to the upper edge of the sleeve 70. Correspondingly, the second end plate 90 is provided with a second mounting hole. During installation, the second connecting terminal 60 is inserted into the second mounting hole, and the second connecting terminal 60 is electrically and sealingly connected to the second end plate 90. The circumferential edge of the second end plate 90 is sealed to the lower edge of the sleeve 70. The above steps can achieve a sealed connection between the winding core and the outer casing, preventing electrolyte leakage from the connection gaps.

[0041] It should be noted that, as Figure 7As shown, the core of this application includes a positive electrode 20, a negative electrode 30, a separator 40, a first connecting terminal 50, and a second connecting terminal 60. The positive electrode 20 is the aforementioned battery electrode, coated with a positive electrode coating, and includes a positive electrode tab 21. The negative electrode 30 is the aforementioned battery electrode, coated with a negative electrode coating, and includes a negative electrode tab 31. The separator 40 separates adjacent positive electrode 20 and negative electrode 30. The positive electrode 20, separator 40, and negative electrode 30 are wound together. The direction of the positive electrode tab 21 is opposite to the direction of the negative electrode tab 31, and the height of the positive electrode tab 21 gradually increases from the innermost layer to the outermost layer. The height of the negative electrode tab 31 gradually increases from the innermost layer to the outermost layer; the first connecting terminal 50 is electrically connected to the positive electrode tab 21, the positive electrode tab 21 extends toward the side wall of the first connecting terminal 50, and the upper end of the positive electrode tab 21 is electrically connected to the side wall of the first connecting terminal 50; the second connecting terminal 60 is electrically connected to the negative electrode tab 31, the negative electrode tab 31 extends toward the side wall of the second connecting terminal 60, and the lower end of the negative electrode tab 31 is electrically connected to the side wall of the second connecting terminal 60. In the above structure, the upper end of the wound positive electrode tab 21 is electrically connected to the side wall of the first connecting terminal 50. The height of the positive electrode tab 21 gradually increases from the inner layer to the outer layer. This allows the tabs on the inner layer to be closer to the first connecting terminal 50 during welding, thus requiring a shorter height to reach the first connecting terminal 50. Conversely, the tabs on the outer layer are farther from the first connecting terminal 50, requiring a higher height to reach it. This method allows the positive electrode tab 21 to be pressed more tightly towards the first connecting terminal 50, improving the reliability of the welding and reducing the internal resistance of the core. The lower end of the wound negative electrode tab 31 is electrically connected to the side wall of the second connecting terminal 60. The height of the negative electrode tab 31 gradually increases from the inner layer to the outer layer. The connection method between the negative electrode tab 31 and the second connecting terminal 60 is the same as that between the positive electrode tab 21 and the first connecting terminal 50, and will not be described again here.

[0042] In the description of this invention, it should be understood that the orientation or positional relationship indicated by directional terms such as "front, back, up, down, left, right", "horizontal, vertical, horizontal" and "top, bottom" is generally based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing this invention and simplifying the description. Unless otherwise stated, these directional terms do not indicate or imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the scope of protection of this invention; the directional terms "inner" and "outer" refer to the inner and outer contours relative to the outline of each component itself.

[0043] For ease of description, spatial relative terms such as "above," "on top of," "on the upper surface of," "above," etc., are used herein to describe the spatial positional relationship of a device or feature as shown in the figures to other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation beyond the orientation of the device as described in the figures. For example, if the device in the figures were inverted, a device described as "above" or "on top of" other devices or structures would subsequently be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below." The device may also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein will be interpreted accordingly.

[0044] Furthermore, it should be noted that the use of terms such as "first" and "second" to define components is merely for the purpose of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore should not be construed as limiting the scope of protection of this invention.

[0045] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A casing for a battery cell, characterized in that, include: Sleeve (70); The first end plate (80) is disposed at the upper end of the sleeve (70); The second end plate (90) is disposed at the lower end of the sleeve (70); The sleeve (70), the first end plate (80) and the second end plate (90) form a receiving cavity. The sleeve (70) includes a reinforcing area (71) and a pressure relief area (72) distributed on the reinforcing area (71). The thickness of the pressure relief area (72) is less than the thickness of the reinforcing area (71). The sleeve (70), the first end plate (80) and the second end plate (90) form a receiving cavity. The sleeve (70) includes a reinforcing part and a pressure relief part. The strength of the material of the reinforcing part is greater than or equal to the strength of the material of the pressure relief part. The reinforcing part and the pressure relief part are sealed together. The pressure relief zone (72) includes multiple zones, and the multiple pressure relief zones (72) are disposed near the upper end and lower end of the sleeve (70); The plurality of pressure relief zones (72) near the upper end of the sleeve (70) are spaced apart in the circumferential direction of the sleeve (70); The plurality of pressure relief zones (72) near the lower end of the sleeve (70) are spaced apart in the circumferential direction of the sleeve (70); In the case where the sleeve (70) includes a reinforcing zone (71) and a pressure relief zone (72), The ratio of the thickness of the pressure relief zone (72) to the thickness of the reinforcement zone (71) is greater than or equal to 0.1 and less than 1; the sleeve (70) is made of non-metallic insulating material; the sleeve (70) is made of fiber reinforced material.

2. The casing of the battery cell according to claim 1, characterized in that, The intervals between two adjacent pressure relief zones (72) are the same.

3. The casing of the battery cell according to claim 1, characterized in that, In the case where the sleeve (70) includes a reinforcing zone (71) and a pressure relief zone (72), The sleeve (70) includes a sleeve body (73) and a first edge (74) disposed at the upper end of the sleeve body (73). The upper surface of the first end plate (80) abuts against the lower surface of the first edge (74), and the first edge (74) is sealed to the first end plate (80). The sleeve (70) further includes a second edging (75) disposed at the lower end of the sleeve body (73), the lower surface of the second end plate (90) abuts against the upper surface of the second edging (75), and the second edging (75) is sealed to the second end plate (90).

4. The casing of the battery cell according to claim 1, characterized in that, In the case where the sleeve (70) includes a reinforcing zone (71) and a pressure relief zone (72), The first end plate (80) is provided with a first through hole (81).

5. The casing of the battery cell according to claim 1, characterized in that, In the case where the sleeve (70) includes a reinforcing zone (71) and a pressure relief zone (72), The second end plate (90) is provided with a second through hole (91).

6. A battery cell, comprising: The outer casing, characterized in that the outer casing is the outer casing according to any one of claims 1 to 5; The core is disposed within the receiving cavity of the outer casing.

7. The battery cell according to claim 6, characterized in that, The core includes a first connecting terminal (50) and a second connecting terminal (60), the first connecting terminal (50) being electrically connected to the first end plate (80) of the housing, and the second connecting terminal (60) being electrically connected to the second end plate (90) of the housing.

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