Housing and battery cell

Abstract

The application provides a shell and an electric core. The shell comprises a shell body and a folding part. The shell body comprises a plurality of side walls, and at least one side wall is provided with a pressure relief port. The folding part is connected with the shell body. The folding part seals the pressure relief port when in a folded state. When the air pressure in the shell reaches a pressure relief pressure, the folding part is impacted by the gas and is in an unfolded state, and the pressure relief port is in communication with the outside. In this way, the folding part in the folded state ensures the sealing of the shell. When the electric core is in thermal runaway, the folding part is impacted by the pressure of the internal gas and is opened to the unfolded state, a pressure relief channel is formed in the folding part, an exhaust port is formed at the end of the folding part, and the pressure relief port is in communication with the outside. That is, the folding part plays the role of the explosion-proof valve in the conventional technology. Compared with the prior art, the shell is designed with a simple processing mode, and the problem that the explosion-proof valve of the electric core is arranged on the shell and is difficult to process in the prior art is solved.

Description

Technical Field

[0001] This application relates to the field of battery technology, specifically to a casing and a battery cell. Background Technology

[0002] In the battery cell structure, the explosion-proof valve plays an important role in ensuring the safety of the battery cell. When the battery cell experiences thermal runaway, it will generate a large amount of gas, which will cause excessive internal pressure. When the gas pressure reaches a certain value, the explosion-proof valve will open to release the internal gas.

[0003] Explosion-proof valves are often mounted on the cover plate. Since the cover plate also contains terminals with electrical connection functions, when the explosion-proof valve opens and releases gas, electrolyte can easily spray out, posing a risk of short circuit and fire. In related technologies, to improve battery pack integration safety and increase cell capacity, some cell designs integrate the explosion-proof valve into the housing, effectively keeping it away from the terminals. However, manufacturing an explosion-proof valve within the housing is more difficult. Summary of the Invention

[0004] In view of this, this application provides a housing and a battery cell to solve the problem that the explosion-proof valve of the battery cell is difficult to process in the housing in the prior art.

[0005] To achieve the above objectives, this application provides the following technical solution:

[0006] A housing, comprising:

[0007] The housing body includes multiple sidewalls, and at least one of the sidewalls is provided with a pressure relief port;

[0008] The folding part is connected to the main body of the housing. When the folding part is in the folded state, it seals the pressure relief port. When the air pressure inside the housing reaches the pressure relief pressure, the folding part is impacted by the gas and unfolds, allowing the pressure relief port to communicate with the outside.

[0009] Optionally, the folded portion is located on the outside of the housing body when it is in the folded state.

[0010] Optionally, the folded portion and the sidewall with the folded portion are an integral continuous structure.

[0011] Optionally, the folded portion extends along the length of the housing body, and the two ends of the folded portion are flush with the two ends of the housing body.

[0012] Optionally, when the folded portion is in the folded state, it is folded into three layers in the wall thickness direction of the side wall; and / or,

[0013] On a projection plane perpendicular to the extension direction of the fold, the fold has a symmetrical structure with the centerline of the pressure relief port as the line of symmetry.

[0014] Optionally, the wall thickness of the main body of the housing is a, and the height of the folded part protruding relative to the main body of the housing when the folded part is in the folded state is 2a.

[0015] Optionally, the preset pressure relief area of ​​the battery cell is S. When the folded part is in the unfolded state, the folded part extends through both ends of the main body of the housing along its length. On the projection plane perpendicular to the length direction of the main body of the housing, the width of the pressure relief port is 2b, the width of the folded part is W, and the height of the folded part protruding relative to the main body of the housing is H, wherein:

[0016] S=8b 2 , W≥2b, H≥2b.

[0017] Optional, 0.1mm≤a≤0.5mm.

[0018] Optionally, the sidewall includes a narrow wall and a wide wall, with the fold located in the narrow wall.

[0019] A battery cell comprising the casing described in any of the above.

[0020] The housing provided in this application is used for assembling battery cells. The housing includes a main body and a folded portion. The main body includes multiple sidewalls, and at least one sidewall has a pressure relief port. The folded portion is connected to the main body. When the folded portion is in the folded state, it seals the pressure relief port. When the gas pressure inside the housing reaches the pressure relief pressure, the folded portion is impacted by the gas and unfolds, allowing the pressure relief port to communicate with the outside. With this configuration, the housing has excess material along the entire circumference enclosed by the sidewalls. Thus, the housing can form a normally closed folded portion by folding a portion of itself. The folded portion in the folded state ensures the airtightness of the housing. When the battery cell experiences thermal runaway, the folded portion is forced open to the unfolded state by the pressure of the internal gas, forming a pressure relief channel in the folded portion. An exhaust port is formed at the end of the folded portion, thereby connecting the pressure relief port with the outside. In other words, the folded portion functions as an explosion-proof valve in conventional technology. Compared to conventional technology, the housing with a folded portion is simple to manufacture, solving the problem of difficult manufacturing of the explosion-proof valve of the battery cell in the housing in the prior art. Attached Figure Description

[0021] 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 only embodiments of this application. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0022] Figure 1 This is a schematic diagram of the battery cell structure provided in an embodiment of this application.

[0023] Figure 2 This is a schematic diagram of the structure of the housing provided in an embodiment of this application.

[0024] Figure 3 This is a schematic diagram of a folded part in a folded state, provided as an embodiment of this application.

[0025] Figure 4 This is a schematic diagram of another folded part in a folded state, provided in an embodiment of this application.

[0026] Figure 5 This is a schematic diagram of the folded portion in an unfolded state, as provided in an embodiment of this application.

[0027] exist Figures 1-5 middle:

[0028] 1. Main body of the shell; 2. Folding section; 3. Cover plate;

[0029] 101. Pressure relief port. Detailed Implementation

[0030] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0031] In its production practice, the applicant found that because the shell is a deep-drawn thin-walled part, welding the explosion-proof valve onto the shell makes welding and sealing difficult, resulting in a low pass rate for sealing the explosion-proof valve and a low yield rate. Moreover, the explosion-proof valve is prone to not fitting tightly with the shell, requiring the addition of pre-pressurization fixtures and secondary shaping processes, which increases costs.

[0032] like Figures 1-5 As shown in the figure, this application provides a housing for assembling battery cells, particularly suitable for square battery cells. The housing includes a housing body 1 and a folding part 2. The housing body 1 includes multiple side walls, and at least one side wall is provided with a pressure relief port 101. The folding part 2 is connected to the housing body 1 and is connected to the pressure relief port 101. When the folding part 2 is in the folded state, it seals the pressure relief port 101. When the air pressure inside the housing reaches the pressure relief pressure, the folding part 2 is impacted by the gas and is in the unfolded state, allowing the pressure relief port 101 to communicate with the outside.

[0033] With this design, the housing has excess material along the entire circumference formed by the side walls. This allows the housing to be folded in a localized manner to form a normally closed folded section 2. The folded section 2 ensures the airtightness of the housing in the folded state. When the battery cell experiences thermal runaway, the folded section 2 is forced open to the unfolded state by the pressure of the internal gas, forming a pressure relief channel in the folded section 2 and an exhaust port at the end of the folded section 2, thereby connecting the pressure relief port 101 to the outside. In other words, the folded section 2 functions as an explosion-proof valve in conventional technology. Compared to conventional technology, the housing design with the folded section 2 is simple to manufacture, solving the problem of the difficulty in manufacturing the explosion-proof valve of the battery cell in the housing in the prior art.

[0034] Furthermore, the folding section 2, which functions as an explosion-proof valve, is integrated into the housing, allowing the explosion-proof valve to be kept away from the positive and negative terminal cover plates 3, achieving thermoelectric separation, preventing fires, and protecting the battery cell. Moreover, the welding process for the explosion-proof valve is eliminated, reducing costs; the folding section 2 is a thin-walled structure that is part of the housing, resulting in a lower overall housing cost.

[0035] For ease of explanation, the thickness direction of the shell body 1 in this application is... Figure 1 The X direction is shown in the figure, the length direction of the main body 1 is shown in the figure as the Y direction, and the width direction of the main body 1 is shown in the figure as the Z direction.

[0036] Regarding the positional relationship between the folded portion 2 and the housing body 1 when the folded portion is in the folded state, in some preferred embodiments, the folded portion 2 is located on the outside of the housing body 1 when the folded portion is in the folded state. With this configuration, after testing and verification, it has been found that when the folded portion 2 is formed on the outside of the housing body 1, the gas generated inside the battery cell is more likely to push open the folded portion 2, allowing it to be in the unfolded state.

[0037] Of course, in addition to the above methods, in some cases, it is also feasible for the folding part 2 to be located inside the housing body 1 when it is in the folded state.

[0038] In some other preferred embodiments, the folded portion 2 and the sidewall with the folded portion 2 are an integral, continuous structure. Considering that the housing is typically a deep-drawn thin-walled part, the housing body 1 and the folded portion 2 are an integral structure. This design allows the housing to be formed by stamping, resulting in a continuous overall structure and high reliability.

[0039] In some other preferred embodiments, the folded portion 2 extends along the length of the housing body 1, and both ends of the folded portion 2 are flush with both ends of the housing body 1. With this configuration, when the housing is assembled with the cover plate 3, the ends of the folded portion 2 in the folded state can be sealed by the cover plate 3, resulting in higher reliability. Simultaneously, when the folded portion 2 is in the unfolded state, the ends naturally form exhaust ports. When the folded portion 2 is unfolded and both ends are open, the resulting flow channel with a regular and symmetrical cross-section reduces flow resistance and facilitates rapid exhaust.

[0040] Of course, besides the above methods, it is also feasible to have the folding part 2 partially disposed rather than through one side wall of the main body 1. Additionally, it is also feasible to design one end of the folding part 2 to form an exhaust port.

[0041] In some other preferred embodiments, when the folding part 2 is in the folded state, it is folded into three layers in the wall thickness direction of the side wall. That is, the folding part 2 first blocks the pressure relief port 101 of the housing body 1, then folds it 180°, and then folds it 180° again, so that the folding part 2 is stacked in three layers along the wall thickness direction. With this configuration, after testing and verification, the folding part 2 is easy to process and not easy to break after being folded twice, and has high reliability.

[0042] In some other preferred embodiments, on a projection plane perpendicular to the extending direction of the folding portion 2, the folding portion 2 has a symmetrical structure with the centerline of the pressure relief port 101 as the line of symmetry. That is, the two sides of the folding portion 2 connected to the housing body 1 are folded in opposite directions to form a double-sided fold. For example, please refer to Figure 3 With this configuration, due to the symmetrical design of the folded section 2, the middle position of the folded section 2 is equivalent to forming a weak point. This allows the gas generated during thermal runaway of the battery cell to gradually impact the folded section 2 from the middle position until the folded section 2 is gradually opened up to the unfolded state. This facilitates more timely and sensitive pressure relief triggering during thermal runaway.

[0043] Of course, in addition to the above methods, it is also feasible to fold only one side of the two sides of the folding part 2 that are connected to the housing body 1 to form a single-sided fold. For example, please refer to Figure 4 .

[0044] In some other preferred embodiments, the wall thickness of the housing body 1 is 'a', and the height of the folded portion 2 protruding from the housing body 1 in the folded state is 2a. With this configuration, the inner surface of the housing body 1 remains flush at the connection point between the housing body 1 and the folded portion 2, which does not affect the predetermined winding shape of the electrode assembly and facilitates the installation of the electrode assembly according to the original design specifications.

[0045] Of course, in addition to the above methods, it is also feasible to keep the outer surface of the housing body 1 flush with the folding part 2 at the connection position.

[0046] In some other preferred embodiments, the preset pressure relief area of ​​the battery cell is S. When the folded part 2 is in the unfolded state, the folded part 2 extends through both ends in the length direction of the housing body 1. On the projection plane perpendicular to the length direction of the housing body 1, that is, on the projection plane perpendicular to the extension direction of the folded part 2, the width of the pressure relief port 101 is 2b, the width of the folded part 2 is W, and the height of the folded part 2 protruding relative to the housing body 1 is H, where: S = 2 × 2b × 2b = 8b 2 W≥2b, H≥2b. That is, b represents half the width of the pressure relief port 101, such as... Figure 3 As shown.

[0047] This design embodies the abstract pressure relief performance requirements through the pressure relief area, and then transforms them into specific and executable structural dimension design rules. Through testing and verification, the parameter design of the folding part 2 that meets the pressure relief requirements can be quickly calculated based on the above relationship, and the pressure relief capacity is higher than that of conventional explosion-proof valves.

[0048] In some other specific embodiments, 0.1mm ≤ a ≤ 0.5mm, and the housing provided in this application is particularly suitable for housings with wall thicknesses within the above range. In the embodiments of this application, the units of a, b, W, and H are all in millimeters, and the unit of S is in square millimeters.

[0049] Generally, the shape of the casing corresponds to the shape of the battery cell. A square battery cell has distinct narrow and wide sides. The main body 1 of the casing has multiple sidewalls, including narrow and wide walls, and the folding portion 2 can be located on either the narrow or wide wall. In some preferred embodiments, the folding portion 2 is located on the narrow wall. This arrangement facilitates the arrangement of the battery cells in a conventional grouping manner, i.e., grouping them along the thickness direction of the battery cells, ensuring efficient space utilization.

[0050] Furthermore, in some preferred embodiments, the folded portion 2 is located in the middle of the narrow wall on the projection plane perpendicular to the length direction of the housing body 1.

[0051] Based on the aforementioned casing, this application embodiment also provides a battery cell, which includes an electrode assembly, a cover plate 3, and the aforementioned casing. The electrode assembly is located within the casing, and the cover plate 3 is connected to the opening of the casing. Since this battery cell has the aforementioned casing, the beneficial effects brought by the casing are described above and will not be repeated here.

[0052] The basic principles of this application have been described above with reference to specific embodiments. However, it should be noted that the advantages, benefits, and effects mentioned in this application are merely examples and not limitations, and should not be considered as essential features of each embodiment of this application. Furthermore, the specific details disclosed above are for illustrative and facilitative purposes only, and are not limitations. These details do not limit the application to the necessity of employing the aforementioned specific details for implementation.

[0053] The block diagrams of devices, apparatuses, devices, and systems involved in this application are merely illustrative examples and are not intended to require or imply that they must be connected, arranged, or configured in the manner shown in the block diagrams. As those skilled in the art will recognize, these devices, apparatuses, devices, and systems can be connected, arranged, and configured in any manner. Words such as “comprising,” “including,” “having,” etc., are open-ended terms meaning “including but not limited to,” and are used interchangeably with them. The terms “or” and “and” as used herein refer to the terms “and / or,” and are used interchangeably with them unless the context clearly indicates otherwise. The term “such as” as used herein refers to the phrase “such as but not limited to,” and is used interchangeably with it.

[0054] It should also be noted that in the apparatus, equipment, and methods of this application, the components or steps can be disassembled and / or recombined. These disassemblies and / or recombinations should be considered as equivalent solutions of this application.

[0055] The above description of the disclosed aspects is provided to enable any person skilled in the art to make or use this application. Various modifications to these aspects will be readily apparent to those skilled in the art, and the general principles defined herein can be applied to other aspects without departing from the scope of this application. Therefore, this application is not intended to be limited to the aspects shown herein, but rather to be accorded the widest scope consistent with the principles and novel features disclosed herein.

[0056] It should be understood that the qualifiers “first,” “second,” “third,” “fourth,” “fifth,” and “sixth” used in the description of the embodiments of this application are only used to more clearly illustrate the technical solutions and are not intended to limit the scope of protection of this application.

[0057] The above description has been given for purposes of illustration and description. Furthermore, this description is not intended to limit the embodiments of this application to the forms disclosed herein. Although numerous exemplary aspects and embodiments have been discussed above, those skilled in the art will recognize certain variations, modifications, alterations, additions, and sub-combinations thereof.

Claims

1. A housing, characterized in that, include: The housing body includes multiple sidewalls, and at least one of the sidewalls is provided with a pressure relief port; The folding part is connected to the main body of the housing. The folding part and the side wall with the folding part are an integral continuous structure. When the folding part is in the folded state, it is located outside the main body of the housing and seals the pressure relief port. When the air pressure inside the housing reaches the pressure relief pressure, the folding part is impacted by the gas and is in the unfolded state, and the pressure relief port is connected to the outside.

2. The housing according to claim 1, characterized in that, The folded portion extends along the length of the main body of the housing, and the two ends of the folded portion are flush with the two ends of the main body of the housing.

3. The housing according to claim 1, characterized in that, When the folded portion is in the folded state, it is folded into three layers in the wall thickness direction of the side wall; and / or, On a projection plane perpendicular to the extension direction of the fold, the fold has a symmetrical structure with the centerline of the pressure relief port as the line of symmetry.

4. The housing according to claim 1, characterized in that, The wall thickness of the main body of the shell is a, and the height of the folded part protruding relative to the main body of the shell when the folded part is in the folded state is 2a.

5. The housing according to claim 1 or 4, characterized in that, The preset pressure relief area of ​​the battery cell is S. When the folded part is in the unfolded state, the folded part extends through both ends of the main body of the housing along its length. On the projection plane perpendicular to the length direction of the main body of the housing, the width of the folded part is W, and the height of the folded part protruding relative to the main body of the housing is H, wherein: S=8b 2 ,W≥2b,H≥2b。 6. The housing according to claim 4, characterized in that, 0.1mm≤a≤0.5mm.

7. The housing according to claim 1, characterized in that, The sidewall includes a narrow wall and a wide wall, and the fold is located on the narrow wall.

8. A battery cell, characterized in that, Includes the housing as described in any one of claims 1-7.

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