Battery cell housing, battery cell, and battery pack

Abstract

The utility model relates to battery technology field provides a kind of battery cell shell, battery cell and battery package, the battery cell shell includes: shell body, shell body is equipped with opening in its length direction one end, opening is suitable for setting cover, shell body and cover are enclosed and are suitable for accommodating cavity of pole group, shell body has the inner wall surface towards accommodating cavity;Wherein, at least one lateral wall of shell body is formed with weld, weld material stack is formed into the support boss that protrudes on inner wall surface, support boss extends from one end to the other end of shell body along length direction, support boss can be supported between inner wall surface and pole group, so that inner wall surface, support boss and pole group are enclosed and form exhaust passage.The battery cell shell can make the gas in accommodating cavity when battery cell thermal runaway, gas can be exhausted to explosion-proof valve along the exhaust passage formed by inner wall surface, support boss and pole group, ensure exhaust effect, improve the safety performance of battery cell.

Description

Technical Field

[0001] This utility model relates to the field of battery technology, and in particular to a cell housing, a cell, and a battery pack. Background Technology

[0002] A lithium-ion battery cell typically consists of a cover plate, end plates, a casing, electrode assembly, and electrolyte. The cover plate and casing form a cavity within which the electrode assembly and electrolyte reside. The cover plate includes terminals, an explosion-proof valve, an injection hole, and a lower plastic insert. The end plates are located between the electrode assembly and the lower plastic insert, and the electrode assembly is electrically connected to the terminals via tabs. A side plate is also provided between the electrode assembly and the casing. In the event of thermal runaway, the side plate melts, creating a venting space between the electrode assembly and the casing to facilitate internal gas flow. The lower plastic insert of the end plates and cover plate secures the electrode assembly along the length of the cell, preventing electrode movement.

[0003] However, the strength and high-temperature resistance of the plastic under the side plates, end plates, inner insulating film, and cover plate are limited, and their melting points are far below the temperature at which the cell experiences thermal runaway. When the cell experiences thermal runaway, these internal structures have all melted and failed. At this point, only the electrode assembly remains inside the cavity. There is a large gap between the electrode assembly and the cover plate and shell, giving the electrode assembly a high degree of freedom within the cell. As the high-temperature, high-pressure gas is directionally exhausted towards the explosion-proof valve, the electrode assembly will randomly move with the high-temperature, high-pressure gas flow, blocking the exhaust channel and greatly reducing the exhaust effect, thus lowering the cell's safety performance. Utility Model Content

[0004] This invention provides a cell housing, a cell, and a battery pack to solve the problem in the prior art where, when a battery experiences thermal runaway, the internal electrode assembly is prone to random movement, which obstructs the exhaust channel and reduces the exhaust effect.

[0005] This utility model provides a battery cell housing, comprising:

[0006] The housing body has an opening at one end in its length direction, the opening being adapted to accommodate a cover plate, the housing body and the cover plate forming a receiving cavity adapted to accommodate an electrode assembly, the housing body having an inner wall surface facing the receiving cavity;

[0007] In this embodiment, at least one sidewall of the housing body is formed with a weld, and the weld material is stacked to form a support boss protruding from the inner wall surface. The support boss extends from one end of the housing body to the other end along the length direction. The support boss can support between the inner wall surface and the electrode group, so that the inner wall surface, the support boss and the electrode group form an exhaust channel.

[0008] According to the present invention, the height of the supporting boss relative to the inner wall surface in its protruding direction relative to the inner wall surface is h, where h ≥ 0.5 mm.

[0009] According to the present invention, a battery cell housing has an h ≤ 1 mm.

[0010] According to the present invention, a battery cell housing is provided, the housing body includes a first sidewall and a second sidewall, the two first sidewalls are arranged opposite to each other in the thickness direction of the housing body, the two second sidewalls are arranged opposite to each other in the width direction of the housing body, and at least one second sidewall is formed with the weld.

[0011] According to the present invention, a battery cell housing is provided, wherein the supporting boss is spaced apart from the two first side walls, the width of the supporting boss is w, and the distance between the two first side walls is C, where 0.2mm≤w / C≤0.3mm and 15mm≤C≤25mm.

[0012] According to the present invention, a battery cell housing has a diameter of 3mm ≤ w ≤ 6mm.

[0013] This utility model also provides a battery cell, including: a cover plate, an electrode assembly, and any one of the above-mentioned battery cell housings, wherein the cover plate is disposed at the opening, and the cover plate and the battery cell housing surround to form a receiving cavity, the electrode assembly is disposed within the receiving cavity, and an explosion-proof valve is provided on the cover plate.

[0014] According to the battery cell provided by this utility model, it also includes:

[0015] The side plate, wherein the pole group has a first side and a second side facing away from each other, the side plate being disposed between the first side and the inner wall surface; wherein, the weld is formed on the side wall of the housing body opposite to the first side, and / or, the weld is formed on the side wall of the housing body opposite to the second side.

[0016] According to the present invention, the thickness of the side plate is t, where 0.2mm≤t≤0.3mm.

[0017] This utility model also provides a battery pack comprising a plurality of the above-mentioned battery cells.

[0018] The battery cell housing, battery cell, and battery pack provided by this utility model utilize weld material on the housing body to form a support boss protruding from the inner wall of the housing body. The support boss extends from one end of the housing body to the other along the length of the housing body. When the battery cell experiences thermal runaway and only the electrode assembly remains in the cavity, the support boss can support the electrode assembly between the electrode assembly and the inner wall, preventing the side of the electrode assembly facing the support boss from directly contacting the inner wall. Furthermore, the inner wall, support boss, and electrode assembly form an exhaust channel connected to the opening of the housing body, allowing the gas in the cavity to be discharged to the explosion-proof valve along the exhaust channel, ensuring the exhaust effect and improving the safety performance of the battery cell. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in this utility model 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 utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0020] Figure 1 This is a schematic diagram of the battery cell housing provided by this utility model.

[0021] Figure 2 yes Figure 1 A magnified view of part A, shown in the middle circle.

[0022] Figure 3 This is one of the exploded structural diagrams of the battery cell provided by this utility model.

[0023] Figure 4 yes Figure 2 A magnified view of part B, shown in the middle circle.

[0024] Figure 5 This is a schematic diagram showing the positional relationship between the battery cell housing, inner insulating film, and side plate in the battery cell provided by this utility model.

[0025] Figure 6 This is the second exploded structural diagram of the battery cell provided by this utility model.

[0026] Figure label:

[0027] 1. Housing body; 101. Receiving cavity; 102. Inner wall surface; 103. Opening; 11. First side wall; 12. Second side wall; 13. Supporting boss; 2. Cover plate; 3. Electrode group; 31. First side; 32. Second side; 4. Side plate; 5. Inner insulating film; 6. End plate. Detailed Implementation

[0028] To make the objectives, technical solutions, and advantages of this utility model clearer, the technical solutions of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0029] In the description of the embodiments of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "first"..."fourth" are numbered for the purpose of clearly identifying product components and do not represent any substantial difference. The terms "installed," "connected," and "linked" should be interpreted broadly; for example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of this utility model according to the specific circumstances. Furthermore, "multiple" means two or more. In the specification and claims, "and / or" indicates at least one of the connected objects, and the character " / " generally indicates that the preceding and following related objects are in an "or" relationship.

[0030] The following is combined Figures 1-6 This invention describes the cell housing, cell, and battery pack of the present invention.

[0031] like Figure 1 As shown, the battery cell housing provided by this utility model includes a housing body 1, with an opening 103 at one end along its length. The housing body 1 and the cover plate 2 form a receiving cavity 101 suitable for accommodating the electrode assembly 3. The housing body 1 has an inner wall surface 102 facing the receiving cavity 101. At least one sidewall of the housing body 1 is formed with a weld seam, and the weld seam material is stacked to form a support boss 13 protruding from the inner wall surface 102. The support boss 13 extends from one end of the housing body 1 to the other end along its length. The support boss 13 can be supported between the inner wall surface 102 and the electrode assembly 3, so that the inner wall surface 102, the support boss 13, and the electrode assembly 3 form an exhaust channel.

[0032] Specifically, the housing body 1 is typically formed by welding metal plates, and has a first connecting edge and a second connecting edge. The first connecting edge and the second connecting edge are welded together to form a weld seam, and the weld seam material is deposited on the inner wall surface 102 to form a supporting boss 13. The supporting boss 13 extends along the length direction of the housing body 1 and connects between opposite ends of the housing body 1. Thus, the exhaust channel formed by the inner wall surface 102, the supporting boss 13, and the electrode assembly 3 connects between the two ends of the housing body 1 along the length direction of the housing body 1. It can be understood that when the supporting boss 13 is supported between the inner wall surface 102 and the electrode assembly 3, exhaust channels are formed on both sides of the supporting boss 13 along its length direction.

[0033] It should be noted that in the cell structure using the housing body 1 provided by this utility model, an inner insulating film 5 is also provided inside the receiving cavity 101, and the inner insulating film 5 covers the outside of the electrode group 3; or, the receiving cavity 101 is provided with an inner insulating film 5 and a side plate 4, the inner insulating film 5 covers the outside of the electrode group 3, and the side plate 4 is disposed inside or outside the inner insulating film 5. When the cell does not experience thermal runaway, the support boss 13 is supported between the inner wall surface 102 and the inner insulating film 5, or between the inner wall surface 102 and the side plate 4. The inner wall surface 102, the support boss 13, and the electrode group 3 can form an exhaust channel, meaning that when the cell experiences thermal runaway and both the inner insulating film 5 and the side plate 4 melt, the electrode group 3 is in direct contact with the support boss 13, that is, when the support boss 13 is supported between the electrode group 3 and the inner wall surface 102, and an exhaust channel is defined between the inner wall surface 102, the support boss 13, and the electrode group 3.

[0034] At least one sidewall of the housing body 1 has a weld. Specifically, see Figure 1 The shell body 1 has a cuboid structure and includes a first sidewall 11 and a second sidewall 12. The two first sidewalls 11 are arranged opposite each other in the thickness direction of the shell body 1, and the two second sidewalls 12 are arranged opposite each other in the width direction of the shell body 1. The two first sidewalls 11 and the two second sidewalls 12 are connected to form a circumferential sidewall in the length direction of the shell body 1. At least one of the two first sidewalls 11 and the two second sidewalls 12 has a weld.

[0035] Optionally, at least one second sidewall 12 is formed with a weld. Specifically, a weld is formed on one of the second sidewalls 12, and in the battery cell's operating state, the second sidewall 12 with the weld is located at the bottom of the battery cell, allowing the battery cell to be supported on the support boss 13. Alternatively, welds are formed on both second sidewalls 12, and in the battery cell's operating state, either second sidewall 12 is located at the bottom of the battery cell, allowing the battery cell to be supported on the support boss 13.

[0036] During manufacturing, after the weld seam of the shell body 1 is welded, the weld seam residue inside the shell body 1 is dimensionally controlled, for example by using a pressure plate to flatten it, so that the height and width of the support boss 13 meet the technical requirements, thereby forming an exhaust channel between the inner wall, the support boss 13 and the pole group 3.

[0037] Among them, see Figure 3 and Figure 6 The housing body 1 has an opening 103 at least at one end along its length, meaning the housing body 1 can have a single-sided opening or a double-sided opening. When the housing body 1 has a single-sided opening, one end of the exhaust channel is connected to the opening 103. When the housing body 1 has a double-sided opening, both ends of the exhaust channel are connected to the two openings 103 one-to-one. One opening 103 is provided with an end plate 6 and a cover plate 2, and the other opening 103 is provided with a cover plate 2. An explosion-proof valve is provided on the cover plate 2 at the opening 103. When the battery cell experiences thermal runaway, the gas in the accommodating cavity 101 can be discharged to the explosion-proof valve along the exhaust channel.

[0038] The battery cell housing provided by this utility model has a support boss 13 protruding from the inner wall surface 102 of the housing body 1 by stacking the weld material on the housing body 1. The support boss 13 extends from one end of the housing body 1 to the other end along the length direction of the housing body 1. When the battery cell experiences thermal runaway, and only the electrode group 3 remains in the receiving cavity 101, the support boss 13 can support the electrode group 3 between the electrode group 3 and the inner wall surface 102, preventing the side of the electrode group 3 facing the support boss 13 from directly contacting the inner wall surface 102. The inner wall surface 102, the support boss 13 and the electrode group 3 form an exhaust channel connected to the opening 103 of the housing body 1, so that the gas in the receiving cavity 101 can be discharged to the explosion-proof valve along the exhaust channel, ensuring the exhaust effect and improving the safety performance of the battery cell.

[0039] In this embodiment of the invention, the height of the supporting boss 13 relative to the inner wall surface 102 in its protruding direction is not less than 0.5 mm. See also Figure 2 The height of the support boss 13 relative to the inner wall surface 102 is h, where h ≥ 0.5 mm. For example, h can be 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, or 1 mm. When the height of the support boss 13 relative to the inner wall surface 102 is less than 0.5 mm, the side of the electrode assembly 3 facing the support boss 13 will still be in direct contact with the inner wall surface 102. By setting the height of the support boss 13 relative to the inner wall surface 102 to be greater than 0.5 mm, it can be ensured that in the event of thermal runaway, the side of the electrode assembly 3 facing the support boss 13 will not be in direct contact with the inner wall surface 102, thereby ensuring that an exhaust channel can be formed between the inner wall surface 102, the support boss 13, and the electrode assembly 3. This also helps to ensure the welding strength of the shell body 1.

[0040] When the height of the support boss 13 relative to the inner wall surface 102 is less than 0.5 mm, the side of the electrode assembly 3 facing the support boss 13 will still be in direct contact with the inner wall surface 102. By setting the height of the support boss 13 relative to the inner wall surface 102 to be greater than 0.5 mm, it can be ensured that in the event of thermal runaway, the side of the electrode assembly 3 facing the support boss 13 will not be in direct contact with the inner wall surface 102, thereby ensuring that an exhaust channel can be formed between the inner wall surface 102, the support boss 13, and the electrode assembly 3.

[0041] Furthermore, h ≤ 1mm. If the support boss 13 is too high, it will occupy a large space in the receiving cavity 101, affecting the energy density of the battery cell and increasing processing time, thus impacting production efficiency. This embodiment, by setting h ≤ 1mm, ensures that an exhaust channel can be formed between the inner wall surface 102, the support boss 13, and the electrode group 3, while also reducing the space occupied by the support boss 13 and the processing time of the support boss 13.

[0042] like Figure 1 and Figure 2 As shown in the embodiment of this utility model, the housing body 1 includes a first sidewall 11 and a second sidewall 12. The two first sidewalls 11 are arranged opposite each other in the thickness direction of the housing body 1, and the two second sidewalls 12 are arranged opposite each other in the width direction of the housing body 1. At least one second sidewall 12 has a weld. The support boss 13 is spaced apart from the two first sidewalls 11.

[0043] It is understood that the width direction of the support boss 13 is consistent with the thickness direction of the housing body 1. The support boss 13 is located between the two first sidewalls 11, and the two sides of the support boss 13 are spaced apart from the corresponding first sidewalls 11. In this way, it is beneficial to achieve stable support for the electrode group 3 by using a support boss 13 with a relatively small width, and when the support boss 13 is supported between the inner wall surface 102 and the electrode group 3, exhaust channels can be formed on both sides of the support boss 13.

[0044] Optionally, the centerline of the support boss 13 along its length coincides with the center of the second sidewall 12, that is, the support boss 13 is located at the exact center of the second sidewall 12, which can further improve the support stability of the support boss 13 against the pole group 3.

[0045] Further, see Figure 2 The width of the supporting boss 13 is w, the distance between the two first sidewalls 11 is C, 0.2mm≤w / C≤0.3mm, and the distance between the two first sidewalls 11 is 15~25mm.

[0046] It is understandable that the ratio of w to C can be any value between 0.2 and 0.3, meaning that when 15mm ≤ C ≤ 25mm, w can be any value between 3 and 7.5mm. For example, w / C can be 0.2, 0.22, 0.24, 0.25, 0.26, 0.28, and 0.3. When w / C is less than 0.2, w is too small, affecting the welding strength. When w / C is greater than 0.3mm, the venting effect is poor. This embodiment, by setting the ratio of w to C to 0.2 to 0.3, can ensure both the welding strength of the shell body 1 and the venting effect.

[0047] Furthermore, 3mm ≤ w ≤ 6mm. For example, w can be 3mm, 4mm, 5mm, or 6mm. When w is greater than 6mm, more solder is required, and the processing time is also longer. In this embodiment, by setting the width of the support boss 13 to 3~6mm, the structural strength of the shell body 1 can be guaranteed, while also taking into account the venting effect, cost, and processing efficiency.

[0048] like Figure 3 and Figure 4 As shown, this utility model embodiment also provides a battery cell, including a cover plate 2, an electrode group 3, and any of the above-mentioned battery cell housings. The cover plate 2 is disposed in the opening 103, and the cover plate 2 and the battery cell housing surround to form a receiving cavity 101. The electrode group 3 is disposed in the receiving cavity 101, and an explosion-proof valve (not shown in the figure) is provided on the cover plate 2.

[0049] The battery cell provided by this utility model has a support boss 13 formed by stacking the weld material of the battery cell shell. When the battery cell experiences thermal runaway, the support boss 13 can support the inner wall surface 102 of the shell body 1 and the electrode group 3, so that the inner wall surface 102, the support boss 13 and the electrode group 3 form an exhaust channel connected to the opening 103 of the shell body 1.

[0050] In some alternative embodiments, the battery cell does not have a side plate 4, meaning that the venting channel within the receiving cavity 101 is not formed by melting the side plate 4. Venting occurs only through the venting channel formed by the inner surface, the support boss 13, and the electrode group 3. This simplifies the battery cell structure, thereby simplifying the battery cell assembly process, improving production efficiency, and reducing production costs. Without the side plate 4, the height of the support boss 13 can be appropriately increased by 0.2-0.3 mm compared to the case with the side plate 4 to ensure effective venting.

[0051] In other alternative embodiments, such as Figure 5 and Figure 6 As shown, the battery cell also includes a side plate 4, and the electrode group 3 has a first side 31 and a second side 32 facing away from each other. The side plate 4 is disposed between the first side 31 and the inner wall surface 102 of the housing body 1. A weld is formed on the side wall of the housing body 1 opposite to the first side 31, and / or a weld is formed on the side wall of the housing body 1 opposite to the second side 32.

[0052] Optionally, see Figure 4 and Figure 5 The first side 31 of the electrode assembly 3 is disposed opposite to one second sidewall 12 of the housing body 1, and the second side 32 is disposed opposite to the other second sidewall 12 of the housing body 1. The side plate 4 is disposed between the first side 31 and the corresponding second sidewall 12, and a weld is formed on at least one of the two second sidewalls 12.

[0053] When a weld is formed on one of the second sidewalls 12, the second sidewall 12 is located at the bottom of the cell during cell use. After thermal runaway of the cell and melting of the side plate 4, the bottom of the electrode assembly 3 is supported on the support boss 13, and an exhaust channel is also formed between the top of the electrode assembly 3 and the housing body 1. Thus, exhaust channels are formed at both the top and bottom of the electrode assembly 3, improving the exhaust effect. When welds are formed on both second sidewalls 12, the side plate 4 can be omitted. After thermal runaway of the cell, exhaust channels can still be formed at both the top and bottom of the electrode assembly 3, which facilitates error prevention in production.

[0054] Among them, see Figure 4 and Figure 5 The battery cell also includes an inner insulating film 5, which covers the outer side of the electrode assembly 3. A side plate 4 can be disposed on the outer side of the inner insulating film 5, for example, fixed to the housing body 1, or fixed to the outer insulating film. Alternatively, the side plate 4 can be disposed on the inner side of the inner insulating film 5, meaning that the side plate 4 and the electrode assembly 3 are together covered within the inner insulating film 5. When the side plate 4 is fixed to the outer side of the outer insulating film or covered within the inner insulating film 5, the side plate 4 provides structural support for the electrode assembly 3 and the inner insulating film 5, preventing wrinkles and damage to the inner insulating film 5 during the battery cell insertion process.

[0055] In some embodiments of this invention, the thickness of the side plate 4 is t, where 0.2mm ≤ t ≤ 0.3mm. For example, the thickness t of the side plate 4 is 0.2mm, 0.25mm, and 0.3mm, etc. Side plates 4 within this thickness range can provide structural support for the electrode assembly 3 and the inner insulating film 5, preventing the inner insulating film 5 from wrinkling or breaking during the cell insertion process. They can also prevent a large gap between the electrode assembly 3 and the housing body 1 after the side plate 4 melts, thereby reducing the movement of the electrode assembly 3.

[0056] This utility model embodiment also provides a battery pack, which includes a plurality of battery cells as described in any of the above embodiments. The plurality of battery cells are arranged side-by-side in the thickness direction of the housing body 1. The battery pack also includes a casing, in which the plurality of battery cells are disposed.

[0057] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model, and not to limit it. Although this utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications 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 utility model.

Claims

1. A battery cell housing, characterized in that, include: The housing body has an opening at one end in its length direction, the opening being adapted to accommodate a cover plate, the housing body and the cover plate forming a receiving cavity adapted to accommodate an electrode assembly, the housing body having an inner wall surface facing the receiving cavity; In this embodiment, at least one sidewall of the housing body is formed with a weld, and the weld material is stacked to form a support boss protruding from the inner wall surface. The support boss extends from one end of the housing body to the other end along the length direction. The support boss can support between the inner wall surface and the electrode group, so that the inner wall surface, the support boss and the electrode group form an exhaust channel.

2. The cell housing according to claim 1, characterized in that, The height of the support boss relative to the inner wall surface in its protruding direction relative to the inner wall surface is h, where h ≥ 0.5 mm.

3. The cell housing according to claim 2, characterized in that, h≤1mm.

4. The cell housing according to any one of claims 1 to 3, characterized in that, The housing body includes a first sidewall and a second sidewall. The two first sidewalls are arranged opposite each other in the thickness direction of the housing body, and the two second sidewalls are arranged opposite each other in the width direction of the housing body. At least one of the second sidewalls has the weld.

5. The cell housing according to claim 4, characterized in that, The supporting boss is spaced apart from the two first sidewalls. The width of the supporting boss is w, and the distance between the two first sidewalls is C, where 0.2mm≤w / C≤0.3mm and 15mm≤C≤25mm.

6. The cell housing according to claim 5, characterized in that, 3mm≤w≤6mm.

7. A battery cell, characterized in that, include: The battery includes a cover plate, an electrode assembly, and a battery cell housing as described in any one of claims 1 to 6, wherein the cover plate is disposed at the opening, the cover plate and the battery cell housing enclose a receiving cavity, the electrode assembly is disposed within the receiving cavity, and an explosion-proof valve is provided on the cover plate.

8. The battery cell according to claim 7, characterized in that, Also includes: The side plate, wherein the pole group has a first side and a second side facing away from each other, the side plate being disposed between the first side and the inner wall surface; wherein, the weld is formed on the side wall of the housing body opposite to the first side, and / or, the weld is formed on the side wall of the housing body opposite to the second side.

9. The battery cell according to claim 8, characterized in that, The thickness of the side plate is t, where 0.2mm ≤ t ≤ 0.3mm.

10. A battery pack, characterized in that, include: Multiple battery cells as described in any one of claims 7 to 9.

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