Battery cell shell, battery and battery pack

Abstract

The utility model relates to the technical field of batteries, and discloses a battery cell shell, a battery and a battery pack, the battery cell shell comprises a first side wall and a second side wall, and the thickness of the first side wall is d1; the second side wall and the first side wall are connected to form a cavity used for accommodating a pole group, the second side wall is provided with at least one mounting hole used for mounting an anti-explosion valve, the thickness of the second side wall is d2, and d2 is greater than d1; and a hollow structure is arranged in the second side wall. The thickness of the second side wall is greater than that of the first side wall, so that a reinforcing effect is achieved, the strength of the second side wall can be increased, the overall strength of the battery cell shell is improved, and the battery cell shell is difficult to crack and high in safety when the battery is subjected to thermal runaway. Meanwhile, the anti-vibration effect of the battery cells in the battery pack can be improved; and the hollow structure is arranged in the second side wall, so that the strength of the second side wall is ensured, the overall mass of the battery cell shell is reduced, and the design requirement of light weight is met.

Description

Technical Field

[0001] The utility model relates to the technical field of batteries, and in particular to a battery cell shell, a battery and a battery pack. Background Art

[0002] Lithium-ion power batteries generally include an internal battery structure and an external battery structure. The internal battery structure mainly includes a battery cell pole group, and the external battery structure mainly includes a battery cell cover and a battery cell shell. The battery cell shell provides a space for the battery cell pole group. The battery cell cover and the battery cell shell are welded together to form a closed space, thereby forming a complete battery structure.

[0003] In blade lithium-ion batteries, the cell shell is usually formed by high-frequency welding and laser welding, and the shell has an open structure on both sides, which is welded with the cell cover. In current blade batteries, in order to reduce production costs and achieve lightweight goals, the cell shell is often made thinner, which results in the shell being far from strong enough. When the battery has thermal runaway, the cell shell is prone to rupture, causing battery failure and safety accidents. Utility Model Content

[0004] In view of this, the utility model provides a battery cell shell, a battery and a battery pack to solve the problems of low strength and poor safety of the battery cell shell.

[0005] In the first aspect, the utility model provides a battery cell shell, including a first side wall and a second side wall, the thickness of the first side wall is d1; the second side wall is connected to the first side wall to form a cavity for accommodating a pole group, the second side wall is provided with at least one mounting hole for installing an explosion-proof valve, the thickness of the second side wall is d2, d2>d1; a hollow structure is provided in the second side wall.

[0006] Beneficial effects: The battery cell shell provided by the utility model has a mounting hole on the second side wall for installing an explosion-proof valve, so the strength of the second side wall needs to be strengthened. Since the thickness of the second side wall is greater than that of the first side wall, it plays a reinforcing role, can increase the strength of the second side wall, improve the overall strength of the battery cell shell, and ensure that the battery cell shell is not prone to rupture when the battery thermal runaway occurs, and has high safety. At the same time, it can increase the anti-vibration effect of the battery cell in the battery pack; and because the second side wall is provided with a hollow structure, this ensures that while ensuring the strength of the second side wall, the overall mass of the battery cell shell is reduced, meeting the lightweight design requirements.

[0007] In an optional embodiment, the hollow structure includes a plurality of through holes penetrating the second side wall.

[0008] Beneficial effect: The hollow structure includes a plurality of through holes, which penetrate the second side wall and are easy to process.

[0009] In an optional embodiment, a plurality of through holes are provided along the length direction of the second side wall and penetrate the second side wall through the mounting hole.

[0010] Beneficial effect: The structural strength of the mounting hole is also increased, and the through hole passes through the mounting hole, which can reduce the weight of the battery cell housing.

[0011] In an optional embodiment, the battery cell housing is formed by an extrusion process.

[0012] Beneficial effect: The battery cell shell is formed by an extrusion process, so that the first side wall and the second side wall are formed in an integrated manner. Compared with the molding process using high-frequency welding and laser welding in the prior art, the overall structural strength of the battery cell shell is increased, especially the structural strength at the explosion-proof valve of the battery cell shell, which increases the welding strength and anti-vibration effect of the explosion-proof valve. In addition, due to the use of welding molding in the prior art, there is a weld on the inner wall of the shell, and when the battery cell pole group and the battery cell shell are assembled, the weld is easy to scratch the battery cell pole group. In order to solve this technical problem, the prior art is to set a longer side plate structure on the contact surface of the pole group and the weld side, and the side plate is used to protect the pole group from being scratched by the weld. The battery cell shell provided by the embodiment of the utility model is formed by extrusion, and the internal flat and weld-free structure can directly avoid the weld inside the battery cell shell from scratching the battery cell pole group, and there is no need to set a side plate structure, which can reduce the overall weight of the battery cell and reduce production costs.

[0013] In an optional embodiment, the thickness d1 of the first side wall ranges from 0.3 mm to 1.2 mm, and the thickness d2 of the second side wall ranges from 2.5 mm to 4 mm.

[0014] Beneficial effect: This arrangement can ensure the strength and lightweight design requirements of the battery cell shell.

[0015] In an optional implementation, the radius of the through hole is r, and the range of r is 0.5 mm to 1.2 mm.

[0016] Beneficial effect: This arrangement can reduce the weight of the battery cell housing while ensuring the strength of the second side wall.

[0017] In an optional implementation, the distance between adjacent through holes is b, and the range of b is 2.5 mm to 5 mm.

[0018] Beneficial effect: This arrangement can ensure that the second side wall of the battery cell shell has greater structural strength while reducing the weight of the battery cell shell.

[0019] In the second aspect, the utility model also provides a battery cell, comprising a battery cell shell of any one of the above technical solutions, as well as an explosion-proof valve and a pole group, wherein the explosion-proof valve is arranged on the mounting hole of the battery cell shell; the pole group is arranged in the shell, and one side wall of the pole group abuts against the inner wall of the second side wall.

[0020] Beneficial effects: Since the battery cell provided in this embodiment includes the above-mentioned battery cell shell, the battery cell has a strong battery cell shell, and when thermal runaway occurs, the battery cell shell is not easy to break, ensuring the safety and effectiveness of the battery. In addition, the battery cell also has all the beneficial effects of the above-mentioned battery cell shell, which will not be repeated here.

[0021] In a third aspect, the utility model also provides a battery pack, comprising the battery cell in the above technical solution.

[0022] Advantageous effect: Since the battery includes cells, the battery pack is safer.

[0023] In an optional embodiment, the battery pack further comprises a battery pack shell. The battery pack shell comprises a bottom wall; the battery cells are arranged side by side in the battery pack shell in a manner of large surface adjacent to each other, the second side wall of the battery cell abuts against the bottom wall, and the bottom wall is provided with an avoidance groove corresponding to the explosion-proof valve position of the battery cell to expose the explosion-proof valve.

[0024] Beneficial effect: With this arrangement, when the gas production inside the battery cell reaches a certain pressure, the explosion-proof valve at the bottom of the battery cell in the battery pack opens to ensure the safety of the battery system. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the specific implementation methods of the utility model or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0026] Figure 1 This is a schematic diagram of the structural decomposition of a battery cell according to an embodiment of the utility model;

[0027] Figure 2 for Figure 1 A schematic diagram of the structural decomposition of the battery cell housing and the explosion-proof valve in the battery cell shown;

[0028] Figure 3 for Figure 2 A side view of the middle shell;

[0029] Figure 4 for Figure 3 A partial enlarged view of the middle A;

[0030] Figure 5 for Figure 2 Axonometric view of the cell housing in FIG.

[0031] Figure 6 for Figure 5 A partial enlarged view of point B in the middle;

[0032] Figure 7 A schematic diagram of the structure of a battery pack in a top view according to an embodiment of the utility model;

[0033] Figure 8 for Figure 7 A schematic diagram of the structure of the battery pack shown is shown from a bottom-up perspective.

[0034] Description of reference numerals:

[0035] 1. Battery cell shell; 101. First side wall; 102. Second side wall; 1021. Mounting hole; 1022. Through hole; 103. Cavity; 2. Battery cell; 201. Explosion-proof valve; 202. Cover plate; 203. Electrode group; 3. Battery pack; 301. Battery pack shell; 3011. Bottom wall; 3012. Avoidance groove. DETAILED DESCRIPTION

[0036] In order to make the purpose, technical solution and advantages of the embodiment of the utility model clearer, the technical solution in the embodiment of the utility model will be clearly and completely described below in conjunction with the drawings in the embodiment of the utility model. Obviously, the described embodiment is a part of the embodiment of the utility model, not all the embodiments. Based on the embodiment of the utility model, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the utility model.

[0037] Combine the following Figures 1 to 8 , describing an embodiment of the utility model.

[0038] According to an embodiment of the present utility model, on the one hand, a battery cell housing 1 is provided, comprising a first side wall 101 and a second side wall 102, wherein the thickness of the first side wall 101 is d1; the second side wall 102 is connected to the first side wall 101 to form a cavity 103 for accommodating an electrode group 203, and the second side wall 102 is provided with at least one mounting hole 1021 for mounting an explosion-proof valve 201, and the thickness of the second side wall 102 is d2, such as Figure 4 As shown, d2>d1; a hollow structure is provided in the second side wall 102 .

[0039] The battery cell shell 1 provided by the utility model has a mounting hole 1021 on the second side wall 102 for mounting the explosion-proof valve 201, so it is necessary to strengthen the strength of the second side wall 102. Since the thickness of the second side wall 102 is greater than that of the first side wall 101, it plays a reinforcing role, can increase the strength of the second side wall 102, improve the overall strength of the battery cell shell 1, and ensure that the battery cell shell 1 is not easy to break when the battery has thermal runaway, and has high safety. At the same time, it can increase the anti-vibration effect of the battery cell 2 in the battery pack 3; and because the second side wall 102 is provided with a hollow structure, it can ensure the strength of the second side wall 102 while reducing the overall mass of the battery cell shell 1, meeting the lightweight design requirements.

[0040] Specifically, the cell housing 1 provided in this embodiment is suitable for a blade lithium battery. The cell housing 1 is an overall rectangular structure. Since the first side wall 101 and the second side wall 102 are connected to form a cavity 103 for accommodating the electrode group 203, the rest is the first side wall 101 except for the second side wall 102. The thickness d1 of the first side wall 101 is the thickness of the conventional cell housing 1, and the thickness d2 of the second side wall 102 is greater than the thickness d1 of the first side wall 101.

[0041] The width dimension X of the battery cell housing 1 is 80 mm to 150 mm, the thickness dimension Y is 12 mm to 20 mm, and the length dimension Z is 200 mm to 1000 mm. In a specific embodiment, the width dimension X of the battery cell housing 1 is 100 mm, the thickness dimension Y is 16 mm, and the length dimension Z is 580 mm.

[0042] In one embodiment, the hollow structure includes a plurality of through holes 1022 penetrating the second side wall 102 .

[0043] Specifically, the hollow structure can be any embodiment, and the shape, size and number of the hollow structure are not limited. The purpose is to reduce the weight of the battery cell housing 1. In this embodiment, the hollow structure includes a plurality of through holes 1022. The through holes 1022 penetrate the second side wall 102 for easy processing. The shape of the through holes 1022 is not limited, including circular, rectangular, elliptical, and polygonal.

[0044] In one embodiment, a plurality of through holes 1022 penetrate the second side wall 102 along the length direction of the second side wall 102 and through the mounting hole 1021 .

[0045] Since the second side wall 102 has a mounting hole 1021 and some through holes 1022 pass through the second side wall 102 through the mounting hole 1021, and since the second side wall 102 where the mounting hole 1021 is located has a relatively large thickness, the structural strength at the mounting hole 1021 is also increased, and the through hole 1022 passes through the mounting hole 1021, which can reduce the weight of the battery cell housing 1.

[0046] In one embodiment, a plurality of through holes 1022 are arranged side by side at equal intervals along the width direction of the second side wall 102 .

[0047] This arrangement can ensure that the strength of the second side wall 102 does not vary uniformly along the width direction.

[0048] The arrangement of the through holes 1022 is not limited, for example, they can also be arranged in a honeycomb shape.

[0049] In one embodiment, the battery cell housing 1 is formed by an extrusion process.

[0050] The battery cell shell 1 is formed by an extrusion process, so that the first side wall 101 and the second side wall 102 are formed in an integrated manner. Compared with the molding process using high-frequency welding and laser welding in the prior art, the overall structural strength of the battery cell shell 1 is increased, especially the structural strength at the explosion-proof valve 201 of the battery cell shell 1, and the welding strength and anti-vibration effect of the explosion-proof valve 201 are increased. In addition, due to the use of welding molding in the prior art, there is a weld on the inner wall of the shell, and when the pole group 203 is assembled with the battery cell shell 1, the weld is easy to scratch the pole group 203. In order to solve this technical problem, the prior art is to set a longer side plate structure on the surface of the pole group 203 in contact with the weld side, and the side plate is used to protect the pole group 203 from being scratched by the weld. The battery cell shell 1 provided in the embodiment of the utility model is formed by extrusion, and the internal flatness and no weld structure can directly avoid the weld inside the battery cell shell 1 from scratching the pole group 203, and there is no need to set a side plate structure, which can reduce the overall weight of the battery 2 and reduce the production cost.

[0051] Specifically, the battery cell housing 1 is made of metal materials such as aluminum alloy and has a high structural strength.

[0052] In one embodiment, the thickness d1 of the first side wall 101 ranges from 0.3 mm to 1.2 mm, and the thickness d2 of the second side wall 102 ranges from 2.5 mm to 4 mm.

[0053] The thickness d1 of the first side wall 101 is controlled within a range of 0.3 mm to 1.2 mm, and the thickness d2 of the second side wall 102 is controlled within a range of 2.5 mm to 4 mm, so as to ensure the strength and lightweight design requirements of the battery cell housing 1 .

[0054] In a specific embodiment, the thickness d1 of the first side wall 101 is 0.5 mm, and the thickness d2 of the second side wall 102 is 2.8 mm.

[0055] In one embodiment, the radius of the through hole 1022 is r, and the range of r is 0.5 mm to 1.2 mm.

[0056] By controlling the radius r of the through hole 1022 within a range of 0.5 mm to 1.2 mm, the weight of the cell housing 1 can be reduced while ensuring the strength of the second side wall 102 .

[0057] In a specific embodiment, Figure 4 As shown, the radius r of the through hole 1022 is 0.75 mm.

[0058] In one embodiment, Figure 4 As shown, the interval between adjacent through holes 1022 is b, and the range of b is 2.5 mm to 5 mm.

[0059] By controlling the interval b between adjacent through holes 1022 within a range of 2.5 mm to 5 mm, it is possible to reduce the weight of the battery cell housing 1 while ensuring that the second side wall 102 of the battery cell housing 1 has a greater structural strength.

[0060] In a specific embodiment, the interval b between adjacent through holes 1022 is 3.5 mm.

[0061] In one embodiment, the number of through holes 1022 is not limited. In this embodiment, five through holes 1022 are provided.

[0062] According to an embodiment of the utility model, in a second aspect, a battery cell 2 is further provided, comprising a battery cell shell 1 of any one of the above technical solutions, and an explosion-proof valve 201 and a pole group 203, wherein the explosion-proof valve 201 is arranged on the mounting hole 1021 of the battery cell shell 1; the pole group 203 is arranged in the shell, and a side wall of the pole group 203 abuts against the inner wall of the second side wall 102.

[0063] Specifically, the explosion-proof valve 201 is welded to the mounting hole 1021 of the second side wall 102 of the battery cell housing 1 by using a laser welding process, and is connected to the battery cell housing 1 as a whole.

[0064] Specifically, the battery cell 2 further includes two cover plates 202 disposed at the positive terminal and the negative terminal. The two cover plates 202 are respectively connected to the two ends of the battery cell housing 1 to seal the electrode group 203 in the cavity 103 of the battery cell housing 1 to form a complete battery cell 2 .

[0065] Since the battery cell 2 provided in this embodiment includes the battery cell shell 1, the battery cell 2 has a relatively strong battery cell shell 1, and when thermal runaway occurs, the battery cell shell 1 is not easily broken, thereby ensuring the safety and effectiveness of the battery. In addition, the battery cell 2 also has all the beneficial effects of the battery cell shell 1, which will not be described in detail here.

[0066] According to an embodiment of the present utility model, in a third aspect, a battery pack 3 is further provided, comprising the battery cell 2 in the above technical solution.

[0067] Since the battery pack 3 includes the battery core 2, the battery pack 3 is safer. In addition, since the battery pack 3 includes the battery core 2, it has the same effect as the battery core 2, which will not be described in detail.

[0068] In an optional embodiment, the battery pack 3 further includes a battery pack housing 301. The battery pack housing 301 includes a bottom wall 3011; the battery cells 2 are arranged side by side in the battery pack housing 301 in a manner of large-surface adjacent, the second side wall 102 of the battery cell 2 abuts against the bottom wall 3011, and the bottom wall 3011 is provided with an avoidance groove 3012 corresponding to the position of the explosion-proof valve 201 of the battery cell 2, so that the explosion-proof valve 201 is exposed.

[0069] With this arrangement, when the gas generated inside the battery cell 2 reaches a certain pressure, the explosion-proof valve 201 at the bottom of the battery cell 2 in the battery pack 3 opens to ensure the safety of the battery system.

[0070] Although the embodiments of the present invention are described in conjunction with the accompanying drawings, those skilled in the art may make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations are all within the scope defined by the appended claims.

Claims

1. A battery cell casing, characterized in that: include: A first side wall, wherein the thickness of the first side wall is d1; The second side wall is connected with the first side wall to form a cavity for accommodating the pole group. The second side wall is provided with at least one mounting hole for installing the explosion-proof valve. The thickness of the second side wall is d2, d2>d1; and a hollow structure is provided inside the second side wall.

2. The battery cell casing according to claim 1, characterized in that: The hollow structure includes a plurality of through holes penetrating the second side wall.

3. The battery cell casing according to claim 2, characterized in that: At least part of the through holes are along the length direction of the second side wall and pass through the second side wall through the mounting hole.

4. The battery cell casing according to any one of claims 1 to 3, characterized in that: The battery cell shell is formed by an extrusion process.

5. The battery cell casing according to any one of claims 1 to 3, characterized in that: The thickness d1 of the first side wall is in the range of 0.3 mm to 1.2 mm, and the thickness d2 of the second side wall is in the range of 2.5 mm to 4 mm.

6. The battery cell casing according to claim 2 or 3, characterized in that: The radius of the through hole is r, and the range of r is 0.5 mm to 1.2 mm.

7. The battery cell casing according to claim 2 or 3, characterized in that: The distance between adjacent through holes is b, and the range of b is 2.5 mm to 5 mm.

8. A battery cell, characterized in that: include: The battery cell casing according to any one of claims 1 to 7, An explosion-proof valve is provided on the mounting hole of the battery cell housing; The pole group is arranged in the shell, and one side wall of the pole group abuts against the inner wall of the second side wall.

9. A battery pack, characterized in that: Comprising the battery cell as claimed in claim 8.

10. The battery pack according to claim 9, characterized in that: Also includes: a battery pack housing, the battery pack housing comprising a bottom wall; The battery cells are arranged side by side in the battery pack shell in a manner of large-surface adjacent ones, the second side walls of the battery cells are in contact with the bottom wall, and the bottom wall is provided with an avoidance groove corresponding to the position of the explosion-proof valve of the battery cell to expose the explosion-proof valve.

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