Battery shell and battery

Abstract

The utility model relates to the field of batteries, in particular to a battery shell and a battery, the battery shell comprises an outer shell and an anti-explosion valve fixedly connected with the outer shell, the outer shell is provided with a through hole, and the anti-explosion valve is arranged on the inner wall of the outer shell and shields the through hole. Under the condition that the technical scheme is adopted, when the gas pressure of the battery shell is greater than the preset pressure level, the explosion-proof valve disclosed by the utility model can be used for timely discharging the internal gas in a cracking manner, so that the safety performance of the battery comprising the battery shell and the battery cell is ensured. The explosion-proof valve is arranged on the inner wall of the shell, so that the requirement on the processing precision between the explosion-proof valve and the outer shell of the battery shell in the production process is reduced, and the processing cost is saved to a certain extent.

Description

Technical Field

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

[0002] At present, the automobile industry is facing huge challenges in energy and environment. Therefore, new energy vehicles with high energy utilization and less environmental pollution have become the main development direction of the automobile industry in the future. Among them, power batteries, as the core components of new energy vehicles, affect the performance of the entire vehicle, so more stringent requirements are put forward for the performance of power batteries. In the case of internal or external short circuit, overcharge or collision of the battery, the power battery may be damaged, causing the power battery to heat up and swell. If the power battery is in a sealed condition, it may even cause an explosion due to the inability to release pressure. Therefore, in order to ensure the safety performance of the power battery, an explosion-proof valve is usually installed on the housing or top cover of the power battery.

[0003] However, the existing explosion-proof valve usually embeds the explosion-proof disc into the cover or top cover of the power battery, and then performs butt welding on the joint. The butt welding connection method has extremely high requirements on the precision of the matching gap between the cover or top cover and the explosion-proof disc, and has high requirements on the production precision of the explosion-proof disc and the cover or top cover. The production is difficult, and it is inevitable that a large number of unqualified products will be produced during the production process, and the production cost will also increase accordingly.

[0004] Accordingly, the art needs a new technical solution to solve the above problems. Utility Model Content

[0005] The utility model aims to solve the above technical problems to a certain extent, that is, to solve the problems of great difficulty and high cost in the production of existing explosion-proof valve components.

[0006] In a first aspect, the utility model provides a battery case, which includes an outer shell and an explosion-proof valve fixedly connected to the outer shell, the outer shell is provided with a through hole, and the explosion-proof valve is close to the inner wall of the outer shell and blocks the through hole.

[0007] In the case of adopting the above technical solution, when the gas pressure inside the battery shell is greater than the preset pressure level, the internal gas can be discharged in time by opening the explosion-proof valve, thereby ensuring the safety of the battery packaged by the battery cell. Specifically, in the case of internal or external short circuit, overcharge or collision of the battery, the battery is damaged and may cause the power battery to heat up and expand. The utility model can release the pressure inside the battery by rupturing the explosion-proof valve, thereby avoiding the explosion.

[0008] The explosion-proof valve is arranged on the inner wall of the battery shell. Compared with the method of embedding the explosion-proof valve into the through hole and performing butt welding, the utility model does not need to perform high-precision adaptation of the edge of the explosion-proof valve and the through hole, which reduces the requirements for the processing accuracy of the explosion-proof valve and the outer shell during the production process, saves the processing cost of the battery shell to a certain extent, and is arranged on the inner wall of the battery shell, which reduces external wear and damage to it, prolongs the service life of the explosion-proof valve, and can be processed and improved efficiency.

[0009] It is understandable that those skilled in the art can flexibly adjust the structure (size and shape), quantity, relative position of the through hole and the explosion-proof valve, as well as the materials of the explosion-proof valve and the housing and the connection method between the two, etc., on the premise of meeting actual needs. Exemplarily, the explosion-proof valve and the through hole cooperate to achieve the function of preventing the battery from exploding. Under the premise of the above technical solution, one explosion-proof valve can correspond to one explosion-proof hole or multiple through holes.

[0010] The explosion-proof valve can be set to be circular, elliptical, rectangular, etc., and those skilled in the art can also flexibly adjust the shape of the through hole. The shape of the through hole can be the same as or different from the shape of the explosion-proof valve.

[0011] For the battery housing, in a possible implementation manner, the explosion-proof valve has a thickness of D1, the outer shell has a wall thickness of D2, and 1≤D1 / D2≤2.

[0012] It is understandable that by limiting the ratio of the thickness D1 of the explosion-proof valve and the wall thickness D2 of the outer shell, on the one hand, it is possible to prevent the thickness of the explosion-proof valve from being too large to affect its explosion-proof effect and the safety of the battery, and on the other hand, it is possible to prevent the thickness of the explosion-proof valve from being too small to affect the structural strength of the explosion-proof valve and the welding effect to the outer shell. The above ratio range ensures that the explosion-proof valve can meet the normal safety requirements of the battery to achieve effective welding and fixation with the outer shell, thereby ensuring the overall structural strength and stability of the battery.

[0013] Through such a configuration, a possible relative thickness relationship between the explosion-proof valve and the outer shell is given when forming the battery shell. For example, the first direction should be a direction that is substantially consistent with the wall thickness of the outer shell.

[0014] For the above battery housing, in a possible implementation manner, 1.5≤D1 / D2≤1.8.

[0015] For the above battery housing, in a possible implementation manner, the explosion-proof valve is in a sheet shape, and the explosion-proof valve is fixedly connected to the outer housing by penetration welding.

[0016] Through such a configuration, a specific structural form of the explosion-proof valve and a specific implementation method of connecting the explosion-proof valve with the outer shell are provided. By superimposing the edge of the explosion-proof valve and the outer shell in the first direction and then performing through-welding to fix the connection, there is no need to precisely fit the explosion-proof valve to the through hole. On the other hand, the process accuracy of welding can be reduced, the efficiency of welding can be improved, and the stability of the structure can be ensured.

[0017] For the battery housing, in a possible implementation manner, the explosion-proof valve is provided with a notch, the notch is projected inwardly to be located inside the through hole, and the distance between the notch and the through hole is H, 0<H≤3mm.

[0018] By such a configuration, the reliability of explosion can be ensured. Specifically, if H is too small (such as a negative value), the notch may be blocked by the outer shell, resulting in the explosion-proof valve being unable to explode. If H is too large, the explosion of the explosion-proof valve will be more difficult due to the notch being in the middle. This will affect the safety performance of the battery due to the failure of the explosion-proof valve.

[0019] For the above battery housing, in a possible implementation manner, a shape formed by the notches is the same as a shape of the through hole.

[0020] By such a structure, it can be better ensured that blasting is easy to occur. The same as mentioned here should be understood as the shapes of the two being roughly the same.

[0021] For the above-mentioned battery housing, in a possible implementation manner, in the second direction, a distance between a central axis of the shape surrounded by the notches and a central axis of the through hole is A, 0≤A≤1 mm.

[0022] For the above-mentioned battery housing, in a possible implementation manner, in the third direction, a distance between a central axis of the shape surrounded by the notches and a central axis of the through hole is B, 0≤B≤1 mm.

[0023] By such a structure (A and / or B), it is possible to effectively avoid the phenomenon that the explosion-proof valve is blocked by the outer shell, resulting in explosion failure or increased explosion difficulty, thereby ensuring the explosion reliability of the explosion-proof valve, and then ensuring the safety of the battery. Taking A as an example, if the value is too large, the explosion failure will occur due to the blocking of the notch, and if the value is too small (such as a negative value), the explosion difficulty will increase due to the explosion position being close to the middle. Especially in the case where the influence of A and B is superimposed, it may have a significant impact on the reliability of the explosion-proof valve. Obviously, the specific form of the second / third direction and the definition of the relative position between the two can be appropriately adjusted according to the actual situation. For example, assuming that at least one of the two corresponding shapes is not an axisymmetric figure, so there is no central axis in theory. At this time, the reference line, reference profile or reference position related to the shape can be defined first, and the central axis of the shape can be accurately determined based on the reference line, reference profile or reference position.

[0024] For the above battery housing, in a possible implementation manner, the explosion-proof valve is an aluminum plate.

[0025] Through such a structure, a specific form of explosion-proof valve is provided.

[0026] In a second aspect, the utility model provides a battery, comprising a battery cell and the battery casing as described in any one of the above items, wherein the battery cell is accommodated in the casing.

[0027] It can be understood that the battery has all the technical effects of the battery housing described in any of the above items, which will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The preferred embodiments of the present invention are described below in conjunction with the accompanying drawings, in which:

[0029] Figure 1 A schematic diagram showing the structure of a battery in one embodiment of the utility model;

[0030] Figure 2 A three-dimensional schematic diagram showing a battery housing according to an embodiment of the utility model;

[0031] Figure 3 A schematic diagram showing the structure of a battery housing according to an embodiment of the utility model;

[0032] Figure 4 Show Figure 3 A schematic cross-sectional view along direction II;

[0033] Figure 5 A schematic diagram showing the relative positions of the through holes and notches of a battery housing according to an embodiment of the utility model.

[0034] Reference numerals list

[0035] 1. Battery housing;

[0036] 11. first shell; 12. second shell;

[0037] 121. outer shell; 122. through hole;

[0038] 13. Explosion-proof valve;

[0039] 131. Notch. DETAILED DESCRIPTION

[0040] The preferred embodiments of the present invention are described below with reference to the accompanying drawings. It should be understood by those skilled in the art that these embodiments are only used to explain the technical principles of the present invention and are not intended to limit the protection scope of the present invention.

[0041] It should be noted that in the description of the present invention, the terms "upper", "lower", "left", "right", "inner", "outer" and the like indicating directions or positional relationships are based on the directions or positional relationships shown in the drawings, which are only for the convenience of description, and do not indicate or imply that the device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0042] In addition, it should be noted that in the description of the present invention, unless otherwise clearly specified and limited, the terms "installation", "setting", and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection, an indirect connection through an intermediate medium, or the internal connection of two components. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0043] As the core component of vehicles, batteries provide the main power source for transportation vehicles. Common batteries include lithium-ion power batteries. Power batteries can be recycled at high rates of partial charge, and their operating temperature range is wide, ranging from -30°C to 95°C. The service life of power batteries is also relatively long.

[0044] Main reference Figures 1 to 3The battery 100 includes a battery housing 1 and a battery cell contained in the battery housing 1. The battery cell mainly includes a positive electrode sheet, a negative electrode sheet and a separator. The positive electrode sheet and the negative electrode sheet are respectively provided with a positive electrode ear and a negative electrode ear, and the positive electrode ear and the negative electrode ear are respectively connected to a positive electrode column and a negative electrode column. The positive / negative electrode ears can be directly connected to the poles corresponding to the polarity and position through a transfer structure (such as a transfer structure is usually a transfer sheet, and the transfer sheet can include but is not limited to a sheet structure made of a copper sheet, an aluminum sheet or other conductive materials) (such as a connection method including but not limited to ultrasonic welding, laser welding, riveting). Among them, the negative electrode of the lithium-ion battery is metallic lithium, and the positive electrode is MnO2.

[0045] In a possible embodiment, the battery housing 1 includes a first housing 11 and a second housing 12, and a partition is provided between the first housing 11 and the second housing 12, and a chamber capable of accommodating a battery cell is formed between the first housing 11 and the partition and between the second housing 12 and the partition.

[0046] Among them, when the battery cell is hit or affected by internal or external circuit failures, the battery cell may become hot and swell, thereby affecting the internal balance of the battery cell, so it is necessary to set an explosion-proof valve 13 on the battery housing 1. When the gas pressure inside the battery cell is greater than the preset pressure level, the internal gas can be discharged in time by the explosion of the explosion-proof valve 13, thereby ensuring the safety of the battery packaged by the battery cell. In this example, the explosion-proof valve 13 is a sheet structure or the explosion-proof valve 13 includes an explosion-proof sheet of a sheet structure, such as a positive arch explosion-proof sheet (system pressure acts on the concave surface of the explosion-proof sheet), a reverse arch explosion-proof sheet (system pressure acts on the convex surface of the explosion-proof sheet), and a plane explosion-proof sheet (system pressure acts on the plane of the explosion-proof sheet). The material and structure of the explosion-proof sheet can be adjusted to achieve the explosion pressure relief of the explosion-proof sheet under the set pressure.

[0047] In a possible implementation, the thickness of the explosion-proof valve 13 (the dimension along the first direction, i.e., the length direction of the battery housing 1) is recorded as D1, and the wall thickness of the outer shell 121 is recorded as D2, where D1 / D2 should satisfy the limitation of 1≤D1 / D2≤2, and preferably, both satisfy the limitation of 1.5≤D1 / D2≤1.8. In a specific example, D1 is 0.5mm and D2 is 0.3mm. The constraint between the thicknesses can ensure the functional reliability of the explosion-proof valve 13 on the basis of ensuring the strength of the battery housing 1.

[0048] By limiting the ratio of the thickness D1 of the explosion-proof valve 13 and the wall thickness D2 of the outer shell 121, on the one hand, it is possible to prevent the thickness of the explosion-proof valve 13 from being too large to affect its explosion-proof effect and the safety of the battery, and on the other hand, it is possible to prevent the thickness of the explosion-proof valve 13 from being too small to affect the structural strength of the explosion-proof valve 13 and the welding effect of the explosion-proof valve 13 to the outer shell 121. The above ratio range ensures that the explosion-proof valve 13 can meet the normal safety requirements of the battery and realize effective welding and fixing with the outer shell 121, thereby ensuring the overall structural strength and stability of the battery.

[0049] Taking the second shell 12 as an example, in a possible embodiment, it includes an outer shell 121 of a cover-like structure, and a through hole 122 (explosion-proof hole) is provided on the outer shell 121. The explosion-proof valve 13 is attached to the inner wall of the outer shell 121 at a position corresponding to the through hole 122 and can cover the through hole. As in this example, the through hole 122 is roughly a strip hole, and the two ends of the strip hole are roughly semicircular structures. The shape of the explosion-proof valve 13 is roughly the same as the through hole 122. The explosion-proof valve 13 completely covers the through hole 122 and has a structure reserved at its edge for penetration welding. Based on this, the explosion-proof valve 13 is fixedly connected to the outer shell 121 by penetration welding.

[0050] It is understandable that those skilled in the art can flexibly set the size and shape of the through hole 122 and the explosion-proof valve 13. For example, the through hole 122 and the explosion-proof valve 13 can both be set to be circular, as long as the radius of the explosion-proof valve 13 is greater than the radius of the through hole 122, and the portion of the explosion-proof valve 13 reserved relative to the through hole 122 can allow penetration welding around the periphery of the through hole 122. The shapes of the through hole 122 and the explosion-proof valve 13 can be the same or different. For example, the through hole 122 can be set to be circular, and the explosion-proof valve 13 can be set to be square.

[0051] The explosion-proof valve 13 is provided with a notch 131 near its outer edge, and the shape of the notch 131 is substantially the same as the shape of its outer edge, and the notch 131 is located inside the through hole 122 when projected into the through hole 122. In this way, when the specified pressure is reached, the explosion-proof valve 13 will explode along the notch to release the pressure inside the battery cell. In order to ensure the reliability of the explosion, the pressure value that the notch 131 can withstand should be smaller than the pressure value that other positions of the explosion-proof valve 13 can withstand.

[0052] Main reference Figure 4In one possible implementation, the cross-section of the notch is roughly a V-shaped structure, and the distance between the outer edge (upper end) of the V-shaped structure and the hole wall of the through hole is H, wherein 0<H≤3mm. Such a setting is mainly to ensure the feasibility of the explosion. Specifically, if H is too small (such as a negative value), the notch may be blocked, resulting in the inability to explode the explosion-proof valve 13, thereby causing the explosion-proof valve 13 to fail to function. If H is too large, the explosion-proof valve 13 will be more difficult to blast due to the center of the notch, such as the explosion-proof valve 13 may not be able to explode in time when the internal pressure of the battery housing 1 reaches the set value.

[0053] Main reference Figure 5 In a possible implementation, the second direction is defined as the horizontal direction and the third direction is defined as the vertical direction. Ideally, the shape formed by the notch 131 of the explosion-proof valve 13 coincides with the central axis (including the horizontal central axis and the vertical central axis) of the through hole. However, in practice, the central axes may not coincide due to reasons such as processing accuracy.

[0054] As in this example, it is assumed that the shape enclosed by the notch 131 is offset ( Figure 5 The dashed line in the middle shows a certain offset to the left and upper side). At this time, the horizontal center axis and the vertical center axis between the shape enclosed by the notch 131 and the edge of the through hole 122 are offset by a certain distance. For example, the offset distance corresponding to the horizontal center axis is recorded as A, and the offset distance corresponding to the vertical center axis is recorded as B. The same principle as the aforementioned H, if A / B is too large, the notch may be blocked and cause blasting failure. If A / B is too small, it may increase the difficulty of blasting. In order to ensure the blasting reliability of the explosion-proof valve 13, and then ensure the safety of the battery, it should be ensured that 0≤A≤1mm, 0≤B≤1mm.

[0055] By such a configuration (A and / or B), the phenomenon that the explosion-proof valve 13 is blocked by the outer shell 121 and causes explosion failure or increased explosion difficulty can be effectively avoided, thereby ensuring the explosion reliability of the explosion-proof valve 13, and then ensuring the safety of the battery. Taking A as an example, if the value is too large, the explosion failure will occur due to the blocking of the notch, and if the value is too small (such as a negative value), the explosion difficulty will increase due to the explosion position being close to the middle. Especially in the case where the influence of A and B is superimposed, the reliability of the explosion-proof valve 13 may be significantly affected. Obviously, the specific form of the second / third direction and the definition of the relative position between the two can be appropriately adjusted according to the actual situation. For example, assuming that at least one of the two corresponding shapes is not an axisymmetric figure, so there is no central axis in theory, then the reference line, reference profile or reference position related to the shape can be defined first, and the central axis of the shape can be accurately determined based on the reference line, reference profile or reference position.

[0056] It can be seen that based on the utility model, in the case of internal or external short circuit, overcharge or collision of the battery, the pressure inside the battery is released by the rupture of the explosion-proof valve 13 of the sheet structure abutting against the inner wall of the battery housing 1, thereby avoiding the battery explosion caused by this. Since the explosion-proof valve 13 is arranged on the inner wall of the battery housing 1. Since there is no need to perform high-precision adaptation of the edge of the explosion-proof valve 13 and the through hole 122, the requirements for the processing accuracy between the explosion-proof valve 13 and the outer shell 121 during the production process are reduced, and the cost of the battery housing 1 is saved to a certain extent. By reasonably limiting the aforementioned A, B, and H, it is ensured that the explosion can reliably occur when the pressure is reached, thereby ensuring the safety performance of the battery.

[0057] When the gas pressure inside the battery cell assembly is greater than the preset pressure level, the internal gas can be discharged in time by opening the explosion-proof valve 13, thereby ensuring the safety of the power battery packaged by the battery cell assembly.

[0058] It is understandable that the above-mentioned replaceable implementations, as well as the replaceable implementations and the preferred implementations, can be used in a cross-coordinated manner to combine new implementations to be suitable for more specific application scenarios.

[0059] In addition, those skilled in the art will appreciate that, although some embodiments described herein include certain features included in other embodiments but not other features, the combination of features of different embodiments is meant to be within the scope of the present invention and form different embodiments, such as burst disks and housings. In the claims of the present invention, any one of the claimed embodiments may be used in any combination.

[0060] So far, the technical solution of the present invention has been described in conjunction with the preferred embodiments shown in the accompanying drawings. However, it is easy for those skilled in the art to understand that the protection scope of the present invention is obviously not limited to these specific embodiments. Without departing from the principle of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will fall within the protection scope of the present invention.

Claims

1. A battery housing, characterized in that: The battery housing comprises an outer shell and an explosion-proof valve fixedly connected to the outer shell. The outer shell is provided with a through hole. The explosion-proof valve is arranged on the inner wall of the outer shell and blocks the through hole.

2. The battery housing according to claim 1, characterized in that: The thickness of the explosion-proof valve is D1, the wall thickness of the outer shell is D2, and 1≤D1 / D2≤2.

3. The battery housing according to claim 2, characterized in that: 1.5≤D1 / D2≤1.

8.

4. The battery housing according to claim 1, characterized in that: The explosion-proof valve is in sheet shape, and is fixedly connected to the outer shell by penetration welding.

5. The battery housing according to claim 1, characterized in that: The explosion-proof valve is provided with a notch, the notch is projected inwardly to be located inside the through hole, and the distance between the notch and the through hole is H, 0<H≤3mm.

6. The battery casing according to claim 5, characterized in that: The shape formed by the notches is the same as the shape of the through hole.

7. The battery case according to claim 5, characterized in that: In the second direction, the distance between the central axis of the shape surrounded by the notches and the central axis of the through hole is A, 0≤A≤1mm.

8. The battery casing according to claim 5, characterized in that: In the third direction, the distance between the central axis of the shape surrounded by the notches and the central axis of the through hole is B, 0≤B≤1mm.

9. The battery casing according to claim 1, characterized in that: The explosion-proof valve is an aluminum plate.

10. A battery, characterized in that: The battery comprises a battery cell and a battery casing according to any one of claims 1 to 9, wherein the battery cell is accommodated in the casing.

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