Battery case and battery

Abstract

Battery housing, comprising: a housing (1) with an opening; a cover plate (2) that seals the opening to form a receiving space, wherein the cover plate (2) has a cover plate body (201) and a limiting projection (202) that is arranged on a side wall of the cover plate body (201), the limiting projection (202) is arranged at an end of the side wall of the cover plate body (201) away from the housing (1) in a thickness direction of the cover plate body (201), the limiting projection (202) overlaps with the opening of the housing (1), a portion of the cover plate body (201) that is arranged in the opening is welded and fixed to the housing (1), and in the thickness direction of the cover plate body (201), a ratio of a height h2 of the limiting projection (202) to a total height h1 of the cover plate (2) is 1:8~1:3.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of battery technology, in particular to a battery housing and a battery. BACKGROUND

[0002] Lithium batteries are widely used in fields such as electric vehicles, power supplies in communications, energy storage, and electronics. An existing lithium-ion power battery comprises a housing, a cover plate, and a battery cell. The housing and cover plate form a housing for the battery cell.

[0003] During the manufacturing process of a lithium-ion power battery, the cover plate and the casing must be firmly connected. A current method for firmly connecting the cover plate is seam welding. When seam welding is used between the casing and the cover plate, the defect rate is relatively high. Therefore, seam welding cannot be used for the welding between the casing and the cover plate, and penetration welding is required. When penetration welding is used on the casing and the cover plate, the area of ​​the cover plate body is smaller than the area of ​​the opening, which makes the cover plate easily fall into the casing, making welding impossible. SUMMARY

[0004] In view of this, the present application provides a battery case and a battery for solving the problem that welding is impossible because the cover plate falls into the case during penetration welding.

[0005] In a first aspect, the present application provides a battery case comprising: a housing having an opening; a cover plate sealing the opening to form a receiving space, wherein the cover plate includes a cover plate body and a restricting projection disposed on a side wall of the cover plate body, the restricting projection is disposed at an end of the side wall of the cover plate body away from the housing in a thickness direction of the cover plate body, the restricting projection overlaps with the opening of the housing 1, a portion of the cover plate body disposed in the opening is welded and fixed to the housing, and in the thickness direction of the cover plate body, a ratio of a height h2 of the restricting projection to a total height h1 of the cover plate is 1:8~1:3.

[0006] In a second aspect, the present application also provides a battery comprising: the above-mentioned battery case and a battery cell arranged in the battery case.

[0007] Advantageous Effects: By providing a restricting projection on the side wall of the cover plate body, the restricting projection overlapping with the opening of the housing, when welding the cover plate to the housing, the restricting projection is used to restrict the position of the cover plate, thereby preventing the cover plate from falling into the housing, which would make welding impossible, thereby effectively solving the problem that welding is impossible because the cover plate falls into the housing during welding of the cover plate to the housing by through-welding.

[0008] If the ratio of the height h2 of the limiting protrusion to the total height h1 of the cover plate is too large, it indicates that the welding area is too small, thereby reducing the fixing strength between the housing and the cover plate; if the ratio of the height of the limiting protrusion to the total height of the cover plate is too small, the limiting ability of the limiting protrusion decreases.

[0009] Therefore, in order to ensure the fixing strength between the housing and the cover plate and the limiting ability of the limiting projection, the ratio of the height h2 of the limiting projection to the total height h1 of the cover plate 2 is 1:8~1:3, that is, by setting the dimension of the height of the limiting projection within an appropriate range, the connection between the housing and the cover plate can be made more stable and the limitation by the limiting projection can be made more reliable. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] To better illustrate the technical solutions in the specific implementations of the present application or the prior art, a brief introduction to the drawings required for describing the specific implementations or the prior art is provided below. It is obvious that the drawings described below represent some implementations of the present application. Those skilled in the art can also create further drawings based on these drawings without any creative effort. Fig. 1 is a perspective view of a battery case according to an embodiment of the present application; Fig. 2 is a plan view of the Fig. 1 shown battery housing; Fig. 3 is a sectional view of the Fig. 2 shown battery case in an AA direction; Fig. 4 is an enlarged partial view of area C in Fig. 3; Fig. 5 is a sectional view of the Fig. 2 shown battery case in a BB direction; Fig. 6 is an enlarged partial view of area D in Fig. 5; and Fig. Figure 7 is an enlarged partial view of area E in Fig. 1. Description of reference symbols 1 housing; 2 cover plate; 201 cover plate body; 2011 plate body; 2012 folded edge; 202 limiting projection; 204 welding area. DETAILED DESCRIPTION

[0011] To clarify the objectives, technical solutions, and advantages of the present application, the technical solutions of the present application are described clearly and completely below in conjunction with the drawings of the embodiments of the present application. It should be understood that the described embodiments are only a portion of the embodiments of the present application and not all embodiments. All other embodiments that a person skilled in the art devises based on the embodiments of the present application without creative effort fall within the scope of the present application.

[0012] The embodiments of the present application are described below in connection with Fig. 1 to 7 described.

[0013] According to an embodiment of the present application, in one aspect, a battery case is provided, comprising: a housing 1 and a cover plate 2. The housing 1 has an opening, and the cover plate 2 seals the opening to form a receiving space. The cover plate 2 has a cover plate body 201 and a restricting projection 202 arranged on a side wall of the cover plate body 201. The restricting projection 202 is arranged at one end of the side wall of the cover plate body 201 away from the housing 1 in a thickness direction of the cover plate body 201, the restricting projection 202 overlapping with the opening of the housing 1. A portion of the cover plate body 201 arranged in the opening is welded and fixed to the housing 1. In the thickness direction of the cover plate body 201, a ratio of a height h2 of the limiting projection 202 to a total height h1 of the cover plate 2 is 1:8~1:3.

[0014] In the battery case of this embodiment, the restricting projection 202 is arranged on the side wall of the cover plate body 201, and the restricting projection 202 overlaps with the opening of the case 1. With this arrangement, when welding the cover plate 2 to the case 1, the restricting projection 202 is used to restrict the position of the cover plate 2, thereby preventing the cover plate 2 from falling into the case 1, which would make welding impossible, thereby effectively solving the problem that welding is impossible because the cover plate 2 falls into the case 1 during penetration welding between the cover plate 2 and the case 1.

[0015] It is noted that the height of the limiting projection 202 refers to the distance from the top of the limiting projection 202 to the bottom of the limiting projection 202, which is the vertical dimension of the limiting projection 202 as shown in Fig. 4, and the total height h1 of the cover plate 2 refers to the distance from the top of the cover plate 2 to the bottom of the cover plate 2, which is the vertical dimension of the cover plate 2 as shown in Fig. 4 refers to.

[0016] Furthermore, if the ratio of the height h2 of the limiting protrusion 202 to the total height h1 of the cover plate 2 is too large, this indicates that the area of ​​the welding portion 204 is too small, thereby reducing the fixing strength between the cover plate body and the casing 1; if the ratio of the height of the limiting protrusion 202 to the total height of the cover plate 2 is too small, the limiting ability of the limiting protrusion 202 decreases.

[0017] Therefore, in order to ensure the fixing strength between the cover plate body and the housing 1 and the restricting ability of the restricting projection 202, the ratio of the height h2 of the restricting projection 202 to the total height h1 of the cover plate 2 is 1:8~1:3, that is, by setting the dimension of the height of the restricting projection 202 within an appropriate range, the connection between the cover plate body and the housing can be made more stable and the restriction by the restricting projection 202 can be made more reliable.

[0018] Furthermore, the range of h2 is within 0.1mm~1mm. If the height h2 of the limiting protrusion 202 is too large, the higher limiting protrusion 202 occupies more space, affecting the design or installation of other components; if the height h2 of the limiting protrusion 202 is too small, the limiting capability of the limiting protrusion 202 is insufficient, thereby reducing the limiting reliability.

[0019] Therefore, when h2 is in the range of 0.1mm~1mm, not only is the limiting ability of the limiting projection 202 ensured, but also there is no impact on the design or installation of other components, thereby facilitating the arrangement of other components.

[0020] In particular, h1 may preferably be 0.2mm, 0.3mm, 0.4mm, 0.45mm, 0.5mm, 0.55mm, 0.6mm, 0.7mm, 0.8mm or 0.9mm.

[0021] Furthermore, the range of h1 is within 0.5mm~4mm. If h1 is too large, it indicates that the overall height of the cover plate 2 is high, and the cover plate 2 occupies a large space in the case 1, which affects the energy density of the single battery and thus affects the battery capacity. If h1 is too small, it indicates that the overall height of the cover plate 2 is low, which causes the welding area 204 to be smaller, and the welding between the folded edge 2012 and the case 1 is not solid, causing the cover plate 2 to easily detach from the case 1 when force is applied to the cover plate 2, which poses a serious safety hazard.

[0022] Thus, h1 in the range of 0.5mm~4mm not only ensures a solid welding between the folded edge 2012 and the housing 1, but also influences the space occupied by the cover plate 2.

[0023] In one embodiment, when the limiting protrusion 202 is continuously distributed in the circumferential direction of the cover plate body 201, the ratio of h2 to h1 is 1:8~1:5. When the limiting protrusion 202 is continuously distributed around the cover plate 2, the limiting protrusion 202 can better limit the position of the cover plate 2. At this time, the dimension of h2 can be reduced to provide an area for welding the cover plate 2, thereby reducing the overall thickness of the cover plate 2, increasing the accommodation space in the battery case 1, and improving the energy density of the single battery.

[0024] In a further embodiment as shown in Fig. 7, when the limiting protrusion 202 is not continuously distributed in the circumferential direction of the cover plate body 201, the ratio of h2 to h1 is 1:6~1:3. When the limiting protrusion 202 is not continuously distributed around the cover plate 2, the limiting ability of the limiting protrusion 202 for the cover plate 2 is unstable. Thus, in order to improve the limiting stability of the limiting protrusion 202, the height of the limiting protrusion must be increased to ensure a stable limiting ability.

[0025] Furthermore, the limiting protrusions 202 are plural in number, and the plural limiting protrusions 202 are spaced apart from each other. The plural limiting protrusions 202 together support and limit the cover plate 2, thereby making the limiting of the cover plate 2 more reliable while also saving some material and reducing material costs.

[0026] Specifically, there are six limiting protrusions 202, and the four side walls of the cover plate body 201 are divided into two long side walls and two short side walls, with two limiting protrusions 202 located on each long side wall and one limiting protrusion 202 located on each short side wall. The six limiting protrusions 202 ensure more reliable limitation of the cover plate 2.

[0027] It is understood that the number of limiting projections 202 is not limited thereto and should be determined according to the specific requirements.

[0028] In an embodiment as shown in Fig. 4, the welding area 204 between the cover plate body 201 and the housing 1 is spaced from the limiting projection 202, which means that the welding area 204 does not overlap the limiting projection 202.

[0029] In order to ensure the welding yield, the welding area 204 between the cover plate 2 and the housing 1 is spaced from the limiting projection, whereby defective welding caused by gaps formed when the projection and the housing 1 overlap can be avoided, thereby improving the welding reliability and thereby ensuring the structural strength between the cover plate 2 and the housing 1, thereby improving the overall structural stability.

[0030] In an embodiment as shown in Fig. 4, a distance L between the welding area 204 and the limiting projection 202 is in the range of 0.03 mm to 0.8 mm. The distance between the welding area 204 and the limiting projection 202 refers to the distance from a side of the welding area 204 facing the limiting projection 202 to a lower end of the limiting projection 202.

[0031] If the distance L between the welding area 204 and the limiting protrusion 202 is too small, it may cause defective welding during the welding process, affecting the welding strength between the cover plate 2 and the casing 1; if the distance L between the welding area 204 and the limiting protrusion 202 is too large, it may cause the cover plate 2 to be too thick, affecting the internal space of the casing 1 of the battery and thereby reducing the energy density of the single battery.

[0032] Thus, the distance L between the welding area 204 and the limiting projection 202 must be kept within a certain range. Within this range, both the welding strength between the cover plate 2 and the housing 1 and the limiting capability of the limiting projection 202 can be ensured.

[0033] In particular, the distance between the welding area 204 and the limiting projection 202 may preferably be 0.1 mm, 0.2 mm, 0.3 mm, 0.35 mm, 0.4 mm, 0.45 mm, 0.5 mm, 0.55 mm, 0.6 mm or 0.7 mm.

[0034] In one embodiment, the cover plate body 201 has a solid structure and the ratio of h2 to h1 is 1:5~1:3. A solid structure refers to a fully solid structure without a cavity or gap therein.

[0035] Furthermore, when the cover plate body 201 has a massive structure, the cover plate body 201 has a larger mass, so when the limiting projection 202 performs limiting, the height of the limiting projection 202 needs to be increased in order to provide a stable limiting function for the cover plate 2 having a large weight.

[0036] In particular, the ratio of h2 to h1 may preferably be 1:4.5, 1:4 or 1:3.5.

[0037] In a further embodiment as shown in Fig. 4, the cover plate body 201 has a hollow structure, and the ratio of h2 to h1 is 1:8~1:5. A hollow structure refers to a structure having a cavity or a hollow part therein, which provides the advantages of lightweight and material saving, thereby not only reducing the weight of the cover plate 2 but also saving material and reducing manufacturing costs.

[0038] Furthermore, when the cover plate body 201 has a hollow structure, the mass of the cover plate body 201 is smaller, whereby the degree of the height of the limiting projection can be somewhat reduced to facilitate subsequent welding.

[0039] In particular, the ratio of h2 to h1 may preferably be 1:7, 1:8, 1:6.5 or 1:6.

[0040] In an embodiment as shown in Fig. 4, the cover plate body 201 includes a plate body 2011 and a folded edge 2012 disposed at an edge of the plate body 2011. The folded edge 2012 extends along a side facing away from the receiving space. The limiting protrusion 202 is disposed on the folded edge 2012. The ratio of a thickness T1 of the folded edge 2012 to a thickness T2 of the housing 1 is 1.2:1~3:1. The plate body 2011 and the folded edge 2012 form a cavity with an opening at the top.

[0041] It is noted that the thickness T1 of the folded edge 2012 refers to the distance between an inner surface and an outer surface of the folded edge 2012, which is a horizontal dimension of the folded edge 2012 as shown in Fig. 4, and the thickness T2 of the housing 1 refers to a distance between an inner surface and an outer surface of the housing 1, which is a horizontal dimension of the housing 1 as shown in Fig. 4 refers to.

[0042] Furthermore, if the ratio of the thickness T1 of the folded edge 2012 to the thickness T2 of the casing 1 is too small, the stability is poor when the restricting protrusion 202 performs restricting, and the holding of the cover plate 2 to the opening of the casing 1 may easily fail, affecting the subsequent welding yield between the casing 1 and the cover plate 2. During welding, there is a higher risk of burn-through in the folded edge 2012, which affects the sealing and reduces the mechanical strength of the welded portion, which can easily lead to damage to the battery when the battery is subjected to external forces during use. If the ratio of the thickness T1 of the folded edge 2012 to the thickness T2 of the casing 1 is too large, this indicates that the folded edge 2012 is too thick relative to the casing 1.When the casing 1 is welded to the folded edge 2012 to improve the welding strength, the casing 1 is easy to burn through and the welding strength increases, which makes the welding area 204 difficult to control and affects the buffer performance.

[0043] Accordingly, when the ratio of the thickness T1 of the folded edge 2012 to the thickness T2 of the casing 1 is in the range of 1.2:1~3:1, the restricting protrusion 202 on the folded edge 2012 provides good restricting strength for the cover plate body 201. Moreover, after welding the casing 1, the casing 1 does not deform during the welding process between the folded edge 2012 and the casing 1, thereby ensuring good welding strength between the casing 1 and the cover plate 2, thereby maintaining the sealing performance and facilitating control of the welding area 204 and ensuring the buffering performance.

[0044] In particular, the ratio of the thickness T1 of the folded edge 2012 to the thickness T2 of the housing 1 may preferably be 1.5:1, 1.8:1, 2:1, 2.2:1 or 2.5:1.

[0045] Furthermore, the thickness of the casing 1 at the opening ranges from 0.1mm to 0.5mm. If the casing 1 is too thick, it will increase the overall weight of the battery and impact the weight of the electric vehicle. A thicker casing 1 requires more material, increasing manufacturing costs and consuming more space, and may not be suitable for space-constrained application scenarios. If the casing 1 is too thin, it has poorer mechanical strength compared to a thicker casing and is easily deformed or damaged by external forces. A thinner casing 1 cannot protect the battery cell as well and cannot effectively prevent damage to the battery cell due to external impact or pressure.

[0046] Therefore, with a thickness of the housing 1 at the opening in the range of 0.1 mm~0.5 mm, the strength of the housing 1 can be ensured and material costs, manufacturing costs and space requirements can be controlled.

[0047] In particular, the thickness of the housing 1 at the opening may preferably be 0.2mm, 0.25mm, 0.3mm, 0.35mm, 0.4mm, 0.45mm or 0.48mm.

[0048] Furthermore, the range of the folded edge 2012 is within 0.2mm~0.9mm. If the thickness of the folded edge 2012 is too small, the folded edge 2012 is easily burned through, and welding slag may be generated between the casing 1 and the folded edge 2012 during the welding process, affecting the safety of the battery. If the folded edge 2012 is too thick, the thicker folded edge 2012 will increase the material usage, resulting in a higher overall weight of the cover plate 2, and the thicker folded edge 2012 will require more material, thereby increasing the manufacturing cost.

[0049] Therefore, with the thickness of the folded edge 2012 in the range of 0.2mm~0.9mm, good welding strength and good sealing performance after welding the housing 1 and the cover plate 2 can be ensured and the control of material consumption and costs can be facilitated.

[0050] In particular, the thickness of the folded edge 2012 may preferably be 0.3mm, 0.4mm, 0.5mm, 0.55mm, 0.6mm, 0.65mm, 0.7mm or 0.8mm.

[0051] In an embodiment as shown in Fig. 4, the welding area 204 between the housing 1 and the cover plate body 201 is located on the outer surface of the housing 1. The folded edge 2012 and the housing 1 are fixed by penetration welding. This means that the welding is performed by penetration from the surface of the housing 1 to the folded edge 2012. Through-penetration welding has advantages such as high-strength connection, good sealing performance, wide application range, and high welding quality.

[0052] Furthermore, the welding area 204 does not penetrate the folded edge 2012 in the arrangement direction of the casing 1 and the folded edge 2012 when the cover plate body 201 has a hollow structure. By not penetrating the folded edge 2012, pinholes or cracks caused by full penetration welding (i.e., welding such that the folded edge 2012 is completely penetrated) can be reduced, thereby improving the sealing performance of the battery, preventing electrolyte leakage or external contaminants from entering the battery, and reducing the risk of leakage. By non-full penetration welding (i.e.,By welding in such a way that the folded edge 2012 is not fully penetrated), the material integrity is maintained, thereby avoiding potential material weakening that may occur with full penetration welding, thereby maintaining the structural strength of the housing 1 and the cover plate 2, and such stress concentration can also be reduced, thereby improving the fatigue resistance of the weld area 204.

[0053] It is noted that the welding area 204 in Fig. 4 is shown as a gray area.

[0054] It is understood that in another embodiment, the folded edge 2012 may also be welded to the housing 1 using a seam welding method, etc.

[0055] In one embodiment, the battery housing is made of stainless steel, ie the cover plate 2 and the housing 1 are made of stainless steel, which results in advantages such as good corrosion resistance, high strength, excellent thermal expansion and heat preservation properties, good penetration resistance, good safety and good weldability.

[0056] It is understood that in another embodiment, the battery housing may also be made of other materials and is not limited thereto.

[0057] In one embodiment, the cover plate body 201 is fixed to the housing 1 by penetration welding. Welding is performed by penetration from the side of the housing 1 to the cover plate body 201, and penetration welding offers advantages such as high-strength connection, good sealing performance, wide-range applicability, and high weld quality.

[0058] In one embodiment, the folded edge 2012 is fixed around the edge of the plate body 2011, and the folded edge 2012 has an interference fit with the inner wall of the housing 1, thereby facilitating the welding of the housing 1 and the cover plate 2 by through-welding, thereby improving the welding efficiency.

[0059] In one embodiment, the plate body 2011 and the folded edge 2012 are formed by bending up the edge of a single plate material. The cover plate 2 is machined from the plate material, thereby simplifying processing and reducing manufacturing costs. As shown in Fig. 7, the limiting projection 202 is formed by punching the folded edge 2012 outward.

[0060] It is understood that in another embodiment, the plate body 2011 and a folded edge 2012 can also be formed separately and firmly connected to each other.

[0061] According to embodiments of the present application, in a further aspect, a battery is also provided, comprising: the above-mentioned battery case and a battery cell arranged in the battery case.

[0062] Furthermore, the battery cell can be a wound battery cell or a stacked battery cell. The battery further comprises terminals and other components. The terminals can be arranged on the battery housing or on the cover plate body 201, and the terminals are connected to electrode tabs of the battery cell by connecting plates.

[0063] It is noted that the battery cell, terminals, and other components may comprise prior art structures not described in detail here.

[0064] According to embodiments of the present application, in yet another aspect, there is also provided a battery pack comprising: the above-mentioned battery.

[0065] Furthermore, the battery pack comprises multiple batteries, and their associated components, when combined, form a complete energy storage unit. The design and structural composition of the battery pack typically requires consideration of several factors, including safety, reliability, thermal management, electrical connections, etc.

[0066] Specifically, the battery pack also includes a battery box, a battery management system, a thermal management system, and so on. The battery box houses the battery. The battery management system monitors and manages the battery status, such as voltage, current, temperature, etc., to ensure safe and efficient battery operation. It can also achieve battery balancing to prevent individual batteries from being overcharged or overdischarged. The thermal management system maintains the battery pack within an optimal operating temperature range, typically achieved through cooling or heating systems, thus helping to improve battery life and safety.

[0067] Although the embodiments of the present application have been described in conjunction with the drawings, those skilled in the art may make various modifications and variations without departing from the spirit and scope of the present application, and such modifications and variations fall within the scope of protection defined by the appended claims.

Claims

[1] Battery housing, comprising: a housing (1) with an opening; a cover plate (2) that seals the opening to form a receiving space, wherein the cover plate (2) has a cover plate body (201) and a limiting projection (202) that is arranged on a side wall of the cover plate body (201), the limiting projection (202) is arranged at an end of the side wall of the cover plate body (201) away from the housing (1) in a thickness direction of the cover plate body (201), the limiting projection (202) overlaps with the opening of the housing (1), a portion of the cover plate body (201) that is arranged in the opening is welded and fixed to the housing (1), and in the thickness direction of the cover plate body (201), a ratio of a height h2 of the limiting projection (202) to a total height h1 of the cover plate (2) is 1:8~1:

3. [2] The battery case according to claim 1, wherein when the restricting projection (202) is continuously distributed in the circumferential direction of the cover plate body (201), the ratio of h2 to h1 is 1:8~1:

5. [3] The battery case according to claim 1, wherein, when the limiting projection (202) is not continuously distributed in the circumferential direction of the cover plate body (201), the ratio of h2 to h1 is 1:6~1:

3. [4] Battery housing according to one of the preceding claims, wherein a welding region (204) between the cover plate body (201) and the housing (1) is spaced from the limiting projection (202). [5] Battery case according to claim 4, wherein a distance L between the welding portion (204) and the limiting projection (202) is in the range of 0.03 mm to 0.8 mm. [6] Battery case according to one of the preceding claims, wherein the cover plate body (201) has a solid structure and the ratio of h2 to h1 is 1:5~1:

3. [7] Battery case according to one of the preceding claims, wherein the cover plate body (201) has a hollow structure and the ratio of h2 to h1 is 1:8~1:

5. [8] The battery case according to claim 7, wherein the cover plate body (201) comprises a plate body (2011) and a folded edge (2012) arranged on an edge of the plate body (2011), the folded edge (2012) extending along a side facing away from the receiving space, the limiting projection (202) is arranged on the folded edge (2012), and a ratio of a thickness T1 of the folded edge (2012) to a thickness T2 of the case (1) is 1.2:1~3:

1. [9] Battery case according to one of the preceding claims, wherein a welding area (204) is arranged between the housing (1) and the cover plate body (201) on the outer surface of the housing (1). [10] Battery housing according to one of the preceding claims, wherein the battery housing is made of stainless steel. [11] A battery comprising: the battery case according to any one of claims 1 to 10 and a battery cell arranged in the battery case.

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