Battery case and battery

Abstract

The present invention relates to the field of battery technology, and discloses a battery shell and a battery. The battery shell includes: a shell having an opening; a cover plate, the cover plate seals the opening to form a receiving cavity, the cover plate includes a cover plate body and a limiting protrusion located on the side wall of the cover plate body, the limiting protrusion is located at one end of the side wall of the cover plate body away from the shell along the thickness direction of the cover plate body, the limiting protrusion overlaps with the opening of the shell, the part of the cover plate body located inside the opening is welded and fixed to the shell, and along the thickness direction of the cover plate body, the ratio of the height h2 of the limiting protrusion to the total height h1 of the cover plate is 1:8~1:3. The limiting protrusion is used to limit the cover plate to prevent the cover plate from falling into the shell and causing the welding to fail; the proportion of the limiting protrusion is set within a suitable range, so that the connection between the cover bodies is more stable and the limiting of the limiting protrusion is reliable.

Description

Technical Field

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

[0002] Lithium batteries are widely used in electric vehicles, communication power supplies, energy storage, electronics, etc. Existing lithium-ion power batteries include a shell, a cover plate, and a battery cell, and the shell and the cover plate form a receiving cavity for receiving the battery cell.

[0003] In the production process of lithium-ion power batteries, the cover plate and the shell need to be fixedly connected. The current fixed connection method is butt welding. When the shell and the cover plate are welded by butt welding, the failure rate is high. Therefore, the welding between the shell and the cover plate cannot be welded by seam welding, but penetration welding is required. When the shell and the cover plate are welded by penetration welding, the area of ​​the cover plate body is smaller than the area of ​​the opening, and the cover plate can easily fall into the shell, resulting in failure to weld. Summary of the invention

[0004] In view of this, the present invention provides a battery casing and a battery to solve the problem that the cover plate falls into the casing and makes welding impossible when the casing and the cover plate are welded by penetration welding.

[0005] In the first aspect, the present invention provides a battery shell, comprising: a shell having an opening; a cover plate, the cover plate sealing the opening to form a accommodating cavity, the cover plate comprising a cover plate body and a limiting protrusion located on the side wall of the cover plate body, the limiting protrusion is located at one end of the side wall of the cover plate body away from the shell along the thickness direction of the cover plate body, the limiting protrusion overlaps with the opening of the shell, the part of the cover plate body located inside the opening is welded and fixed to the shell, and along the thickness direction of the cover plate body, the ratio of the height h2 of the limiting protrusion to the total height h1 of the cover plate is 1:8~1:3.

[0006] In a second aspect, the present invention further provides a battery, comprising: the above-mentioned battery casing and a battery cell arranged inside the battery casing.

[0007] Beneficial effect: A limiting protrusion is set on the side wall of the cover body, and the limiting protrusion overlaps with the opening of the shell. When welding the cover and the shell, the limiting protrusion is used to limit the cover to prevent the cover from falling into the shell and causing welding to fail. This effectively solves the problem of the cover falling into the shell and causing welding to fail when the shell and the cover are welded by penetration 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 means that the area of ​​the welding position is too small and the fixing strength between the cover body and the shell is reduced; 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 is reduced.

[0009] Therefore, in order to ensure the fixing strength between the cover body and the shell and the limiting ability of the limiting protrusion, the ratio of the height h2 of the limiting protrusion to the total height h1 of the cover plate 2 is 1:8~1:3, that is, the height ratio of the limiting protrusion is set within an appropriate range, so that the connection between the cover body and the cover body is more stable and the limiting of the limiting protrusion is reliable. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] In order to more clearly illustrate the specific implementation methods of the present invention 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 present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0011] Figure 1 A three-dimensional diagram of a battery housing according to an embodiment of the present invention;

[0012] Figure 2 for Figure 1 A top view of the battery housing shown;

[0013] Figure 3 for Figure 2 AA sectional view of the battery casing shown;

[0014] Figure 4 for Figure 3 A partial enlarged schematic diagram of C in the middle;

[0015] Figure 5 for Figure 2 A BB sectional view of the battery casing shown;

[0016] Figure 6 for Figure 5 A partial enlarged schematic diagram of D in the middle;

[0017] Figure 7 for Figure 1 A partial enlarged schematic diagram of E in the figure.

[0018] Description of reference numerals:

[0019] 1. Shell;

[0020] 2. Cover plate; 201. Cover plate body; 2011. Plate body; 2012. Folding edge; 202. Limiting protrusion; 204. Welding area. DETAILED DESCRIPTION

[0021] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention.

[0022] Combine the following Figures 1 to 7 , describing an embodiment of the present invention.

[0023] According to an embodiment of the present invention, on the one hand, a battery casing is provided, comprising: a shell 1 and a cover plate 2, the shell 1 having an opening; the cover plate 2 seals the opening to form a accommodating cavity, the cover plate 2 comprises a cover plate body 201 and a limiting protrusion 202 located on the side wall of the cover plate body 201, the limiting protrusion 202 is located at one end of the side wall of the cover plate body 201 away from the shell 1 along the thickness direction of the cover plate body 201, the limiting protrusion 202 overlaps with the opening of the shell 1, the part of the cover plate body 201 located inside the opening is welded and fixed to the shell 1, and along the thickness direction of the cover plate body 201, the ratio of the height h2 of the limiting protrusion 202 to the total height h1 of the cover plate 2 is 1:8~1:3.

[0024] In the battery casing using this embodiment, a limiting protrusion 202 is provided on the side wall of the cover body 201, and the limiting protrusion 202 overlaps with the opening of the shell 1. When welding the cover 2 and the shell 1, the limiting protrusion 202 is used to limit the cover 2 to prevent the cover 2 from falling into the shell 1 and causing welding to fail. This effectively solves the problem of the cover 2 falling into the shell 1 and causing welding to fail when the shell 1 and the cover 2 are welded by penetration welding.

[0025] It should be noted that the height of the limiting protrusion 202 refers to the distance from the top to the bottom of the limiting protrusion 202, that is, Figure 4 The vertical dimension of the middle limit protrusion 202, the total height h1 of the cover plate 2 refers to the distance from the top to the bottom of the cover plate 2, which is also Figure 4 The vertical dimension of the middle cover plate 2.

[0026] Furthermore, if the height h2 of the limiting protrusion 202 accounts for too large a proportion of the total height h1 of the cover plate 2, it means that the area of ​​the welding area 204 is too small and the fixing strength between the cover body and the shell 1 is reduced; if the height of the limiting protrusion 202 accounts for too small a proportion of the total height of the cover plate 2, the limiting ability of the limiting protrusion 202 is reduced.

[0027] Therefore, in order to ensure the fixing strength between the cover body and the shell 1 and the limiting ability of the limiting protrusion 202, the ratio of the height h2 of the limiting protrusion 202 to the total height h1 of the cover plate 2 is 1:8~1:3, that is, the height ratio of the limiting protrusion 202 is set within an appropriate range, so that the connection between the cover body and the cover body is more stable and the limiting of the limiting protrusion 202 is reliable.

[0028] Furthermore, the range of h2 is 0.1 mm to 1 mm. If the height h2 of the limiting protrusion 202 is large, the higher limiting protrusion 202 will occupy more space, affecting the design or installation of other components; if the height h2 of the limiting protrusion 202 is small, the limiting ability of the limiting protrusion 202 is insufficient, thereby reducing the limiting reliability.

[0029] Therefore, when h2 is within the range of 0.1 mm to 1 mm, it not only ensures the limiting ability of the limiting protrusion 202, but also does not affect the design or installation of other components, thus facilitating the arrangement of other components.

[0030] Specifically, h1 may preferably be 0.2 mm, 0.3 mm, 0.4 mm, 0.45 mm, 0.5 mm, 0.55 mm, 0.6 mm, 0.7 mm, 0.8 mm or 0.9 mm.

[0031] Furthermore, the range of h1 is 0.5 mm to 4 mm. If h1 is large, it means that the overall height of the cover plate 2 is high, and the cover plate 2 occupies a large space inside the shell 1, which in turn affects the energy density of the single battery, thereby affecting the capacity of the battery. If h1 is small, it means that the overall height of the cover plate 2 is low, making the welding area 204 smaller, and the welding between the folded edge 2012 and the shell 1 is not firm, and the cover plate 2 is easy to separate from the shell 1 when the cover plate 2 is subjected to force, which poses a great safety hazard.

[0032] Therefore, h1 is within the range of 0.5 mm to 4 mm, which not only ensures that the folded edge 2012 is firmly welded to the shell 1, but also controls the space occupied by the cover plate 2 to ensure the energy density of the battery.

[0033] In one embodiment, when the limiting protrusions 202 are continuously distributed around the cover plate body 201, the ratio of h2 to h1 is 1:8 to 1:5. When the limiting protrusions 202 are continuously distributed around the cover plate 2, the limiting protrusions 202 can better limit the cover plate 2, and at this time, the proportion of h2 can be reduced, providing an area for welding the cover plate 2, thereby reducing the thickness of the entire cover plate 2, increasing the accommodation space inside the battery shell 1, and increasing the energy density of the single battery.

[0034] In another embodiment, if Figure 7As shown, when the limiting protrusions 202 are discontinuously distributed around the cover plate body 201, the ratio of h2 to h1 is 1:6 to 1:3. When the limiting protrusions 202 are discontinuously arranged around the cover plate 2, the limiting ability of the limiting protrusions 202 on the cover plate 2 is unstable. Therefore, in order to improve the stability of the limiting protrusions 202, the proportion of the protrusion height needs to be increased to ensure stable limiting ability.

[0035] Furthermore, there are a plurality of limiting protrusions 202, and the limiting protrusions 202 are arranged at intervals. The limiting protrusions 202 support and limit the cover plate 2 together, so that the limiting of the cover plate 2 is more reliable, and certain materials can be saved, saving material costs.

[0036] Specifically, the number of the limiting protrusions 202 is six, and the four side walls of the cover body 201 are divided into two long side walls and two short side walls. Each long side wall is provided with two limiting protrusions 202, and each short side wall is provided with a limiting protrusion 202. The cover 2 is limited by the six limiting protrusions 202, and the limiting is more reliable.

[0037] It is understandable that the number of the limiting protrusions 202 is not limited thereto and needs to be set according to specific needs.

[0038] In one embodiment, Figure 4 As shown, the welding area 204 between the cover body 201 and the housing 1 is spaced from the limiting protrusion 202 , that is, the welding area 204 and the limiting protrusion 202 do not overlap.

[0039] In order to ensure the welding yield, the welding area 204 between the cover plate 2 and the shell 1 is set with a limit interval, which can avoid the occurrence of cold welding due to the gap formed by the overlap between the protrusion and the shell 1, improve the welding reliability, and then ensure the structural strength between the cover plate 2 and the shell 1, and enhance the stability of the overall structure.

[0040] In one embodiment, Figure 4 As shown, the distance L between the welding area 204 and the limiting protrusion 202 ranges from 0.03 mm to 0.8 mm. The distance between the welding area 204 and the limiting protrusion 202 refers to the distance between the side of the welding area 204 facing the limiting protrusion 202 and the bottom end of the limiting protrusion 202.

[0041] If the distance L between the welding area 204 and the limiting protrusion 202 is too small, it will cause cold welding during the welding process, thereby affecting the welding strength between the cover plate 2 and the shell 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, thereby affecting the space inside the battery shell 1 and reducing the energy density of the single battery.

[0042] Therefore, the distance L between the welding area 204 and the limiting protrusion 202 needs to be controlled within a certain range. Within this range, both the strength of the welding between the cover plate 2 and the shell 1 and the limiting ability of the limiting protrusion 202 can be guaranteed.

[0043] Specifically, the spacing between the welding area 204 and the limiting protrusion 202 may preferably range from 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.

[0044] In one embodiment, the cover body 201 is a solid structure, and the ratio of h2 to h1 is 1:5 to 1:3. The solid structure refers to a complete entity structure without any cavity or gap inside.

[0045] Furthermore, when the cover body 201 is a solid structure, the cover body 201 has a large mass. Therefore, when the limiting protrusion 202 is limiting, it is necessary to increase the proportion of the height of the limiting protrusion 202 to play a stable limiting function in the high-weight cover 2.

[0046] Specifically, the ratio of h2 to h1 may preferably be 1:4.5, 1:4 or 1:3.5.

[0047] In another embodiment, if Figure 4 As shown, the cover plate body 201 is a hollow structure, and the ratio of h2 to h1 is 1:8 to 1:5. The hollow structure refers to a structure with a cavity or hollow part inside. The hollow structure has the advantages of light weight and material saving, which not only reduces the weight of the cover plate 2, but also saves materials and reduces manufacturing costs.

[0048] Furthermore, when the cover body 201 is a hollow structure, the mass of the cover body 201 is relatively small. Therefore, under this condition, the proportion of the limit height can be reduced a little to facilitate subsequent welding.

[0049] Specifically, the ratio of h2 to h1 may preferably be 1:7, 1:8, 1:6.5, or 1:6.

[0050] In one embodiment, Figure 4 As shown, the cover body 201 includes a plate body 2011 and a folded edge 2012 located at the edge of the plate body 2011, the folded edge 2012 extends along the side away from the accommodating cavity, the limiting protrusion 202 is arranged on the folded edge 2012, and the ratio of the thickness T1 of the folded edge 2012 to the thickness T2 of the shell 1 is 1.2:1~3:1. The plate body 2011 and the folded edge 2012 surround a cavity with an opening at the top.

[0051] It should be noted that the thickness T1 of the folded edge 2012 refers to the distance between the inner side and the outer side of the folded edge 2012, that is, Figure 4 The lateral dimension of the middle fold 2012, the thickness T2 of the shell 1 refers to the distance between the inner surface and the outer surface of the shell 1, that is, Figure 4 The lateral dimension of the housing 1.

[0052] Furthermore, if the ratio of the thickness T1 of the folded edge 2012 to the thickness T2 of the shell 1 is too small, the stability of the limiting protrusion 202 is poor when it is limited, and the cover plate 2 is prone to not being able to hang on the opening of the shell 1, affecting the subsequent welding yield of the shell 1 and the cover plate 2. During the welding process, there is a greater risk of the folded edge 2012 being welded through, affecting the seal, and also reducing the mechanical strength of the welding part, which is easy to cause damage to the battery when it is subjected to external force during use; if the ratio of the thickness T1 of the folded edge 2012 to the thickness T2 of the shell 1 is too large, it means that the folded edge 2012 is too large relative to the thickness of the shell 1. When the shell 1 and the folded edge 2012 are welded and fixed, in order to improve the welding strength, the shell 1 is easily welded through. At the same time, it leads to an increase in welding power, which makes it difficult to control the welding area 204, affecting the buffering performance.

[0053] Therefore, when the ratio of the thickness T1 of the folded edge 2012 to the thickness T2 of the shell 1 is in the range of 1.2:1~3:1, the limiting protrusion 202 on the folded edge 2012 has better limiting stability on the cover plate body 201, and during the welding process of the folded edge 2012 and the shell 1, the shell 1 will not be deformed after welding. The welding strength of the shell 1 and the cover plate 2 is better after welding, which ensures the sealing performance, and can also facilitate the control of the welding area 204 to ensure the buffering performance.

[0054] Specifically, the ratio of the thickness T1 of the folded edge 2012 to the thickness T2 of the shell 1 may preferably be 1.5:1, 1.8:1, 2:1, 2.2:1 or 2.5:1.

[0055] Furthermore, the thickness of the shell 1 at the opening ranges from 0.1mm to 0.5mm. If the shell 1 is thicker, the overall weight of the battery will increase, which will in turn affect the weight of the electric vehicle. A thicker shell 1 requires more materials, which will increase manufacturing costs and take up more space, and may not be suitable for space-constrained application scenarios. If the shell 1 is thinner, it is not as strong as a thicker shell 1 in terms of mechanical strength, and is easily deformed or damaged by external forces. A thinner shell 1 has a weaker ability to protect the battery cell, and may not be able to effectively prevent damage to the battery cell caused by external impact or extrusion.

[0056] Therefore, the thickness of the shell 1 at the opening is within the range of 0.1 mm to 0.5 mm, which can ensure the strength of the shell 1 while controlling material cost, manufacturing cost, and occupied space.

[0057] Specifically, the thickness of the shell 1 at the opening may preferably be 0.2 mm, 0.25 mm, 0.3 mm, 0.35 mm, 0.4 mm, 0.45 mm or 0.48 mm.

[0058] Furthermore, the thickness of the folded edge 2012 ranges from 0.2 mm to 0.9 mm. If the thickness of the folded edge 2012 is too small, the folded edge 2012 is easily welded through to form welding slag during the welding process between the shell 1 and the folded edge 2012, which affects the safety of the battery. If the thickness of the folded edge 2012 is too thick, the thicker folded edge 2012 will increase the amount of material used, resulting in an increase in the overall weight of the cover plate 2. The thicker folded edge 2012 requires more material, which will increase the manufacturing cost.

[0059] Therefore, the thickness of the folded edge 2012 is in the range of 0.2 mm to 0.9 mm, which ensures the welding strength between the shell 1 and the cover plate 2 after welding, has good sealing performance, and is also convenient for controlling material consumption and cost.

[0060] Specifically, the thickness of the folded edge 2012 may preferably be 0.3 mm, 0.4 mm, 0.5 mm, 0.55 mm, 0.6 mm, 0.65 mm, 0.7 mm or 0.8 mm.

[0061] In one embodiment, Figure 4 As shown, the welding area 204 between the shell 1 and the cover body 201 is located on the outer surface of the shell 1. The folded edge 2012 is fixed to the shell 1 by penetration welding, and the welding is performed from the surface of the shell 1 to the folded edge 2012. The penetration welding has the advantages of high-strength connection, good sealing, wide applicability, and high welding quality.

[0062] Furthermore, when the cover body 201 is a hollow structure, the welding area 204 does not penetrate the folded edge 2012 along the arrangement direction of the shell 1 and the folded edge 2012. The welding area 204 does not penetrate the folded edge 2012, which can reduce the fine holes or cracks caused by full penetration welding, thereby improving the sealing of the battery, preventing electrolyte leakage or external pollutants from entering the battery, and reducing the risk of leakage. Incomplete penetration welding retains the integrity of the material and avoids the material weakening that may occur during full penetration welding, thereby maintaining the structural strength of the shell 1 and the cover 2, and can also reduce such stress concentration and improve the fatigue resistance of the welding area 204.

[0063] It should be noted that the welding area 204 is Figure 4 The gray area in .

[0064] It is understandable that, in another embodiment, the folded edge 2012 and the shell 1 may also be butt-welded.

[0065] In one embodiment, the battery shell is made of stainless steel, that is, the cover plate 2 and the shell 1 are both made of stainless steel. Stainless steel has the advantages of good corrosion resistance, high strength, excellent thermal expansion performance and thermal insulation performance, good impermeability, good safety, and weldability.

[0066] It is understandable that in another embodiment, the battery housing may be made of other materials, and is not limited thereto.

[0067] In one embodiment, the cover body 201 is fixed to the housing 1 by penetration welding. The welding is performed by penetrating from the side of the housing 1 to the cover body 201. Penetration welding has the advantages of high-strength connection, good sealing, wide applicability, and high welding quality.

[0068] In one embodiment, the folded edge 2012 is arranged around the edge of the plate body 2011, and the folded edge 2012 is interference fit with the inner wall of the shell 1, so that the shell 1 and the cover plate 2 can be welded together conveniently by penetration welding, thereby improving welding efficiency.

[0069] In one embodiment, the plate body 2011 and the folded edge 2012 are formed by bending the edge of a plate upward, and the cover plate 2 is processed by the plate, which is simple to process and reduces the manufacturing cost. Figure 7 As shown, the limiting protrusion 202 is formed by punching the folded edge 2012 outward.

[0070] It is understandable that, in another embodiment, the plate body 2011 and the folded edge 2012 may also be formed separately and fixedly connected.

[0071] According to an embodiment of the present invention, on the other hand, a battery is provided, comprising: the above-mentioned battery casing and a battery cell arranged inside the battery casing.

[0072] Furthermore, the battery cell can be a wound battery cell or a laminated battery cell. The battery also includes a pole, etc. The pole can be arranged on the battery shell or on the cover body 201, and the pole is connected to the pole ear of the battery cell through a connecting piece.

[0073] It should be noted that the battery cells, poles, etc. can all adopt the structures in the prior art, which will not be described in detail here.

[0074] According to another aspect of an embodiment of the present invention, a battery pack is provided, comprising: the above-mentioned battery.

[0075] Furthermore, a battery pack combines multiple batteries and their related components to form a complete energy storage unit. The design and structural composition of a battery pack usually need to consider multiple factors, including but not limited to safety, reliability, thermal management, electrical connections, etc.

[0076] Specifically, the battery pack also includes a battery box, a battery management system, a thermal management system, etc. The battery box is used to hold the battery. The battery management system is responsible for monitoring the battery status, such as voltage, current, temperature, etc., and managing it to ensure the battery is safe and efficient. It can also achieve battery balancing to prevent individual batteries from being overcharged or over-discharged. The thermal management system is used to maintain the battery pack within an optimal operating temperature range, usually achieved through a cooling or heating system, which helps to improve battery life and safety.

[0077] Although the embodiments of the present invention have been 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 casing, characterized in that: include: A housing (1) having an opening; A cover plate (2) seals the opening to form a receiving cavity, the cover plate (2) comprising a cover plate body (201) and a limiting protrusion (202) located on a side wall of the cover plate body (201), the limiting protrusion (202) being located at an end of the side wall of the cover plate body (201) away from the shell (1) along the thickness direction of the cover plate body (201), the limiting protrusion (202) overlapping the opening of the shell (1), the portion of the cover plate body (201) located inside the opening being welded and fixed to the shell (1), the cover plate body (201) being a hollow structure, and along the thickness direction of the cover plate body (201), the ratio of the height h2 of the limiting protrusion (202) to the total height h1 of the cover plate (2) is 1:8~1:5; The welding area (204) between the cover plate body (201) and the shell (1) is spaced apart from the limiting protrusion (202); The distance L between the welding area (204) and the limiting protrusion (202) ranges from 0.03 mm to 0.8 mm; The cover plate body (201) comprises a plate body (2011) and a folded edge (2012) located at the edge of the plate body (2011), the folded edge (2012) extending along a side away from the accommodating cavity, the limiting protrusion (202) being arranged on the folded edge (2012), and the ratio of the thickness T1 of the folded edge (2012) to the thickness T2 of the shell (1) being 1.2:1 to 3:

1.

2. The battery housing according to claim 1, characterized in that: The welding area (204) between the shell (1) and the cover plate body (201) is located on the outer surface of the shell (1).

3. The battery housing according to claim 1, characterized in that: The battery shell is made of stainless steel.

4. A battery, characterized in that: include: A battery casing as claimed in any one of claims 1 to 3 and a battery cell arranged inside the battery casing.

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