Battery cell housing, battery cell, and battery pack

Abstract

The utility model relates to battery technology field discloses electric core shell, electric core and battery package, wherein the electric core shell mainly includes: bottom plate and a plurality of side plates, a plurality of side plates are surrounded in the four around of bottom plate, and form the accommodating cavity with the opening with bottom plate, and the connecting place of adjacent side plates is equipped with transition arc section, and the inside of one end of transition arc section close to the opening is equipped with step part, and step part is suitable for with the cover plate subassembly of electric core connects, the average thickness of each side plate is T1, along the direction perpendicular to the thickness of bottom plate, the radius of outside side of transition arc section is R1, the radius of inside side arc of step part is R2, satisfy 0.1mm 2 <=(R1-R2) x T1 <=2mm 2 The utility model discloses through control (R1-R2) x T1 in proper range, can ensure that side plate and transition arc section have enough support strength under the premise of guaranteeing effective support cover plate subassembly, avoid weak area breakage, and the space utilization of electric core is higher, is favorable to promote the energy density of electric core.

Description

Technical Field

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

[0002] Battery packs offer advantages such as high energy density, high power density, numerous cycle times, and long storage time, making them widely used in new energy vehicles, power storage systems, and new energy storage power supplies. A battery pack typically consists of multiple battery cells.

[0003] The battery cell includes a housing, electrode assembly, and cover plate assembly. The housing contains the electrolyte and electrode assembly, and the cover plate assembly is installed at the opening of the housing to form a sealed space for sealing and protecting the electrode assembly and electrolyte.

[0004] Currently, existing battery cells typically have a step stamped at the open end of the casing. This step can support the cover plate assembly, facilitating subsequent welding of the cover plate assembly to the casing. However, the area from the step to the open end on the casing is relatively thin, easily forming a weak zone. When the internal pressure of the battery cell is high, this weak zone is prone to damage, causing sealing failure or even thermal runaway. Utility Model Content

[0005] In view of this, the present invention provides a battery cell housing, a battery cell, and a battery pack to solve the problem that the battery cell housing has a stepped support cover assembly at the open end, which creates a weak area in the housing. The internal pressure of the battery cell is relatively high, and the weak area is prone to damage, resulting in sealing failure or even thermal runaway.

[0006] In a first aspect, this utility model provides a battery cell housing, comprising:

[0007] Base plate;

[0008] Multiple side plates are arranged around the base plate and form an open receiving cavity with the base plate. A transition arc segment is provided at the connection between adjacent side plates. A step portion is provided on the inner side of the end of the transition arc segment near the opening. The step portion is adapted to be connected to the cover plate assembly of the battery cell. The thickness of the transition arc segment above the step portion is less than the thickness of the transition arc segment below the step portion.

[0009] The average thickness of each of the side plates is T1. Along a direction perpendicular to the thickness of the base plate, the radius of the outer arc of the transition segment is R1, and the radius of the inner arc of the step is R2, both satisfying 0.1 mm. 2 ≤(R1-R2)×T1≤2mm 2 .

[0010] Secondly, this utility model also provides a battery cell, comprising:

[0011] Cover plate assembly;

[0012] In the aforementioned cell housing, the cover plate assembly covers the side of the cell housing with the opening and is connected to the stepped portion.

[0013] Thirdly, the present invention also provides a battery pack, comprising: at least one of the above-mentioned battery cells.

[0014] Beneficial Effects: The cell casing of the above technical solution utilizes a cavity formed by a base plate and multiple side plates to accommodate the cell's electrode assembly. A transition arc segment is provided at the connection point of adjacent side plates, enabling a smooth transition and preventing injury to the cell and operators from sharp edges. The stepped portion on the transition arc segment effectively supports the cover plate assembly, facilitating its fixation to the side plates. By controlling (R1-R2)×T1 within a suitable range, sufficient support strength is ensured for the side plates and transition arc segment while guaranteeing effective support for the cover plate assembly. This prevents damage to the cell casing due to internal cell pressure, resulting in a better sealing effect, reduced risk of thermal runaway, and improved cell safety and reliability. Furthermore, the stepped portion is located on the inner side, not occupying internal cell space, resulting in higher space utilization and improving the cell's energy density. Attached Figure Description

[0015] To more clearly illustrate the specific embodiments of this utility model or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0016] Figure 1 This is an exploded view of a battery cell according to an embodiment of the present invention;

[0017] Figure 2 This is a top view of a battery cell housing according to an embodiment of the present utility model;

[0018] Figure 3 for Figure 2 A magnified view of part A in the diagram.

[0019] Explanation of reference numerals in the attached figures:

[0020] 1. Base plate; 2. Side plate; 201. First sub-side plate; 202. Second sub-side plate; 3. Receiving cavity; 4. Transition arc segment; 5. Step section; 6. Cover plate assembly; 601. Transition fillet; 7. Pole group. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0022] In this embodiment of the invention, a "cell" refers to a single battery cell capable of independent charging and discharging. The components of a cell may include a positive electrode, a negative electrode, a separator, an electrolyte, and a cell casing for encapsulating the positive electrode, negative electrode, separator, and electrolyte. The cell in this embodiment may be a lithium-ion cell, a potassium-ion cell, a sodium-ion cell, a lithium-sulfur cell, etc., with lithium-ion cells being particularly preferred. During the charging and discharging process, active ions repeatedly insert and extract between the positive and negative electrode plates. The electrolyte acts as a conductor of ions between the positive and negative electrode plates.

[0023] The following is combined with Figures 1 to 3 The following describes embodiments of the present invention.

[0024] According to embodiments of the present invention, on the one hand, such as Figure 1 As shown, a battery cell housing is provided, mainly comprising: a base plate 1 and multiple side plates 2. The multiple side plates 2 surround the base plate 1 and form an open receiving cavity 3 with the base plate 1. A transition arc segment 4 is provided at the connection between adjacent side plates 2. A step portion 5 is provided on the inner side of the end of the transition arc segment 4 near the opening. The step portion 5 is adapted to connect with the cover plate assembly 6 of the battery cell. The thickness of the transition arc segment 4 at the upper part of the step portion 5 is less than the thickness of the transition arc segment 4 at the lower part of the step portion 5.

[0025] Furthermore, the average thickness of each side plate 2 is T1. Along the direction perpendicular to the thickness of the base plate 1, the radius of the outer arc of the transition segment 4 is R1, and the radius of the inner arc of the step portion 5 is R2, satisfying 0.1mm. 2 ≤(R1-R2)×T1≤2mm 2 .

[0026] Therefore, the battery cell housing provided in this embodiment utilizes a cavity 3 formed by a base plate 1 and multiple side plates 2 to accommodate the electrode assembly 7 of the battery cell. A transition arc segment 4 is provided at the connection point of adjacent side plates 2, enabling a smooth transition and preventing sharp edges from injuring the battery cell and operators. A step portion 5 is provided on the transition arc segment 4 to effectively support the cover plate assembly 6, facilitating the fixation of the cover plate assembly 6 to the side plates 2. By controlling (R1-R2)×T1 within a suitable range, while ensuring effective support for the cover plate assembly 6, sufficient support strength is ensured for the side plates 2 and the transition arc segment 4, preventing damage to the battery cell housing due to internal pressure within the battery cell. This results in a good sealing effect, reduces the risk of thermal runaway, and improves the safety and reliability of the battery cell. Furthermore, the step portion 5 is located on the inner side, not occupying the internal space of the battery cell, resulting in high space utilization and improving the energy density of the battery cell.

[0027] Specifically, the stepped portion 5 is used to support the cover plate assembly 6. The transition arc 4 is thinned in the area between the top of the stepped portion 5 and the opening, thus forming a weak area. After measuring the thickness of each side plate 2, the average thickness T1 of each side plate 2 can be obtained by taking the average value. The side of the cell casing closer to the opening is the upper part, i.e., the top, and the side closer to the bottom plate 1 is the lower part, i.e., the bottom.

[0028] It should be noted that the shape of the cell casing needs to correspond to the shape of the cell electrode assembly, and the number of side plates 2 should be set accordingly. For example, the cell can be a square cell, in which case the cell casing is a cuboid structure with four side plates 2, and the bottom plate 1 is a rectangular plate, with the four side plates 2 surrounding the bottom plate 1. Transition arc segments 4 can also be provided between the bottom plate 1 and each side plate 2.

[0029] It is understood that in other embodiments, the shape of the battery cell casing can be selected as needed, including regular or irregular polygons, such as triangles, rectangles, pentagons, hexagons, etc.

[0030] It should be noted that the difference between the radius of the outer arc of the transition segment 4 and the radius of the inner arc of the step 5, i.e., R1-R2, directly determines the degree of thinning of the step 5, that is, the structural strength of the weak area. The smaller the value of R1-R2, the larger the thickness of the step 5 and the higher the structural strength, but the smaller the support area of ​​the step 5, resulting in poorer support for the cover plate assembly 6. The larger the value of R1-R2, the larger the support area of ​​the step 5 and the better the support for the cover plate assembly 6, but the relatively smaller the thickness of the step 5, the lower the structural strength, the more prone it is to damage, and the risk of thermal runaway exists.

[0031] Furthermore, the greater the average thickness T1 of each side plate 2, the higher the support strength, and correspondingly, the higher the structural strength of the weak area. However, the cell casing occupies more space in the cell, resulting in lower energy density and heavier weight, leading to higher manufacturing costs. Conversely, the smaller the average thickness T1 of each side plate 2, the smaller the space occupied by the cell casing, resulting in higher energy density. However, the weak areas are more prone to failure, leading to poorer safety performance.

[0032] Therefore, by controlling (R1-R2)×T1 within a suitable range, this embodiment of the utility model can balance the supporting strength of the battery cell housing and the effective connection of the cover plate assembly 6, thus ensuring the supporting stability of the cover plate assembly 6.

[0033] In one embodiment, 2mm≤R1≤4mm.

[0034] In one embodiment, 2mm≤R2≤3.5mm.

[0035] In one embodiment, 0.2mm ≤ T1 ≤ 1.5mm.

[0036] For example, in this embodiment of the present invention, the radius R1 of the outer arc of the transition segment 4 can be 2.5 mm, the radius R2 of the inner arc of the step portion 5 can be 2 mm, and the average thickness T1 of each side plate 2 can be 0.2 mm, then (R1-R2)×T1 is 0.1 mm. 2 Alternatively, the radius R1 of the outer arc of the transition segment 4 can be 3.5 mm, the radius R2 of the inner arc of the step 5 can be 2.5 mm, and the average thickness T1 of each side plate 2 can be 0.5 mm. Then (R1-R2)×T1 is 0.5 mm. 2 Alternatively, the radius R1 of the outer arc of the transition segment 4 can be 4mm, the radius R2 of the inner arc of the step 5 can be 2mm, and the average thickness T1 of each side plate 2 can be 1mm. Then (R1-R2)×T1 is 2mm. 2 .

[0037] It should be noted that this embodiment of the utility model does not restrict the connection method of the base plate 1, the side plate 2 and each transition arc segment 4, and any existing connection method can be selected as needed.

[0038] In one embodiment, the base plate 1, each side plate 2, each transition arc segment 4, and the step portion 5 are integrally formed. For example, the base plate 1, side plates 2, and transition arc segments 4 are integrally formed by stretching with a mold, and the step portion 5 is formed on the transition arc segments 4 by stamping.

[0039] In one embodiment, the base plate 1 and the side plate 2 can be processed and formed separately, then welded and fixed, and a chamfer is opened at the connection between the base plate 1 and the side plate 2 to form a transition arc segment 4. Finally, a step portion 5 is stamped on the transition arc segment 4.

[0040] In one embodiment, such as Figure 2 and Figure 3 As shown, the side plate 2 includes a pair of first sub-side plates 201 and a pair of second sub-side plates 202. The pair of first sub-side plates 201 are disposed opposite each other on both sides of the base plate 1 in the width direction, and the pair of second sub-side plates 202 are disposed opposite each other on both sides of the base plate 1 in the length direction. The thickness of the first sub-side plate 201 is T2, and the thickness of the second sub-side plate 202 is T3, satisfying 0.15mm. 2 ≤(R1-R2)×T2≤1.6mm 2 0.15mm 2 ≤(R1-R2)×T3≤1.8mm 2 .

[0041] Specifically, the length direction of the base plate 1 is as follows: Figure 2 As shown by arrow L in the diagram, the width direction of base plate 1 is as follows: Figure 2 As indicated by the arrow W in the diagram.

[0042] It should be noted that when the base plate 1 and the side plate 2 are stamped as a whole to form the stepped part 5, after stamping, the length of the first sub-side plate 201 located on both sides of the width direction of the base plate 1 is relatively long, and its thickness T2 is generally less than the thickness T3 of the second sub-side plate 202. Therefore, the weak area near the second sub-side plate 202 is more prone to damage. Therefore, by controlling the values ​​of (R1-R2)×T2 and (R1-R2)×T3 within a suitable range, it is possible to further ensure that the side plate 2 and the transition arc segment 4 have sufficient support strength, avoid damage to the cell shell due to the internal pressure of the cell, and effectively support the cover plate assembly 6.

[0043] In one embodiment, 0.3mm ≤ T2 ≤ 1mm.

[0044] In one embodiment, 0.3mm ≤ T3 ≤ 1.2mm.

[0045] For example, in this embodiment of the present invention, the radius R1 of the outer arc of the transition segment 4 can be 3mm, the radius R2 of the inner arc of the step portion 5 can be 2.5mm, the thickness T2 of the first sub-side plate 201 can be 0.5mm, and the thickness T3 of the second sub-side plate 202 can be 1mm. Then, (R1-R2)×T2 is 0.25mm. 2 (R1-R2)×T3 is 0.5mm 2 .

[0046] In one embodiment, the step portion 5 extends along the depth direction of the receiving cavity 3 to the bottom plate 1 and is connected to the bottom plate 1 to ensure that the step portion 5 has sufficient strength and facilitates the processing of the step portion 5.

[0047] In one embodiment, such as Figure 3 As shown, along the direction perpendicular to the thickness of the base plate 1, the radius of the inner arc of the transition segment 4 is R3, which satisfies 2mm≤R3≤3mm.

[0048] According to an embodiment of the present invention, on the other hand, as... Figure 1 As shown, a battery cell is also provided, including: a cover plate assembly 6 and a battery cell housing, the cover plate assembly 6 covering the side of the battery cell housing with an opening and connected to the step portion 5.

[0049] Therefore, the battery cell provided in this embodiment utilizes a cavity 3 formed by a base plate 1 and multiple side plates 2 to accommodate the electrode assembly 7 of the battery cell. A transition arc 4 is provided at the connection point of adjacent side plates 2, enabling a smooth transition and preventing sharp edges from injuring the battery cell and operators. A step 5 is provided on the transition arc 4 to effectively support the cover plate assembly 6, facilitating the fixation of the cover plate assembly 6 to the side plates 2. By controlling (R1-R2)×T1 within a suitable range, while ensuring effective support for the cover plate assembly 6, sufficient support strength is ensured for the side plates 2 and the transition arc 4, preventing damage to weak areas due to internal pressure within the battery cell. This results in a better sealing effect, reduces the risk of thermal runaway, and improves the safety and reliability of the battery cell. Furthermore, the step 5 is located on the inner side, not occupying the internal space of the battery cell, resulting in higher space utilization and improving the energy density of the battery cell.

[0050] Specifically, such as Figure 1 As shown, the battery cell also includes an electrode assembly 7, which is located within the housing space enclosed by the base plate 1 and the side plate 2. The electrode assembly 7 is also provided with electrode tabs, which are electrically connected to the electrode posts on the cover plate assembly 6 via electrical connecting pieces. The cover plate assembly 6 is first interference-fitted with the side of the battery cell housing with an opening, and then abuts against the stepped portion 5 on the inner side of the side plate 2. The stepped portion 5 supports the cover plate assembly 6, and finally, the cover plate assembly 6 is welded and fixed to each side plate 2 around its perimeter.

[0051] In one embodiment, the four corners of the cover plate assembly 6 are provided with transition fillets 601 corresponding to the transition arc segments 4. The radius of the transition fillets 601 is R4, which satisfies 1.95mm≤R4≤2.85mm. The transition fillets 601 are interference-fitted with the transition arc segments 4 so as to initially install the cover plate assembly 6 on the cell housing.

[0052] In one embodiment, the width of the fitting gap between the outer peripheral wall of the cover plate assembly 6 and the inner wall of the side plate 2 is L1, which satisfies 0.02mm≤L1≤0.1mm.

[0053] According to an embodiment of the present invention, another aspect provides a battery pack, comprising: at least one battery cell.

[0054] Since the battery pack includes battery cells and has the same effect as the battery cells, it will not be elaborated on here.

[0055] To achieve the basic functions of the battery pack, the battery pack in this embodiment may also include other necessary modules or components, such as a battery management system and a heat dissipation system. It should be noted that any suitable existing structure can be selected from the other necessary modules or components included in the battery pack. To clearly and concisely illustrate the technical solution provided in this embodiment, the above-mentioned parts will not be repeated here, and the accompanying drawings have also been simplified accordingly. However, it should be understood that the scope of the embodiments of this utility model is not limited thereto.

[0056] Although embodiments of the present invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. An electric cell housing, characterized by, include: Base plate (1); Multiple side plates (2) are arranged around the bottom plate (1) and form an open receiving cavity (3) with the bottom plate (1). A transition arc segment (4) is provided at the connection between adjacent side plates (2). A step portion (5) is provided on the inner side of the end of the transition arc segment (4) near the opening. The step portion (5) is adapted to be connected to the cover plate assembly (6) of the battery cell. The thickness of the transition arc segment (4) at the upper part of the step portion (5) is less than the thickness of the transition arc segment (4) at the lower part of the step portion (5). The average thickness of each of the side plates (2) is T1. Along the direction perpendicular to the thickness of the base plate (1), the radius of the outer arc of the transition segment (4) is R1, and the radius of the inner arc of the step portion (5) is R2, satisfying 0.1mm. 2 ≤(R1-R2)×T1≤2mm 2 .

2. The cell case of claim 1, wherein, 2mm≤R1≤4mm.

3. The cell case of claim 1, wherein, 2mm≤R2≤3.5mm.

4. The cell case of claim 1, wherein, 0.2mm≤T1≤1.5mm.

5. The cell case of claim 1, wherein, The side plate (2) includes a pair of first sub-side plates (201) and a pair of second sub-side plates (202). The pair of first sub-side plates (201) are disposed opposite each other on both sides of the base plate (1) in the width direction, and the pair of second sub-side plates (202) are disposed opposite each other on both sides of the base plate (1) in the length direction. The thickness of the first sub-side plate (201) is T2, and the thickness of the second sub-side plate (202) is T3, satisfying 0.15mm. 2 ≤(R1-R2)×T2≤1.6mm 2 0.15mm 2 ≤(R1-R2)×T3≤1.8mm 2 .

6. The cell housing of claim 5, wherein, 0.3mm≤T2≤1mm.

7. The cell case of claim 5, wherein, 0.3mm≤T3≤1.2mm.

8. The cell case according to any one of claims 1 to 7, characterized by, The stepped portion (5) extends along the depth direction of the receiving cavity (3) to the bottom plate (1) and is connected to the bottom plate (1).

9. The cell case according to any one of claims 1 to 7, characterized by, Along the direction perpendicular to the thickness of the base plate (1), the radius of the inner arc of the transition segment (4) is R3, which satisfies 2mm≤R3≤3mm.

10. An electric cell characterized by include: Cover plate assembly (6); According to any one of claims 1 to 9, the cover plate assembly (6) covers the side of the battery cell housing with an opening and is connected to the step portion (5).

11. The electric cell of claim 10, wherein, The cover plate assembly (6) has a transition fillet (601) at the four corners corresponding to the transition arc segment (4), and the radius of the transition fillet (601) is R4, which satisfies 1.95mm≤R4≤2.85mm.

12. The electric cell of claim 10, wherein, The width of the fitting gap between the outer peripheral wall of the cover plate assembly (6) and the inner wall of the side plate (2) is L1, which satisfies 0.02mm≤L1≤0.1mm.

13. A battery pack, characterized by include: At least one battery cell according to any one of claims 10 to 12.

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