Cell casing assembly, cell and battery pack

Abstract

This utility model relates to the field of battery technology and discloses a cell housing assembly, a cell, and a battery pack. The cell housing assembly includes a housing body and a cover plate body. The housing body has an opening at one end and includes a bottom wall and multiple side walls surrounding the bottom wall. The connection between adjacent side walls has a transition fillet. At least one side wall has a step on its inner side near the opening, extending to the transition fillet. The portion of the housing body from the opening to the step forms a thinned wall. The cover plate body covers the opening and abuts against the step. The corners of the cover plate body have first fillets corresponding to the transition fillets. The inner wall of the thinned wall extending to the transition fillet forms a second fillet. The radius of the first fillet is R1, the radius of the second fillet is R2, and the thickness of the step is T1, satisfying 0.27 ≤ |R1-R2| / T1 ≤ 26. This utility model, by controlling |R1-R2| / T1 within a suitable range, ensures that the thinned wall has sufficient structural strength.

Description

Technical Field

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

[0002] Battery packs are widely used in various fields such as transportation power supply, power storage, and new energy storage power supply. A battery pack typically consists of multiple battery cells.

[0003] A battery cell typically consists of a casing, a cover plate, and electrode assemblies. The casing and cover plate are welded together to form a sealed space protecting the electrode assemblies. To facilitate welding the casing and cover plate, a step is usually provided on the inner wall of the casing. This step supports and limits the cover plate before welding the casing and cover plate together. However, with the step on the casing, the portion between the casing opening and the step is relatively thin. Under the influence of internal cell pressure, the casing is prone to breakage in this thinner area, ultimately leading to thermal runaway. Utility Model Content

[0004] In view of this, the present invention provides a cell housing assembly, a cell, and a battery pack to solve the problem that after a step is set on the inner side of the housing, there is a weak area, which makes the housing easy to break and causes thermal runaway.

[0005] In a first aspect, this utility model provides a battery cell housing assembly, comprising:

[0006] The shell body has an opening at one end. The shell body includes a bottom wall and a plurality of side walls surrounding the bottom wall. The connection between adjacent side walls is provided with a transition rounded corner. At least one side wall has a stepped portion on its inner side near the opening end, and the stepped portion extends to the transition rounded corner. The portion of the shell body from the opening to the stepped portion forms a thinned wall.

[0007] The cover plate body is placed over the opening and abuts against the step portion. The four corners of the cover plate body are provided with a first rounded corner corresponding to the transition rounded corner.

[0008] The thinned wall extends to the inner wall at the transition fillet to form a second fillet. The radius of the first fillet is R1, the radius of the second fillet is R2, and the thickness of the step portion is T1, satisfying 0.27≤|R1-R2| / T1≤26.

[0009] Secondly, this utility model also provides a battery cell, comprising:

[0010] The pole group is equipped with pole tabs;

[0011] In the aforementioned battery cell housing assembly, the electrode group is disposed within the housing body, and the electrode tab is electrically connected to the cover plate body.

[0012] Thirdly, the present invention also provides a battery pack, comprising: at least one of the above-mentioned battery cells.

[0013] Beneficial Effects: The cell housing assembly of the above technical solution features a stepped section on the side wall of the housing body, which effectively supports the cover plate body, facilitating welding and fixing of the cover plate body to the housing body. By controlling |R1-R2| / T1 within a suitable range, sufficient support strength of the thinned wall can be ensured, reducing the risk of housing body breakage and thus improving the reliability and safety of the cell. If the value of |R1-R2| / T1 is too large, the stepped section will be too thin, making it difficult to effectively support the cover plate body, and the transition fillet will be too thin. If the value of |R1-R2| / T1 is too small, the thinned wall will be too thin, easily leading to thermal runaway, and the bond between the cover plate body and the housing body will be weak, posing a risk of collapse during subsequent welding. Attached Figure Description

[0014] 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.

[0015] Figure 1 This is a schematic diagram of the structure of a battery cell housing assembly according to an embodiment of the present utility model;

[0016] Figure 2 for Figure 1 A magnified view of part A in the diagram;

[0017] Figure 3 This is a top view of the housing body of a battery cell housing assembly according to an embodiment of the present utility model;

[0018] Figure 4 for Figure 3 A magnified view of part B in the diagram;

[0019] Figure 5 This is a top view of the cover plate body of a battery cell housing assembly according to an embodiment of the present utility model.

[0020] Explanation of reference numerals in the attached figures:

[0021] 1. Shell body; 101. Opening; 102. Bottom wall; 103. Side wall; 104. Transition fillet; 105. Stepped part; 106. Thinned wall; 107. Second fillet; 2. Cover plate body; 201. First fillet. Detailed Implementation

[0022] 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.

[0023] The following is combined Figures 1 to 5 The following describes embodiments of the present invention.

[0024] According to embodiments of the present invention, on the one hand, such as Figure 1 and Figure 2 As shown, a battery cell housing assembly is provided, mainly comprising: a housing body 1 and a cover plate body 2. The housing body 1 has an opening 101 at one end. The housing body 1 includes a bottom wall 102 and a plurality of side walls 103 surrounding the bottom wall 102. A transition fillet 104 is provided at the connection between adjacent side walls 103. At least one side wall 103 has a stepped portion 105 on its inner side near the opening 101, and the stepped portion 105 extends to the transition fillet 104. A thinned wall 106 is formed in the portion of the housing body 1 from the opening 101 to the stepped portion 105. The cover plate body 2 covers the opening 101 and abuts against the stepped portion 105. A first fillet 201 is provided at the corners of the cover plate body 2 corresponding to the transition fillet 104. The thinned wall 106 extends to the inner wall at the transition fillet 104 to form a second fillet 107. The radius of the first fillet 201 is R1, the radius of the second fillet 107 is R2, and the thickness of the step portion 105 is T1, satisfying 0.27≤|R1-R2| / T1≤26.

[0025] Therefore, the battery cell housing assembly provided in this embodiment of the present invention, with a stepped portion 105 on the side wall 103 of the housing body 1, can effectively support the cover plate body 2, so that the cover plate body 2 can be welded and fixed to the housing body 1. By controlling |R1-R2| / T1 within a suitable range, it can be ensured that the thinned wall 106 has sufficient supporting strength, reducing the risk of damage to the housing body 1, thereby improving the reliability and safety of the battery cell. If the value of |R1-R2| / T1 is too large, the stepped portion 105 is too thin, making it difficult to effectively support the cover plate body 2, and the transition fillet 104 is too thin. If the value of |R1-R2| / T1 is too small, the thinned wall 106 is too thin, making it easy to break and cause thermal runaway, and the firmness between the cover plate body 2 and the housing body 1 is low, posing a risk of collapse during subsequent welding.

[0026] Specifically, the bottom wall 102 and multiple side walls 103 form a receiving cavity for accommodating the electrode assembly, and an opening 101 is formed on the side of the side wall 103 away from the bottom wall 102. The opening 101 is used to install the electrode assembly of the battery cell and the cover plate body 2. The cover plate body 2 closes the opening 101.

[0027] It should be noted that the first rounded corner 201 of the cover plate body 2 and the second rounded corner 107 of the thinned wall 106 are interference-fitted to achieve the initial fixation of the cover plate body 2 and the shell body 1. At the same time, the step portion 105 supports the cover plate body 2, and then the cover plate body 2 and the shell body 1 are welded and fixed. The difference between the radius of the first rounded corner 201 and the radius of the second rounded corner 107, i.e., R1-R2, directly determines the firmness of the interference fit between the cover plate body 2 and the shell body 1. Among them, the radius R2 of the second rounded corner 107 determines the thickness of the side wall 103 of the shell body 1 occupied by the step portion 105, which also affects the firmness of the interference fit between the cover plate body 2 and the shell body 1. The thickness T1 of the step portion 105 directly determines the support area of ​​the step portion 105, that is, the support capacity for the cover plate body 2. If T1 is too large, the thinned wall 106 will be too thin, and the risk of thermal runaway will increase significantly. If T1 is too small, the support area will be too small, and it will be difficult to effectively support the cover plate body 2.

[0028] For example, in the embodiments of this utility model, the value of |R1-R2| / T1 can be 0.27, 0.5, 1, 2, 3, 5, 8, 10, 12, 15, 18, 20, 23, 25, 26, etc.

[0029] In one embodiment, such as Figure 5 As shown, 1.95mm≤R1≤2.85mm.

[0030] For example, in this embodiment of the present invention, the radius R1 of the first fillet 201 can be 1.95mm, 2.1mm, 2.3mm, 2.5mm, 2.7mm, 2.85mm, etc.

[0031] In one embodiment, such as Figure 4 As stated, 2mm≤R2≤3.5mm.

[0032] For example, in this embodiment of the present invention, the radius R2 of the second fillet 107 can be 2mm, 2.5mm, 3mm, 3.5mm, etc.

[0033] In one embodiment, such as Figure 4 As stated, 0.05mm≤T1≤0.3mm.

[0034] For example, in the embodiments of the present invention, the thickness T1 of the step portion 105 can be 0.05mm, 0.1mm, 0.15mm, 0.2mm, 0.25mm, 0.3mm, etc.

[0035] It should be noted that the present invention does not limit the processing technology of the shell body 1, and any existing connection method can be selected as needed.

[0036] In one embodiment, the bottom wall 102 and each side wall 103 of the shell body 1 are integrally formed, for example by stamping, and then by stamping to form the stepped portion 105.

[0037] In one embodiment, such as Figure 3 As shown, the stepped portion 105 is provided on the sidewalls 103 on opposite sides along the length direction of the shell body 1, and 0.35≤|R1-R2| / T1≤26.

[0038] It should be noted that after the shell body 1 is formed by stamping, the thickness of the longer side wall 103 is relatively thinner than that of the shorter side wall 103. Therefore, the stepped portion 105 is set on the side walls 103 on both sides of the shell body 1 along the length direction, that is, on the relatively thicker side wall 103. This can make full use of the thickness advantage of the thicker side wall 103, and ensure that the stepped portion 105 has sufficient strength to support the cover plate body 2, while ensuring that the thinned wall 106 has sufficient support strength and reducing the risk of damage to the shell body 1.

[0039] In one embodiment, such as Figure 3 and Figure 4 As shown, the thickness of the sidewalls 103 on both sides of the shell body 1 along the length direction is T2, and the thickness of the sidewalls 103 on both sides of the shell body 1 along the width direction is T3, satisfying T2≥T3, 0.3mm≤T2≤1.2mm, and 0.3mm≤T3≤1mm.

[0040] Specifically, the length direction of the shell body 1 is as follows: Figure 3 As indicated by arrow L in the diagram, the width direction of the shell body 1 is as follows: Figure 3 As indicated by the arrow W in the diagram.

[0041] For example, in this embodiment of the present invention, the thickness T2 of the sidewalls 103 on both sides of the shell body 1 along the length direction can be 0.3mm, 0.6mm, 0.9mm, 1.2mm, etc. The thickness T3 of the sidewalls 103 on both sides of the shell body 1 along the width direction can be 0.3mm, 0.5mm, 0.8mm, 1mm, etc.

[0042] In one embodiment, after the cover plate body 2 is placed over the opening 101, the width of the fitting gap between the outer peripheral wall of the cover plate body 2 and the inner wall of the shell body 1 is L1, which satisfies 0.02mm≤L1≤0.1mm, so that the cover plate body 2 and the shell body 1 can be welded and fixed.

[0043] According to an embodiment of the present invention, another aspect provides a battery cell, mainly comprising: an electrode assembly and a battery cell housing assembly. The electrode assembly is provided with tabs. The electrode assembly is disposed within the housing body 1 of the battery cell housing assembly, and the tabs are electrically connected to the cover plate body 2.

[0044] Therefore, the battery cell provided in this embodiment of the present invention has a stepped portion 105 on the side wall 103 of the shell body 1, which can effectively support the cover plate body 2 so that the cover plate body 2 can be welded and fixed to the shell body 1. By controlling |R1-R2| / T1 within a suitable range, it can be ensured that the thinned wall 106 has sufficient supporting strength, reducing the risk of damage to the shell body 1, thereby improving the reliability and safety of the battery cell. If the value of |R1-R2| / T1 is too large, the stepped portion 105 is too thin and cannot effectively support the cover plate body 2, and the transition fillet 104 is too thin. If the value of |R1-R2| / T1 is too small, the thinned wall 106 is too thin and is prone to damage leading to thermal runaway. Furthermore, the firmness between the cover plate body 2 and the shell body 1 is low, and there is a risk of collapse during subsequent welding.

[0045] It should be noted that, in this embodiment of the invention, "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 housing assembly 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 battery charging and discharging, active ions repeatedly insert and extract between the positive and negative electrode. The electrolyte acts as a conductor of ions between the positive and negative electrode. The cell in this embodiment may be a square cell, in which case the casing 1 has a cuboid structure with four side walls 103 surrounding the bottom wall 102.

[0046] It is understood that in other embodiments, the shape of the shell body 1 can be selected as needed, including regular or irregular polygons, such as triangles, rectangles, pentagons, hexagons, etc. Furthermore, both the shell body 1 and the cover plate body 2 can be made of aluminum.

[0047] According to an embodiment of the present invention, in another aspect, a battery pack is also provided, comprising: at least one battery cell.

[0048] Since the battery pack includes battery cells and has the same effect as the battery cells, it will not be elaborated on here.

[0049] 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.

[0050] 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 electrochemical cell housing assembly, comprising: include: The shell body (1) has an opening (101) at one end. The shell body (1) includes a bottom wall (102) and a plurality of side walls (103) surrounding the bottom wall (102). The connection between adjacent side walls (103) is provided with a transition fillet (104). At least one side wall (103) has a step portion (105) on the inner side near the end of the opening (101), and the step portion (105) extends to the transition fillet (104). The portion of the shell body (1) from the opening (101) to the step portion (105) forms a thinned wall (106). The cover plate body (2) is placed over the opening (101) and abuts against the step portion (105). The corners of the cover plate body (2) are provided with a first rounded corner (201) corresponding to the transition rounded corner (104). The thinned wall (106) extends to the inner wall of the transition fillet (104) to form a second fillet (107), the radius of the first fillet (201) is R1, the radius of the second fillet (107) is R2, and the thickness of the step portion (105) is T1, satisfying 0.27≤|R1-R2| / T1≤26.

2. The cell can assembly of claim 1, wherein, 1.95mm≤R1≤2.85mm.

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

4. The cell can assembly of claim 1, wherein, 0.05mm≤T1≤0.3mm.

5. The cell can assembly of claim 1, wherein, The stepped portion (105) is provided on the sidewalls (103) on opposite sides of the shell body (1) along the length direction, and 0.35≤|R1-R2| / T1≤26.

6. The cell can assembly of claim 5, wherein, The thickness of the sidewalls (103) on both sides of the shell body (1) along the length direction is T2, and the thickness of the sidewalls (103) on both sides of the shell body (1) along the width direction is T3, satisfying T2≥T3, 0.3mm≤T2≤1.2mm, and 0.3mm≤T3≤1mm.

7. The electrochemical cell housing assembly of claim 5, wherein, The outer wall of the first fillet (201) is interference-fitted with the inner wall of the second fillet (107).

8. The cell case assembly of any one of claims 1 to 7, wherein, The shell body (1) is integrally formed by stamping, and the stepped part (105) is formed by secondary stamping.

9. The cell housing assembly according to any one of claims 1 to 7, characterized in that, The width of the fitting gap between the outer peripheral wall of the cover plate body (2) and the inner wall of the shell body (1) is L1, which satisfies 0.02mm≤L1≤0.1mm.

10. An electric cell characterized by include: The pole group is equipped with pole tabs; According to any one of claims 1 to 9, the electrode group is disposed inside the housing body (1), and the electrode tab is electrically connected to the cover plate body (2).

11. A battery pack, characterized by include: At least one battery cell as described in claim 10.

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