Battery cell housing assembly, battery 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 mainly includes a housing and a cover plate. The housing has an opening at at least one end, and its inner wall has a groove along the circumferential direction. The cover plate includes a first sub-plate and a second sub-plate. The cross-sectional area of ​​the second sub-plate in the X-Y plane is smaller than that of the first sub-plate in the X-Y plane, forming a stepped surface between the first and second sub-plates. The stepped surface is welded to the end face of the housing with the opening. A gap is left between the outer peripheral wall of the second sub-plate and the inner wall of the housing, and a protrusion is provided corresponding to the groove. The protrusion is inserted into the groove, and along the Z-direction, there is an assembly gap between the two sides of the protrusion and the groove wall. The cover plate and housing of this utility model are respectively provided with protrusions and grooves. The protrusions are inserted into the grooves to form a snap-fit ​​structure, ensuring a firm connection and preventing the cover plate from popping out during pre-pressing, significantly improving the assembly and welding yield of the cell.

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] In existing battery structures, the cell casing and cover plate are welded together to form a sealed space that accommodates the electrode assembly. The welding process between the cover plate and the casing is as follows: first, assembly steps are set on the periphery of the cover plate, and it is pre-pressed into the casing. Then, the casing and the cover plate are fixed by laser spot welding. Finally, the casing and the cover plate are fully laser welded to achieve overall fixation and sealing.

[0003] During the pre-pressing and spot welding process, the cover plate is subject to the pressure of entering the shell and the pressure generated by the bending of the electrode tab. After the cover plate is pre-pressed into the shell, there is a risk that it will pop out of the shell, resulting in poor assembly and welding yield of the battery cell. 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 existing cover plates may pop out of the housing after being pre-pressed into the housing, resulting in poor assembly and welding yield of the cell.

[0005] In a first aspect, this utility model provides a battery cell housing assembly, comprising: The housing has an opening at at least one end along the Z direction, and the inner wall of the housing has a circumferential groove near the opening. The cover plate includes a first sub-plate and a second sub-plate connected along the Z direction. The cross-sectional area of ​​the second sub-plate in the XY plane is smaller than that of the first sub-plate in the XY plane, so as to form a stepped surface between the first sub-plate and the second sub-plate. The stepped surface is welded to the end face of the housing with the opening. The outer peripheral wall of the second sub-plate has a gap with the inner wall of the housing and a protrusion is provided corresponding to the groove. The protrusion is inserted into the groove. Along the Z direction, there is an assembly gap between the two sides of the protrusion and the groove wall of the groove.

[0006] Beneficial Effects: In this utility model, after the cover plate and housing are pre-pressed together, the protrusion of the second sub-plate can be inserted into the groove on the inner wall of the housing to form a snap-fit ​​structure, ensuring a firm connection. This reduces the risk of the cover plate popping off the housing, significantly improving the assembly and welding yield of the battery cell. The stepped surface between the first and second sub-plates of the cover plate is welded to the end face of the housing to fix the cover plate to the housing. Furthermore, a gap is left between the outer peripheral wall of the second sub-plate and the inner wall of the housing. Along the Z-direction, assembly gaps are left between the two sides of the protrusion and the groove wall, respectively. These two gaps are connected, forming an exhaust path during welding to promptly release the gas generated during welding, preventing welding spatter and improving weld performance and further increasing the welding yield.

[0007] In one optional embodiment, the width of the assembly gap along the Z direction is L1, satisfying 0.02 mm ≤ L1 ≤ 0.1 mm.

[0008] Beneficial effects: By controlling L1 within a suitable range, it can be ensured that the assembly gap forms a sufficiently large exhaust passage during welding, thereby timely venting of the gas generated during welding, while avoiding excessive width of the assembly gap, which would increase the risk of the cover plate popping out of the housing.

[0009] In one optional embodiment, the height of the protrusion along the Z direction is H1, which satisfies 0.1 mm ≤ H1 ≤ 0.5 mm.

[0010] Beneficial effects: By controlling H1 within a suitable range, it is possible to ensure smooth pre-pressing of the cover plate and the housing, and reduce the risk of the cover plate popping out of the housing. If the value of H1 is too large, the cover plate will be difficult to install into the housing; if the value of H1 is too small, the connection between the cover plate and the housing will be difficult to guarantee, and the cover plate will easily pop out of the housing.

[0011] In one optional embodiment, the groove width along the Z direction is L2, satisfying 0.15 mm ≤ L2 ≤ 0.55 mm.

[0012] Beneficial effects: By controlling L2 within a suitable range, it is possible to ensure that the groove has a suitable width to accommodate the protrusion and form an effective assembly gap.

[0013] In one optional embodiment, the groove depth along the X or Y direction is T2, and the thickness of the housing along the X or Y direction is T3, satisfying 1 / 3≤T2 / T3≤2 / 3.

[0014] Beneficial effects: By controlling T2 / T3 within a suitable range, it is possible to ensure that the part of the shell with the groove has sufficient strength, avoid the shell becoming too thin locally due to the groove, resulting in low local strength, and at the same time ensure that the groove has sufficient depth to accommodate the protrusion.

[0015] In one alternative implementation, 0.1 mm ≤ T2 ≤ 0.5 mm.

[0016] Beneficial effect: By controlling T2 within a suitable range, it can be ensured that the groove has enough space to accommodate the protrusion, so that the cover plate can be smoothly pre-pressed into place.

[0017] In one optional embodiment, the thickness of the protrusion along the X or Y direction is T1, satisfying 0.1 mm ≤ T1 ≤ 0.3 mm.

[0018] Beneficial effects: By controlling T1 within a suitable range, it can be ensured that the protrusion has sufficient strength after being inserted into the groove, preventing the protrusion from breaking. At the same time, it avoids the protrusion being too large, which would make it difficult to assemble the cover plate and the housing. The thickness of the protrusion is slightly greater than the depth of the groove, so that the protrusion and groove form an interference fit, improving the stability during pre-press assembly.

[0019] In one optional embodiment, the second sub-plate has a first chamfer around its end face away from the first sub-plate; And / or, the inner periphery of the housing with the opening end is provided with a second chamfer, and the connection between the first sub-plate and the second sub-plate is provided with a connecting bevel around the periphery corresponding to the second chamfer.

[0020] Beneficial effects: The first chamfer on the second sub-plate prevents scraping between the end face of the second sub-plate furthest from the first sub-plate and the housing during assembly, thus preventing the formation of metal wires and shavings that could affect the assembly of the cover and housing. The second chamfer on the housing, along with connecting bevels corresponding to the second chamfer around the connection between the first and second sub-plates, prevents scraping between the connection between the first and second sub-plates and the inner circumference of the housing with the opening during assembly, thus preventing the formation of metal wires and shavings that could affect the assembly of the cover and housing.

[0021] Secondly, this utility model also provides a battery cell, comprising: pole group; The aforementioned battery cell housing assembly further includes a terminal post on the cover plate, and the electrode group is disposed inside the housing and electrically connected to the terminal post.

[0022] Beneficial Effects: In this invention, after the cover plate and housing are pre-pressed together, the protrusion of the second sub-plate can be inserted into the groove on the inner wall of the housing to form a snap-fit ​​structure, ensuring a firm connection. This reduces the risk of the cover plate popping off the housing, significantly improving the assembly and welding yield of the battery cell. The stepped surface between the first and second sub-plates of the cover plate is welded to the end face of the housing to fix the cover plate to the housing. Furthermore, a gap is left between the outer peripheral wall of the second sub-plate and the inner wall of the housing. Along the Z-direction, assembly gaps are left between the two sides of the protrusion and the groove wall, respectively. These two gaps are connected, forming an exhaust path during welding to promptly release the gas generated during welding, preventing welding spatter and improving weld performance and further increasing the welding yield.

[0023] Thirdly, the present invention also provides a battery pack, comprising: at least one of the above-mentioned battery cells.

[0024] Beneficial effects: Since the battery pack includes battery cells, it has the same effects as the battery cells, which will not be repeated here. Attached Figure Description

[0025] 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.

[0026] Figure 1 This is a schematic diagram of the structure of a battery cell according to an embodiment of the present utility model; Figure 2 This is an exploded view of a battery cell according to an embodiment of the present utility model; Figure 3 This is a side view of a battery cell according to an embodiment of the present utility model; Figure 4 for Figure 3 Sectional view at point AA; Figure 5 for Figure 4 A magnified view of a section at point B in the middle; Figure 6 This is a schematic diagram of the structure of a cover plate for a battery cell according to an embodiment of the present utility model; Figure 7 This is a structural schematic diagram of a cover plate for a battery cell according to an embodiment of the present utility model from another perspective; Figure 8 for Figure 7 A magnified view of a section at point C; Figure 9 This is a schematic diagram of the casing of a battery cell according to an embodiment of the present utility model; Figure 10 for Figure 9 A magnified view of point D in the image.

[0027] Explanation of reference numerals in the attached figures: 1. Housing; 101. Opening; 102. Groove; 103. Second chamfer; 2. Cover plate; 201. First sub-plate; 202. Second sub-plate; 203. Stepped surface; 204. Protrusion; 205. First chamfer; 206. Connecting slope; 207. Pole post; 3. Pole group. Detailed Implementation

[0028] 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.

[0029] The following is combined with Figures 1 to 10 The following describes embodiments of the present invention.

[0030] 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 including: a housing 1 and a cover plate 2. The housing 1 has an opening 101 at at least one end along the Z direction, and the inner wall of the housing 1 has a groove 102 along the circumferential direction near the opening 101. The cover plate 2 includes a first sub-plate 201 and a second sub-plate 202 connected along the Z direction. The cross-sectional area of ​​the second sub-plate 202 in the XY plane is smaller than the cross-sectional area of ​​the first sub-plate 201 in the XY plane, so as to form a stepped surface 203 between the first sub-plate 201 and the second sub-plate 202. The stepped surface 203 is welded to the end face of the housing 1 with the opening 101. The outer peripheral wall of the second sub-plate 202 is left with a gap from the inner wall of the housing 1, and a protrusion 204 is provided corresponding to the groove 102. The protrusion 204 is inserted into the groove 102. Along the Z direction, there is an assembly gap between the two sides of the protrusion 204 and the groove wall of the groove 102.

[0031] Therefore, it can be seen that in the battery cell housing assembly provided by this utility model embodiment, after the cover plate 2 and the housing 1 are pre-pressed together, the protrusion 204 of the second sub-plate 202 can be inserted into the groove 102 of the inner wall of the housing 1 and form a snap-fit ​​structure, which is firmly connected. This reduces the risk of the cover plate 2 popping off the housing 1 and significantly improves the assembly and welding yield of the battery cell. The stepped surface 203 between the first sub-plate 201 and the second sub-plate 202 of the cover plate 2 is welded to the end face of the housing 1 to fix the cover plate 2 to the housing 1. Moreover, there is a gap between the outer peripheral wall of the second sub-plate 202 and the inner wall of the housing 1. Along the Z direction, there is an assembly gap between the two sides of the protrusion 204 and the groove wall of the groove 102. The two gaps are connected and can form an exhaust passage during welding to discharge the gas generated during welding in time, avoid the formation of welding explosions, improve the weld performance, and further improve the welding yield.

[0032] Specifically, in the Z direction, such as Figure 1 and Figure 2 As shown by arrow Z in the diagram, the X direction is as follows: Figure 1 and Figure 2 As shown by arrow X in the diagram, the Y direction is as follows: Figure 1 and Figure 2 As indicated by arrow Y, the XY plane is the plane formed by the X and Y directions.

[0033] To facilitate installation, a stepped surface 203 with a uniform width distribution is formed between the first sub-plate 201 and the second sub-plate 202.

[0034] In embodiments of this utility model, "shell 1" is a component used to provide a receiving space to house components such as the electrode assembly 3, the diaphragm, and the electrolyte, and to isolate them from the outside environment. The material of shell 1 includes, but is not limited to, copper, iron, aluminum, stainless steel, and aluminum alloy.

[0035] In this embodiment of the invention, the "cover plate 2" is used to close the opening 101 of the housing 1 and is welded to the housing 1 to form a sealed space for accommodating the electrode assembly 3. The cover plate 2 can be made of aluminum alloy, stainless steel, etc.

[0036] It should be noted that the shapes of the protrusion 204 and the groove 102 are not limited in this embodiment of the invention, and any existing structure can be selected as needed. For example, as Figure 9 and Figure 10 As shown, the groove 102 extends circumferentially along the housing 1 to form an annular groove. Correspondingly, as... Figure 7 and Figure 8 As shown, protrusion 204 is an annular protrusion. The stepped surface 203 and the end face of the shell 1 can be laser welded.

[0037] In one embodiment, such as Figure 5As shown, the width of the assembly gap along the Z direction is L1, which satisfies 0.02 mm ≤ L1 ≤ 0.1 mm. By controlling L1 within a suitable range, it can be ensured that the assembly gap forms a sufficiently large exhaust passage during welding, thereby timely venting of the gas generated during welding, while avoiding an excessively wide assembly gap that would increase the risk of the cover plate 2 popping out of the housing 1.

[0038] For example, the value of L1 in this embodiment of the present invention can be 0.02 mm, 0.04 mm, 0.06 mm, 0.08 mm, 0.1 mm, etc.

[0039] In one embodiment, such as Figure 5 As shown, the height of the protrusion 204 along the Z direction is H1, satisfying 0.1 mm ≤ H1 ≤ 0.5 mm. By controlling H1 within a suitable range, it is possible to ensure smooth pre-pressing of the cover plate 2 and the housing 1, and reduce the risk of the cover plate 2 popping out of the housing 1. If the value of H1 is too large, the cover plate 2 will be difficult to install into the housing 1; if the value of H1 is too small, the connection between the cover plate 2 and the housing 1 will be difficult to guarantee, and the cover plate 2 will easily pop out of the housing 1.

[0040] For example, the value of H1 in this embodiment of the present invention can be 0.1 mm, 0.2 mm, 0.3 mm, 0.4 mm, 0.5 mm, etc.

[0041] In one embodiment, such as Figure 5 As shown, the groove width of the groove 102 along the Z direction is L2, which satisfies 0.15 mm ≤ L2 ≤ 0.55 mm. By controlling L2 within a suitable range, it can be ensured that the groove 102 has a suitable width to accommodate the protrusion 204 and form an effective assembly clearance.

[0042] For example, the value of L2 in this embodiment of the present invention can be 0.15 mm, 0.25 mm, 0.35 mm, 0.45 mm, 0.55 mm, etc.

[0043] In one embodiment, such as Figure 5 As shown, the groove depth of the groove 102 along the X or Y direction is T2, and the thickness of the shell 1 along the X or Y direction is T3, satisfying 1 / 3 ≤ T2 / T3 ≤ 2 / 3. By controlling T2 / T3 within a suitable range, it can be ensured that the part of the shell 1 with the groove 102 has sufficient strength, avoiding the shell 1 from becoming too thin locally due to the groove 102, resulting in low local strength, while ensuring that the groove 102 has sufficient depth to accommodate the protrusion 204.

[0044] Furthermore, in one embodiment, 0.1 mm ≤ T2 ≤ 0.5 mm. By controlling T2 within a suitable range, it can be ensured that the groove 102 has sufficient space to accommodate the protrusion 204, so that the cover plate 2 can be smoothly pre-pressed onto the cover plate 2.

[0045] For example, in this embodiment of the present invention, the value of T2 can be 0.1 mm and the value of T3 can be 0.3 mm, then T2 / T3 is 1 / 3. Alternatively, the value of T2 can be 0.5 mm and the value of T3 can be 0.75 mm, then T2 / T3 is 2 / 3. Alternatively, the value of T2 can be 0.3 mm and the value of T3 can be 0.6 mm, then T2 / T3 is 0.5.

[0046] In one embodiment, such as Figure 5 As shown, the thickness of the protrusion 204 along the X or Y direction is T1, satisfying 0.1 mm ≤ T1 ≤ 0.3 mm. By controlling T1 within a suitable range, it can be ensured that the protrusion 204 has sufficient strength after being inserted into the groove 102, preventing the protrusion 204 from breaking. At the same time, it can be prevented that the protrusion 204 is too large, which would make it difficult to assemble the cover plate 2 and the housing 1. The thickness of the protrusion 204 is slightly greater than the groove depth of the groove 102, so that the protrusion 204 and the groove 102 form an interference fit, improving the stability during pre-press assembly.

[0047] For example, the value of T1 in this embodiment of the present invention can be 0.1 mm, 0.2 mm, 0.3 mm, etc.

[0048] In one embodiment, such as Figure 5 and Figure 8 As shown, the second sub-plate 202 has a first chamfer 205 around its end face away from the first sub-plate 201. By providing the first chamfer 205 on the second sub-plate 202, when the cover plate 2 is assembled with the housing 1, it can prevent the end face of the second sub-plate 202 away from the first sub-plate 201 from rubbing against the housing 1, which would result in the formation of metal wires and metal shavings, thereby affecting the assembly of the cover plate 2 and the housing 1.

[0049] Furthermore, in one embodiment, such as Figure 5 and Figure 10 As shown, the inner periphery of the housing 1 with the opening 101 has a second chamfer 103, and the connection area between the first sub-plate 201 and the second sub-plate 202 has a connecting slope 206 corresponding to the second chamfer 103. By providing the second chamfer 103 to the housing 1 and the connecting slope 206 corresponding to the second chamfer 103 at the connection area between the first sub-plate 201 and the second sub-plate 202, when the cover plate 2 is assembled with the housing 1, it can prevent scratching between the connection area between the first sub-plate 201 and the second sub-plate 202 and the inner periphery of the housing 1 with the opening 101, which would lead to the formation of metal wires and metal shavings, thus affecting the assembly of the cover plate 2 and the housing 1.

[0050] It should be noted that the first chamfer 205 and the second chamfer 103 can be either right angles or rounded corners as needed. This embodiment of the utility model does not impose too many restrictions on this.

[0051] According to an embodiment of the present invention, another aspect provides a battery cell, which mainly includes: an electrode group 3 and a battery cell housing assembly. The cover plate 2 of the battery cell housing assembly is also provided with a pole post 207. The electrode group 3 is disposed in the housing 1 and electrically connected to the pole post 207.

[0052] In this embodiment of the present invention, after the cover plate 2 and the housing 1 are pre-pressed together, the protrusion 204 of the second sub-plate 202 can be inserted into the groove 102 on the inner wall of the housing 1 to form a snap-fit ​​structure, ensuring a firm connection. This reduces the risk of the cover plate 2 popping off the housing 1 and significantly improves the assembly and welding yield of the battery cell. The stepped surface 203 between the first sub-plate 201 and the second sub-plate 202 of the cover plate 2 is welded to the end face of the housing 1 to fix the cover plate 2 to the housing 1. Moreover, a gap is left between the outer peripheral wall of the second sub-plate 202 and the inner wall of the housing 1. Along the Z direction, there are assembly gaps between the two sides of the protrusion 204 and the groove wall of the groove 102, respectively. The two gaps are connected, which can form an exhaust passage during welding to promptly discharge the gas generated during welding, avoid the formation of welding explosions, improve weld performance, and further improve the welding yield.

[0053] Specifically, such as Figures 2 to 4 As shown, the pole post 207 on the cover plate 2 extends to the outer surface of the cover plate 2 for connection with the busbar to electrically connect multiple cells into a whole.

[0054] In the embodiments of this utility model, "cell" refers to a single battery cell capable of independent charging and discharging. The components of a cell include a positive electrode, a negative electrode, a separator, an electrolyte, and a casing 1 for encapsulating the positive electrode, negative electrode, separator, and electrolyte. The portions of the positive and negative electrode containing active material constitute the main body of the electrode assembly 3, while the portions of the positive and negative electrode without active material each constitute a tab. The tabs include positive and negative tabs, which may be located together at one end of the main body or at opposite ends of the main body.

[0055] This utility model embodiment does not have any particular limitations on the type or shape of the battery cell, which can be a blade battery cell or a square battery cell, etc. Taking a blade battery cell as an example, the housing 1 of the blade battery cell has openings 101 at both ends, and each is covered by a cover plate 2.

[0056] According to an embodiment of the present invention, in another aspect, a battery pack is also provided, comprising: at least one battery cell.

[0057] Since the battery pack includes battery cells and has the same effect as the battery cells, it will not be elaborated on here.

[0058] In the embodiments of the utility model, the "battery pack" is formed by combining a certain number of battery cells into a battery module and placing them in a housing to protect the battery cells from external impacts, heat, vibration, etc. The battery pack also includes a battery management system (BMS), a thermal management system, an electrical connection system (high-voltage / low-voltage connectors, wiring harnesses, etc.), structural components (shell, brackets, etc.), and protective components, forming a complete functional unit that can directly output electrical energy.

[0059] 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. A battery cell housing assembly, characterized in that, include: The housing has an opening at at least one end along the Z direction, and the inner wall of the housing has a circumferential groove at the end near the opening. The cover plate includes a first sub-plate and a second sub-plate connected along the Z direction. The cross-sectional area of ​​the second sub-plate in the XY plane is smaller than that of the first sub-plate in the XY plane, so as to form a stepped surface between the first sub-plate and the second sub-plate. The stepped surface is welded to the end face of the housing with the opening. The outer peripheral wall of the second sub-plate has a gap with the inner wall of the housing and a protrusion is provided corresponding to the groove. The protrusion is inserted into the groove. Along the Z direction, there is an assembly gap between the two sides of the protrusion and the groove wall of the groove.

2. The cell housing assembly according to claim 1, characterized in that, The width of the assembly gap along the Z direction is L1, which satisfies 0.02 mm ≤ L1 ≤ 0.1 mm.

3. The cell housing assembly according to claim 1, characterized in that, The height of the protrusion along the Z direction is H1, which satisfies 0.1 mm ≤ H1 ≤ 0.5 mm.

4. The cell housing assembly according to claim 1, characterized in that, The groove width along the Z direction is L2, which satisfies 0.15 mm ≤ L2 ≤ 0.55 mm.

5. The cell housing assembly according to claim 1, characterized in that, The groove depth along the X or Y direction is T2, and the thickness of the shell along the X or Y direction is T3, satisfying 1 / 3≤T2 / T3≤2 / 3.

6. The cell housing assembly according to claim 5, characterized in that, 0.1 mm ≤ T2 ≤ 0.5 mm.

7. The cell housing assembly according to claim 5, characterized in that, The thickness of the protrusion along the X or Y direction is T1, which satisfies 0.1 mm ≤ T1 ≤ 0.3 mm.

8. The cell housing assembly according to any one of claims 1 to 7, characterized in that, The second sub-plate has a first chamfer around its end face away from the first sub-plate; And / or, the inner periphery of the housing with the opening end is provided with a second chamfer, and the connection between the first sub-plate and the second sub-plate is provided with a connecting bevel around the periphery corresponding to the second chamfer.

9. A battery cell, characterized in that, include: pole group; According to any one of claims 1 to 8, the battery cell housing assembly further includes a terminal post on the cover plate, and the electrode group is disposed inside the housing and electrically connected to the terminal post.

10. A battery pack, characterized in that, include: At least one battery cell as described in claim 9.

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