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, including: shell plate material, shell plate material is formed the shell body and forms two adjacent bending edges, two adjacent bending edges all are equipped with bending strengthening part that folds to Z direction and Y direction in turn, the welding connection of adjacent bending strengthening part, the welding joint forms the weld, the weld extends along the X direction, and the two bending strengthening parts of welding form the upper concave vent groove in the shell body inside. The utility model forms the weld on the bending strengthening part that protrudes outward, can avoid the weld scratch damage the insulating film outside the pole group in the process that the pole group enters the shell, thereby avoids the pole group direct contact with the shell body, that is, avoids the short circuit risk. In addition, the bending strengthening part forms the upper concave vent groove in the shell body inside, forms the exhaust space, and the electric core is conveniently exhausted smoothly. Moreover, still can improve the weld place periphery strength to improve the anti -deformation ability of shell body.

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] A battery cell typically consists of a casing and a cover plate forming a sealed space to house the electrode assembly. To protect the electrode assembly, its outer perimeter is usually covered with an insulating film. The casing is generally made of sheet metal that has been bent and then welded together.

[0003] Due to inherent defects in the welding process, it is inevitable that the height of the inner weld seam of the casing will exceed the inner surface of the casing. During the process of inserting the electrode assembly into the casing, the inner weld seam can easily scratch the insulating film on the outside of the electrode assembly, causing the electrode assembly to come into direct contact with the casing and creating a short circuit risk. Utility Model Content

[0004] In view of this, the present invention provides a cell housing, a cell, and a battery pack to solve the problem that the weld seam formed by the housing welding will scratch the insulating film outside the electrode assembly during the electrode assembly insertion process, causing the electrode assembly to directly contact the housing and cause a short circuit.

[0005] In a first aspect, the present invention provides a battery cell housing, comprising: a housing plate, wherein the housing plate is bent to form a housing body and forms two adjacent folded edges, each of the two adjacent folded edges is provided with a bending reinforcement portion that bends sequentially in the Z and Y directions, the adjacent bending reinforcement portions are welded together, a weld is formed at the welded connection, the weld extends in the X direction, and the two welded bending reinforcement portions form an upwardly recessed venting groove on the inner side of the housing body.

[0006] Beneficial effects: The cell casing of this utility model has the weld seam formed on the outwardly protruding bent reinforcement. During the insertion of the electrode assembly into the casing, the weld seam does not come into contact with the insulating film. Therefore, it can prevent the weld seam from scratching and damaging the insulating film outside the electrode assembly, thereby preventing the electrode assembly from directly contacting the casing body and avoiding the risk of short circuit. In addition, the bent reinforcement forms an upwardly recessed venting groove on the inner side of the casing body, creating an exhaust space to facilitate the smooth exhaust of the cell and improve the safety of the cell in use. Moreover, the bent reinforcement can also improve the strength around the weld seam, thereby improving the deformation resistance of the casing body.

[0007] In one optional embodiment, the weld includes an outer weld located outside the bent reinforcement along the Z direction and an inner weld located inside the bent reinforcement. The inner weld is accommodated within the vent groove, and along the Z direction, the inner surface of the inner weld does not exceed the inner surface of the shell body on the side where the inner weld is located.

[0008] Beneficial effects: The inner weld is contained within the ventilation groove, and the inner surface of the inner weld does not exceed the inner surface of the shell body on the side where the inner weld is located. During the process of inserting the electrode assembly into the shell, a gap is left between the inner weld and the insulating film outside the electrode assembly, thereby preventing the inner weld from contacting the insulating film and scratching or damaging the insulating film.

[0009] In one optional embodiment, along the Z direction, the height by which the outer surface of the bent reinforcement extends beyond the outer surface of the shell body is H1, and the thickness of the shell body is H2, satisfying 0 < H1 / H2 ≤ 2.

[0010] Beneficial effects: By controlling H1 / H2 within a suitable range, the weld position can be appropriately raised, preventing the inner weld from contacting and scratching the insulating film, while simultaneously improving the structural strength of the casing at the weld. If the value of H1 / H2 is too small, the weld elevation height is small, and the inner weld is still prone to scratching the insulating film. If the value of H1 / H2 is too large, the overall height of the casing is too large, which can easily affect the energy density of the battery cell.

[0011] In one alternative implementation, 0.1 mm ≤ H1 ≤ 0.5 mm; And / or, 0.15 mm ≤ H2 ≤ 1.5 mm.

[0012] Beneficial effects: The bending reinforcement is formed by bending. During the bending process, the thickness of the folded edge remains basically unchanged. Controlling the height H1 of the outer surface of the bending reinforcement beyond the outer surface of the shell body is equivalent to controlling the groove depth of the ventilation groove. This allows sufficient height space to be left at the ventilation groove to accommodate the inner weld, avoiding direct contact between the inner weld and the insulating film.

[0013] In one alternative embodiment, the outer periphery of the shell body is covered with an insulating layer that covers the outer weld.

[0014] Beneficial effects: The insulating layer protects the casing body and covers the outer weld seam inside the insulating layer, which can prevent the outer weld seam from scratching other components, thereby further improving the safety of the battery cell.

[0015] In one optional embodiment, the total width of the bent reinforcement along the Y direction is W1, and the width of the shell body along the Y direction is W2, satisfying 1 / 5≤W1 / W2≤2 / 3.

[0016] Beneficial effects: The side of the shell body with the weld is usually also used to support the electrode assembly. If the value of W1 / W2 is too small, the bent reinforcement is too narrow, the area available for welding is narrow, and it is difficult to weld the two folded edges into a whole. If the value of W1 / W2 is too large, the shell body cannot effectively support the electrode assembly, and the area of ​​the unbent area on the side with the weld is too small, which poses a risk of deformation.

[0017] In one alternative implementation, 8 mm ≤ W2 ≤ 30 mm.

[0018] Beneficial effects: Blade cells need to be closely arranged in groups, and the width of the casing directly affects the number of cells that can be accommodated in the battery pack. By controlling W2 within a suitable range, it is possible to ensure that the battery pack has a high energy density.

[0019] Secondly, this utility model also provides a battery cell, comprising: The aforementioned battery cell housing has an opening at at least one end of the housing body along the Z direction; The electrode assembly is covered with an insulating film on its outer periphery and is disposed within the shell body; A cover plate is placed over the opening and connected to the shell body.

[0020] Beneficial effects: In this utility model, the weld seam of the battery cell casing is formed on the outwardly protruding bent reinforcement portion. During the insertion of the electrode assembly into the casing, the weld seam does not come into contact with the insulating film. Therefore, it can prevent the weld seam from scratching and damaging the insulating film outside the electrode assembly, thereby preventing the electrode assembly from directly contacting the casing body and avoiding the risk of short circuit. In addition, the bent reinforcement portion forms an upwardly recessed venting groove on the inner side of the casing body, creating an exhaust space to facilitate smooth venting of the battery cell. Moreover, the bent reinforcement portion can also improve the strength around the weld seam, thereby improving the deformation resistance of the casing body.

[0021] In one optional embodiment, an assembly gap is provided between the shell body and the insulating film, and the venting groove communicates with the assembly gap.

[0022] Beneficial effects: The venting groove and assembly gap can form an exhaust channel for circulating gas. During normal use of the battery cell and in the event of thermal runaway, the gas generated by the electrode assembly can be quickly discharged, preventing gas from accumulating inside the battery cell and thus improving the safety of battery cell use.

[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 elaborated 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 1This 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 for Figure 2 A magnified view of part A in the diagram; Figure 4 This is a partial cross-sectional view of a battery cell according to an embodiment of the present utility model.

[0027] Explanation of reference numerals in the attached figures: 1. Shell body; 101. Bending reinforcement; 102. Weld; 1021. Outer weld; 1022. Inner weld; 103. Ventilation groove; 2. Electrode assembly; 3. Insulating film; 4. Cover plate. 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] 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.

[0030] Battery packs serve as a rechargeable power source in electrical devices. These devices include, but are not limited to, mobile phones, tablets, laptops, electric toys, power tools, electric vehicles, electric cars, ships, and spacecraft. Electric toys include stationary or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys. Spacecraft include airplanes, rockets, space shuttles, and spacecraft. Electric vehicles include pure electric vehicles, hybrid electric vehicles, and range-extended electric vehicles.

[0031] 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 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, 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.

[0032] This invention does not impose any particular limitation on the type of diaphragm; any known porous membrane with good chemical and mechanical stability can be selected. As an example, the main material of the diaphragm can be selected from at least one of glass fiber, nonwoven fabric, polyethylene, polypropylene, polyvinylidene fluoride, and ceramics.

[0033] This invention does not impose any particular limitations on the type or shape of the battery cell; it can be a blade cell or a prismatic cell, etc. The battery cell in this invention can 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. The electrode assembly process is a crucial step in the battery cell manufacturing process, directly affecting the cell's performance and safety.

[0034] The following is combined Figures 1 to 4 The following describes embodiments of the present invention.

[0035] According to an embodiment of the present invention, in one aspect, a battery cell housing is provided, comprising: a housing plate, the housing plate being bent to form a housing body 1 and forming two adjacent folded edges, each of the two adjacent folded edges being provided with a bending reinforcement portion 101 that bends sequentially in the Z direction and the Y direction, the adjacent bending reinforcement portions 101 being welded together, the welded connection forming a weld 102, the weld 102 extending in the X direction, and the two welded bending reinforcement portions 101 forming an upwardly recessed venting groove 103 on the inner side of the housing body 1.

[0036] Therefore, the battery cell housing provided in this embodiment of the present invention forms the weld 102 on the outwardly protruding bending reinforcement 101. During the insertion of the electrode assembly 2 into the housing, the weld 102 does not contact the insulating film 3. Thus, the weld 102 can avoid scratching or damaging the insulating film 3 outside the electrode assembly 2, thereby preventing the electrode assembly 2 from directly contacting the housing body 1, and thus avoiding the risk of short circuit. In addition, the bending reinforcement 101 forms an upwardly recessed venting groove 103 on the inner side of the housing body 1, forming an exhaust space, which facilitates the smooth exhaust of the battery cell and improves the safety of the battery cell. Moreover, the bending reinforcement 101 can also improve the periphery strength at the weld 102, thereby improving the deformation resistance of the housing body 1.

[0037] In traditional blade battery cells, to support the electrode assembly 2 and prevent the weld 102 from scratching the insulating film 3 outside the electrode assembly 2, a side plate is usually provided between the narrow side of the bottom of the electrode assembly 2 and the housing body 1, with the weld 102 acting directly on the side plate. This embodiment of the invention improves the supporting strength of the housing body 1 by providing an outwardly protruding bending reinforcement 101, which can directly support the electrode assembly 2 and also prevent the weld 102 from contacting and scratching the insulating film 3. Therefore, this embodiment of the invention can eliminate the side plate of traditional blade battery cells, thereby simplifying the battery cell structure, reducing usage costs, and improving battery cell production efficiency.

[0038] Specifically, in the Z direction, such as Figure 1 and Figure 2 As shown by arrow Z in the diagram, the Y direction is as follows: Figure 1 and Figure 2 As shown by the arrow Y in the diagram, the X direction is as follows: Figure 1 and Figure 2 As indicated by the arrow X in the diagram.

[0039] It should be noted that the shell body 1 can also be formed by welding multiple shell plates together, thus forming multiple welds 102. The number and position of the bending reinforcement 101 can be set according to the number and position of the welds 102.

[0040] In this embodiment of the invention, the "shell body 1" is a component used to provide a receiving space to house and isolate components such as the positive electrode, negative electrode, separator, and electrolyte of the battery cell from the outside environment. The shell body 1, formed by bending the shell sheet, has openings at both ends, and an internal receiving cavity communicating with the openings. The bending reinforcement 101, formed by bending the shell sheet, has multiple bending sections, thus acting as a reinforcing rib to increase the strength of the sheet material near the weld 102, thereby increasing the resistance of the area near the weld 102 to external forces. Without the bending reinforcement 101, external forces would easily concentrate on the weaker sides of the weld 102, causing the weld 102 to crack. The weld 102 is the trace formed by the welding connection of the bending reinforcement 101.

[0041] In one embodiment, such as Figure 4 As shown, the weld 102 includes an outer weld 1021 located outside the bending reinforcement 101 along the Z direction and an inner weld 1022 located inside the bending reinforcement 101. The inner weld 1022 is accommodated in the ventilation groove 103. Along the Z direction, the inner surface of the inner weld 1022 does not exceed the inner surface of the shell body 1 on the side where the inner weld 1022 is located.

[0042] The inner weld 1022 is housed within the ventilation groove 103, and the inner surface of the inner weld 1022 does not exceed the inner surface of the shell body 1 on the side where the inner weld 1022 is located. During the process of inserting the electrode assembly 2 into the shell, a gap is left between the inner weld 1022 and the insulating film 3 outside the electrode assembly 2, thereby preventing the inner weld 1022 from contacting the insulating film 3 and scratching or damaging the insulating film 3.

[0043] Furthermore, in one embodiment, such as Figure 4 As shown, along the Z-direction, the height by which the outer surface of the bent reinforcing part 101 extends beyond the outer surface of the shell body 1 is H1, and the thickness of the shell body 1 is H2, satisfying 0 < H1 / H2 ≤ 2. By controlling H1 / H2 within a suitable range, the position of the weld 102 can be appropriately raised, preventing the inner weld 1022 from contacting and scratching the insulating film 3, while simultaneously improving the structural strength of the shell body 1 at the weld 102. If the value of H1 / H2 is too small, the height of the weld 102 will be small, and the inner weld 1022 will still easily scratch the insulating film 3. If the value of H1 / H2 is too large, the overall height of the shell body 1 will be too large, which may affect the energy density of the battery cell.

[0044] Furthermore, in one embodiment, 0.1 mm ≤ H1 ≤ 0.5 mm.

[0045] And / or, 0.15 mm ≤ H2 ≤ 1.5 mm.

[0046] like Figure 3 and Figure 4 As shown, the bending reinforcement 101 of this utility model embodiment is formed by bending. During the bending process, the thickness of the folded edge remains basically unchanged. The height H1 of the outer surface of the bending reinforcement 101 exceeding the outer surface of the shell body 1 is controlled to control the groove depth of the ventilation groove 103, so that sufficient height space can be left at the ventilation groove 103 to accommodate the inner weld 1022 and avoid the inner weld 1022 from directly contacting the insulating film 3.

[0047] Furthermore, in one embodiment, 0.5 ≤ H1 / H2 ≤ 2.

[0048] For example, in this embodiment of the present invention, the value of H1 can be 0.1 mm, the value of H2 can be 0.15 mm, then H1 / H2 is 0.67; or the value of H1 can be 0.3 mm, the value of H2 can be 0.6 mm, then H1 / H2 is 0.5; or the value of H1 can be 0.5 mm, the value of H2 can be 0.25 mm, then H1 / H2 is 2.

[0049] In one embodiment, the outer periphery of the housing body 1 is covered with an insulating layer (not shown in the figure), which covers the outer weld 1021. The insulating layer is used to protect the housing body 1. By enclosing the outer weld 1021 within the insulating layer, it is possible to prevent the outer weld 1021 from scratching with other components, thereby further improving the safety of the battery cell.

[0050] It should be noted that the material of the insulating layer is not limited in this embodiment of the utility model. Any existing material can be selected as needed. For example, the insulating layer is a blue film, which can be made of PI (polyimide) or PET (polyethylene terephthalate).

[0051] In one embodiment, such as Figure 4 As shown, the total width of the bent reinforcing part 101 along the Y direction is W1, and the width of the shell body 1 along the Y direction is W2, satisfying 1 / 5 ≤ W1 / W2 ≤ 2 / 3. The side of the shell body 1 where the weld 102 is provided is usually also used to support the pole group 2. If the value of W1 / W2 is too small, the bent reinforcing part 101 will be too narrow, the area available for welding will be narrow, and it will be difficult to weld the two folded edges into a whole. If the value of W1 / W2 is too large, the shell body 1 will be unable to effectively support the pole group 2, and the area of ​​the unbent area on the side where the weld 102 is provided will be too small, posing a risk of deformation.

[0052] Furthermore, in one embodiment, 8 mm ≤ W2 ≤ 30 mm. The blade cells need to be closely arranged in groups, and the width of the housing 1 directly affects the number of cells that can be accommodated in the battery pack. By controlling W2 within a suitable range, it is possible to ensure that the battery pack has a high energy density.

[0053] Furthermore, in one embodiment, 1.6 mm ≤ W1 ≤ 20 mm.

[0054] For example, in this embodiment of the present invention, the value of W1 can be 1.6 mm and the value of W2 can be 8 mm, then W1 / W2 is 0.2, or 1 / 5; or the value of W1 can be 10 mm and the value of W2 can be 20 mm, then W1 / W2 is 0.5; or the value of W1 can be 20 mm and the value of W2 can be 30 mm, then W1 / W2 is 2 / 3.

[0055] According to an embodiment of the present invention, on the other hand, as... Figure 1 and Figure 2 As shown, a battery cell is also provided, mainly comprising: a battery cell housing, an electrode assembly 2, and a cover plate 4. The housing body 1 of the battery cell housing has an opening at at least one end along the Z direction. The electrode assembly 2 is covered by an insulating film 3 and disposed inside the housing body 1. The cover plate 4 covers the opening and is connected to the housing body 1.

[0056] The battery cell provided in this embodiment of the invention has a weld 102 formed on an outwardly protruding bent reinforcing portion 101 in the battery cell housing. During the insertion of the electrode assembly 2 into the housing, the weld 102 does not contact the insulating film 3. Therefore, it can prevent the weld 102 from scratching and damaging the insulating film 3 outside the electrode assembly 2, thereby preventing the electrode assembly 2 from directly contacting the housing body 1, thus avoiding the risk of short circuit. In addition, the bent reinforcing portion 101 forms an upwardly recessed venting groove 103 on the inner side of the housing body 1, forming an exhaust space to facilitate smooth exhaust of the battery cell. Moreover, the bent reinforcing portion 101 can also improve the periphery strength at the weld 102, thereby improving the deformation resistance of the housing body 1.

[0057] Specifically, the cover plate 5 is also equipped with components such as pole posts, explosion-proof valves, and liquid injection holes, among which the pole posts are electrically connected to the tabs of the pole group 1.

[0058] In one embodiment, an assembly gap is provided between the housing body 1 and the insulating film 3, and the venting groove 103 communicates with the assembly gap. The venting groove 103 and the assembly gap can form an exhaust channel for circulating gas, which can quickly discharge the gas generated by the electrode group 2 during normal use of the battery cell and in the event of thermal runaway, preventing gas from accumulating inside the battery cell, thereby improving the safety of the battery cell.

[0059] According to an embodiment of the present invention, in another aspect, a battery pack is also provided, comprising: at least one of the above-described battery cells.

[0060] Since the battery pack includes battery cells and has the same effect as the battery cells, it will not be elaborated on here.

[0061] 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, characterized in that, include: The shell plate is bent to form a shell body and forms two adjacent folded edges. Each of the two adjacent folded edges is provided with a bending reinforcement that bends sequentially in the Z and Y directions. The adjacent bending reinforcements are welded together to form a weld at the welded joint. The weld extends in the X direction. The two welded bending reinforcements form an upwardly recessed venting groove on the inner side of the shell body.

2. The cell housing according to claim 1, characterized in that, The weld includes an outer weld located outside the bent reinforcement along the Z direction and an inner weld located inside the bent reinforcement. The inner weld is accommodated in the venting groove, and along the Z direction, the inner surface of the inner weld does not exceed the inner surface of the shell body on the side where the inner weld is located.

3. The cell housing according to claim 2, characterized in that, Along the Z direction, the height by which the outer surface of the bent reinforcement extends beyond the outer surface of the shell body is H1, and the thickness of the shell body is H2, satisfying 0 < H1 / H2 ≤ 2.

4. The cell housing according to claim 3, characterized in that, 0.1 mm ≤ H1 ≤ 0.5 mm; And / or, 0.15 mm ≤ H2 ≤ 1.5 mm.

5. The cell housing according to claim 2, characterized in that, The outer periphery of the shell body is covered with an insulating layer, which covers the outer weld.

6. The cell housing according to any one of claims 1 to 5, characterized in that, The total width of the bent reinforcement along the Y direction is W1, and the width of the shell body along the Y direction is W2, satisfying 1 / 5≤W1 / W2≤2 / 3.

7. The cell housing according to claim 6, characterized in that, 8 mm ≤ W2 ≤ 30 mm.

8. A battery cell, characterized in that, include: The battery cell housing according to any one of claims 1 to 7, wherein the housing body has an opening at at least one end along the Z direction; The electrode assembly is covered with an insulating film on its outer periphery and is disposed within the shell body; A cover plate is placed over the opening and connected to the shell body.

9. The battery cell according to claim 8, characterized in that, An assembly gap is provided between the shell body and the insulating film, and the venting groove communicates with the assembly gap.

10. A battery pack, characterized in that, include: At least one battery cell as described in claim 8 or 9.

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