Cylindrical battery cell shell, cylindrical battery cell and battery module

Abstract

The utility model provides a cylindrical battery cell shell, a cylindrical battery cell and a battery module, and belongs to the technical field of batteries. The cylindrical battery cell shell comprises a shell and a cap assembly, the shell is cylindrical, the first end, in the axial direction, of the shell is open, the second end, in the axial direction, of the shell is closed, and the cap assembly covers the first end. At least one pressure relief structure is arranged at the position, away from the first end and the second end, of the shell. The cap assembly comprises a cap plate, a pole piece, a collector plate and an insulating sleeve; the cap plate covers the first end to seal the first end; a pole through hole is formed in the axis of the cap plate, the pole piece is arranged in the pole through hole in a penetrating manner, and the current collecting piece is located on the end face, facing the interior of the shell, of the cap plate and electrically connected with the pole piece; and the insulating sleeves are positioned between the pole piece and the pole via hole and between the current collector and the cap plate. According to the cylindrical battery cell shell, the pressure relief structure is arranged on the side wall of the shell, so that pressure relief can be prevented from being blocked by the soldering lug when a module is assembled, and the safety and reliability of the cylindrical battery cell can be ensured.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of batteries, in particular to a cylindrical battery cell shell, a cylindrical battery cell and a battery module. BACKGROUND

[0002] The current explosion-proof valve design of the cylindrical battery cell is generally the head of the battery cell, or a double explosion-proof valve structure of the head and the bottom. When the cylindrical battery cell has a safety problem (such as overcharge, short circuit, thermal runaway, etc.), it can open the pressure relief in time to prevent explosion.

[0003] However, when the cylindrical battery cell is assembled into a module, the head and the bottom of the cylindrical battery cell need to be welded with welding pieces. The welding pieces may block the explosion-proof valve and block the pressure relief, thereby reducing the safety and reliability of the cylindrical battery cell. CONTENT OF THE UTILITY MODEL

[0004] The present application provides a cylindrical battery cell shell, a cylindrical battery cell and a battery module, which can solve the problem that the head and the bottom of the cylindrical battery cell need to be welded with welding pieces, the welding pieces block the explosion-proof valve and block the pressure relief, thereby reducing the safety and reliability of the cylindrical battery cell.

[0005] The technical solution is as follows:

[0006] On the one hand, a cylindrical battery cell shell is provided, which comprises a shell and a cap assembly.

[0007] The shell is cylindrical, the first end of the shell along the axial direction is open, the second end of the shell along the axial direction is closed, and the cap assembly is provided on the first end.

[0008] At least one pressure relief structure is provided at a position of the shell away from the first end and the second end.

[0009] The cap assembly comprises a cap plate, a pole piece, a current collecting piece and an insulating sleeve.

[0010] The cap plate is provided on the first end to close the first end. The axial center of the cap plate is provided with a pole hole, the pole piece is provided in the pole hole, the current collecting piece is located on the end face of the cap plate facing the inside of the shell, and the current collecting piece is electrically connected with the pole piece.

[0011] The insulating sleeve is located between the pole piece and the pole hole, and between the current collecting piece and the cap plate, so that the pole piece and the current collecting piece are insulated from each other.

[0012] In some embodiments, the at least one pressure relief structure is a groove structure on the outer side wall of the shell.

[0013] In some embodiments, the ratio of the depth of the groove structure to the thickness of the shell is 10%-80%.

[0014] In some embodiments, the shell is a punch forming structure, and the at least one pressure relief structure is a reserved groove structure of a processed raw material surface of the shell.

[0015] In some embodiments, the pole piece and the current collector tab are an integral structure.

[0016] In some embodiments, the inner wall of the first end is provided with a positioning step, and the cap plate is located on the positioning step and is welded to the first end.

[0017] In another aspect, a cylindrical battery cell is provided, which comprises the cylindrical battery cell shell described in the present application.

[0018] In some embodiments, the cylindrical battery cell further comprises a winding core structure, which is located in the shell, and the winding core structure comprises a positive electrode tab and a negative electrode tab, the positive electrode tab is electrically connected to the current collector tab, and the negative electrode tab is electrically connected to the shell.

[0019] In another aspect, a battery module is provided, which comprises at least one cylindrical battery cell described in the present application.

[0020] In some embodiments, the number of cylindrical battery cells is multiple, the multiple cylindrical battery cells are arranged in a linear array, and the direction of the at least one pressure relief structure of each cylindrical battery cell is perpendicular to the array direction.

[0021] In some embodiments, the directions of the at least one pressure relief structure on the multiple cylindrical battery cells arranged in a linear array are the same.

[0022] The technical solutions provided in the present application have at least the following beneficial effects:

[0023] The cap assembly of the cylindrical battery cell shell in the present application is arranged at the first end of the shell. Since the sidewall of the shell is provided with a pressure relief structure, when the internal pressure of the cylindrical battery cell using the cylindrical battery cell shell is out of control, the pressure relief structure can be broken, thereby achieving the pressure relief function. Therefore, the explosion-proof valve does not need to be arranged at the bottom of the cap assembly and the shell, so that the welding sheet welded at the head and the bottom of the cylindrical battery cell during module assembly can avoid blocking the pressure relief, and the safety and reliability of the cylindrical battery cell can be ensured. In addition, the cap assembly only comprises the stacked cap plate, the current collector tab, and the insulating sleeve therebetween. The thickness of the cap assembly is greatly reduced, the occupation of the internal space of the shell is reduced, and the utilization rate of the internal space of the shell can be improved by more than 4%, which is beneficial to improving the energy density of the cylindrical battery cell. BRIEF DESCRIPTION OF DRAWINGS

[0024] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the embodiment description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative effort on the basis of these drawings.

[0025] Figure 1 is a structural schematic diagram of a cylindrical battery cell shell provided by the embodiments of the present application;

[0026] Figure 2 is an exploded view of the structural schematic diagram of the cylindrical battery cell shell provided by the embodiments of the present application;

[0027] Figure 3 is a structural schematic diagram of a cap assembly provided by the embodiments of the present application;

[0028] Figure 4 is an exploded view of the structural schematic diagram of the cap assembly provided by the embodiments of the present application;

[0029] Figure 5 is a structural schematic diagram of a pressure relief structure provided by the embodiments of the present application;

[0030] Figure 6 is a structural schematic diagram of a cylindrical battery cell shell provided by another embodiment of the present application;

[0031] Figure 7 is a structural schematic diagram of a cylindrical battery cell provided by the embodiments of the present application;

[0032] Figure 8 is a structural schematic diagram of a battery module provided by the embodiments of the present application.

[0033] The reference signs in the drawings represent the following respectively:

[0034] 1, shell;

[0035] 101, first end; 102, second end;

[0036] 11, pressure relief structure; 12, positioning step;

[0037] 2, cap assembly;

[0038] 21, cap plate; 211, pole post via hole; 22, pole post piece; 23, current collector tab; 24, insulating sleeve; 241, sleeve portion; 242, gasket portion;

[0039] 3, roll core structure;

[0040] 31, positive electrode tab; 32, negative electrode tab;

[0041] 100, cylindrical battery cell;

[0042] a, array direction. DETAILED DESCRIPTION

[0043] The exemplary embodiments will be described in detail herein with reference to the attached drawings. In the following description, unless otherwise indicated, like numbers in the attached drawings refer to the same or similar elements. The following detailed description includes specific details for the purpose of providing a thorough understanding of the exemplary embodiments. However, it will be apparent to those skilled in the art that the exemplary embodiments can be practiced without these specific details. In some instances, well-known structures and components are not described in detail in order to avoid obscuring the understanding of the present description.

[0044] In the description of the present application, it needs to be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate the orientation or positional relationship based on the drawings, and are only for the purpose of facilitating the description of the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation of the present application. Figure 1 The orientation or positional relationship shown is only for the purpose of facilitating the description of the present application and simplifying the description, and does not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation of the present application.

[0045] Unless otherwise defined, all technical terms used in the embodiments of the present application have the same meanings as commonly understood by one of ordinary skill in the art.

[0046] In order to make the purpose, technical scheme and advantages of the present application more clear, the embodiments of the present application will be further described in detail below with reference to the drawings.

[0047] In one aspect, in combination with Figure 1 , Figure 2 , Figure 3 and Figure 4 shown, the present embodiment provides a cylindrical battery cell shell, which comprises a shell 1 and a cap assembly 2.

[0048] The shell 1 is cylindrical, the first end 101 of the shell 1 is open along the axial direction, the second end 102 of the shell 1 is closed along the axial direction, and the cap assembly 2 is covered on the first end 101; at least one pressure relief structure 11 is arranged at a position of the shell 1 away from the first end 101 and the second end 102.

[0049] The cap assembly 2 comprises a cap plate 21, a pole piece 22, a current collector 23 and an insulating sleeve 24.

[0050] The cap plate 21 is arranged on the first end 101 to seal the first end 101; the axial center of the cap plate 21 is provided with a pole post through hole 211, the pole post member 22 is arranged in the pole post through hole 211, and the current collector plate 23 is located on the end face of the cap plate 21 towards the inside of the shell 1 and is electrically connected with the pole post member 22.

[0051] The insulating sleeve 24 is located between the pole post member 22 and the pole post through hole 211 and between the current collector plate 23 and the cap plate 21 to insulate the pole post member 22 and the current collector plate 23 from the cap plate 21 respectively.

[0052] The cap assembly 2 of the cylindrical battery cell shell in the embodiment is arranged on the first end 101 of the shell 1, and since the side wall of the shell 1 is provided with the pressure relief structure 11, when the internal pressure of the cylindrical battery cell 100 is out of control, the pressure relief structure 11 can be broken to realize the pressure relief function, so the bottom of the cap assembly 2 and the shell 1 does not need to be arranged with an explosion-proof valve, thereby avoiding that the welding sheet welded on the head and the bottom of the cylindrical battery cell 100 blocks the pressure relief during the module assembly, and ensuring the safety and reliability of the cylindrical battery cell 100; in addition, the cap assembly 2 only includes the stacked cap plate 21, the current collector plate 23 and the insulating sleeve 24 therebetween, the thickness of the cap assembly 2 is greatly reduced, the occupation of the internal space of the shell 1 is reduced, thereby the utilization rate of the internal space of the shell 1 can be improved by more than 4%, which is beneficial to improve the energy density of the cylindrical battery cell 100.

[0053] In some possible implementations, the at least one pressure relief structure 11 is located away from the first end 101 and the second end 102, and since the shell 1 is cylindrical, the at least one pressure relief structure 11 is located on the outer side wall of the shell 1.

[0054] In some possible implementations, the number of pressure relief structures 11 on the outer side wall of the shell 1 is, for example, one, two, three, etc.

[0055] In some possible implementations, the insulating sleeve 24 includes a sleeve portion 241 arranged in the pole post through hole 211 and a gasket portion 242 arranged at the bottom of the cap plate 21. The sleeve portion 241 is sleeved on the pole post member 22 to realize the insulating connection between the pole post member 22 and the pole post through hole 211, and the gasket portion 242 is arranged between the current collector plate 23 and the bottom surface of the cap plate 21 to realize the insulating connection between the current collector plate 23 and the bottom surface of the cap plate 21.

[0056] Exemplarily, the insulating sleeve 24 is supported by an insulating material, which includes but is not limited to polyamide (also known as nylon), polycarbonate (PC), fiber glass (FG), polyethylene (PE), polyether, polyethylene glycol terephthalate (PET), polymethyl methacrylate (PMMA), polypropylene (PP), polystyrene (PS), polyvinyl chloride (PVC), and the like. Any one of the above materials or a combination of any ones of the above materials can be used to form the embodiment.

[0057] In some possible implementations, the pole piece 22 is welded to the current collector tab 23.

[0058] In combination Figure 5 As shown, in some embodiments, the at least one pressure relief structure 11 is a groove structure on the outer side wall of the shell 1.

[0059] With the above arrangement, the groove structure formed on the outer side wall of the shell 1 by stamping, laser etching, or the like, as the pressure relief structure 11, can reduce the local thickness of the side wall of the shell 1, aiming to reduce the strength of the side wall of the shell 1 at the corresponding position, so that when the internal pressure of the cylindrical battery cell 100 increases, the high-pressure gas can break the side wall of the shell 1 where the pressure relief structure 11 is located, achieving pressure relief and exhaust, and reducing the risk of explosion of the cylindrical battery cell 100.

[0060] In some possible implementations, the shape of the groove structure includes but is not limited to linear, circular, polygonal, and the like. Exemplarily, the shape of the groove structure is quadrangular.

[0061] In some embodiments, the ratio of the depth of the at least one pressure relief structure 11, i.e., the groove structure, to the thickness of the shell 1 is 10%-80%.

[0062] With the above arrangement, when the depth of the pressure relief structure 11 and the thickness of the shell 1 satisfy the above ratio range, the side wall of the shell 1 where the pressure relief structure 11 is located can be broken after the internal pressure increases, achieving pressure relief and exhaust.

[0063] Exemplarily, the ratio of the depth of the pressure relief structure 11 to the thickness of the shell 1 is, for example, 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80, and the like.

[0064] In some embodiments, the shell 1 is a stamping structure, and the at least one pressure relief structure 11 is a reserved groove structure on a material surface of the shell 1.

[0065] In the embodiment, the shell 1 is a stamping structure, which can be formed by stamping process. The forming method is simple, the forming efficiency is high, and the product quality is good. On this basis, by reserving a specific groove structure on the material surface, when the material is stamped into the shell 1, the reserved groove structure can be formed on the outer side wall of the shell 1 to form the pressure relief structure 11 described above.

[0066] In some embodiments, the pole piece 22 and the current collector tab 23 are integrated structures. By integrating the pole piece 22 and the current collector tab 23, the number of parts in the cap assembly 2 can be reduced, and the production and assembly efficiency of the cap assembly 2 can be improved.

[0067] In combination Figure 6 As shown in the drawings, in some embodiments, the inner wall of the first end 101 is provided with a positioning step 12, and the cap plate 21 is located on the positioning step 12 and is welded to the first end 101.

[0068] Through the above arrangement, the cap assembly 2 can use the cap plate 21 to axially press against the positioning step 12 to realize the positioning of the cap plate assembly and the shell 1, and realize the reliable sealing connection between the shell 1 and the cap assembly 2 through the welding connection between the cap plate and the shell 1 side wall of the first end 101.

[0069] In some possible implementations, the positioning step 12 is a roll forming structure, and the outer wall of the first end 101 is roll processed by a rolling machine to make the inner wall of the first end 101 protrude inward to form an annular positioning step 12.

[0070] On the other hand, the embodiment provides a cylindrical battery cell 100, which includes the cylindrical battery cell shell of the present application.

[0071] The cylindrical battery cell 100 of the embodiment adopts the cylindrical battery cell shell of the present application and has all the beneficial technical effects of all the embodiments herein.

[0072] In combination Figure 7 As shown in the drawings, in some embodiments, the cylindrical battery cell 100 further includes a winding core structure 3; the winding core structure 3 is located in the shell 1, and the winding core structure 3 includes a positive electrode tab 31 and a negative electrode tab 32, the positive electrode tab 31 is electrically connected to the current collector tab 23, and the negative electrode tab 32 is electrically connected to the shell 1.

[0073] Through the above arrangement, the pole piece 22 of the cylindrical battery cell 100 can serve as a positive electrode, and the shell 1 can serve as a negative electrode. Due to the simple structure of the cap assembly 2 and the longer axial length of the winding core structure 3, the volume is correspondingly increased, so that the cylindrical battery cell 100 has a higher energy density.

[0074] Exemplarily, the winding core structure 3 is a full-tab winding core. Compared with a conventional winding core, the full-tab winding core needs to occupy a certain axial space, which will cause a decrease in space utilization. In the embodiment, the full-tab winding core can be compensated in space due to the small thickness of the cap assembly 2.

[0075] In some possible implementations, the positive electrode tab 31 is welded to the current collector tab 23, and the negative electrode tab 32 is welded to the shell 1.

[0076] In some possible implementations, the shell 1 is filled with electrolyte, and the winding core structure 3 is immersed in the electrolyte.

[0077] On the other hand, the embodiment provides a battery module, which includes at least one cylindrical battery cell 100 of the present application.

[0078] The battery module of the embodiment adopts the cylindrical battery cell 100 of the present application and has all the beneficial technical effects of all the embodiments herein.

[0079] In combination with Figure 8 As shown in the drawings, in some embodiments, the number of cylindrical battery cells 100 is multiple, the multiple cylindrical battery cells 100 are arranged in a linear array, and the direction of at least one pressure relief structure 11 of each cylindrical battery cell 100 is perpendicular to the array direction a.

[0080] Through the above arrangement, the pressure relief structure 11 of each cylindrical battery cell 100 in the battery module of the embodiment is arranged perpendicular to the array direction a. When one or more cylindrical battery cells 100 appear thermal runaway and release pressure and exhaust, there is no other cylindrical battery cell 100 in the jet direction of the high-pressure gas, which will not cause a series effect on the adjacent cylindrical battery cell 100, thereby reducing the risk of series runaway of the battery module and improving the safety and reliability of the battery module.

[0081] In combination with Figure 8 As shown in the drawings, in some embodiments, the direction of at least one pressure relief structure 11 on the multiple cylindrical battery cells 100 arranged in a linear array is the same, so that when one or more cylindrical battery cells 100 appear thermal runaway and release pressure and exhaust, the jet direction of the high-pressure gas is the same, which further reduces the risk of series runaway of the battery module.

[0082] It should be noted that, in the present application, unless specifically stated and limited otherwise, the "on" or "under" of a first feature to a second feature can include that the first and second features are in direct contact, or that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, the "on", "above" and "above" of the first feature to the second feature includes that the first feature is directly above and obliquely above the second feature, or only indicates that the horizontal height of the first feature is higher than that of the second feature. The "under", "below" and "below" of the first feature to the second feature includes that the first feature is directly below and obliquely below the second feature, or only indicates that the horizontal height of the first feature is less than that of the second feature.

[0083] In the description of the present application, the description of the terms "certain embodiments", "one embodiment", "some embodiments", "illustrative embodiments", "example", "specific example" or "some examples" means that the specific features, structures, materials or characteristics described in connection with the embodiments or examples are included in at least one embodiment or example of the present application.

[0084] The above is only an embodiment of the present application, and is not used to limit the present application. Any modification, equivalent replacement, improvement, etc. made within the principles of the present application shall be included in the protection scope of the present application.

Claims

1. A cylindrical battery cell casing, characterized in that, The cylindrical battery cell housing includes: a housing (1) and a cap assembly (2); The housing (1) is cylindrical, with the first end (101) of the housing (1) open along the axial direction and the second end (102) closed along the axial direction. The cap assembly (2) is placed on the first end (101). The housing (1) is provided with at least one pressure relief structure (11) at a position away from the first end (101) and the second end (102); The cap assembly (2) includes a cap plate (21), a pole piece (22), a current collector (23), and an insulating sleeve (24); The cap plate (21) is placed on the first end (101) to close the first end (101); the cap plate (21) has a pole through hole (211) at its axis, the pole piece (22) is inserted in the pole through hole (211), the current collector (23) is located on the end face of the cap plate (21) facing the inside of the housing (1) and is electrically connected to the pole piece (22); The insulating sleeve (24) is located between the pole piece (22) and the pole through hole (211), and between the current collector (23) and the cap plate (21), so that the pole piece (22) and the current collector (23) are respectively insulated from the cap plate (21).

2. The cylindrical battery cell casing according to claim 1, characterized in that, The at least one pressure relief structure (11) is a groove structure on the outer side wall of the housing (1).

3. The cylindrical battery cell casing according to claim 2, characterized in that, The ratio of the depth of the groove structure to the thickness of the shell (1) is 10%-80%.

4. The cylindrical battery cell casing according to claim 2, characterized in that, The shell (1) is a stamped structure, and the at least one pressure relief structure (11) is a pre-reserved groove structure on the surface of the raw material of the shell (1).

5. The cylindrical battery cell casing according to claim 1, characterized in that, The pole piece (22) and the current collector (23) are an integral structure.

6. The cylindrical battery cell casing according to any one of claims 1 to 5, characterized in that, The inner wall of the first end (101) is provided with a positioning step (12), and the cap plate (21) is located on the positioning step (12) and is welded to the first end (101).

7. A cylindrical battery cell, characterized in that, The cylindrical battery cell (100) includes the cylindrical battery cell housing as described in any one of claims 1 to 6.

8. The cylindrical battery cell according to claim 7, characterized in that, The cylindrical cell (100) also includes a wound core structure (3); the wound core structure (3) is located inside the housing (1), and the wound core structure (3) includes a positive electrode tab (31) and a negative electrode tab (32). The positive electrode tab (31) is electrically connected to the current collector (23), and the negative electrode tab (32) is electrically connected to the housing (1).

9. A battery module, characterized in that, The battery module includes at least one cylindrical cell (100) as described in claim 7 or 8.

10. The battery module according to claim 9, characterized in that, The number of cylindrical cells (100) is multiple, and the multiple cylindrical cells (100) are arranged in a linear array, and the orientation of the at least one pressure relief structure (11) of each cylindrical cell (100) is perpendicular to the array direction (a).

11. The battery module according to claim 10, characterized in that, The at least one pressure relief structure (11) on the plurality of cylindrical cells (100) arranged in a linear array has the same orientation.

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