Battery cell and battery cell group

Abstract

The utility model relates to the technical field of batteries, and discloses a battery cell and a battery cell group. The first pole group and the second pole group are arranged side by side along the length direction and are jointly positioned in the shell; the first tab and the second tab are welded and connected to form a welding mark; the fixing assembly is arranged between the first pole group and the second pole group, and the fixing assembly is suitable for fixing the relative position of the first pole group and the second pole group and forming a receding notch for connection of the first pole lug and the second pole lug; the shell anti-explosion valve is arranged on the shell, and the shell anti-explosion valve is arranged close to the fixing assembly in the length direction. According to the battery cell provided by the utility model, the pole group with a split structure is adopted, so that the length of a single pole piece can be reduced, the process requirement for manufacturing an extra-long battery cell is reduced, the supporting difficulty is reduced, meanwhile, structural parts such as a cover plate do not need to be arranged for each battery cell, the cost increase caused by the increase of the structural parts is avoided, and the cost reduction is realized; and compared with a mode of connecting a plurality of complete battery cells in series, more space is saved.

Description

Technical Field

[0001] The utility model relates to the technical field of batteries, in particular to a battery cell and a battery cell group. Background Art

[0002] In related technologies, battery cells are generally short, and the overall capacity increase is limited by process conditions. For very long cells, bending and deformation often occur due to electrode group strength issues, resulting in reduced yield. Especially for extra-long cells, the molding process is demanding and the support is difficult. While connecting multiple cells in series can achieve capacity increases, the need for structural components such as covers for each cell increases costs and wastes significant space.

[0003] In addition, as the length of the battery cell increases, when the battery cell experiences thermal runaway, the high-temperature gas cannot be released quickly due to the long path, thereby reducing the safety performance of the battery cell. Utility Model Content

[0004] In view of this, the present invention provides a battery cell and a battery cell group to solve the problem that the battery cell is difficult to manufacture and is not easy to release high-temperature gas in thermal runaway when the battery cell is long.

[0005] In a first aspect, the present invention provides a battery cell, comprising:

[0006] case;

[0007] The first pole group and the second pole group are arranged side by side along the length direction and are located together in the housing; a first pole tab extends from one end of the first pole group close to the second pole group, and a second pole tab extends from one end of the second pole group close to the first pole group; the first pole tab and the second pole tab are welded to form a weld mark;

[0008] A fixing assembly is provided between the first electrode group and the second electrode group, and is suitable for fixing the relative positions of the first electrode group and the second electrode group and forming a clearance gap for the connection between the first electrode tab and the second electrode tab;

[0009] The shell explosion-proof valve is arranged on the shell, and is arranged close to the fixed component along the length direction.

[0010] Beneficial effects: The battery cell provided by the embodiment of the present invention can reduce the length of a single pole piece by adopting a pole group with a split structure, reduce the process requirements for making extra-long pole pieces, reduce the difficulty of support, and at the same time, there is no need to set structural parts such as cover plates for each pole piece, thereby avoiding the cost increase caused by the increase in structural parts, achieving cost reduction, and saving more space than the method of connecting multiple complete pole pieces in series. The size of the battery cell can achieve a longer specification, achieving the purpose of increasing capacity and reducing costs. The battery cell includes two pole groups arranged side by side along the length direction. By adopting a pole group with a split structure, the two pole groups arranged side by side along the length direction are connected, thereby shortening the length of a single pole group and reducing defects such as wrinkles, deformation, layer crossover, and fracture caused by excessive pole piece length. It is possible to increase the capacity of the battery cell and achieve the connection of adjacent pole groups by setting a fixed component.

[0011] When the first and second pole groups are arranged side by side along the length and housed together in a housing, the housing becomes longer. If explosion-proof valves were only provided at both ends of the housing along the length, the gas path would be too long to be quickly released in the event of thermal runaway, reducing the safety of the battery cell. This embodiment provides a housing explosion-proof valve within the housing, locating it close to the fixed assembly along the length. This increases the exhaust path, improves exhaust efficiency, shortens the airway travel, and thus improves battery cell safety.

[0012] In an optional embodiment, the first electrode tab and the second electrode tab are horizontally welded;

[0013] The direction in which the relief notch penetrates the fixing component is parallel to the length direction.

[0014] Beneficial Effects: The design can restrain the first and second tabs and protect the connection between the two tabs, preventing accidental overlap and improving the safety of the battery cell. Furthermore, the direction of the notch extending through the fixing assembly is parallel to the length, allowing the two tabs to be welded horizontally, simplifying the process, further reducing internal resistance, shortening the tab length, and reducing the space occupied within the battery cell.

[0015] In an optional embodiment, the fixing assembly includes:

[0016] The first fixing member and the second fixing member are detachably connected along the thickness direction;

[0017] The first fixing member is at least partially recessed on one side facing the second fixing member to form a first clearance groove, and the second fixing member is at least partially recessed on one side facing the first fixing member to form a second clearance groove. The first clearance groove and the second clearance groove together form a clearance notch.

[0018] Beneficial effect: The fixing assembly can simplify the assembly process by adopting a method in which the first fixing member and the second fixing member are connected to each other along the thickness direction. After the first pole tab and the second pole tab are welded, the first fixing member and the second fixing member are respectively installed toward the middle position along both sides of the thickness direction, which does not interfere with the normal connection between the first pole tab and the second pole tab, and can guide the bending path of the first pole tab and the second pole tab.

[0019] In an optional embodiment, the battery cell further includes:

[0020] A first support plate is disposed between the fixing assembly and the first electrode group along the length direction, and the first support plate is provided with an opening suitable for the first electrode tab to pass through;

[0021] And / or, a second support plate is disposed between the fixing assembly and the second electrode group along the length direction, and the second support plate is provided with an opening suitable for the second electrode tab to pass through.

[0022] Beneficial effect: The dimension of the support plate in the height direction matches the dimension of the pole group end face in the height direction, and the dimension of the support plate in the thickness direction matches the dimension of the pole group end face in the thickness direction. Therefore, by setting the support plate, the internal force of the battery cell can be balanced, the unbalanced support of the pole group can be avoided, and the pole group can be prevented from being easily damaged when it moves.

[0023] In an optional embodiment, the housing is formed with an opening on at least one side along the length direction; the assembly formed by the first pole group and the second pole group is pushed into the housing through the opening;

[0024] The battery also includes:

[0025] The third support plate is arranged on one side of the tail end of the assembly formed by the first pole group and the second pole group along the thrust direction.

[0026] Beneficial effect: By arranging a third support plate on one side of the tail end of the assembly formed by the first pole group and the second pole group along the thrust direction, it is possible to ensure that the thrust is balanced when the pole group is inserted into the shell, so that the assembly formed by the first pole group and the second pole group can be smoothly inserted into the shell, avoiding bias and improving assembly efficiency.

[0027] In an optional embodiment, the housing is provided with openings on both sides along the length direction; and the battery cell further comprises:

[0028] The first cover plate and the second cover plate are respectively arranged to cover the openings on both sides of the shell along the length direction;

[0029] A first explosion-proof valve is provided on the first cover plate;

[0030] The second explosion-proof valve is arranged on the second cover plate.

[0031] Beneficial effects: By respectively providing a first cover plate and a second cover plate at both ends of the battery cell along the length direction, and directly connecting the internal pole groups with pole ears, the number of structural spaces is reduced, and there is no need to provide a cover plate and other structural parts for each battery cell, thereby avoiding the cost increase caused by the increase in structural parts, achieving cost reduction, and reducing the internal resistance of the battery cell. At the same time, by providing a first explosion-proof valve on the first cover plate and a second explosion-proof valve on the second cover plate, the first explosion-proof valve and the second explosion-proof valve are respectively located on both sides of the shell along the length direction, and cooperate with the shell explosion-proof valve provided near the fixed component along the length direction, so that explosion-proof valves can be arranged in multiple places of the battery cell, thereby increasing the exhaust efficiency, shortening the airway stroke, and thus improving the safety of the battery cell. When thermal runaway occurs in the battery cell, the high-temperature gas can be discharged nearby, avoiding the situation where the gas path is too long to be released quickly.

[0032] In an optional embodiment, the battery cell further includes:

[0033] A side plate is provided in the shell and is located on a side of the shell where the shell explosion-proof valve is provided;

[0034] The side plates extend along the length direction and abut against the first pole group and the second pole group at the same time.

[0035] Beneficial Effects: Because electrode groups are prone to damage during movement, the provision of side plates can prevent imbalanced electrode group support. Furthermore, when thermal runaway occurs in the battery cell, the electrode groups, propelled by gas, move toward the side near the housing explosion-proof valve. By providing side plates on the side of the housing where the housing explosion-proof valve is located, the first and second electrode groups can be brought into contact, preventing gas path blockage caused by the electrode groups blocking the explosion-proof valve.

[0036] In an optional embodiment, the battery cell further includes:

[0037] The insulating film is coated on the outer side of the whole formed by the first pole group, the fixed component and the second pole group.

[0038] Beneficial effect: Wrapping the insulating film on the outside of the whole formed by the first pole group, the fixed component and the second pole group can make the first pole group, the fixed component and the second pole group form an integral structure, which is convenient for subsequent assembly and plays an insulating and protective role.

[0039] In an optional embodiment, the battery cell includes a support plate, and the support plate includes at least one of a first support plate, a second support plate, and a third support plate;

[0040] Along the length direction, the thickness of the support plate is T, which satisfies: 0.3mm<T<1mm;

[0041] Along the length direction, the distance between the end faces of the first pole group and the second pole group that are close to each other is W, which satisfies: 4mm≤W≤8mm;

[0042] And it meets the following requirements: 2T+W<10mm.

[0043] Beneficial Effects: By limiting the upper limit of the support plate's thickness, it is possible to prevent the support plate from being too thick, which would otherwise occupy a large space. By limiting the lower limit of the support plate's thickness, it is possible to prevent the support plate from being too thin, which would result in insufficient strength and affect the support effect. Furthermore, by limiting the thickness of 2T + W to less than 10mm, it is possible to save space inside the battery cell and avoid excessive space occupation.

[0044] In a second aspect, the present invention further provides a battery cell pack, comprising: a plurality of battery cells as described above;

[0045] A plurality of battery cells are stacked along the thickness direction to form a battery cell group.

[0046] Since the battery cell group includes the battery cells and has the same effect as the battery cells, it will not be described in detail here. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] In order to more clearly illustrate the specific implementation methods of the utility model or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0048] Figure 1 A schematic diagram of a battery cell of the present utility model;

[0049] Figure 2 This is an exploded schematic diagram of the battery cell of the present utility model;

[0050] Figure 3 This is a front view of the battery cell of the present invention with the shell and insulating film removed;

[0051] Figure 4 for Figure 3 Schematic diagram of the AA section;

[0052] Figure 5 This is a top view of the battery cell of the present invention;

[0053] Figure 6 for Figure 5 Schematic diagram of the middle BB section;

[0054] Figure 7 A top view of the first pole group, the second pole group, and the support plate of the utility model in an assembled state;

[0055] Figure 8 A schematic diagram of a support plate of the present invention;

[0056] Figure 9A schematic diagram of a fixing assembly of the present invention;

[0057] Figure 10 This is a schematic diagram of the disassembled state of the fixing component of the present invention.

[0058] Description of reference numerals:

[0059] 1. Shell; 2. Insulation film; 3. Side plate; 41. First pole group; 411. First pole tab; 42. Second pole group; 421. Second pole tab; 43. Welding mark;

[0060] 5. Fixing assembly; 51. First fixing member; 511. First clearance groove; 52. Second fixing member; 521. Second clearance groove; 53. Clearance notch;

[0061] 61. First cover plate; 62. Second cover plate;

[0062] 71. First explosion-proof valve; 72. Second explosion-proof valve; 73. Shell explosion-proof valve;

[0063] 8. Support plate; 81. First support plate; 82. Second support plate; 83. Third support plate; 84. Opening. DETAILED DESCRIPTION

[0064] To make the purpose, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the embodiments described are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without making creative efforts shall fall within the scope of protection of the present invention.

[0065] In the description of this utility model, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are intended solely to facilitate the description of this utility model and simplify the description. They do not indicate or imply that the devices or components referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on this utility model. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0066] In the description of this utility model, it should be noted that, unless otherwise expressly specified or limited, the terms "installed," "connected," and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; mechanical connections, electrical connections; direct connections, indirect connections through an intermediate medium, and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in this utility model based on specific circumstances.

[0067] In addition, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0068] The capacity of a battery cell refers to the amount of charge it can store, i.e. milliampere-hours (mAh), which determines the lifespan of the cell. As the length of the cell increases, the capacity increase is significant. However, due to electrode group strength issues, very long cells often bend and deform, resulting in a reduction in yield. The overall capacity increase space is limited by process conditions; especially for extra-long cells, the molding process is demanding and difficult to support. Therefore, in related technologies, the cell structure is generally short. While the method of connecting multiple cells in series can achieve capacity increases, since each cell requires structural components such as a cover plate, this results in an increase in structural components and increased costs, and a significant waste of space.

[0069] In addition, as the length of the battery cell increases, when the battery cell experiences thermal runaway, the gas cannot be released quickly due to the long path, thereby reducing the safety performance of the battery cell.

[0070] The battery cells provided by the embodiments of the present invention, by employing multiple split-structure electrode groups, can reduce the length of individual electrode pieces, lower the process requirements for manufacturing extra-long battery cells, and reduce the difficulty of supporting them. Furthermore, there is no need to provide structural components such as cover plates for each battery cell, thus avoiding the cost increase caused by the increase in structural components and achieving cost reduction. Compared with the method of connecting multiple complete battery cells in series, this method is more space-saving. The battery cell size can be extended to achieve the purpose of increasing capacity and reducing costs.

[0071] The following combination Figures 1 to 10 , describing the embodiments of the present utility model.

[0072] According to an embodiment of the present invention, on the one hand, a battery cell is provided, comprising:

[0073] Shell 1;

[0074] The first pole group 41 and the second pole group 42 are arranged side by side along the length direction and are located together in the housing 1. A first pole tab 411 extends from one end of the first pole group 41 close to the second pole group 42, and a second pole tab 421 extends from one end of the second pole group 42 close to the first pole group 41. The first pole tab 411 and the second pole tab 421 are welded together to form a weld mark 43.

[0075] The fixing assembly 5 is disposed between the first electrode group 41 and the second electrode group 42. The fixing assembly 5 is adapted to fix the relative positions of the first electrode group 41 and the second electrode group 42 and to form a clearance gap 53 for the connection between the first electrode tab 411 and the second electrode tab 421.

[0076] The shell explosion-proof valve 73 is disposed on the shell 1 and is disposed close to the fixing assembly 5 along the length direction.

[0077] The battery cell of this embodiment includes two electrode groups arranged side by side along the length. By adopting a split-structure electrode group, the two electrode groups arranged side by side along the length are connected, thereby shortening the length of a single electrode group and reducing defects such as wrinkling, deformation, layer cross-linking, and fracture caused by excessive electrode length. This can achieve an increase in battery cell capacity, and the connection of adjacent electrode groups is achieved by providing a fixing assembly 5.

[0078] It should be noted that the length direction refers to the direction in which the longest side of each side of the electrode group extends, the thickness direction refers to the direction perpendicular to the large surface of the electrode group, wherein the large surface of the electrode group is the surface with the largest external surface area in the electrode group, and the height direction refers to the direction perpendicular to both the length direction and the thickness direction. In this embodiment, the height direction can be parallel to the vertical direction. In addition, the length direction, thickness direction, and height direction are as shown in the attached figure. Figure 3 、 Figure 4 Directions shown are for reference only.

[0079] The first electrode tab 411 is welded to the second electrode tab 421 . In this embodiment, the first electrode tab 411 and the second electrode tab 421 have opposite polarities.

[0080] In this embodiment, the fixing assembly 5 is suitable for fixing the relative position of the first pole group 41 and the second pole group 42, playing an isolating and supporting role, and effectively fixing the two pole groups. It prevents the first pole group 41 and the second pole group 42 from getting close to each other and squeezing the pole ear, and prevents the first pole group 41 and the second pole group 42 from moving away from each other and pulling the pole ear. It meets the demand for the first pole group 41 and the second pole group 42 to be connected through the pole ear, improves the energy density, and realizes the capacity increase of the battery cell. At the same time, it plays a safety protection role in the connection between the first pole ear 411 and the second pole ear 421, and can ensure the relative position of the first pole group 41 and the second pole group 42, so that the first pole group 41 and the second pole group 42 are more easily connected to the external circuit as a whole.

[0081] In addition, the electrode group size of the battery cell can be matched in a variety of ways, such as long and short size matching, equal size matching, to maximize adaptability to equipment production lines.

[0082] When the first and second pole groups 41, 42 are arranged side by side along the length and housed together in the housing 1, the housing 1 becomes longer. If explosion-proof valves were only provided at both ends of the housing 1 along the length, the gas would not be quickly released in the event of thermal runaway due to the long gas path, thus reducing the safety of the battery cell. This embodiment provides a housing explosion-proof valve 73 in the housing 1, and places the housing explosion-proof valve 73 near the fixing assembly 5 along the length. This increases the exhaust channel, improves exhaust efficiency, shortens the gas path, and thus improves battery cell safety.

[0083] In this embodiment, the shell explosion-proof valve 73 is preferably arranged in the middle position of the shell 1 along the length direction.

[0084] In some embodiments, combined Figure 4 As shown, the first electrode tab 411 and the second electrode tab 421 are horizontally welded;

[0085] The direction in which the clearance notch 53 penetrates the fixing component 5 is parallel to the length direction.

[0086] Since the first pole ear 411 and the second pole ear 421 are both flexible structures, after the pole ears are bent, if a bump occurs, it is easy for the pole ears to overlap with other charged structures, resulting in insufficient protection for the pole ears. In addition, when the pole ears are connected by C-type or S-type bending, it is easy to cause the pole ears to be longer, resulting in the pole ears occupying more space.

[0087] In this embodiment, the first and second tabs 411 and 421 are welded horizontally. A fixing assembly 5 is provided between the first and second tabs 41 and 42. The fixing assembly 5 is adapted to guide the extension path of the first and second tabs 411 and 421, thereby constraining the first and second tabs 411 and 421 and protecting the connection between the two tabs, thereby preventing accidental overlap and improving the safety of the battery cell. Furthermore, the direction in which the clearance notch 53 extends through the fixing assembly 5 is parallel to the length direction, allowing the two tabs to be welded horizontally, thereby simplifying the process, further reducing internal resistance, saving tab length, and reducing the internal space occupied by the battery cell.

[0088] In some embodiments, combined Figure 9 、 Figure 10 As shown, the fixing assembly 5 includes:

[0089] The first fixing member 51 and the second fixing member 52 are detachably connected along the thickness direction;

[0090] The first fixing member 51 is at least partially recessed on one side facing the second fixing member 52 to form a first clearance groove 511 , and the second fixing member 52 is at least partially recessed on one side facing the first fixing member 51 to form a second clearance groove 521 . The first clearance groove 511 and the second clearance groove 521 together form a clearance gap 53 .

[0091] The fixing component 5 can simplify the assembly process by adopting a method in which the first fixing member 51 and the second fixing member 52 are connected to each other along the thickness direction. After the first pole ear 411 and the second pole ear 421 are welded, the first fixing member 51 and the second fixing member 52 are respectively installed toward the middle position along both sides of the thickness direction, which does not interfere with the normal connection between the first pole ear 411 and the second pole ear 421, and can guide the bending path of the first pole ear 411 and the second pole ear 421.

[0092] After the first fixing member 51 is connected to the second fixing member 52 , the pole group can be supported while ensuring force balance and reducing the risk of damaging the pole group.

[0093] In addition, after the first fixing member 51 is connected to the second fixing member 52 , since the tabs are located in the clearance gap 53 , other areas of the fixing assembly 5 can protect the first tab 411 and the second tab 421 along the height direction to prevent damage to the tabs.

[0094] In some embodiments, combined Figure 4 、 Figure 7 As shown, the battery cell includes a support plate 8 , and the support plate 8 includes at least one of a first support plate 81 , a second support plate 82 , and a third support plate 83 .

[0095] In this embodiment, the battery cell further includes:

[0096] A first support plate 81 is disposed between the fixing assembly 5 and the first electrode group 41 along the length direction. The first support plate 81 has an opening 84 suitable for the first electrode tab 411 to pass through.

[0097] And / or, the second support plate 82 is disposed between the fixing assembly 5 and the second electrode group 42 along the length direction, and the second support plate 82 is provided with an opening 84 suitable for the second electrode tab 421 to pass through.

[0098] The dimension of the support plate 8 along the height direction matches the dimension of the end face of the electrode group along the height direction, and the dimension of the support plate 8 along the thickness direction matches the dimension of the end face of the electrode group along the thickness direction. Therefore, by providing the support plate 8, it is possible to ensure that the internal force of the battery cell is balanced, avoid unbalanced support of the electrode group, and prevent the electrode group from being easily damaged when it moves.

[0099] The support plate 8 is provided with an opening 84 suitable for the tab to pass through, thereby preventing the tab from interfering with the installation of the support plate 8 .

[0100] In some embodiments, combined Figure 4 、 Figure 7 As shown, the housing 1 is formed with an opening on at least one side along the length direction; the assembly formed by the first pole group 41 and the second pole group 42 is pushed into the housing 1 through the opening;

[0101] The battery also includes:

[0102] The third support plate 83 is disposed on one side of the tail end of the assembly formed by the first pole group 41 and the second pole group 42 along the thrust direction.

[0103] It should be noted that when the combination formed by the first pole group 41 and the second pole group 42 is pushed into the shell 1 through the opening, for example, the first pole group 41 enters the shell 1 first, and then the second pole group 42 enters the shell 1. At this time, the side of the tail end along the thrust direction refers to the end of the second pole group 42 facing away from the first pole group 41.

[0104] On the contrary, if the second pole group 42 enters the housing 1 first and then the first pole group 41 enters the housing 1 , the side of the tail end along the thrust direction refers to the end of the first pole group 41 away from the second pole group 42 .

[0105] By providing a third support plate 83 on one side of the tail end of the assembly formed by the first pole group 41 and the second pole group 42 along the thrust direction, it is possible to ensure that the thrust is balanced when the pole group is inserted into the shell, so that the assembly formed by the first pole group 41 and the second pole group 42 can be smoothly inserted into the shell, avoiding bias and improving assembly efficiency.

[0106] In some embodiments, combined Figure 6 As shown, the housing 1 has openings on both sides along the length direction; the battery cell also includes:

[0107] The first cover plate 61 and the second cover plate 62 are respectively provided to cover the openings on both sides of the housing 1 along the length direction;

[0108] A first explosion-proof valve 71 is provided on the first cover plate 61;

[0109] The second explosion-proof valve 72 is provided on the second cover plate 62 .

[0110] In this embodiment, the first cover plate 61 covers one end of the first electrode group 41 away from the first electrode tab 411 along the length direction; the second cover plate 62 covers one end of the second electrode group 42 away from the second electrode tab 421 along the length direction.

[0111] In this embodiment, a battery cell includes two electrode groups arranged side by side along the length direction as an example. By respectively providing a first cover plate 61 and a second cover plate 62 at both ends of the battery cell along the length direction, and directly connecting the internal electrode groups with electrode ears, the number of structural spaces is reduced, and there is no need to provide structural parts such as cover plates for each battery cell, thereby avoiding the increase in cost caused by the increase in structural parts, achieving cost reduction, and reducing the internal resistance of the battery cell.

[0112] At the same time, by providing a first explosion-proof valve 71 on the first cover plate 61 and a second explosion-proof valve 72 on the second cover plate 62, the first explosion-proof valve 71 and the second explosion-proof valve 72 are respectively located on either side of the housing 1 along the length direction. In conjunction with the housing explosion-proof valve 73 provided along the length direction near the fixing assembly 5, explosion-proof valves are arranged at multiple locations on the battery cell, increasing exhaust efficiency, shortening the airway travel, and thereby improving battery cell safety. In the event of thermal runaway in the battery cell, high-temperature gases can be discharged nearby, avoiding the situation where the gas path is long and cannot be quickly released.

[0113] Combine Figure 6 As shown, when thermal runaway occurs in the battery cell, the high-temperature gas generated in various places inside the battery cell will be discharged in the direction indicated by the arrow, so that the high-temperature gas can be discharged nearby, ensuring the number of exhaust channels and avoiding the situation where the gas path is too long to be released quickly.

[0114] In some embodiments, combined Figure 2 、 Figure 3 As shown, the battery cell also includes:

[0115] The side plate 3 is provided in the housing 1 and is located on the side of the housing 1 where the housing explosion-proof valve 73 is provided;

[0116] The side plate 3 extends along the length direction and abuts against the first pole group 41 and the second pole group 42 at the same time.

[0117] Since the electrode assembly is easily damaged during movement, the side plate 3 is provided to prevent imbalanced electrode assembly support. Furthermore, when thermal runaway occurs in the battery cell, the electrode assembly will be propelled by gas to move toward the side near the housing explosion-proof valve 73. By providing the side plate 3 on the side of the housing 1 where the housing explosion-proof valve 73 is located, the first electrode assembly 41 and the second electrode assembly 42 can be brought into contact, preventing the electrode assembly from blocking the explosion-proof valve and causing gas blockage.

[0118] The side plate 3 abuts against the first pole group 41 and the second pole group 42 at the same time. By adopting an integral side plate, the number of parts can be reduced and the assembly process can be simplified.

[0119] In some embodiments, combined Figure 2 As shown, the battery cell also includes:

[0120] The insulating film 2 covers the outer side of the whole formed by the first electrode group 41 , the fixing assembly 5 and the second electrode group 42 .

[0121] Wrapping the insulating film 2 around the outer side of the whole formed by the first pole group 41 , the fixing assembly 5 and the second pole group 42 enables the first pole group 41 , the fixing assembly 5 and the second pole group 42 to form an integral structure, facilitating subsequent assembly and providing insulation protection.

[0122] By coating the entire battery with the insulating film, there is no need to coat the first electrode group 41, the fixing assembly 5 and the second electrode group 42 separately, which reduces material usage, saves costs and improves the overall energy density of the battery assembly.

[0123] In some embodiments, the fixing component 5 is connected to the first electrode group 41 by adhesive bonding or thermal melting; and / or, the fixing component 5 is connected to the second electrode group 42 by adhesive bonding or thermal melting.

[0124] By securing the fixing assembly 5 to the first electrode group 41 and the second electrode group 42, respectively, the three can be ensured to form a whole, preventing the first electrode group 41 and the second electrode group 42 from approaching each other and squeezing the electrode tabs, and preventing the first electrode group 41 and the second electrode group 42 from moving away from each other and pulling the electrode tabs. This satisfies the requirement for the first electrode group 41 and the second electrode group 42 to be connected via the electrode tabs, improves energy density, and achieves cell capacity expansion. At the same time, it provides a safety protection for the connection between the first electrode tab 411 and the second electrode tab 421, and can ensure the relative position of the first electrode group 41 and the second electrode group 42, making it easier for the first electrode group 41 and the second electrode group 42 to connect to the external circuit as a whole.

[0125] In this embodiment, the fixing component 5 can be made of insulating material.

[0126] In some embodiments, combined Figure 7 As shown, the battery cell includes a support plate 8, and the support plate 8 includes at least one of a first support plate 81, a second support plate 82, and a third support plate 83;

[0127] Along the length direction, the thickness of the support plate 8 is T, which satisfies: 0.3mm<T<1mm;

[0128] Along the length direction, the distance between the end faces of the first pole group 41 and the second pole group 42 that are close to each other is W, which satisfies: 4mm≤W≤8mm;

[0129] And it meets the following requirements: 2T+W<10mm.

[0130] By limiting the upper limit of the thickness of the support plate 8, it is possible to prevent the support plate 8 from being too thick and taking up too much space. By limiting the lower limit of the thickness of the support plate 8, it is possible to prevent the support plate 8 from being too thin and causing insufficient strength, thereby affecting the supporting effect.

[0131] By limiting 2T+W to less than 10mm, the internal space of the battery cell can be saved and excessive space occupation can be avoided.

[0132] According to an embodiment of the present invention, on the other hand, there is also provided a battery cell pack, comprising: a plurality of battery cells as described above;

[0133] A plurality of battery cells are stacked along the thickness direction to form a battery cell group.

[0134] Obviously, the above embodiments are merely examples for the purpose of clarity of explanation and are not intended to limit the implementation methods. Although the embodiments of the present invention have been described in conjunction with the accompanying drawings, those skilled in the art may make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations are all within the scope defined by the present invention.

Claims

1. A battery cell, characterized in that: include: case; The first pole group and the second pole group are arranged side by side along the length direction and are located together in the housing; A first pole tab extends from one end of the first pole group close to the second pole group, and a second pole tab extends from one end of the second pole group close to the first pole group; the first pole tab is welded to the second pole tab to form a weld mark; A fixing assembly is disposed between the first electrode group and the second electrode group, the fixing assembly being adapted to fix the relative positions of the first electrode group and the second electrode group and forming a clearance gap for the connection between the first electrode tab and the second electrode tab; The shell explosion-proof valve is arranged on the shell, and is arranged close to the fixing component along the length direction.

2. The battery cell according to claim 1, characterized in that The first electrode tab and the second electrode tab are horizontally welded; The direction in which the clearance notch penetrates the fixing component is parallel to the length direction.

3. The battery cell according to claim 1, characterized in that The fixing assembly includes: The first fixing member and the second fixing member are detachably connected along the thickness direction; The first fixing member is at least partially recessed on one side facing the second fixing member to form a first clearance groove, and the second fixing member is at least partially recessed on one side facing the first fixing member to form a second clearance groove. The first clearance groove and the second clearance groove together form the clearance gap.

4. The battery cell according to claim 1, characterized in that The battery cell further comprises: a first support plate, disposed between the fixing assembly and the first electrode group along a length direction, the first support plate being provided with an opening suitable for the first electrode tab to pass through; And / or, a second support plate is provided between the fixing assembly and the second electrode group along the length direction, and the second support plate is provided with an opening suitable for the second electrode tab to pass through.

5. The battery cell according to claim 4, characterized in that: The shell is formed with an opening on at least one side along the length direction; The assembly formed by the first pole group and the second pole group is pushed into the housing through the opening; The battery cell further comprises: The third support plate is arranged on one side of the tail end of the assembly formed by the first pole group and the second pole group along the thrust direction.

6. The battery cell according to claim 5, characterized in that The shell is formed with openings on both sides along the length direction; the battery core further includes: A first cover plate and a second cover plate are respectively provided to cover the openings on both sides of the shell along the length direction; a first explosion-proof valve, disposed on the first cover plate; The second explosion-proof valve is arranged on the second cover plate.

7. The battery cell according to any one of claims 1 to 6, characterized in that: The battery cell further comprises: a side plate, disposed in the shell and located on a side of the shell where the shell explosion-proof valve is provided; The side plate extends along the length direction and abuts against the first pole group and the second pole group at the same time.

8. The battery cell according to any one of claims 1 to 6, characterized in that: The battery cell further comprises: An insulating film is coated on the outer side of the whole formed by the first pole group, the fixed component and the second pole group.

9. The battery cell according to claim 4 or 5, characterized in that: The battery cell includes a support plate, and the support plate includes at least one of a first support plate, a second support plate, and a third support plate; Along the length direction, the thickness of the support plate is T, which satisfies: 0.3mm<T<1mm; Along the length direction, the distance between the end faces of the first pole group and the second pole group that are close to each other is W, which satisfies: 4mm≤W≤8mm; And it meets the following requirements: 2T+W<10mm.

10. A battery cell pack, characterized in that: comprising a plurality of battery cells according to any one of claims 1 to 9; A plurality of the battery cells are stacked along the thickness direction to form the battery cell group.

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