Single battery and battery pack

Abstract

The utility model belongs to the technical field of batteries, and discloses a single battery and a battery pack. The single battery comprises a fixed frame and a plurality of electrode assemblies, connecting tabs are arranged at two ends of each electrode assembly along a first direction, and the plurality of electrode assemblies are connected in series end to end along the first direction; the connecting tabs close to each other in two adjacent electrode assemblies are in lap joint with each other, an accommodating groove is formed in the end part, close to the other electrode assembly, of one electrode assembly, and the two connecting tabs which are in lap joint with each other are accommodated in the accommodating groove; the fixing frame is arranged on the periphery of the electrode assemblies in a surrounding mode, and a containing cavity for containing the electrode assemblies is formed. According to the single battery, the battery core in the single battery is divided into a plurality of electrode assemblies, so that the length of the single electrode assembly can be reduced, undesirable phenomena such as surface wrinkles, deformation, layer channeling and breakage caused by overlong electrode assemblies are avoided, and meanwhile, the fixed frame is used for fixing the connected electrode assemblies, so that the use safety of the single battery is improved.

Description

Technical Field

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

[0002] As lithium-ion battery technology matures, it is widely used as a power battery in electric vehicles and energy storage, leading to increasing demands for performance and safety. Lithium-ion cells are core components for safety and assembly, and their structural design is crucial to the safety of the entire pack.

[0003] Existing battery cell structures are generally short, and the overall capacity improvement space is limited by process conditions. Therefore, the battery cell structure is developing in the direction of longer cells. However, for longer cells, the electrode group often bends and deforms due to its strength issues, resulting in reduced product yield. If multiple short cells are directly connected in series to form a long cell, it will increase the structural cost and waste space. Currently, the molding process requirements for long cells and extra-long cells are high, and the internal support structure of the battery cell is difficult to manufacture. At the same time, the tabs of long cells are prone to overlap when bent, which provides insufficient protection. The tabs are connected with C-shaped or S-shaped bends, which makes the tabs longer and requires more space. On the other hand, due to the long length of the battery cell, when the battery cell experiences thermal runaway, the gas cannot be released quickly due to the long and obstructed path, which reduces the safety performance of the battery cell. In addition, the internal electrode group support of the battery cell is prone to imbalance, and the electrode group is easily damaged when it moves.

[0004] Therefore, there is an urgent need to provide a new type of single cell and battery pack to solve the above technical problems in the prior art. Utility Model Content

[0005] One purpose of the present utility model is to provide a single cell battery that can achieve good support inside a long cell structure and has higher structural strength, thereby improving the safety of the single cell battery.

[0006] To achieve this purpose, the present invention adopts the following technical solutions:

[0007] The single battery includes a fixed frame and a plurality of electrode assemblies, both ends of the electrode assemblies along a first direction are provided with connecting tabs, the plurality of electrode assemblies are connected in series end to end along the first direction, and the connecting tabs close to each other in two adjacent electrode assemblies are overlapped with each other; wherein, in the two adjacent electrode assemblies, one of the electrode assemblies is provided with a receiving groove at the end close to the other electrode assembly, and the two overlapping connecting tabs are accommodated in the receiving groove; the fixed frame is arranged around the outer periphery of the plurality of electrode assemblies and forms a receiving cavity for accommodating the plurality of electrode assemblies.

[0008] Optionally, an insulating support plate is sandwiched between two adjacent electrode assemblies, the insulating support plate is provided with a support hole, and the connecting tab is passed through the support hole.

[0009] Optionally, two side walls of the fixing frame that are opposite to each other along the second direction are provided with fixing holes, and the insulating support plate is clamped in the fixing holes.

[0010] Optionally, the above-mentioned single battery also includes a battery shell and two cover plate assemblies, the above-mentioned electrode assembly and the above-mentioned fixing frame are both arranged in the above-mentioned battery shell, and the above-mentioned battery shell is provided with opening structures at both ends along the above-mentioned first direction, and the above-mentioned cover plate assemblies are sealed and arranged in the opening structures one by one.

[0011] Optionally, at least one of the two cover plate assemblies comprises a cover plate body, the cover plate body is integrally formed with a pole protrusion, and the connecting tabs are correspondingly connected to the pole protrusion.

[0012] Optionally, at least one of the two end surfaces of the battery housing that are opposite to each other along the second direction is provided with an explosion-proof valve.

[0013] Optionally, a plurality of explosion-proof valves are provided, and each explosion-proof valve corresponds to one of the electrode assemblies.

[0014] Optionally, outer walls of several of the electrode assemblies are covered with an insulating film, and the insulating film is sandwiched between the battery shell and the outer walls of the electrode assemblies.

[0015] Optionally, both ends of the fixing frame along the first direction are provided with avoidance holes, and the connecting tabs located at the outermost ends along the first direction are passed through the avoidance holes in a one-to-one correspondence.

[0016] Another object of the present invention is to provide a battery pack, which specifically includes a single battery as described in any of the above solutions.

[0017] Beneficial effects:

[0018] The single cell battery of the present invention is formed by connecting several electrode assemblies end to end in series to form a long battery cell. A fixing frame is then used to surround the outer periphery of the electrode assembly to surround and fix the electrode assembly, thereby fixing two adjacent electrode assemblies and improving the structural strength of the long battery cell. At the same time, one of the two adjacent electrode assemblies is provided with a receiving groove near the end of the other electrode assembly, and the two overlapping connecting tabs are accommodated in the above-mentioned receiving groove, thereby reducing the overall length of the multiple electrode assemblies after being connected in series. The single cell battery divides the internal battery cell into several electrode assemblies, which can reduce the length of a single electrode assembly and avoid undesirable phenomena such as surface wrinkling, deformation, layer crossover, and fracture caused by excessively long electrode assemblies. At the same time, the fixing frame fixes the connected electrode assemblies, thereby improving the safety of the single cell battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is an exploded view of a single battery provided in a specific embodiment of the present utility model;

[0020] Figure 2 This is an exploded view of a single battery provided by a specific embodiment of the present utility model with the battery housing and insulating film hidden;

[0021] Figure 3 This is an axonometric diagram of a battery cell provided by a specific embodiment of the present invention with some structures hidden;

[0022] Figure 4 It is an axonometric view of the insulating support plate provided in a specific embodiment of the present utility model.

[0023] In the picture:

[0024] 100, electrode assembly; 110, connecting tab; 120, receiving tank;

[0025] 200, fixed frame; 201, accommodating cavity; 202, avoidance hole; 203, fixing hole; 210, insulating support plate; 211, support hole;

[0026] 300, battery housing; 301, opening structure; 310, cover assembly; 311, cover body; 312, pole protrusion; 320, explosion-proof valve; 330, insulating film. DETAILED DESCRIPTION

[0027] The present invention will be further described in detail below with reference to the accompanying drawings and examples. It should be understood that the specific embodiments described herein are intended only to illustrate the present invention and are not intended to limit the present invention. It should also be noted that, for ease of description, the accompanying drawings only illustrate portions relevant to the present invention, not all of its components.

[0028] In the description of this utility model, unless otherwise specified or limited, the terms "connected," "connect," and "fixed" should be understood in a broad sense. For example, they can refer to fixed connection, detachable connection, or integration; mechanical connection or electrical connection; direct connection or indirect connection through an intermediate medium; internal communication between two components or interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in this utility model based on the specific circumstances.

[0029] In the present invention, unless otherwise expressly specified or limited, a first feature being "above" or "below" a second feature may include the first and second features being in direct contact, or may include the first and second features being in contact not directly but through another feature between them. Moreover, a first feature being "above," "above," and "above" a second feature may include the first feature being directly above or obliquely above the second feature, or may simply mean that the first feature is higher in level than the second feature. A first feature being "below," "below," and "below" a second feature may include the first feature being directly below or obliquely below the second feature, or may simply mean that the first feature is lower in level than the second feature.

[0030] In the description of this embodiment, the terms "upper," "lower," "right," and other orientations or positional relationships are based on the orientations or positional relationships shown in the accompanying drawings and are intended solely for ease of description and simplified operation. 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 the present invention. Furthermore, the terms "first" and "second" are used solely for descriptive purposes and have no special meaning.

[0031] The first direction described in this embodiment is Figures 1 to 3 The X direction shown in is the length direction of the single battery, and the second direction is Figures 1 to 3 The Y direction shown in FIG, ie, the width direction of the single battery, the first direction and the second direction are perpendicular to each other.

[0032] like Figure 1 Figure 2As shown, the single battery includes a fixed frame 200 and a plurality of electrode assemblies 100, and the electrode assemblies 100 are provided with connecting tabs 110 at both ends along the first direction. The plurality of electrode assemblies 100 are connected in series end to end along the first direction, and the connecting tabs 110 close to each other in two adjacent electrode assemblies 100 are overlapped with each other; wherein, in the two adjacent electrode assemblies 100, one of the electrode assemblies 100 is provided with a receiving groove 120 at the end close to the other electrode assembly 100, and the two overlapping connecting tabs 110 are accommodated in the receiving groove 120; the fixed frame 200 is arranged around the outer periphery of the plurality of electrode assemblies 100, and forms an accommodating cavity 201 for accommodating the plurality of electrode assemblies 100.

[0033] The single cell in this embodiment is formed by connecting several electrode assemblies 100 end to end in series to form a long battery cell, and then using a fixing frame 200 to be arranged around the periphery of the electrode assembly 100 to surround and fix the electrode assembly 100, thereby fixing the two adjacent electrode assemblies 100 and improving the structural strength of the long battery cell. At the same time, one of the two adjacent electrode assemblies 100 is provided with a receiving groove 120 near the end of the other electrode assembly 100, and the two overlapping connecting tabs 110 are accommodated in the above-mentioned receiving groove 120, thereby reducing the overall length of the several electrode assemblies 100 after being connected in series. The single cell divides the internal battery cell into several electrode assemblies 100, which can reduce the length of a single electrode assembly 100 and avoid surface wrinkles, deformation, layer crossover, fracture and other undesirable phenomena caused by the excessive length of the electrode assembly 100. At the same time, the fixing frame 200 fixes the connected electrode assemblies 100, thereby improving the safety of the single cell.

[0034] Preferably, the fixing frame 200 is integrally formed by injection molding, which reduces the number of parts and simplifies the assembly process.

[0035] Specifically, the two overlapping connecting tabs 110 are fixed by horizontal welding, which can simplify the process, further reduce the internal resistance, and save the length of the connecting tabs 110, reduce the space occupied by the connecting tabs 110 inside the single cell, and improve the energy density of the single cell.

[0036] like Figure 1 and Figure 4As shown, optionally, an insulating support plate 210 is sandwiched between two adjacent electrode assemblies 100. The insulating support plate 210 is provided with a support hole 211, and the connecting tab 110 is inserted into the support hole 211. The insulating support plate 210 not only supports and fixes the connecting tab 110, but also insulates and separates the two adjacent electrode assemblies 100, thereby providing insulation. When the long battery cell structure formed by the plurality of electrode assemblies 100 is pushed into the interior of the battery casing 300, it balances the thrust and limits the position, thereby improving the efficiency of the long battery cell structure being inserted into the casing.

[0037] Furthermore, the above-mentioned single cell also includes a battery housing 300 and two cover plate assemblies 310. The above-mentioned electrode assembly 100 and the above-mentioned fixing frame 200 are both disposed within the above-mentioned battery housing 300. The above-mentioned battery housing 300 is provided with an opening structure 301 at both ends along the above-mentioned first direction. The above-mentioned cover plate assemblies 310 are sealed and disposed in a one-to-one correspondence with the opening structure 301. After the plurality of electrode assemblies 100 and the fixing frame 200 are fixed to form a long battery cell structure, they can be pushed into the interior of the battery housing 300 through the opening structure 301. The opening structure 301 is then sealed using the cover plate assembly 310 to complete the assembly of the single cell.

[0038] In this embodiment, at least one of the two cover plate assemblies 310 includes a cover plate body 311, and the cover plate body 311 is integrally formed with a pole protrusion 312, and the connecting tab 110 is correspondingly connected to the pole protrusion 312. Specifically, one of the cover plate assemblies 310 in this embodiment has a structure in which the cover plate body 311 is integrally formed with the pole protrusion 312, which is the positive electrode cover plate, and the other is a conventional cover plate structure, namely the negative electrode cover plate. The positive electrode cover plate is specifically a plain aluminum sheet, which can simplify the structure of the cover plate assembly 310, improve the space utilization rate of the battery cell, and improve the energy density.

[0039] Optionally, at least one of the two end surfaces of the battery housing 300 that are opposite each other along the second direction is provided with an explosion-proof valve 320. In this embodiment, the explosion-proof valve 320 is provided on the two end surfaces of the battery housing 300 that are opposite each other along the second direction, rather than on the cover plate assembly 310. This simplifies the structure of the cover plate assembly 310, reduces the number of structural components, reduces production costs, and reduces the internal resistance of the long battery cell structure.

[0040] Please continue to refer to Figure 1Specifically, a plurality of explosion-proof valves 320 are provided, and each explosion-proof valve 320 is provided corresponding to one of the electrode assemblies 100. In this embodiment, the explosion-proof valves 320 can be provided simultaneously on the same end face of the battery housing 300, or separately on different end faces. Specifically, in this embodiment, two electrode assemblies 100 are provided, that is, two explosion-proof valves 320 are provided correspondingly. The two explosion-proof valves 320 are provided at intervals on one of the two end faces of the battery housing 300 that are opposite to each other along the second direction, so as to realize corresponding explosion-proof pressure relief for each electrode assembly 100. The explosion-proof pressure relief path will not be blocked by other components, thereby shortening the pressure relief path and improving the safety of the battery.

[0041] It should be noted that the insulating support plate 210 insulates and separates two adjacent electrode assemblies 100, so that each electrode assembly 100 is accommodated in different chambers separated by the fixed frame 200 and the insulating support plate 210. Each electrode assembly 100 can correspond to an annular exhaust channel. When thermal runaway occurs in the electrode assembly 100, the pressure can be quickly relieved and exhausted from the corresponding annular exhaust channel, and the pressure can be relieved from the corresponding explosion-proof valve 320. The pressure relief and exhaust effect is better, which can improve the safety of the single cell.

[0042] Optionally, the outer walls of several of the electrode assemblies 100 are coated with an insulating film 330, and the insulating film 330 is sandwiched between the battery housing 300 and the outer wall of the electrode assembly 100. When assembling the single battery in this embodiment, the multiple electrode assemblies 100 are first connected end to end, and then the fixing frame 200 is fixed to the sides of the multiple electrode assemblies 100 by gluing or hot-melt fixing to form the required long battery cell structure. The outer surface of the long battery cell structure is then coated with an insulating insulating film 330. The insulating film 330 is slit at the position corresponding to the explosion-proof valve 320 to facilitate pressure relief and exhaust. The insulating film 330 is a commonly used Mylar film. The coated long battery cell structure is then pushed into the interior of the battery housing 300 and the cover assembly 310 is installed to complete the assembly of the single battery.

[0043] like Figure 2 and Figure 3 As shown, optionally, the fixing frame 200 is provided with fixing holes 203 on two opposite side walls along the second direction, and the insulating support plate 210 is snapped into the fixing holes 203. In this way, the insulating support plate 210 can be fixed to the fiber, preventing the insulating support plate 210 from loosening during transportation, thereby improving the stability and reliability of the connection.

[0044] Furthermore, the fixing frame 200 is provided with avoidance holes 202 at both ends along the first direction, and the connecting tabs 110 located at the outermost ends along the first direction are respectively passed through the avoidance holes 202. The avoidance holes 202 not only enable the connecting tabs 110 of the electrode assembly 100 to pass through the fixing frame 200 and connect to the cover plate assembly 310, thereby supporting the connecting tabs 110, but also shorten the length of the connecting tabs 110, thereby reducing production costs.

[0045] In this embodiment, the wall thickness of the fixing frame 200 is L, the thickness of the insulating support plate 210 is H, the thickness of the insulating film 330 is T, and the dimension of the receiving groove 120 along the first direction is W; 5 mm < W < 10 mm, 0.5 mm < L < 3 mm, 0.5 mm < H < 2 mm, and 0.1 mm < T < 0.3 mm. Those skilled in the art may select the values ​​of the above parameters according to specific needs, and detailed description thereof will not be given here.

[0046] Another object of the present invention is to provide a battery pack, which specifically includes a single cell as described in any of the above schemes. The battery pack can be used for pure electric vehicles, hybrid vehicles, ships, energy storage equipment, etc., which will not be described in detail here. The battery pack uses the above-mentioned single cells for power supply, so it has all the beneficial effects of the single cells described in any of the above schemes, which will not be described in detail here. Specifically, the single cells used in the battery pack can reduce the length of a single electrode assembly 100, avoiding surface wrinkles, deformation, layer crossover, fractures and other adverse phenomena caused by the electrode assembly 100 being too long. At the same time, the fixed frame 200 protects the electrode assemblies 100 connected end to end, thereby improving the safety of the battery pack.

[0047] Obviously, the above-described embodiments of the present invention are merely examples for the purpose of clearly illustrating the present invention and are not intended to limit the manner in which the present invention is to be implemented. A person skilled in the art would be able to make various obvious changes, readjustments, and substitutions without departing from the scope of protection of the present invention. It is not necessary and impossible to enumerate all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the claims of the present invention.

Claims

1. A single cell battery, characterized in that: include: A plurality of electrode assemblies (100), each of the electrode assemblies (100) being provided with connecting tabs (110) at both ends along a first direction, the plurality of electrode assemblies (100) being connected in series end to end along the first direction, the connecting tabs (110) close to each other in two adjacent electrode assemblies (100) being overlapped with each other; wherein, in the two adjacent electrode assemblies (100), an end of one of the electrode assemblies (100) close to the other electrode assembly (100) is provided with a receiving groove (120), and the two overlapping connecting tabs (110) are accommodated in the receiving groove (120); A fixed frame (200) is arranged around the outer periphery of the plurality of electrode assemblies (100) and forms an accommodating cavity (201) for accommodating the plurality of electrode assemblies (100).

2. The single cell according to claim 1, characterized in that: An insulating support plate (210) is sandwiched between two adjacent electrode assemblies (100), the insulating support plate (210) is provided with a support hole (211), and the connecting tab (110) is inserted into the support hole (211).

3. The single cell according to claim 2, characterized in that: The fixing frame (200) is provided with fixing holes (203) on two side walls opposite to each other along the second direction, and the insulating support plate (210) is clamped in the fixing holes (203).

4. The single cell according to claim 1, characterized in that: The single cell further comprises a battery housing (300) and two cover plate assemblies (310); the electrode assembly (100) and the fixing frame (200) are both arranged in the battery housing (300); both ends of the battery housing (300) along the first direction are provided with opening structures (301); the cover plate assemblies (310) are sealed and arranged in a one-to-one correspondence with the opening structures (301).

5. The single cell according to claim 4, characterized in that: At least one of the two cover plate assemblies (310) comprises a cover plate body (311), the cover plate body (311) is integrally formed with a pole protrusion (312), and the connecting tab (110) is correspondingly connected to the pole protrusion (312).

6. The single cell according to claim 4, characterized in that: At least one of the two end surfaces of the battery housing (300) that are arranged opposite to each other along the second direction is provided with an explosion-proof valve (320).

7. The single cell according to claim 6, characterized in that: A plurality of explosion-proof valves (320) are provided, and each explosion-proof valve (320) is provided corresponding to one electrode assembly (100).

8. The single cell according to claim 4, characterized in that: The outer walls of a plurality of the electrode assemblies (100) are covered with an insulating film (330), and the insulating film (330) is sandwiched between the battery housing (300) and the outer wall of the electrode assembly (100).

9. The single cell according to any one of claims 1 to 8, characterized in that: Both ends of the fixing frame (200) along the first direction are provided with avoidance holes (202), and the connecting tabs (110) located at the outermost ends along the first direction are passed through the avoidance holes (202) in a one-to-one correspondence.

10. A battery pack, characterized in that: The invention comprises a single cell according to any one of claims 1 to 9.

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