Aluminum bar, battery module and battery pack

Abstract

The utility model relates to an aluminum bar, a battery module and a battery pack. The aluminum bar comprises a connecting part and a transition part. The number of the connecting parts is two, and the two connecting parts are respectively used for connecting corresponding battery cell poles in the battery module; the transition part is electrically connected between the two connecting parts, and the transition part can respond to the temperature and block the current between the two connecting parts at the preset temperature. The aluminum bar provided by the utility model is automatically powered off when reaching the preset temperature, the temperature of the aluminum bar is not required to be detected by a storage battery management system, and the corresponding aluminum bar is not required to be powered off, so that the response speed of the aluminum bar is greatly improved, and further diffusion of thermal runaway is prevented.

Description

Technical Field

[0001] This application relates to the technical field of batteries, and particularly to an aluminum bar, a battery module, and a battery pack. Background Art

[0002] A battery pack includes a plurality of battery modules. Each battery module includes a plurality of single cells connected in series by aluminum bars. When a certain single cell undergoes thermal runaway, a relatively large current will be continuously generated, resulting in a rapid temperature rise of the corresponding aluminum bar. In related structures, the temperature of the corresponding aluminum bar is detected by a BMS (Battery Management System) - battery management system, and power is cut off for the aluminum bar with abnormal temperature to prevent the thermal runaway of the battery pack. However, this method has a relatively long response time and a high dependence on the battery management system (BMS). Summary of the Utility Model

[0003] Based on this, it is necessary to provide an aluminum bar to solve the problems in related structures that it is necessary to rely on the battery management system (BMS) to detect and cut off the current flowing through the aluminum bar with abnormal temperature, and the response time to thermal runaway is relatively long.

[0004] An aluminum bar is used in a battery module. The aluminum bar includes a connecting portion and a transition portion. The number of connecting portions is two, and the two connecting portions are respectively used to connect the corresponding cell poles in the battery module; the transition portion is electrically connected between the two connecting portions, and the transition portion can respond to temperature and block the current between the two connecting portions at a predetermined temperature.

[0005] In one embodiment, the transition portion is configured as a flexible conductive component, and the flexible conductive component includes a conductor and an insulating layer. The conductor is electrically connected to the corresponding two connecting portions, and the conductor is configured to melt when reaching a predetermined temperature. The insulating layer wraps and connects the conductor.

[0006] In one embodiment, the number of conductors is configured as single or multiple. When the number of conductors is configured as multiple, the multiple conductors are arranged at intervals.

[0007] In one embodiment, both ends of the conductor respectively extend out of the insulating layer and form exposed portions; the exposed portions are respectively welded to the corresponding connecting portions on the corresponding sides, or multiple exposed portions on the same side of the flexible conductive component are connected to a bus bar, and are welded to the corresponding connecting portions on the corresponding sides through the bus bar.

[0008] In one embodiment, the transition portion is sheet-shaped, and the transition portion has a pre-bent portion to adapt to the assembly space between the two connecting portions.

[0009] In one embodiment, the transition portion is configured as a metal-insulator phase change material, and when the transition portion reaches a predetermined temperature, the transition portion can change from a metallic state to an insulating state.

[0010] In one embodiment, the metal-insulator phase change material is configured as vanadium or tungsten bronze.

[0011] In one embodiment, the two connecting portions are plate-shaped and have a projection overlapping area in the thickness direction, and the transition portion is clamped and fixed in the projection overlapping area between the two connecting portions.

[0012] The present application also provides a battery module, which includes a CCS, a plurality of battery cells, and a plurality of aluminum bars as described in any one of the above embodiments. The CCS has a bus bar bundle, and a plurality of aluminum bars are electrically connected to the bus bar bundle.

[0013] The present application also provides a battery pack, which includes the battery module described in the above embodiments.

[0014] Compared with the prior art, for the aluminum bar provided by the present application, when a single battery cell undergoes thermal runaway and causes the corresponding aluminum bar to rapidly heat up to a predetermined temperature, the transition portion causes the corresponding aluminum bar to cut off power by itself, thereby quickly cutting off the current between the battery cell that has undergone thermal runaway and other battery cells. Compared with the related structure, it is necessary to rely on the battery management system to detect the temperature of the aluminum bar and cut off the power of the corresponding aluminum bar, which greatly improves the response speed of the aluminum bar and does not require the battery management system to detect, thereby facilitating the prevention of further spread of thermal runaway. Description of the Drawings

[0015] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0016] Figure 1 It is a schematic structural diagram of the battery module provided by the present application;

[0017] Figure 2 It is a schematic structural diagram of the aluminum bar in one embodiment provided by the present application;

[0018] Figure 3 It is a partial schematic diagram of the transition portion in one embodiment provided by the present application.

[0019] Reference numerals: 100, battery module; 10, aluminum bar; 11, connecting part; 12, transition part; 121, pre-bent part; 122, avoidance space; 13, flexible conductive component; 131, conductor; 132, exposed part; 133, insulating layer; 20, battery cell; 40, end plate; 50, cable tie. Detailed implementation manners

[0020] In order to make the above objects, features, and advantages of the present application more obvious and understandable, the following will describe in detail the specific implementation manners of the present application with reference to the accompanying drawings. Many specific details are set forth in the following description to fully understand the present application. However, the present application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without departing from the connotation of the present application. Therefore, the present application is not limited by the specific embodiments disclosed below.

[0021] It should be noted that when a component is referred to as being "fixed to" or "disposed on" another component, it can be directly on the other component or there can also be an intermediate component. When a component is considered to be "connected" to another component, it can be directly connected to the other component or there may be an intermediate component at the same time. The terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used in the description of the present application are only for the purpose of illustration and do not represent the only implementation manner.

[0022] In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one of such features. In the description of the present application, the meaning of "a plurality" is at least two, such as two, three, etc., unless otherwise specifically defined.

[0023] In the present application, unless otherwise clearly specified and limited, the first feature being "on" or "under" the second feature can be that the first feature is in direct contact with the second feature, or the first feature and the second feature are indirectly in contact through an intermediate medium. Moreover, the first feature being "above", "over" and "on top of" the second feature can be that the first feature is directly above or 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 first feature being "under", "below" and "beneath" the second feature can be that the first feature is directly below or obliquely below the second feature, or only indicates that the horizontal height of the first feature is less than that of the second feature.

[0024] Unless otherwise defined, all technical and scientific terms used in the specification of this application have the same meaning as commonly understood by those skilled in the technical field to which this application belongs. The terms used in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application. The term "and / or" used in the specification of this application includes any and all combinations of one or more of the related listed items.

[0025] Please refer to Figures 1 to 2 , this application provides an aluminum bar 10, which is used in a battery module 100. The aluminum bar 10 includes a transition portion 12 and two connecting portions 11. The two connecting portions 11 are respectively used to connect the corresponding electrode posts of the battery cells 20 in the battery module 100. The transition portion 12 is electrically connected between the two connecting portions 11, and the transition portion 12 can respond to temperature and block the current between the two connecting portions 11 at a predetermined temperature. It should be noted that the transition portion 12 can respond to temperature and block the current between the two connecting portions 11 at a predetermined temperature, which means that the transition portion 12 can melt at a predetermined temperature to block the current between the two connecting portions 11; it can also be that the transition portion 12 becomes insulated at a predetermined temperature to block the current between the two connecting portions 11. In this way, when a single battery cell 20 has a thermal runaway and causes the corresponding aluminum bar to quickly heat up to a predetermined temperature, the transition portion 12 enables the corresponding aluminum bar 10 to cut off the power by itself, thereby quickly cutting off the current between the battery cell 20 with thermal runaway and other battery cells 20. Compared with the related structure, it is necessary to rely on the battery management system (BMS) to detect the temperature of the aluminum bar and cut off the power of the corresponding aluminum bar, which greatly improves the response speed of the aluminum bar 10 and does not need to rely on the battery management system (BMS), thus helping to prevent the further spread of thermal runaway.

[0026] The transition portion 12 is sheet-shaped, and the transition portion 12 has a pre-bent portion 121 to adapt to the assembly space between the two connecting portions 11. Specifically, the pre-bent portion 121 protrudes toward one side along the thickness direction of the transition portion 12, and a clearance space 122 is formed on the other side. The clearance space 122 is used to avoid the partition between two adjacent battery cells 20.

[0027] The following specifically introduces two embodiments of the aluminum bar 10.

[0028] Embodiment 1

[0029] Please refer to Figures 1 to 3, the transition part 12 is configured as a flexible conductive component 13, and the flexible conductive component 13 includes a conductor 131 and an insulating layer 133. The conductor 131 is electrically connected to two corresponding connection parts 11, and when the conductor 131 is configured to reach a predetermined temperature and can be fused, the insulating layer 133 wraps and connects the conductor 131. The conductor 131 functions as a fuse, so that when its temperature reaches the predetermined temperature, it can block the current conduction by fusing. The insulating layer 133 functions as a protection to prevent the fused conductor 131 from affecting other surrounding components. And, since the transition part 12 is configured as the flexible conductive component 13, when the battery cell 20 expands normally and causes a change in the gap between the battery cells 20, compared with the aluminum bar in the related structure, the flexible conductive component 13 can absorb a larger gap, so as to adapt to the change in the distance between the battery cells 20. When the battery module or the battery pack is impacted, the flexible conductive component 13 can also absorb a larger vibration impact, which is beneficial to improving the safety of the battery pack.

[0030] Optionally, the conductor 131 can be configured as a copper wire that is easily fusible. When the battery pack or the battery module 100 is subjected to a severe mechanical impact, the copper wire in the flexible conductive component 13 breaks preferentially, so as to quickly cut off the current to avoid the further spread of thermal runaway caused by the mechanical impact.

[0031] The number of the conductors 131 is configured as single or multiple. When the number of the conductors 131 is configured as multiple, the multiple conductors 131 are arranged at intervals.

[0032] Furthermore, both ends of the conductor 131 respectively extend out of the insulating layer 133 and form exposed parts 132. The exposed parts 132 are used for welding with the corresponding connection parts 11. Among them, the exposed parts 132 can be directly welded to the connection parts 11 on the corresponding sides respectively. Or, multiple exposed parts 132 on the same side of the flexible conductive component 13 are connected to a bus bar, and are welded to the connection parts 11 on the corresponding sides through the bus bar.

[0033] Exemplarily, the transition part 12 is configured as a flexible printed circuit board FPC or a flexible flat cable FFC.

[0034] Embodiment Two

[0035] Please refer to Figures 1 to 2 , the transition part 12 is configured as a metal-insulator phase change material, and when the transition part 12 reaches a predetermined temperature, the transition part 12 can change from a metallic state to an insulating state.

[0036] Optionally, the metal-insulator phase change material is configured as vanadium or tungsten bronze, etc.

[0037] Further, the two connecting portions 11 are plate-shaped and have a projection overlapping area in the thickness direction, and the transition portion 12 is clamped and fixed in the projection overlapping area between the two connecting portions 11. In this way, the connection area between the transition portion 12 and the two connecting portions 11 can be increased.

[0038] The present application also provides a battery module 100, which includes a CCS (Cell Connection System), that is, a cell connection system, a plurality of cells 20, and the aluminum bar 10 described in any one of the above embodiments. The CCS has a bus bar bundle, and a plurality of aluminum bars 10 are electrically connected to the bus bar bundle.

[0039] Specifically, the battery module 100 further includes a plurality of separators, two end plates 40, and two heat insulation pads. The plurality of cells 20 are arranged along their own thickness direction. Each separator is clamped between two adjacent cells 20 and at least part of the separator extends out of the surface of the cell 20. The two end plates 40 are attached to the outer surfaces of the cells 20 at the ends along the thickness direction of the cells 20. The two heat insulation pads are attached to the outer surfaces of the cells 20 at the ends along the length direction of the cells 20. The tie straps 50 are bundled along the circumference of the battery module 100 on the outer surfaces of the end plates 40 and the heat insulation pads. Among them, the heat insulation pads are used to isolate the battery module 100 that has thermal runaway from other normally operating battery modules.

[0040] The present application also provides a battery pack, which includes the aluminum bar 10 or the battery module 100 described in any one of the above embodiments.

[0041] The technical features of the above embodiments can be combined arbitrarily. For the sake of concise description, not all possible combinations of the technical features in the above embodiments are described. However, as long as the combinations of these technical features do not conflict, they should be considered as the scope described in this specification.

[0042] The above embodiments only represent several implementation manners of the present application. The description is relatively specific and detailed, but it should not be construed as a limitation on the scope of the patent application. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present application, several modifications and improvements can still be made, and these all belong to the protection scope of the present application. Therefore, the patent protection scope of the present application should be subject to the appended claims.

Claims

1. An aluminum bar, which is used in a battery module, is characterized in that, The aluminum bar includes: Connecting parts (11), the number of the connecting parts (11) is two, and the two connecting parts (11) are respectively used for connecting the corresponding electrode posts of the battery cells (20) in the battery module (100); A transition part (12), the transition part (12) is electrically connected between the two connecting parts (11), and the transition part (12) can respond to temperature and block the current between the two connecting parts (11) at a predetermined temperature; The transition part (12) is configured as a flexible conductive component (13), and the flexible conductive component (13) includes a conductor (131) and an insulating layer (133), the conductor (131) is electrically connected to the corresponding two connecting parts (11), and the conductor (131) is configured to be able to melt when reaching a predetermined temperature, and the insulating layer (133) wraps and connects the conductor (131).

2. The aluminum strip according to claim 1, characterized in that, The number of the conductors (131) is configured to be single or multiple. When the number of the conductors (131) is configured to be multiple, the multiple conductors (131) are arranged at intervals.

3. The aluminum strip according to claim 2, characterized in that, Both ends of the conductor (131) respectively extend out of the insulating layer (133) and form exposed parts (132); The exposed parts (132) are respectively welded to the connecting parts (11) on the corresponding sides, or, multiple exposed parts (132) on the same side of the flexible conductive component (13) are connected to a bus bar, and are welded to the connecting parts (11) on the corresponding sides through the bus bar.

4. The aluminum bar according to claim 1, characterized in that The transition part (12) is sheet-shaped, and the transition part (12) has a pre-bent part (121) to adapt to the assembly space between the two connecting parts (11).

5. A battery module, characterized in that, The battery module (100) includes a CCS, multiple battery cells (20), and multiple aluminum bars (10) as described in any one of claims 1-4, the CCS has a bus bar bundle, and the multiple aluminum bars (10) are electrically connected to the bus bar bundle.

6. A battery pack, characterized in that, The battery pack includes the battery module as described in claim 5.

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