Battery cell limiting plate, battery module, battery pack and electric vehicle

Abstract

The embodiment of the utility model provides a battery cell limiting plate, a battery module, a battery pack and an electric vehicle, and relates to the technical field of batteries. The battery cell limiting plate is used for spacing two adjacent columns of battery cells, and at least part of the plate surface of the battery cell limiting plate forms a breakable area; and the breakable area is used for breaking under the condition of over-limit expansion of the battery cell. And the battery cell limiting plates are arranged between two adjacent rows of battery cells, so that the battery cells can be limited and restrained in the interval direction. According to the battery module, the breakable area is arranged, so that the expansion stress generated by the breakable area of the battery cell limiting plate can be released in the breakable area of the battery cell limiting plate under the conditions of self-discharge, abnormal short circuit, lithium precipitation and thermal runaway, namely over-limit expansion, so that the contact of battery cell parts is reduced, and the safety performance of the battery module is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of batteries, and in particular to a battery core limiting plate, a battery module, a battery pack and an electric vehicle. Background Art

[0002] Power batteries are the energy core of electric vehicles, providing power for electric vehicles. Power batteries generally include cylindrical, square and soft-pack cells. During normal use of the battery, as the number of cycles increases, square and soft-pack cells will expand, causing the thickness of the cells to increase. In order to ensure the cycle life of square cells and soft-pack cells, the structural design must ensure a certain preload, and at the end of the entire pack life, the structural design must be able to withstand the expansion force of the cell without damage.

[0003] However, under abnormal conditions, such as self-discharge, abnormal short circuit, lithium deposition and thermal runaway, the thickness of the battery cell will increase greatly, affecting adjacent battery cells. Therefore, it is necessary to release the stress caused by the increase in thickness and reduce the contact between battery cells to ensure the safety of the entire package. Utility Model Content

[0004] The utility model provides a battery cell limiting plate, a battery module, a battery pack and an electric vehicle, which can release the stress generated by the battery cell after the battery cell expands abnormally, reduce the contact between the battery cells, and thus ensure the safety of the entire battery module.

[0005] The embodiments of the present invention can be implemented as follows:

[0006] An embodiment of the utility model provides a battery cell limiting plate, which is used to space two adjacent columns of battery cells, and at least a portion of the plate surface of the battery cell limiting plate forms a breakable area; the breakable area is used to break when the battery cell expands beyond the limit.

[0007] In an optional embodiment, the breakable area is narrow in the middle and wide at both sides along a direction perpendicular to the arrangement direction of the battery cells in each column and the direction perpendicular to the interval between two adjacent columns of the battery cells.

[0008] In an optional embodiment, the breakable zone includes a breakable zone body and a hollow layer, and the hollow layer is located in the breakable zone body.

[0009] In an optional embodiment, the battery cell limiting plate includes a spacer portion and a limiting portion, the spacer portion is connected to the limiting portion to form a "T"-shaped structure; the spacer portion is used to fit with the side of the battery cell; the limiting portion is used to fit with the top edge of the battery cell; the breakable area is provided on the spacer portion.

[0010] In an optional implementation, the limiting portion is a hollow structure.

[0011] In an optional implementation, the battery cell limiting plate is provided with a heating wire installation groove, and the heating wire installation groove is used for installing the heating wire.

[0012] In an optional implementation, the battery cell limiting plate includes a limiting member body and a liquid cooling plate, and the liquid cooling plate is located in the limiting member body.

[0013] An embodiment of the utility model also provides a battery module, comprising multiple columns of battery cells and the battery cell limiting plates described in any of the above-mentioned embodiments, wherein the multiple columns of battery cells are arranged at intervals; the battery cell limiting plates are respectively installed between two adjacent columns of battery cells and on the side of the outermost column of battery cells away from the adjacent column of battery cells.

[0014] An embodiment of the utility model further provides a battery pack, comprising a housing and the battery module described in the above embodiment, wherein the battery module is disposed in the housing.

[0015] An embodiment of the utility model further provides an electric vehicle, comprising the battery pack in the above embodiment.

[0016] The beneficial effects of the battery cell limiting plate, battery module, battery pack and electric vehicle of the utility model embodiment include:

[0017] The cell limit plate is used to separate two adjacent columns of cells, and at least part of the plate surface of the cell limit plate forms a breakable area; the breakable area is used to break when the cell expands beyond the limit. By setting the cell limit plate between two adjacent columns of cells, the cells can be limited in the spacing direction. By setting the breakable area, the cell can release the expansion stress generated in the breakable area of ​​the cell limit plate in the case of self-discharge, abnormal short circuit, lithium deposition and thermal runaway, that is, in the case of excessive expansion, thereby reducing the contact of the cell parts and improving the safety performance of the battery module. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions of the embodiments of the utility model, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the utility model and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0019] Figure 1 A schematic diagram of a battery module provided in an embodiment of the present utility model;

[0020] Figure 2 A schematic diagram of a battery cell limiting plate provided in an embodiment of the utility model;

[0021] Figure 3 A schematic diagram of a first situation of a breakable area of ​​a cell limiting plate provided in an embodiment of the utility model;

[0022] Figure 4 A schematic diagram of a second situation of a breakable area of ​​a cell limiting plate provided in an embodiment of the utility model;

[0023] Figure 5 A schematic diagram of a third situation of a breakable area of ​​a cell limiting plate provided in an embodiment of the utility model;

[0024] Figure 6 It is a schematic diagram of the fourth situation of the breakable area of ​​the battery cell limiting plate provided in the embodiment of the utility model.

[0025] Icon: 1000-battery module; 100-battery cell limiting plate; 110-spacer; 111-breakable area; 1111-breakable area body; 1112-hollow layer; 112-heating wire installation groove; 120-limiting part; 130-limiting member body; 200-battery cell; 300-end plate. DETAILED DESCRIPTION

[0026] In order to make the purpose, technical scheme and advantages of the embodiments of the utility model clearer, the technical scheme in the embodiments of the utility model will be clearly and completely described below in conjunction with the drawings in the embodiments of the utility model. Obviously, the described embodiments are part of the embodiments of the utility model, not all of the embodiments. Generally, the components of the embodiments of the utility model described and shown in the drawings here can be arranged and designed in various different configurations.

[0027] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the present invention to be protected, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0028] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0029] In the description of the present utility model, it should be noted that if the terms "upper", "lower", "inside", "outside", etc. appear, the orientation or position relationship indicated is based on the orientation or position relationship shown in the accompanying drawings, or is the orientation or position relationship in which the utility model product is usually placed when used. It is only for the convenience of describing the utility model and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it cannot be understood as a limitation on the present utility model.

[0030] In addition, the terms “first”, “second”, etc., if used, are merely used to distinguish between the descriptions and should not be understood as indicating or implying relative importance.

[0031] It should be noted that, in the absence of conflict, the features in the embodiments of the present invention may be combined with each other.

[0032] The power battery is the energy core of electric vehicles and provides power for electric vehicles. Power batteries generally include cylindrical, square and soft-pack cells. During the normal use of the battery in the vehicle, as the number of cycles increases, the square and soft-pack cells will expand, causing the thickness of the cells to increase. In order to ensure the cycle life of square cells and soft-pack cells, the structural design must ensure a certain preload force, and at the end of the life of the entire package, the structural design can withstand the expansion force of the cells without damage. However, under abnormal conditions, such as self-discharge, abnormal short circuit, lithium deposition and thermal runaway, the thickness of the cells will increase greatly, affecting adjacent cells. Therefore, it is necessary to release the stress caused by the increase in thickness and reduce the contact between cells to ensure the safety of the entire package.

[0033] Based on this, please refer to Figure 1 and Figure 2 The battery cell limiting plate 100, battery module 1000, battery pack and electric vehicle provided in the embodiment of the utility model can effectively improve the above-mentioned technical problems. The electric vehicle includes a vehicle body and a battery pack, the battery pack is arranged in the vehicle body, and the battery pack provides electric energy for the vehicle body to realize various functions of the vehicle body.

[0034] The battery pack in this embodiment includes a housing and a battery module 1000, and the battery module 1000 is disposed in the housing. In addition, the battery pack may also include a BMS (battery management system), and the battery management system is electrically connected to the battery cell 200. Of course, the battery pack may also include other structural devices according to specific usage requirements, which are not limited here.

[0035] Specifically, the battery module 1000 includes multiple columns of battery cells 200 and battery cell limiting plates 100. The multiple columns of battery cells 200 are arranged at intervals. The battery cell limiting plates 100 are respectively installed between two adjacent columns of battery cells 200 and on the side of the outermost column of battery cells 200 away from the adjacent column of battery cells 200. Foam is arranged between two adjacent battery cells 200 in each column of battery cells 200. When the battery cell 200 is working, it will cause a certain amount of heat, and will produce a certain amount of thermal expansion and contraction at different temperatures, causing the battery cell 200 to produce a certain volume expansion. Since the foam has compression rebound performance, the foam arranged between each battery cell 200 in the battery cell 200 group can absorb the stress caused by the thermal expansion and contraction of the battery cell 200, thereby playing a buffering role for the battery cell 200, and the foam arranged between each battery cell 200 in the battery cell 200 group also has the function of heat insulation and shock absorption. The battery module 1000 of this embodiment further includes end plates 300, which are arranged on both sides of each column of battery cells 200, and are connected to the battery cell limiting plates 100 to jointly fix and limit the battery cells 200. Of course, the battery module 1000 may also include other structures, which are not limited here.

[0036] The specific structure of the battery cell limiting plate 100 will be described in detail below.

[0037] Figure 1 A schematic diagram of a battery module 1000 provided in an embodiment of the present utility model; Figure 2 Schematic diagram of a cell limiting plate 100 provided in an embodiment of the utility model, as shown Figure 1 and Figure 2 As shown, the cell limiting plate 100 is used to separate two adjacent columns of cells 200, and at least part of the plate surface of the cell limiting plate 100 is formed with a breakable area 111; the breakable area 111 is used to break when the cell 200 expands beyond the limit. When the cell 200 expands abnormally, that is, expands beyond the limit, a first expansion force is generated, and the first expansion force can cause the breakable area 111 of the cell limiting plate 100 to break; when the cell 200 expands normally, a second expansion force is generated, and the second expansion force cannot cause the breakable area 111 of the cell limiting plate 100 to break.

[0038] By setting a cell limit plate 100 between two adjacent columns of cells 200, the cell 200 can be limited and constrained in the spacing direction. The cell limit plate 100 has a breakable area 111. When the cell 200 expands beyond the limit, a first expansion force is generated, and the first expansion force can cause the breakable area 111 of the cell limit plate 100 to break. Excessive expansion refers to the expansion that occurs when the cell 200 is in abnormal conditions such as self-discharge, abnormal short circuit, lithium deposition and thermal runaway. Excessive expansion will cause the thickness of the cell 200 to increase sharply, and it may contact the normal cell 200 next to it, which will cause safety problems in the entire battery module 1000 or battery pack. The breakable area 111 is set, so that when the cell 200 expands beyond the limit, the expansion stress generated by it can be released in the breakable area 111 of the cell limit plate 100, reducing the contact of the cell 200, thereby improving the safety performance of the battery module 1000 or battery pack.

[0039] When the battery cell 200 expands under normal circumstances, that is, after the battery cell 200 is charged and discharged for multiple cycles, the expansion occurs due to long-term cyclic use. The expansion stress generated at this time cannot cause the breakable area 111 of the battery cell limiting plate 100 to break. This design can ensure that the battery cell 200 does not damage the battery cell limiting plate 100 under normal circumstances, ensuring the normal operation of the entire battery module 1000 or battery pack.

[0040] In addition to limiting the spacing of the cells 200 in each column, in order to limit the height of the cells 200, please refer to Figure 2 The cell limiting plate 100 in this embodiment includes a spacer 110 and a limiting portion 120. The spacer 110 is connected to the limiting portion 120 to form a "T"-shaped structure; the spacer 110 is used to fit with the side of the cell 200; the limiting portion 120 is used to fit with the top edge of the cell 200; and a breakable area 111 is provided on the spacer 110. That is, the cell limiting plate 100 is set between two adjacent columns of cells 200. Since the cell limiting plate 100 is a "T"-shaped structure, it can also limit the movement of the cell 200 in the up and down directions. And the cell limiting plate 100 is installed between two adjacent columns of cells 200 or on the side of the outermost column of cells 200 away from the adjacent column of cells 200.

[0041] Please continue reading Figure 2 In order to save materials and reduce production costs, the limiting portion 120 in this embodiment is a hollow structure.

[0042] Thermal management of the battery is extremely important for the battery cell 200. In order to properly manage the thermal performance of the battery cell 200 and to save space and installation time, please continue to refer to Figure 2The cell limiting plate 100 in this embodiment is provided with a heating wire installation groove 112, and the heating wire installation groove 112 is used to install the heating wire. Specifically, in this embodiment, a plurality of heating wire installation grooves 112 are spaced apart on the two outer sides of the spacer 110 of the cell limiting plate 100, so that when the ambient temperature is low, the heating wires on the cell limiting plate 100 heat two adjacent columns at the same time, ensuring that the cell 200 is charged and discharged normally.

[0043] In addition, the battery cell 200 will generate a large amount of heat during the continuous charging and discharging process, causing the temperature of the battery cell 200 to rise. In order to keep the battery cell 200 at a normal operating temperature, it is also necessary to cool the battery cell 200 when the temperature of the battery cell 200 is high. The battery cell limit plate 100 in this embodiment includes a limit member body 130 and a liquid cooling plate (not shown in the figure), and the liquid cooling plate is located in the limit member body 130. The liquid cooling plate is arranged in the limit member body 130, which can save installation space while ensuring the temperature of the battery cell 200. In addition, in addition to arranging the liquid cooling plate in the limit member body 130, the liquid cooling plate can also be designed to be in the shape of the battery cell limit plate 100, that is, the liquid cooling plate can be used for multiple purposes, which can not only achieve cooling, but also limit the movement of the battery cell 200 along the spacing direction of each column or the up and down direction.

[0044] By integrating the heating wire and the liquid cooling plate into the battery cell limiting plate 100 , space can be saved, and the installation process is simplified, thus saving the installation time of the battery module 1000 .

[0045] Figure 3 It is a schematic diagram of a first situation of the breakable area 111 of the battery cell limiting plate 100 provided in an embodiment of the utility model; Figure 4 This is a schematic diagram of the second situation of the breakable area 111 of the battery cell limiting plate 100 provided in the embodiment of the utility model, please refer to Figure 3 and Figure 4 , the above-mentioned "battery cell limiting plate 100 has a breakable area 111", specifically, the breakable area 111 in this embodiment is narrow in the middle and wide on both sides along the direction perpendicular to the arrangement direction of each column of battery cells 200 and the direction perpendicular to the spacing between two adjacent columns of battery cells 200. Narrow in the middle and wide on both sides can be that the widths of both ends of the breakable area 111 gradually decrease toward the middle and shrink to the same point. Of course, it can also be that after the widths of both ends of the breakable area 111 decrease to a certain width toward the middle along the extension direction, there is a section in the middle that is the minimum width. The minimum width is determined according to the magnitude of the first expansion force generated by the battery cell 200 under abnormal circumstances and the magnitude of the second expansion force generated by the battery cell 200 under normal circumstances. The design of the minimum width must ensure that no breakage occurs under the action of the second expansion force, but that breakage occurs under the action of the first expansion force.

[0046] Figure 5It is a schematic diagram of a third situation of the breakable area 111 of the battery cell limiting plate 100 provided in an embodiment of the utility model; Figure 6 This is a schematic diagram of a fourth situation of the breakable area 111 of the battery cell limiting plate 100 provided in the embodiment of the utility model, please refer to Figure 5 and Figure 6 The breakable region 111 includes a breakable region body 1111 and a hollow layer 1112. The hollow layer 1112 is located in the breakable region body 1111. Specifically, Figure 5 As shown, the breakable area 111 includes a hollow layer 1112, and the hollow layer 1112 is located in the center of the breakable area body 1111, that is, a hole is dug in the breakable area body 1111, and the breakable area body 1111 and the hollow layer 1112 form a "U" shape in the cross section. Figure 6 As shown, the breakable area 111 includes two hollow layers 1112, and the two hollow layers 1112 are arranged in the breakable area body 1111 at intervals, that is, the breakable area body 1111 and the two hollow layers 1112 are in an "8" shape in cross section. Of course, the breakable area 111 can also be provided with three, four or more hollow layers 1112, and the multiple hollow layers 1112 are all located in the breakable area body 1111. The specific number and distribution of the hollow layers 1112 are determined by the first expansion force and the second expansion force. It is sufficient to ensure that the breakable area 111 will not break under the action of the second expansion force, but will break under the action of the first expansion force.

[0047] According to a battery cell limiting plate 100 provided in this embodiment, its working principle is as follows:

[0048] When the battery cell 200 is in an abnormal condition, such as self-discharge, abnormal short circuit, lithium deposition and thermal runaway, the thickness of the battery cell 200 will increase greatly. At this time, the battery cell 200 will generate a first expansion force, which acts on the battery cell limiting plate 100, causing the breakable area 111 of the battery cell limiting plate 100 to break, thereby releasing the first expansion force. After the first expansion force is released, the contact between two adjacent columns of battery cells 200 can be reduced, avoiding the abnormal battery cell 200 from affecting the adjacent battery cell 200, thereby causing a chain reaction and causing more serious safety problems.

[0049] When the battery cell 200 is charged and discharged for many times, it will expand, causing the thickness of the battery cell 200 to increase. In this case, the battery cell 200 will generate a second expansion force, and the battery cell 200 will squeeze the battery cell limiting plate 100, but will not damage the battery cell limiting plate 100, thereby ensuring the cycle life of the battery module 1000 or the battery pack.

[0050] In summary, the battery cell limiting plate 100 is used to space two adjacent columns of battery cells 200, and at least part of the plate surface of the battery cell limiting plate 100 forms a breakable area 111; the breakable area 111 is used to break when the battery cell 200 expands beyond the limit. By setting the battery cell limiting plate 100 between two adjacent columns of battery cells 200, the battery cells 200 can be limited and constrained in the spacing direction. By setting the breakable area 111, the battery cell 200 can release the expansion stress generated in the breakable area 111 of the battery cell limiting plate 100 in the case of self-discharge, abnormal short circuit, lithium deposition and thermal runaway, that is, in the case of excessive expansion, thereby reducing the contact between the battery cells 200 and improving the safety performance of the battery module 1000.

[0051] The above is only a specific implementation of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by any technician familiar with the technical field within the technical scope disclosed in the present invention should be included in the protection scope of the present invention.

Claims

1. A battery cell limiting plate, the battery cell limiting plate (100) being used to space two adjacent rows of battery cells (200), characterized in that: At least part of the plate surface of the battery cell limiting plate (100) forms a breakable area (111); the breakable area (111) is used to break when the battery cell (200) expands beyond the limit.

2. The battery cell limiting plate according to claim 1, characterized in that: The breakable area (111) is narrow in the middle and wide at both sides along a direction perpendicular to the arrangement direction of the battery cells (200) in each column and the spacing direction between two adjacent columns of the battery cells (200).

3. The battery cell limiting plate according to claim 1, characterized in that: The breakable region (111) comprises a breakable region body (1111) and a hollow layer (1112), wherein the hollow layer (1112) is located inside the breakable region body (1111).

4. The battery cell limiting plate according to claim 1, characterized in that: The battery cell limiting plate (100) comprises a spacer (110) and a limiting portion (120); the spacer (110) is connected to the limiting portion (120) to form a "T"-shaped structure; the spacer (110) is used to be arranged in contact with the side of the battery cell (200); the limiting portion (120) is used to be arranged in contact with the top edge of the battery cell (200); and the breakable area (111) is arranged on the spacer (110).

5. The battery cell limiting plate according to claim 4, characterized in that: The limiting portion (120) is a hollow structure.

6. The battery cell limiting plate according to claim 1, characterized in that: The battery core limiting plate (100) is provided with a heating wire installation groove (112), and the heating wire installation groove (112) is used for installing the heating wire.

7. The battery cell limiting plate according to any one of claims 1 to 6, characterized in that: The battery cell limiting plate (100) comprises a limiting component body (130) and a liquid cooling plate, wherein the liquid cooling plate is located inside the limiting component body (130).

8. A battery module, characterized in that: It comprises a plurality of columns of battery cells (200) and a battery cell limiting plate (100) as claimed in any one of claims 1 to 7, wherein the plurality of columns of battery cells (200) are arranged at intervals; the battery cell limiting plate (100) is respectively installed between two adjacent columns of battery cells (200) and on a side of the battery cells (200) in an outermost column away from the battery cells (200) in an adjacent column.

9. A battery pack, characterized in that: It comprises a shell and the battery module (1000) according to claim 8, wherein the battery module (1000) is arranged in the shell.

10. An electric vehicle, characterized in that: A battery pack comprising the battery pack of claim 9.

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