Battery cell, battery pack and vehicle

Abstract

According to the battery cell, the battery pack and the vehicle, a positive pole column or a negative pole column in each battery cell is electrically connected with a connecting piece, two battery cells can be directly and electrically connected through the connecting pieces on the two battery cells, and a busbar and a wire harness isolation plate do not need to be arranged, so that the occupation of the space in the height direction of the battery cells can be reduced, the height of the battery cells can be increased, and the service life of the battery cells is prolonged. And the energy density of the battery pack is increased. Moreover, when the battery cell is assembled in place, the positions of the connecting pieces are determined at the same time, and only two connecting pieces with an electric connection relationship need to be fixed, so that the assembly is simple, and the production cost is relatively low; in addition, for the battery pack adopting a battery cell top cooling scheme, the cooling capacity of the heat dissipation component can quickly reach the battery cell, and the cooling efficiency of the heat dissipation component on the battery cell is improved.

Description

Technical Field

[0001] This application relates to the field of batteries, and in particular to a battery cell, a battery pack, and a vehicle. Background Technology

[0002] Currently, battery packs typically consist of multiple cells 100', each cell 100' having a casing, electrode assembly, positive terminal, and negative terminal. The electrode assembly is encapsulated inside the casing and is electrically connected to external circuitry via two terminals. Series and parallel connections between cells 100' are typically achieved by riveting plates to the outer ends of the terminals located within the casing. Figure 1 (Not shown in the image), the riveting plate is welded to the busbar 300', and the series and parallel connections between the cells 100' are realized through the busbar 300' to form a battery pack.

[0003] Please see Figure 1 As shown in the figure, a battery pack has several cells 100', and the terminals of adjacent cells 100' are welded together via busbars 300'. Because there are many cells 100', the number of busbars 300' is also relatively large. For ease of assembly, the current flexible printed circuit board (FPC) 400' sampling structure and busbars 300' are pre-installed on the wire harness isolation plate 200' to form a cell connection system, and then welded to the terminals of the cells 100'. This is a common structure for connecting cells 100' in this field.

[0004] The cell connection system requires a significant amount of space in the height of the cells, which affects the height of the cells to some extent, and consequently the energy density of the battery pack. Summary of the Invention

[0005] The purpose of this application is to provide a battery cell that can improve the energy density of a battery pack and is easy to assemble. Another purpose of this application is to provide a battery pack and a vehicle having the above-mentioned battery cell.

[0006] This application provides a battery cell, comprising:

[0007] case;

[0008] The positive terminal and the negative terminal, both having a first portion located outside the housing;

[0009] Each of the first portions is electrically connected to the connector, and the two battery cells are directly electrically connected through the connectors provided on them.

[0010] Compared to current technologies that use busbars to connect the terminals of two cells, this embodiment features connectors electrically connected to both the positive and negative terminals. The two cells can be directly connected via these connectors, eliminating the need for busbars and wiring harness isolation plates. This reduces the space occupied in the cell's height direction, allowing for increased cell height and consequently, increased battery pack energy density. Furthermore, the positions of the connectors are determined simultaneously when the cells are assembled; only the two electrically connected connectors need to be fixed, simplifying assembly and reducing production costs.

[0011] In addition, for battery packs that use a top-cooling solution for the battery cells, the cooling energy from the heat dissipation components can quickly reach the battery cells, improving the efficiency of the heat dissipation components in cooling the battery cells.

[0012] In one example, the connector is provided with a contact portion, and the contact portions of two connectors abut against each other to achieve an electrical connection.

[0013] In one example, the contact portion is disposed on the first surface or the second surface of the connector, and the contact portions of the two directly electrically connected connectors overlap and abut against each other, with the first surface and the second surface arranged along the height direction of the battery cell.

[0014] In one example, the first surface or the second surface has a recessed surface, the contact portion being at least a portion of the recessed surface, and the recessed surface of one of the two directly electrically connected connectors being located on the first surface and the recessed surface of the other being located on the second surface.

[0015] In one example, the connector on the positive terminal is defined as a first connector, and the connector on the negative terminal is defined as a second connector. The recessed surface of the first connector is located on the first surface of the first connector, and the recessed surface of the second connector is located on the second surface of the second connector.

[0016] In one example, the contact portion is located on the end face of the connector away from the first portion.

[0017] In one example, the end of the connector away from the first part is provided with a socket or plug to enable direct electrical connection between the two connectors.

[0018] In one example, the length of the recessed surface is configured to extend to and support the housing of the adjacent battery cell.

[0019] In one example, the connector extends along the stacking direction of the battery cells, or the extension direction of the connector forms an angle with the stacking direction of the battery cells.

[0020] In addition, this application embodiment also provides a battery pack including a plurality of cells as described in any of the above claims, wherein each of the cells is electrically connected through each of the connectors.

[0021] Furthermore, embodiments of this application also provide a vehicle, including a vehicle body, on which the battery cells described in any of the above claims, or / and the battery pack described above, are disposed.

[0022] The battery pack and vehicle in this application embodiment have the aforementioned battery cells, and therefore both also have the aforementioned technical effects of the battery cells. Attached Figure Description

[0023] Figure 1 This is an exploded view of the internal structure of the current battery pack;

[0024] Figure 2 This is a schematic diagram of the main components of the battery pack in one embodiment of this application;

[0025] Figure 3 This is a schematic diagram of the battery cell structure in an embodiment of this application;

[0026] Figure 4 This is a schematic diagram of adjacent battery cells arranged along the stacking direction in an unassembled state in an embodiment of this application;

[0027] Figure 5 for Figure 4 CC end face view of the structure shown;

[0028] Figure 6 for Figure 5 A magnified view of a local area at point A in the middle;

[0029] Figure 7 for Figure 2 Enlarged view of a portion of the image;

[0030] Figure 8 This is a schematic diagram of two battery cells in an assembled state according to another embodiment of this application;

[0031] Figure 9 for Figure 8 View of the DD end face.

[0032] in, Figure 1 The one-to-one correspondence between the reference numerals and component names in the attached drawings is as follows:

[0033] 100' battery cell; 200' wire harness isolation board; 300' busbar; 400' flexible printed circuit board;

[0034] in, Figures 2 to 9 The one-to-one correspondence between the reference numerals and component names in the attached drawings is as follows:

[0035] 100 cell; 101 first cell; 102 second cell;

[0036] 1. Housing; 11. Top cover plate; 11a. Explosion-proof valve; 2. Pole group; 3. Positive pole; 31. First part; 32. Second part; 4. Negative pole; 5. First connector; 51. First recessed surface; 52. First end face; 6. Second connector; 61. Second recessed surface; 63. Second end face. Detailed Implementation

[0037] In response to the technical problem mentioned in the background art that the cell connection system occupies a large cell height, the inventors of this application have conducted extensive research and found that the main reason for the above-mentioned technical problem is that: currently, each busbar needs to be pre-fixed to the wire harness isolation plate and then welded to the riveting plate, resulting in a relatively large thickness of the component formed by the busbar and the wire harness isolation plate.

[0038] In addition to the aforementioned technical issues, busbars and wire harness isolation panels have high production costs and are complex to assemble.

[0039] In addition, battery cells release a large amount of heat during operation, requiring timely cooling. Some battery packs employ a top-cooling solution, placing the heat dissipation components on top of the cells. When using this method, the cooling energy from the heat dissipation components must pass through the busbar and wiring harness isolation plate to reach the cell. The busbar and wiring harness isolation plate generate thermal resistance, reducing the efficiency of the heat dissipation components in cooling the cell.

[0040] Therefore, overcoming at least one of the above-mentioned defects is a technical problem that those skilled in the art need to solve.

[0041] This application uses the example of each cell being upright, i.e., the tabs of each cell being located at the top of the cell, to introduce the technical solution and technical effect. Of course, the technical solution disclosed in this application is also applicable to battery packs with cells inverted or side-mounted.

[0042] Please refer to Figure 2 , Figure 2 This is a schematic diagram of the main components of the battery pack in one embodiment of this application.

[0043] This application embodiment provides a battery pack, the battery pack including a housing ( Figure 2 (Not shown in the diagram) and several battery cells located inside the enclosure. The battery cells are stacked along the x-direction to form a row of battery cell assemblies. The enclosure may contain one row of battery cell assemblies, or at least two rows of battery cell assemblies arranged along the y-direction. All battery cells are connected in series and / or in parallel according to rules to form a power supply. Figure 2 The example shown is an example of all the cells connected in series. Of course, the connection method of each cell in the battery pack is not limited to the electrical connection method described in this application.

[0044] Please combine Figure 3 , Figure 4 , Figure 5 and Figure 6 understand, Figure 3 This is a schematic diagram of the battery cell structure in an embodiment of this application. Figure 4 This is a schematic diagram of adjacent battery cells arranged along the stacking direction in an unassembled state in an embodiment of this application; Figure 5 for Figure 4 CC section view of the structure shown; Figure 6 for Figure 5 A magnified view of a local area at point A in the middle. Figure 4 and Figure 5 The cell structures in the two applications are basically the same. For the sake of brevity in describing the technical solution, adjacent cells are defined as the first cell and the second cell, respectively.

[0045] In this embodiment, a battery cell 100 includes a housing 1 and an electrode assembly 2 encapsulated inside the housing 1. The housing 1 has an opening at its upper end, and an upper cover plate 11 is provided at the opening. Typically, the upper cover plate 11 is installed at the opening of the housing 1 after the electrode assembly 2 is installed inside the housing 1. The electrode assembly 2 is used to store electrical energy and has two tabs, a positive tab and a negative tab. For the safety of the battery cell 100, an explosion-proof valve 11a is provided on the upper cover plate 11.

[0046] The battery cell 100 also has a positive terminal 3 and a negative terminal 4. Both the positive terminal 3 and the negative terminal 4 have a second portion 32 located inside the housing 1 and a first portion 31 located outside the housing 1. The first portion 31 typically passes through the upper cover plate 11 to be located outside the housing 1. The positive terminal tab is electrically connected to the second portion 32 of the positive terminal 3, and the negative terminal tab is electrically connected to the second portion 32 of the negative terminal 4. In this way, the electrical energy of the electrode group 2 can be delivered to the outside of the housing 1 through the positive terminal 3 and the negative terminal 4. The positive terminal 3 and the positive terminal tab, and the negative terminal 4 and the negative terminal tab are fixedly electrically connected. Specific fixing methods can include laser welding, brazing, ultrasonic welding, etc.

[0047] This application embodiment illustrates a specific example where the positive terminal 3 and the negative terminal 4 are located on top of the battery cell 100. Typically, the upper cover plate 11 has two mounting through holes, respectively positioned opposite the positive terminal 3 and the negative terminal 4. The first portion 31 of the positive terminal 3 and the first portion 31 of the negative terminal 4 protrude from the two mounting through holes. The gap between the positive terminal 3 or the negative terminal 4 and the corresponding mounting through hole needs to be sealed using a sealing component to prevent air leakage, thereby preventing the internal environment of the casing from affecting the operation of the electrode assembly 2 inside the housing 1. The sealing component can be a sealing ring, which is fitted onto the positive terminal 3 and the negative terminal 4. The sealing ring can seal the gap between the mounting through hole of the upper cover plate 11 and the corresponding terminal. The sealing ring can be an elastic sealing ring such as a fluororubber sealing ring, or it can be a rigid material sealing ring, such as a ceramic sealing ring.

[0048] Although specific structures such as sealing rings and electrode tabs are not shown in the accompanying drawings, this does not prevent those skilled in the art from understanding and implementing the technical content described above in this application.

[0049] The shapes of the positive terminal 3 and the negative terminal 4 can be determined according to the specific product. For example, the positive terminal 3 and the negative terminal 4 can be cylindrical, or they can be other shapes, such as polygonal columns.

[0050] In this embodiment, the battery cell 100 also includes a connector. Each first part 31 is electrically connected to a connector, meaning that the positive terminal 3 is electrically connected to a connector, and the negative terminal 4 is also electrically connected to a connector. The connector and the terminal to which it is electrically connected can be integrally formed. The connector and the terminal to which it is electrically connected can also be fixedly connected, i.e., the connector and the terminal to which they are electrically connected are separate structures, fixed together as a whole by other processes. The connector and the terminal can be fixedly connected by riveting, welding, screwing, or interference fitting. For example, the first part 31 of the positive terminal 3 or the negative terminal 4 is provided with a riveting groove, and the connector is riveted into the riveting groove. The riveting process is relatively simple.

[0051] In this embodiment, the connector also has good conductivity. The materials of the positive terminal 3, the negative terminal 4, and the connector can be the same or different. The materials of the positive terminal 3, the negative terminal 4, and the connector can be single-component materials, such as copper or aluminum, which have good conductivity, or composite materials with different components, such as copper or aluminum, which have good conductivity, as long as good conductivity can be achieved.

[0052] In this embodiment, both the positive terminal 3 and the negative terminal 4 have connectors, allowing one cell 100 to be directly electrically connected to a corresponding connector on another cell 100 via these connectors. For the sake of brevity in describing the technical solution, this application defines the connector on the positive terminal 3 as the first connector 5 and the connector on the negative terminal 4 as the second connector 6. Please refer to... Figure 5 The first connector 5 on the positive terminal 3 of the first battery cell 101 is directly electrically connected to the second connector 6 on the negative terminal 4 of the second battery cell 102. Normally, the two connectors are directly and fixedly electrically connected.

[0053] Compared to the current technology that uses a busbar to achieve electrical connection between the terminals of two battery cells 100, in this embodiment, both the positive terminal 3 and the negative terminal 4 are electrically connected to connectors. The two connectors of the two battery cells 100 can be directly electrically connected to achieve electrical connection between the two battery cells 100, eliminating the need for a busbar and wiring harness isolation plate. This reduces the space occupied in the height direction of the battery cells 100, which is beneficial for increasing the height of the battery cells 100 and thus increasing the energy density of the battery pack. Furthermore, when the battery cells 100 are assembled, the positions of the connectors are also determined simultaneously. Only the two connectors with electrical connection need to be fixed, simplifying assembly and reducing production costs.

[0054] In addition, for battery packs that use a top cooling solution for cell 100, the cooling energy of the heat dissipation components can quickly reach cell 100, improving the efficiency of the heat dissipation components in cooling cell 100.

[0055] In this embodiment, the connector is provided with a contact portion. Two connectors abut against each other through these contact portions to achieve electrical connection. The contact area is relatively large, resulting in high reliability of the electrical connection. In a specific example, the connectors in two battery cells 100 that are connected can be electrically connected by welding, which offers high reliability. Figure 4 and Figure 5 For example, the first connector 5 on the positive terminal 3 of the first battery cell 101 and the second connector 6 on the negative terminal 4 of the second battery cell 102 are connected by welding. In this embodiment, the two connectors are fixed by welding, which is a simple process and a reliable fixation.

[0056] In one embodiment, a contact portion is disposed on a first surface or a second surface of the connector, and the first and second surfaces are arranged along the height direction of the battery cell 100. When two directly electrically connected connectors are welded, the contact portions of the two connectors overlap and are welded together. Please refer to... Figure 5 and Figure 6It is understood that the contact portion of the first connector 5 on the positive terminal 3 of the first cell 101 is located on the first surface, and the contact portion of the second connector 6 on the negative terminal 4 of the second cell 102 is located on the second surface. The first surface is the surface facing upwards (the surface away from the housing 1), and the second surface is the surface facing downwards (the surface towards the housing 1). Of course, it is also feasible for the contact portion of the first connector 5 on the positive terminal 3 to be located on the second surface, and the contact portion of the second connector 6 on the negative terminal 4 to be located on the first surface.

[0057] In this embodiment, the two directly electrically connected connectors are stacked and welded together to form a single unit, resulting in high reliability. The length L1 of the contact portion can be reasonably selected based on the reliability of the welded fixation.

[0058] After the corresponding connectors of the first battery cell 101 and the second battery cell 102 are welded, in order to minimize the height of the welding position, the embodiments of this application also make the following settings.

[0059] In this embodiment, the first or second surface has a recessed surface, and the contact portion is at least a part of the recessed surface; that is, the contact portion can be the entire recessed surface or a part of the recessed surface. In two directly electrically connected connectors, the recessed surface of one is located on the first surface, and the recessed surface of the other is located on the second surface. For the sake of simplicity in describing the technical solution, this application defines the recessed surface on the first connector 5 as the first recessed surface 51, and the recessed surface on the second connector 6 as the second recessed surface 61, as follows... Figure 6 As shown, the depth H1 of the recessed surface 51 on the first connector 5 on the positive terminal 3 of the first cell 101 is basically equal to the depth H2 of the recessed surface 61 on the second connector 6 on the negative terminal 4 of the second cell 102. In this way, after the first connector 5 of the first cell 101 and the second connector 6 of the second cell 102 are welded, the thickness at the welding position will not increase.

[0060] In this embodiment, the recessed surface 51 of the first connector 5 is located on the first surface of the first connector 5, and the recessed surface 61 of the second connector 6 is located on the second surface of the second connector 6. This allows for quick differentiation of the positive terminal 3 and the negative terminal 4 of the battery cell 100 by varying the positions of the recessed surfaces, thus preventing incorrect assembly of the battery cell 100.

[0061] In the above embodiments, the connector extends radially along the positive terminal 3 or the negative terminal 4. Specifically, the length of the recessed surface on the connector is configured to extend to and support the casing of the adjacent cell. Figure 5 and Figure 6As can be seen, the recessed surface 51 of the first connector 5 of the first battery cell 101 is located above the housing 1 of the second battery cell and can be directly or indirectly supported by the housing 1 of the second battery cell. Similarly, the recessed surface 61 of the second connector 6 of the second battery cell 102 also extends partially above the housing 1 of the first battery cell and can be supported by the housing 1 of the first battery cell 101. When installed in this way, the second connector 6 of the second battery cell 102 can extend above the housing 1 of the first battery cell 101, and the housing 1 of the first battery cell 101 can support the end of the second connector 6. Similarly, the first connector 5 of the first battery cell 101 can extend above the housing 1 of the second battery cell 102, and the housing 1 of the second battery cell 102 can support the end of the first connector 5. Thus, the housing 1 can provide a certain degree of support for the two connectors after connection, which helps to improve the overall strength. Of course, the support between the connector and the housing can be an insulating support, and an insulating material layer can be further provided between them to improve the insulation performance.

[0062] In another embodiment, the first connector 5 and the second connector 6 can be end-face welded, that is, the contact portion is located on the end face of the connector. The welding between the first connector 5 on the positive terminal 3 of the first battery cell 101 and the second connector 6 on the negative terminal 4 of the second battery cell 102 can also be performed in the following manner: Please refer to... Figure 8 and Figure 9 The end faces of the first connector 5 and the second connector 6 are fixed together by welding. Specifically, the first connector 5 has a first end face 52, and the second connector 6 has a second end face 62. The first end face 52 and the second end face 62 are approximately vertical surfaces, and they are fitted together and fixedly connected by welding. In this embodiment, the structure of the first connector 5 and the second connector 6 is relatively simple.

[0063] Of course, the first connector 5 and the second connector 6 can also be other structures, as long as the welding between the two is reliable.

[0064] In another specific embodiment, the end of the connector away from the first portion 31 is provided with a socket or a plug-in body. For example, the first connector 5 on the positive terminal 3 of the first battery cell 101 and the second connector 6 on the negative terminal 4 of the second battery cell 102 have a socket on one end and a plug-in body on the other, and the plug-in body can be inserted into the socket. The number of sockets can be one or more. Correspondingly, the shape and number of plug-in bodies depend on the shape and number of sockets. The plug-in body can be in the form of a pin or a plug block.

[0065] In this embodiment of the application, the connector extends along the stacking direction x of the battery cell 100, such as... Figure 2 and Figure 7As shown, the connectors that connect adjacent cells 100 in the same cell 100 assembly extend along the x-direction.

[0066] Of course, the extension direction of the connector can also be at an angle to the stacking direction of the battery cells 100, please refer to [link / reference]. Figure 7 The first connector 5 and the second connector 6, which are directly electrically connected at point B (circled in the image), extend along the y-direction between the two battery cell 100 assemblies. The y-direction is approximately perpendicular to the x-direction. Of course, depending on the arrangement of the two rows of battery cell 100 assemblies, the extension direction of the extension segment may not be perpendicular to the x-direction, and the included angle between them may be acute or obtuse.

[0067] The connector in this embodiment can be a plate with a predetermined thickness, resulting in a simple structure. Of course, the connector can also be a column or a conductor of other shapes.

[0068] This application also provides a vehicle, which includes a vehicle body and is provided with the battery cell 100 described in any of the above embodiments, or / and the battery pack described above.

[0069] The battery pack and vehicle in this embodiment have the aforementioned battery cell 100, and therefore the battery pack and vehicle also have the aforementioned technical effects of the battery cell 100.

[0070] For other structures of the battery pack, please refer to the current technology; this application will not elaborate further.

[0071] In the description of embodiments of this application, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus.

[0072] In the embodiments of this application, "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship.

[0073] This document uses specific examples to illustrate the principles and implementation methods of this application. The descriptions of the embodiments above are only for the purpose of helping to understand the method and core ideas of this application. It should be noted that those skilled in the art can make several improvements and modifications to this application without departing from the principles of this application, and these improvements and modifications also fall within the protection scope of the claims of this application.

Claims

1. A battery cell, characterized in that, include: case; The positive terminal and the negative terminal, both having a first portion located outside the housing; Each of the first portions is electrically connected to the connector, and the two battery cells are directly electrically connected through the connectors provided on them.

2. The battery cell according to claim 1, characterized in that, The connector is provided with a contact portion, and the contact portions of two connectors abut against each other to achieve electrical connection.

3. The battery cell according to claim 2, characterized in that, The contact portion is disposed on the first surface or the second surface of the connector, and the contact portions of the two directly electrically connected connectors overlap and abut against each other, with the first surface and the second surface arranged along the height direction of the battery cell.

4. The battery cell according to claim 3, characterized in that, The first surface or the second surface has a recessed surface, the contact portion is at least a portion of the recessed surface, and the recessed surface of one of the two directly electrically connected connectors is located on the first surface, and the recessed surface of the other is located on the second surface.

5. The battery cell according to claim 4, characterized in that, The connector on the positive terminal is defined as the first connector, and the connector on the negative terminal is defined as the second connector. The recessed surface of the first connector is located on the first surface of the first connector, and the recessed surface of the second connector is located on the second surface of the second connector.

6. The battery cell according to claim 4 or 5, characterized in that, The length of the recessed surface is configured to extend to and support the housing of the adjacent battery cell.

7. The battery cell according to claim 2, characterized in that, The contact portion is located on the end face of the connector away from the first portion.

8. The battery cell according to claim 1, characterized in that, The end of the connector away from the first part is provided with a socket or plug to enable direct electrical connection between the two connectors.

9. The battery cell according to any one of claims 1 to 5, 7 and 8, characterized in that, The connector extends along the stacking direction of the battery cells, or the extension direction of the connector forms an angle with the stacking direction of the battery cells.

10. A battery pack, characterized in that, It includes several battery cells as described in any one of claims 1 to 9, wherein each of the battery cells is electrically connected via each of the connectors.

11. A vehicle, comprising a vehicle body, characterized in that, The vehicle body is provided with the battery cell as described in any one of claims 1 to 9, or / and the battery pack as described in claim 10.

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