End plate, battery pack and vehicle

Abstract

The end plate comprises an end plate main body and a heat preservation layer, the end plate main body is provided with a battery cell connecting surface and a cavity structure, the cavity structure is filled with a heat insulation medium, the heat preservation layer and the end plate main body are arranged in a stacked mode, and the heat preservation layer is located on the side, away from the battery cell connecting surface, of the end plate main body. According to the battery pack disclosed by the embodiment of the utility model, the heat insulation performance of the battery cells at the end parts in a low-temperature environment can be improved through the double heat insulation effects of the heat insulation medium and the heat insulation layer in the cavity structure, so that the heat insulation performance of the whole battery pack in the low-temperature environment can be improved.

Description

Technical Field

[0001] This utility model relates to the field of battery pack technology, and in particular to an end plate, a battery pack, and a vehicle. Background Technology

[0002] A battery pack includes cell packs, a housing, etc. In related technologies, end plates are usually connected to both ends of the cell packs. After the cell packs are connected to the end plates, they are fixed together into the housing.

[0003] In the battery pack, one side of the end plate is in contact with the large surface of the end cell, and the other side of the end plate is in contact with the expansion beam in the housing through adhesive.

[0004] However, when the ambient temperature is low, the cells at the end will transfer heat to the expansion beam through the end plate, and then to other areas of the battery pack through the expansion beam, eventually dissipating the heat into the environment. This results in poor heat preservation performance of the cells at the end, which in turn leads to poor heat preservation performance of the entire battery pack. Utility Model Content

[0005] This utility model provides an end plate, a battery pack, and a vehicle, aiming to at least solve the technical problem of poor thermal insulation performance of the end cells in low-temperature environments in the prior art.

[0006] In a first aspect of this utility model, an end plate is provided, comprising:

[0007] The end plate body has a cell connection surface and a cavity structure, and the cavity structure is filled with a heat insulation medium.

[0008] The insulation layer is stacked on top of the end plate body, and the insulation layer is located on the side of the end plate body away from the cell connection surface.

[0009] Optionally, the end plate body also has an insulation layer connection surface opposite to the cell connection surface, and the cavity structure includes a plurality of holes formed on the insulation layer connection surface.

[0010] Optionally, the cavity structure includes a buffer cavity formed on the cell connection surface.

[0011] Optionally, the insulation layer is an aerogel insulation layer;

[0012] And / or, the thickness of the insulation layer is greater than or equal to 0.5 mm and less than or equal to 10 mm.

[0013] Optionally, the insulation layer is bonded to the end plate body.

[0014] Optionally, the cross-sectional area of ​​several of the holes accounts for 50%-80% of the area of ​​the connection surface of the insulation layer;

[0015] And / or, the thickness of the hole is greater than or equal to 5% of the thickness of the end plate body, and less than or equal to 20% of the thickness of the end plate body.

[0016] Optionally, the hole is circular in shape;

[0017] The diameter of the hole is greater than or equal to 1 mm and less than or equal to 20 mm.

[0018] Optionally, the cross-sectional area of ​​the buffer cavity accounts for 50%-90% of the area of ​​the cell connection surface;

[0019] And / or, the thickness of the buffer cavity is greater than or equal to 5% of the thickness of the end plate body, and less than or equal to 80% of the thickness of the end plate body.

[0020] In a second aspect of this invention, a battery pack is also provided, including a cell assembly and an end plate as described above connected to an end of the cell assembly.

[0021] In a third aspect of this invention, a vehicle is also provided, including the battery pack described above.

[0022] In this embodiment of the utility model, on the one hand, the cavity structure is filled with a heat insulation medium, so that the cavity structure can play a role in heat insulation. On the other hand, the heat insulation layer itself plays a role in heat insulation. Through the dual heat insulation effect of the heat insulation medium in the cavity structure and the heat insulation layer, the heat insulation performance of the end cell in low temperature environment can be improved, thereby improving the heat insulation performance of the entire battery pack in low temperature environment. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below.

[0024] Figure 1 This is a three-dimensional structural diagram of the end plate provided in the embodiment of this utility model;

[0025] Figure 2 This is a cross-sectional view of the end plate provided in an embodiment of the present utility model.

[0026] Figure 3 This is a schematic diagram of the structure of the end plate body in the embodiment of this utility model.

[0027] Figure label:

[0028] 1-End plate body, 11-Cell connection surface, 12-Insulation layer connection surface, 13-Hole, 14-Buffer cavity, 2-Insulation layer. Detailed Implementation

[0029] The technical solutions of the present invention will now be described with reference to the accompanying drawings in the embodiments of the present invention.

[0030] The embodiments described herein are for illustrative purposes only and are not intended to limit the scope of the invention. The invention will be described more specifically in the following paragraphs by way of example with reference to the accompanying drawings. It should be noted that the drawings are in a very simplified form and use non-precise proportions, and are only used to facilitate and clarify the illustration of the embodiments of the invention.

[0031] Currently, in battery packs, one side of the end plate is in contact with the large surface of the end cells, while the other side of the end plate is in contact with the expansion beam in the housing via adhesive. However, at low ambient temperatures, the end cells transfer heat through the end plate to the expansion beam, and then through the expansion beam to other areas of the housing, ultimately dissipating the heat into the environment. This results in poor insulation performance of the end cells, leading to poor insulation performance of the entire battery pack. To address these issues, this invention provides an end plate, a battery pack, and a vehicle, which are described in detail below.

[0032] Firstly, referring to Figures 1 to 3 The end plate provided in this embodiment of the utility model includes an end plate body 1 and a heat insulation layer 2. The end plate body 1 has a cell connection surface 11 and a cavity structure. The cavity structure is filled with a heat insulation medium. The heat insulation layer 2 is stacked with the end plate body 1, and the heat insulation layer 2 is located on the side of the end plate body 1 away from the cell connection surface 11.

[0033] End plates are used to connect to the ends of the battery cell assembly along its length. A battery cell assembly is typically formed by stacking multiple cells along its length. The battery cell assembly is used in a battery pack, which includes a housing. The end plates serve to absorb the expansion forces of the cells and facilitate heat transfer between the cells and the housing.

[0034] The cavity structure refers to one or more hollow chambers formed on the end plate body 1. These hollow chambers can be completely sealed or connected to the outside. The cavity structure can be a single large chamber or composed of multiple small chambers. The insulating medium filling the cavity structure is preferably air. After the end plate body 1 is manufactured, air from the environment enters the cavity structure, thus filling it with air. In other embodiments, the insulating medium filling the cavity structure can be a liquid material or a solid material, such as aerogel or flame-retardant polyurethane foam.

[0035] The cell connecting surface 11 in the end plate body 1 is used to connect with the end of the cell assembly. Specifically, the cell connecting surface 11 is used to adhere to the end of the cell assembly. The end plate body 1 can be made of an insulating material, such as plastic. When the end plate body 1 is made of an insulating material, it has electrical insulation properties and better heat insulation performance compared to metal materials.

[0036] The thickness of the end plate body 1 can be 1mm-10mm, and the thickness of the insulation layer 2 can be 0.5mm-10mm. The insulation layer 2 is used to connect with the expansion beam in the box. The insulation layer 2 can be an aerogel insulation layer, a flame-retardant polyurethane foam insulation layer, a rock wool insulation layer, etc. The connection method between the end plate body 1 and the insulation layer 2 can be adhesive bonding, snap-fitting, hot-melt welding, etc.

[0037] The insulation layer 2 can be a single layer structure, or it can be composed of multiple strip structures. When the insulation layer 2 is composed of multiple strip structures, the multiple strip structures can be arranged at intervals along the length direction of the end plate body 1, or they can be arranged at intervals along the width direction of the end plate body 1.

[0038] The shape and size of the insulation layer 2 are preferably matched with the shape and size of the end plate body 1. For example, when the shape of the end plate body 1 is square, the shape of the insulation layer 2 is square, the length of the insulation layer 2 is equal to the length of the end plate body 1, and the width of the insulation layer 2 is equal to the width of the end plate body 1.

[0039] In this embodiment of the invention, on the one hand, the cavity structure is filled with a heat-insulating medium, thereby enabling the cavity structure to perform a heat insulation function. On the other hand, the heat insulation layer 2 itself also performs a heat insulation function. Through the dual heat insulation effect of the heat-insulating medium inside the cavity structure and the heat insulation layer 2, the heat insulation performance of the end cells in low-temperature environments can be improved, thereby improving the heat insulation performance of the entire battery pack in low-temperature environments. When the heat-insulating medium filling the cavity structure is air, the air inside the cavity structure is a good heat-insulating medium, thus enabling the cavity structure to perform a heat insulation function.

[0040] In an optional embodiment of the present invention, the end plate body 1 further has a heat insulation layer connecting surface 12 opposite to the cell connecting surface 11, and the cavity structure includes a plurality of holes 13 formed on the heat insulation layer connecting surface 12.

[0041] The cell connection surface 11 and the insulation layer connection surface 12 are opposite each other along the thickness direction of the end plate body 1. The insulation medium filled in the hole 13 can be air, liquid material, or solid material, such as aerogel, flame-retardant polyurethane foam, etc. The insulation medium filled in the hole 13 is preferably air. The shape of the hole 13 can be circular, elliptical, triangular, square, polygonal, etc.

[0042] The holes 13 are arranged in multiple rows and columns, with the rows parallel to the length of the end plate body 1 and the columns parallel to the width of the end plate body 1. The number of rows of holes 13 can be 2-8, and the number of columns can be 2-15. In this embodiment, the arrangement of the holes 13 ensures the thermal insulation performance of the end plate. Furthermore, compared to a large cavity, it avoids excessively weakening the structural strength of the end plate, thus ensuring its structural strength.

[0043] In an optional embodiment of the present invention, the cavity structure includes a buffer cavity 14 formed on the cell connection surface 11.

[0044] The buffer cavity 14 is used to reserve a certain space for the expansion of the battery cell, so as to buffer the expansion of the battery cell. After the battery cell expands, the expanded part can extend into the buffer cavity 14 so that the end plate can bear a certain amount of the expansion force of the battery cell. The shape of the cross-section of the buffer cavity 14 perpendicular to the thickness direction of the end plate body 1 can be square, square with rounded corners, trapezoid, rhombus, ellipse, circle, etc. The geometric center of the buffer cavity 14 is preferably aligned with the geometric center of the end plate body 1, that is, the buffer cavity 14 is opened in the middle of the battery cell connection surface 11.

[0045] The insulating medium filled in the buffer cavity 14 is preferably air. In this embodiment, on the one hand, the buffer cavity 14 can reserve a certain space for the expansion of the battery cell to buffer the expansion of the battery cell; on the other hand, the air inside the buffer cavity 14 is a good insulating medium, and the buffer cavity 14 can also play a role in heat preservation.

[0046] Preferably, the cavity structure includes both a plurality of holes 13 formed on the insulation layer connection surface 12 and a buffer cavity 14 formed on the cell connection surface 11. The holes 13 may be connected to the buffer cavity 14, or they may not be connected to the buffer cavity 14. After the cell expands, it may fill the buffer cavity 14. In this case, although the buffer cavity 14 does not provide thermal insulation, the holes 13 still provide thermal insulation to ensure the thermal insulation performance of the cell at the end after the cell expands and fills the buffer cavity 14.

[0047] In one optional embodiment of this utility model, the insulation layer 2 is an aerogel insulation layer; and / or, the thickness of the insulation layer 2 is greater than or equal to 0.5 mm and less than or equal to 10 mm.

[0048] Preferably, the thickness of the insulation layer 2 is less than the thickness of the end plate body 1. The thickness of the insulation layer 2 can be 0.5mm, 1mm, 2mm, 3mm, 5mm, etc. Aerogel insulation layers have low thermal conductivity, meaning they offer lower thermal conductivity. At the same thickness, aerogel insulation layers can provide superior thermal insulation performance. Aerogel insulation layers have low density, which is beneficial for the lightweight design of the end plate. Aerogel insulation layers also have excellent high-temperature resistance and fire resistance. When the thickness of the insulation layer 2 is within the above-mentioned range, thermal insulation performance can be guaranteed, while also helping to control material costs.

[0049] In an optional embodiment of this utility model, the insulation layer 2 is bonded to the end plate body 1. Specifically, the insulation layer 2 is bonded to the end plate body 1 using an adhesive, such as a liquid adhesive or double-sided adhesive strip. Bonding the insulation layer 2 to the end plate body 1 improves the bonding strength between the insulation layer 2 and the end plate body 1.

[0050] In an optional embodiment of this utility model, the cross-sectional area of ​​a plurality of holes 13 accounts for 50%-80% of the area of ​​the insulation layer connection surface 12; and / or, the thickness of the holes 13 is greater than or equal to 5% of the thickness of the end plate body 1, and less than or equal to 20% of the thickness of the end plate body 1.

[0051] The cross-sectional area of ​​the plurality of holes 13 is the sum of the areas of all the cross-sections of the holes 13 perpendicular to the thickness direction of the end plate body 1. Specifically, the cross-sectional area of ​​the plurality of holes 13 accounts for 50%, 60%, 70%, 80%, etc., of the area of ​​the insulation layer connection surface 12. Let T represent the thickness of the end plate body 1, then the thickness of the holes 13 can be 5%T, 10%T, 12%T, 15%T, 20%T, etc. Preferably, the thickness of the holes 13 is less than the thickness of the buffer cavity 14. When the proportion of the cross-sectional area of ​​the plurality of holes 13 to the area of ​​the insulation layer connection surface 12 is within the above range, the thermal insulation effect of the end plate can be effectively improved.

[0052] In an optional embodiment of this utility model, the hole 13 is circular in shape; the diameter of the hole 13 is greater than or equal to 1 mm and less than or equal to 20 mm. The diameter of the hole 13 can be 1 mm, 3 mm, 5 mm, 10 mm, 15 mm, 20 mm, etc. When the hole 13 is circular, the structure is simple and easy to process.

[0053] In an optional embodiment of this utility model, the cross-sectional area of ​​the buffer cavity 14 accounts for 50%-90% of the area of ​​the cell connection surface 11; and / or, the thickness of the buffer cavity 14 is greater than or equal to 5% of the thickness of the end plate body 1, and less than or equal to 80% of the thickness of the end plate body 1.

[0054] The cross-sectional area of ​​the buffer cavity 14 is the area of ​​the cross-section of the buffer cavity 14 perpendicular to the thickness direction of the end plate body 1. Specifically, the cross-sectional area of ​​the buffer cavity 14 accounts for 50%, 60%, 70%, 80%, 90%, etc., of the area of ​​the cell connection surface 11. When the proportion of the cross-sectional area of ​​the buffer cavity 14 to the area of ​​the cell connection surface 11 is within the above range, sufficient space can be reserved for cell expansion, the buffer cavity 14 has good thermal insulation effect, and it can ensure effective connection between the end plate and the end of the cell assembly. Let T represent the thickness of the end plate body 1, then the thickness of the buffer cavity 14 can be 5%T, 40%T, 50%T, 60%T, 80%T, etc.

[0055] Secondly, this utility model provides a battery pack, which includes a cell assembly and an end plate connected to the end of the cell assembly. The end plate includes an end plate body 1 and a heat insulation layer 2. The end plate body 1 has a cell connection surface 11 and a cavity structure. The cavity structure is filled with a heat insulation medium. The heat insulation layer 2 is stacked with the end plate body 1, and the heat insulation layer 2 is located on the side of the end plate body 1 away from the cell connection surface 11.

[0056] The battery cell assembly has two end plates connected to its two ends along its length. The battery cell assembly is typically formed by stacking multiple battery cells along its length. The cell connection surface 11 in the end plate can be bonded to the end of the battery cell assembly. Specifically, the cell connection surface 11 is bonded to the end of the battery cell assembly using an adhesive, such as a liquid adhesive or double-sided tape. When the end plate and battery cell assembly are assembled, the geometric center of the end plate is preferably aligned with the geometric center of the battery cell at the end.

[0057] In this embodiment of the present invention, on the one hand, the cavity structure is filled with a heat insulation medium, so that the cavity structure can play a role in heat insulation. On the other hand, the heat insulation layer 2 itself plays a role in heat insulation. Through the dual heat insulation effect of the heat insulation medium in the cavity structure and the heat insulation layer 2, the heat insulation performance of the end cell in low temperature environment can be improved, thereby improving the heat insulation performance of the entire battery pack in low temperature environment.

[0058] The battery pack also includes a housing, which includes an expansion beam. After the cell assembly and end plate are connected, they are placed together and fixed into the housing. After the cell assembly and housing are fixed, the end plate and expansion beam are bonded together with potting compound.

[0059] Thirdly, this utility model embodiment also provides a vehicle including the battery pack provided in the second aspect above.

[0060] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, 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. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0061] It should be noted that when a component is described as "fixed to" another component, it can be directly on the other component or may have a component in between. When a component is considered "connected to" another component, it can be directly connected to the other component or may have a component in between. When a component is considered "set on" another component, it can be directly set on the other component or may have a component in between. The terms "vertical," "horizontal," "left," "right," and similar expressions used in this document are for illustrative purposes only.

[0062] The various embodiments in this specification are described in a related manner. Similar or identical parts between embodiments can be referred to mutually. Each embodiment focuses on describing the differences from other embodiments. In particular, the system embodiments are basically similar to the method embodiments, so the description is relatively simple; relevant parts can be referred to the descriptions of the method embodiments.

[0063] The above are merely preferred embodiments of this utility model and are not intended to limit the scope of protection of this utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model are included within the scope of protection of this utility model.

[0064] The end plate, battery pack, and vehicle provided by this utility model have been described in detail above. Specific examples have been used to illustrate the principle and implementation of this utility model. The description of the above embodiments is only for the purpose of helping to understand the structure and core idea of ​​this utility model. At the same time, for those skilled in the art, there will be changes in the specific implementation and application scope based on the idea of ​​this utility model. Therefore, the content of this specification should not be construed as a limitation of this utility model.

Claims

1. An end plate, characterized in that, include: The end plate body has a cell connection surface and a cavity structure, and the cavity structure is filled with a heat insulation medium. The insulation layer is stacked on top of the end plate body, and the insulation layer is located on the side of the end plate body away from the cell connection surface.

2. The end plate according to claim 1, characterized in that, The end plate body also has an insulation layer connection surface opposite to the cell connection surface, and the cavity structure includes a plurality of holes formed on the insulation layer connection surface.

3. The end plate according to claim 1 or 2, characterized in that, The cavity structure includes a buffer cavity formed on the cell connection surface.

4. The end plate according to claim 1, characterized in that, The insulation layer is an aerogel insulation layer; And / or, the thickness of the insulation layer is greater than or equal to 0.5 mm and less than or equal to 10 mm.

5. The end plate according to claim 1, characterized in that, The insulation layer is bonded to the end plate body.

6. The end plate according to claim 2, characterized in that, The cross-sectional area of ​​several of the holes accounts for 50%-80% of the area of ​​the connection surface of the insulation layer; And / or, the thickness of the hole is greater than or equal to 5% of the thickness of the end plate body, and less than or equal to 20% of the thickness of the end plate body.

7. The end plate according to claim 2, characterized in that, The hole is circular in shape; The diameter of the hole is greater than or equal to 1 mm and less than or equal to 20 mm.

8. The end plate according to claim 3, characterized in that, The cross-sectional area of ​​the buffer cavity accounts for 50%-90% of the area of ​​the cell connection surface; And / or, the thickness of the buffer cavity is greater than or equal to 5% of the thickness of the end plate body, and less than or equal to 80% of the thickness of the end plate body.

9. A battery pack, characterized in that, It includes a cell assembly and an end plate as described in any one of claims 1 to 8 connected to the end of the cell assembly.

10. A vehicle, characterized in that, Includes the battery pack as described in claim 9.

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