A battery pack and an electric device

Abstract

The application discloses a battery pack and an electric device, and belongs to the technical field of battery heating. The battery pack comprises battery monomers and a heating piece. The battery monomers have a first direction, a second direction and a third direction which intersect with each other. The battery monomers have a first surface oppositely arranged along the first direction and a second surface oppositely arranged along the second direction. The area of the first surface is larger than that of the second surface. A plurality of battery monomers are arranged along the first direction. The heating piece is arranged on the first surface of the battery monomers. The heating piece is provided with a hollow part in the center, and the hollow part penetrates through the heating piece. Through the above technical scheme, the hollow part is additionally arranged in the center of the heating piece, so that the influence of the expansion force caused by the center deformation of the battery monomers on the heating piece can be reduced during the use of the battery pack, the service life of the battery pack is prolonged, and the heating piece can be tightly combined with the battery monomers.

Description

Technical Field

[0001] This application relates to the field of battery heating technology, and more particularly to a battery pack and electrical device. Background Technology

[0002] Under low-temperature conditions, the performance of lithium-ion power batteries faces severe challenges. Specifically, the charging rate of the cells is significantly reduced at low temperatures, and some cells cannot be charged below 0°C. Furthermore, low-temperature charging poses serious safety hazards, as lithium plating is highly likely to occur at the negative electrode. When the deposited lithium metal crystals form lithium dendrites, they can penetrate the separator, causing an internal short circuit in the power battery and potentially triggering catastrophic accidents such as thermal runaway. To ensure the charging speed and safe operation of the cells in low-temperature environments, the power batteries must undergo preheating treatment to reach a suitable operating temperature.

[0003] Currently, heating film solutions, as a low-cost heating method, are still commonly used as heating elements for battery cells. However, during long-term charge-discharge cycles, lithium batteries undergo significant deformation in both length and width directions due to volume changes in the electrode materials. This expansion force acting on the surface heating film may lead to the risk of the film peeling off from the battery surface. Once the heating film experiences localized delamination due to expansion stress, the area detached from the battery surface will experience dry burning due to the loss of heat conduction medium. As the temperature in the dry-burning area continues to rise, when it exceeds the heat resistance limit of the adhesive, the bonding strength between the adhesive layer and the battery will decrease sharply, making it difficult to withstand the mechanical stress generated by battery deformation. This, in turn, leads to large-area delamination of the heating film, creating a vicious cycle. Utility Model Content

[0004] This application provides a battery pack and an electrical device, which aims to reduce the impact of expansion force caused by the deformation of the center of the battery cell on the heating element during the use of the battery pack, extend the service life of the battery pack, and ensure that the heating element can be tightly attached to the battery cell.

[0005] To achieve the above objectives, according to a first aspect of this application, a battery pack is provided, comprising:

[0006] A single battery cell has a first direction, a second direction, and a third direction that intersect each other in pairs. The single battery cell has a first surface that is opposite to each other along the first direction and a second surface that is opposite to each other along the second direction. The area of ​​the first surface is larger than the area of ​​the second surface. A plurality of the single battery cells are arranged along the first direction.

[0007] A heating element is disposed on the first side of the battery cell, and a hollow portion is provided in the center of the heating element, the hollow portion extending through the heating element.

[0008] Optionally, the hollowed-out portion can be one or more of a rectangular, square, circular, or porous structure.

[0009] Optionally, the outer contour of the heating element coincides with the outer contour of the first surface.

[0010] Optionally, the area of ​​the hollow portion accounts for 20%-30% of the area of ​​the heating element.

[0011] Optionally, the heating element is provided with a first terminal and a second terminal, the first terminals of two adjacent heating elements are attached to each other, and the second terminals of two adjacent heating elements are attached to each other.

[0012] Optionally, both the first terminal and the second terminal are disposed along the second direction.

[0013] Optionally, the battery pack further includes a first wiring harness and a second wiring harness, wherein the first wiring harness is used to connect the first terminals that are attached to each other, and the second wiring harness is used to connect the second terminals that are attached to each other.

[0014] Optionally, the battery pack further includes a heat insulation component located between two adjacent battery cells and sandwiched between two adjacent heating components.

[0015] Optionally, the outer contour of the heat insulation element coincides with the outer contour of the heating element.

[0016] According to a second aspect of this application, an electrical device is provided, including the aforementioned battery pack.

[0017] In the battery pack of this application embodiment, by using the above technical solution, the heating element is set on the first side of the battery cell with a larger side area. This not only increases the heating area of ​​the battery cell and improves the heating efficiency of the battery cell, but also reduces the impact of the expansion force caused by the deformation of the battery cell center on the heating element during battery pack use by adding a through-hole portion in the center of the heating element. This extends the service life of the battery pack, ensures that the heating element can be tightly attached to the battery cell, reduces the risk of the heating element peeling off from the battery cell due to the expansion force, avoids the phenomenon of dry burning caused by local delamination between the heating element and the battery cell, and further prevents the heating element from temperature rising due to local dry burning. This solves the problem of large-area delamination in the bonding area between the heating element and the battery cell.

[0018] Other features and advantages of this application will be described in detail in the following detailed description section. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] To gain a more complete understanding of this application and its beneficial effects, the following description will be provided in conjunction with the accompanying drawings, wherein the same reference numerals in the following description denote the same parts.

[0021] Figure 1 This is a schematic diagram of the overall structure of the battery pack provided in an exemplary embodiment of this disclosure;

[0022] Figure 2 This is a partial exploded structural diagram of the battery pack provided in an exemplary embodiment of this disclosure;

[0023] Figure 3 This is a schematic diagram of the structure of the heating element provided in an exemplary embodiment of this disclosure;

[0024] Figure 4 yes Figure 1 An enlarged schematic diagram of part A in the middle;

[0025] Figure 5 yes Figure 4 Enlarged schematic diagram of part B in the middle;

[0026] Figure 6 This is a schematic diagram of the structure of the heat insulation component provided in an exemplary embodiment of this disclosure.

[0027] Explanation of reference numerals in the attached figures:

[0028] 100, Battery cell; 101, First side; 102, Second side; 200, Heating element; 201, Hollowed-out portion; 210, First terminal; 220, Second terminal; 300, First wiring harness; 400, Second wiring harness; 500, Heat insulation element; 501, Recessed portion; X, First direction; Y, Second direction; Z, Third direction. Detailed Implementation

[0029] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the protection scope of this application.

[0030] According to the first aspect of this application, referring to Figures 1 to 3This disclosure provides a battery pack including individual battery cells 100 and heating elements 200. The battery pack includes multiple individual battery cells 100 and multiple heating elements 200. The individual battery cells 100 are cubic in shape. The heating elements 200 have a heating film structure.

[0031] Specifically, each battery cell 100 has a first direction X, a second direction Y, and a third direction Z that intersect each other. Each battery cell 100 has a first surface 101 positioned opposite each other along the first direction X, and a second surface 102 positioned opposite each other along the second direction Y. The area of ​​the first surface 101 is larger than the area of ​​the second surface 102. Multiple battery cells 100 are arranged sequentially along the first direction X. The first direction X, the second direction Y, and the third direction Z are perpendicular to each other. When the battery cell 100 is cubic in shape, the first direction X is the width direction of the battery cell 100, the second direction Y is the length direction of the battery cell 100, and the third direction Z is the height direction of the battery cell 100. Multiple battery cells 100 are arranged sequentially along the first direction X, such that adjacent battery cells 100 are connected to each other by the first surface 101 with the larger area.

[0032] A heating element 200 is disposed on the first surface 101 of the battery cell 100. A hollow portion 201 is provided at the center of the heating element 200, extending through the heating element 200. The heating element 200 is in the form of a heating film. Optionally, the heating element 200 can be a silicone grease heating film or a PI heating film. Of course, the heating element 200 can also have other structural forms, all within the scope of this application. When the battery cell 100 is assembled into a battery pack, the heating element 200 is fixed to the first surface 101 of the battery cell 100 using adhesive bonding. Arranging the heating element 200 on the first surface 101 of the battery cell 100 maximizes the heating area and achieves the best heating effect. The hollow portion 201 located at the center of the heating element 200 can buffer the expansion force at the center of the battery cell 100, preventing the heating element 200 from separating from or even detaching from the battery cell 100 after being subjected to expansion force during long-term use.

[0033] By employing the aforementioned technical solution, and by placing the heating element 200 on the first surface 101 of the battery cell 100 of the battery pack, which has a larger side area, not only can the heating area of ​​the heating element 200 on the battery cell 100 be increased, thus improving the heating efficiency of the battery cell 100, but also, by adding a through-hole portion 201 in the center of the heating element 200, the impact of the expansion force caused by the deformation of the center of the battery cell 100 on the heating element 200 during battery pack use can be reduced, thereby extending the service life of the battery pack. This ensures that the heating element 200 can be tightly attached to the battery cell 100, reducing the risk of the heating element 200 peeling off from the battery cell 100 due to the expansion force, avoiding the phenomenon of dry burning caused by local delamination between the heating element 200 and the battery cell 100, and further preventing the heating element 200 from experiencing a temperature rise due to local dry burning, thus solving the problem of large-area delamination in the bonding area between the heating element 200 and the battery cell 100.

[0034] In some embodiments, please refer to Figure 2 and Figure 3 The hollow portion 201 can be one or more of a rectangular, square, circular, or porous structure. Specifically, in the first direction X of the battery cell 100, the hollow portion 201 can be a regular shape such as a rectangle, square, circle, or porous shape. From a manufacturing perspective, the regular-shaped hollow portion 201 is easier to process and form on the heating element 200, which can reduce the manufacturing difficulty and cost of the heating element 200 and facilitate industrial production.

[0035] Of course, in other embodiments, the hollow part 201 can also be irregular in shape, which can also buffer the expansion force at the center of the battery cell 100, and prevent the heating element 200 from separating from or even falling off the battery cell 100 after being subjected to the expansion force. All of these are within the protection scope of this application.

[0036] In some embodiments, please refer to Figure 1 and Figure 2 The outer contour of the heating element 200 coincides with the outer contour of the first surface 101. Specifically, when the battery cell 100 has a cubic structure, the first surface 101 is rectangular or square. In the first direction X, the surface where the heating element 200 and the battery cell 100 are attached has the same rectangular or square shape as the first surface 101. Therefore, by setting the surface of the heating element 200 that is attached to the battery cell 100 to have the same shape as the first surface 101, during the assembly process of the heating element 200 and the battery cell 100, it is only necessary to keep the outer contour of the heating element 200 and the outer contour of the first surface 101 coincided to ensure the correct bonding of the heating element 200 and the battery cell 100, reducing the assembly difficulty between the heating element 200 and the battery cell 100, facilitating operation, and facilitating positioning and installation in the process.

[0037] It should be noted that the bonding joint between the heating element 200 and the outer contour of the battery cell 100 is prone to separation. Therefore, during the bonding process between the heating element 200 and the battery cell 100, more adhesive needs to be applied to the bonding joint between the heating element 200 and the battery cell 100 to ensure a stronger connection between the heating element 200 and the battery cell 100 at the outer contour, prevent separation, and improve the quality of the battery pack.

[0038] In some embodiments, referring to 3, the area of ​​the hollow portion 201 accounts for 20%-30% of the area of ​​the heating element 200. Specifically, in the second direction Y, the area of ​​the outer contour of the heating element 200 is S1, and the area of ​​the outer contour of the hollow portion 201 is S2. When the battery cell 100 is a cube, the shape of the first face 101 is a square or rectangle. When the outer contour of the heating element 200 and the first face 101 coincide, the area S1 of the outer contour of the heating element 200 can be calculated by multiplying the side length of the first face 101 in the second direction Y and the side length in the third direction Z. When the hollow portion 201 is a square or rectangle, the area S2 of the hollow portion 201 can be calculated by multiplying the side length of the hollow portion 201 in the second direction Y and the side length in the third direction Z. Furthermore, when the hollow portion 201 is circular or has a porous structure, the area S2 of the hollow portion 201 can be calculated using the formula for the area of ​​a circle, which will not be elaborated here.

[0039] The area of ​​the hollow portion 201 is set to 20%-30% of the total area of ​​the heating element 200. This allows the heating element 200 to adequately buffer the aging expansion of the battery cell 100 during use, preventing localized delamination due to expansion stress. Simultaneously, after removing the hollow portion 201, the heating element 200 retains 70%-80% of its heating portion, fully meeting the heating requirements of the battery cell 100 and ensuring its heating rate and effectiveness.

[0040] In some embodiments, please Figures 1 to 3 Further reference Figure 4 and Figure 5The heating element 200 is provided with a first terminal 210 and a second terminal 220. The first terminals 210 of two adjacent heating elements 200 are attached to each other, and the second terminals 220 of two adjacent heating elements 200 are attached to each other. Specifically, both the first terminal 210 and the second terminal 220 are electrically connected to the heating element 200. One of the first terminal 210 and the second terminal 220 can serve as the negative terminal of the heating element 200, and the other serves as the positive terminal of the heating element 200. Through the action of the negative and positive terminals, the heating element 200 can heat the first surface 101 of the battery cell 100. During the assembly of the battery pack, the battery cells 100 with the heating element 200 attached to their first surface 101 are connected sequentially along the first direction X, and the first terminals 210 and the second terminals 220 on the heating elements 200 of two adjacent battery cells 100 are respectively attached to each other. Therefore, it is possible to connect the first terminals 210 of the heating elements 200 of two adjacent battery cells 100 to each other, and also to connect the second terminals 220 of the heating elements 200 of two adjacent battery cells 100 to each other. When supplying power to the heating elements 200 in the battery pack, it is only necessary to connect the first terminals 210 that are attached to each other in pairs, and to connect the second terminals 220 that are attached to each other in pairs. This helps to reduce the complexity of the wiring harness connection inside the battery pack and simplify the wiring harness connection of the battery pack.

[0041] It should be noted that in some examples, the first terminal 210 and the second terminal 220 can be structures led out from the heating element 200, that is, the first terminal 210, the second terminal 220 and the heating element 200 are an integral structure. In other examples, the first terminal 210, the second terminal 220 and the heating element 200 can be separate components connected together by welding or other methods.

[0042] In some embodiments, please refer to Figures 1 to 5The first terminal 210 and the second terminal 220 are both arranged along the second direction Y. Specifically, the first terminal 210 and the second terminal 220 are both arranged on the heating element 200 along the second direction Y. After the heating element 200 is installed on the first surface 101 of the battery cell 100, the first terminal 210 and the second terminal 220 extend along the length direction of the battery cell 100. The battery cell 100 has a top and a bottom along the third direction Z (i.e., the height direction). The positive and negative terminals of the battery cell 100 are generally arranged on the top of the battery cell 100, and the bottom of the battery cell 100 is used to connect with the contact surface to support the battery cell 100. Thus, by placing the first terminal 210 and the second terminal 220 on the side of the battery cell 100 along its length, it is possible to avoid the first terminal 210 and the second terminal 220 occupying the layout space of the positive and negative terminal busbar between the battery cells 100 when the first terminal 210 and the second terminal 220 are placed on the top of the battery cell 100, and also to avoid the problem of the first terminal 210 and the second terminal 220 being squeezed by themselves when placed at the bottom of the battery cell 100.

[0043] It should be noted that the first terminal 210 and the second terminal 220 can be located on the same side of the heating element 200 or on opposite sides of the heating element 200; no single limitation is made here. When the first terminal 210 and the second terminal 220 are located on the same side of the heating element 200, this type of heating element 200 is mounted on the battery cell 100, with both the first terminal 210 and the second terminal 220 located on the same side along the length of the battery cell 100. The first terminals 210 and the second terminals 220 of the heating elements 200 of two adjacent battery cells 100 are all in contact with each other on the same side of the battery cell 100. Therefore, compared to the configuration where the first terminal 210 and the second terminal 220 are located on opposite sides of the heating element 200, the wiring harnesses used to connect the first terminal 210 and the second terminal 220 are all located on the same side of the battery pack, which is more convenient for wiring.

[0044] In some embodiments, please continue to refer to Figures 1 to 5 The battery pack also includes a first wiring harness 300 and a second wiring harness 400. The first wiring harness 300 is used to connect mutually bonded first terminals 210, and the second wiring harness 400 is used to connect mutually bonded second terminals 220. Specifically, within the battery pack, among multiple sets of adjacent pairs of battery cells 100, the first terminals 210 bonded between heating elements 200 on adjacent first surfaces 101 can be connected in series under the action of the first wiring harness 300, and the second terminals 220 bonded between heating elements 200 on adjacent first surfaces 101 can be connected in series under the action of the second wiring harness 400. In this way, the positive and negative terminals of all heating elements 200 within the battery pack can be connected, allowing the heating elements 200 to heat the battery cells 100 through the larger area of ​​the first surface 101.

[0045] In some embodiments, please Figure 1 , Figure 2 , Figure 4 and Figure 5 Further reference Figure 6 The battery pack also includes a heat insulation component 500, which is located between two adjacent battery cells 100 and sandwiched between two adjacent heating elements 200. Specifically, the heat insulation component 500 is a plate-shaped material. The heat insulation component 500 can be a plate-shaped structure made of aerogel material, and the thickness of the plate-shaped structure can be adjusted according to actual conditions. A recessed portion 501 can also be provided in the center of the heat insulation component 500. The shape of the recessed portion 501 can match the shape of the hollow portion 201. The thickness of the heat insulation component 500 at the recessed portion 501 is smaller than the thickness of other parts of the heat insulation component 500, that is, the heat insulation component 500 is appropriately thinned at the recessed portion 501. The recessed portion 501 can be provided on only one side of the heat insulation component 500, or it can be provided on both sides of the heat insulation component 500. When the recess 501 is provided only on one side of the heat insulation component 500, the thinning depth of the recess 501 is 10% of the thickness of the heat insulation component 500, that is, the thickness of the heat insulation component 500 at the recess 501 is 90% of the thickness of the other parts of the heat insulation component 500. When the recess 501 is provided on both sides of the heat insulation component 500, the thinning depth of each recess 501 is 10% of the thickness of the heat insulation component 500, that is, the thickness of the heat insulation component 500 at the recess 501 is 80% of the thickness of the other parts of the heat insulation component 500. Thus, by providing the recess 501, a certain buffer space can be provided for the battery cells 100 on both sides. The heat insulation component 500 can be tightly connected to the heating element 200 by using double-sided adhesive, so that one side of each heating element 200 can be fixed to the first side 101 of the battery cell 100 by adhesive, and the other side of each heating element 200 can be fixed to the heat insulation component 500 by adhesive. By setting up the heat insulation component 500, not only can a buffer space be provided for the expansion of the battery cell 100, but also the heat transfer between the battery cells 100 can be slowed down when thermal runaway occurs, preventing the thermal spread of the battery cell 100 and providing emergency time for the staff.

[0046] In some embodiments, please refer to Figure 1 , Figure 2 , Figure 4 and Figure 5The outer contours of the heat insulation component 500 and the heating component 200 coincide. Specifically, when the heating component 200 is rectangular or square, the heat insulation component 500 and the heating component 200 are set to the same rectangular or square shape in the first direction X. Therefore, by setting the heat insulation component 500 to have the same shape as the heating component 200, during the assembly process of the heat insulation component 500 and the heating component 200, it is only necessary to keep the outer contours of the heat insulation component 500 and the heating component 200 coincided to ensure proper bonding between them. This reduces the assembly difficulty between the heat insulation component 500 and the heating component 200, facilitates operation, and is beneficial for positioning and installation in the process.

[0047] According to a second aspect of this disclosure, an electrical device is provided, including the battery pack described in the embodiments. This electrical device possesses all the beneficial effects of the aforementioned battery pack, which will not be elaborated further herein.

[0048] In the description of this application, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more features. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0049] In the above embodiments, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions in other embodiments.

[0050] The embodiments, implementation methods, and related technical features of this application can be combined and substituted for each other without conflict.

[0051] The above are merely preferred embodiments of this application and are not intended to limit this application in any way. Any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of this application without departing from the scope of the technical solution of this application shall still fall within the scope of the technical solution of this application.

Claims

1. A battery pack, characterized in that, include: A single battery cell (100) has a first direction (X), a second direction (Y) and a third direction (Z) that intersect each other in pairs. The single battery cell (100) has a first surface (101) that is disposed opposite to each other along the first direction (X) and a second surface (102) that is disposed opposite to each other along the second direction (Y). The area of ​​the first surface (101) is larger than the area of ​​the second surface (102). A plurality of the single battery cells (100) are arranged along the first direction (X). A heating element (200) is disposed on the first surface (101) of the battery cell (100). A hollow part (201) is provided in the center of the heating element (200), and the hollow part (201) penetrates through the heating element (200).

2. The battery pack according to claim 1, characterized in that, The hollowed-out part (201) is one or more of a rectangular, square, circular or porous structure.

3. The battery pack according to claim 1, characterized in that, The outer contour of the heating element (200) coincides with the outer contour of the first surface (101).

4. The battery pack according to claim 3, characterized in that, The area of ​​the hollow portion (201) accounts for 20%-30% of the area of ​​the heating element (200).

5. The battery pack according to claim 1, characterized in that, The heating element (200) is provided with a first terminal (210) and a second terminal (220). The first terminals (210) of two adjacent heating elements (200) are attached to each other, and the second terminals (220) of two adjacent heating elements (200) are attached to each other.

6. The battery pack according to claim 5, characterized in that, Both the first terminal (210) and the second terminal (220) are arranged along the second direction (Y).

7. The battery pack according to claim 5, characterized in that, The battery pack also includes a first wiring harness (300) and a second wiring harness (400), the first wiring harness (300) being used to connect the first terminal (210) which is attached to each other, and the second wiring harness (400) being used to connect the second terminal (220) which is attached to each other.

8. The battery pack according to claim 1, characterized in that, The battery pack also includes a heat insulation component (500), which is located between two adjacent battery cells (100) and sandwiched between two adjacent heating components (200).

9. The battery pack according to claim 8, characterized in that, The outer contour of the heat insulation element (500) coincides with the outer contour of the heating element (200).

10. An electrical appliance, characterized in that, Includes the battery pack as described in any one of claims 1 to 9.

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