Heat dissipation assembly and battery pack

Abstract

The utility model relates to the technical field of batteries, in particular to a heat dissipation assembly and a battery pack, the heat dissipation assembly is used for the battery pack, the heat dissipation assembly is arranged between two adjacent battery cells, the heat dissipation assembly comprises a heat dissipation body, and the heat dissipation body comprises a first film layer, a second film layer, a liquid absorption part and a gas-liquid phase change part. The first film layer and the second film layer are oppositely arranged in the first direction, and a heat storage cavity is defined by the first film layer and the second film layer. And the liquid absorption part and the gas-liquid phase change part are sealed in the heat storage cavity. When the temperature of the heat dissipation assembly is not higher than the preset temperature, the gas-liquid phase change part is liquid and is absorbed in the liquid absorption part. When the temperature of the heat dissipation assembly reaches the preset temperature, at least part of the gas-liquid phase change part can be vaporized. According to the heat dissipation assembly and the battery pack, the heat dissipation efficiency between the adjacent battery cells is improved, the temperature uniformity of the battery cells is improved, forming of the heat dissipation assembly and fixing of the battery pack are facilitated, and cyclic utilization of the gas-liquid phase change part is achieved.

Description

Technical Field

[0001] The present application relates to the field of battery technology, and in particular to a heat dissipation component and a battery pack. Background Art

[0002] With the increasing popularity of new energy vehicles, the demand for vehicle convenience is becoming increasingly higher. To meet faster charging speeds, many power batteries are equipped with fast charging capabilities. However, as fast charging capabilities continue to improve, the heat generated by charging will also increase exponentially. Although cooling systems can assist in dissipating heat, the cooling system's limited capacity cannot effectively dissipate all the heat. When the battery temperature is too high, it can cause the electrolyte inside the battery cell to decompose, causing safety issues. Utility Model Content

[0003] The purpose of this application is to provide a heat dissipation assembly and battery pack to, to a certain extent, address the existing technical problem that as fast charging capabilities continue to improve, the heat generated by charging also increases exponentially. Although a cooling system can assist in dissipating heat, the heat dissipation system's limited capacity cannot effectively remove all the heat. When the battery temperature is too high, the electrolyte inside the battery cell will decompose, causing safety issues.

[0004] According to a first aspect of the present application, a heat dissipation assembly is provided for a battery pack, wherein the battery pack includes a plurality of battery cells stacked along a first direction, and the heat dissipation assembly is provided between two adjacent battery cells;

[0005] The heat dissipation component includes a heat dissipation body, and the heat dissipation body includes a first film layer, a second film layer, a liquid absorption part and a gas-liquid phase change part;

[0006] The first film layer and the second film layer are arranged to form a heat storage cavity;

[0007] The liquid absorption part and the gas-liquid phase change part are both sealed in the heat storage cavity;

[0008] When the temperature of the heat dissipation component is not higher than a predetermined temperature, the gas-liquid phase change portion is liquid and is absorbed in the liquid absorption portion;

[0009] When the temperature of the heat dissipation component reaches the predetermined temperature, at least a portion of the gas-liquid phase change portion can be vaporized.

[0010] Preferably, when the temperature of the heat dissipation component is not higher than a predetermined temperature, the air pressure in the heat storage chamber is negative pressure.

[0011] Preferably, when the temperature of the heat dissipation component is not higher than the predetermined temperature, the air pressure in the heat storage chamber is 10 2 ~10 5 Pa.

[0012] Preferably, the liquid absorbing part is a water-absorbing resin, water-absorbing cotton or liquid-absorbing paper.

[0013] Preferably, the gas-liquid phase change portion is water or mineral oil.

[0014] Preferably, the heat dissipation assembly includes a heat insulating portion and at least two heat dissipation bodies, and the at least two heat dissipation bodies are stacked along the first direction, with the heat insulating portion being provided between two adjacent heat dissipation bodies.

[0015] Preferably, there are two heat dissipation bodies, and the second film layers of the two heat dissipation bodies are arranged facing each other.

[0016] Preferably, the first film layer is an aluminum-plastic film;

[0017] And / or, the second film layer is a plastic film.

[0018] Preferably, when the temperature of the heat dissipation component is not higher than a predetermined temperature, the volume of the heat storage cavity is defined as V;

[0019] The maximum volume of the heat storage chamber is 0.1V to 3V.

[0020] According to the second aspect of the present application, a battery pack is provided, comprising the heat dissipation assembly described in any of the above technical solutions and a plurality of the above battery cells, thus having all the beneficial technical effects of the heat dissipation assembly, which will not be described in detail here.

[0021] Compared with the prior art, the present invention has the following advantages:

[0022] The heat dissipation assembly provided in the present application forms a heat storage cavity by surrounding the first film layer and the second film layer opposite to each other, and seals both the liquid absorption part and the gas-liquid phase change part in the heat storage cavity. In this way, when the heat dissipation component is arranged between two adjacent battery cells, once the temperature of the battery cells exceeds a predetermined temperature, the gas-liquid phase change portion can undergo a vaporization reaction, absorbing the heat of the battery cells, thereby achieving heat dissipation between the battery cells; when the temperature of the battery cells returns to room temperature, the gas-liquid phase change portion can liquefy into a liquid state and be adsorbed in the liquid absorption portion. On the one hand, arranging the heat dissipation component between the battery cells not only improves the heat dissipation efficiency between adjacent battery cells, but also allows the temperature to be transferred in the gas-liquid phase change portion within the heat absorption portion, effectively improving the temperature uniformity of the battery cells; on the other hand, the liquid absorption portion can absorb the liquid gas-liquid phase change portion, causing the gas-liquid phase change portion to solidify, which not only facilitates the molding of the heat dissipation component and the fixation of the battery pack at room temperature, but also realizes the recycling of the gas-liquid phase change portion through the vaporization / liquefaction characteristics of the gas-liquid phase change portion. That is, when the battery cell temperature exceeds the predetermined temperature, the gas-liquid phase change portion vaporizes and absorbs heat and precipitates into the liquid absorption portion; when the battery cell temperature returns to room temperature, the gas-liquid phase change portion can liquefy and be absorbed by the liquid absorption portion.

[0023] In order to make the above-mentioned objects, features and advantages of the present application more obvious and easy to understand, preferred embodiments are given below and described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the specific implementation methods of the present application or the technical solutions in the prior art, the following is a brief introduction to the drawings required for use in the specific implementation methods or the description of the prior art. Obviously, the drawings described below are some implementation methods of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0025] Figure 1 A schematic diagram of the exploded structure of the heat dissipation assembly provided in an embodiment of the present application;

[0026] Figure 2 Schematic diagram of the exploded structure of the battery pack provided in an embodiment of the present application.

[0027] Reference numerals:

[0028] 10-heat dissipation assembly; 1-heat dissipation body; 11-first film layer; 12-second film layer; 13-liquid absorption part; 2-thermal insulation part; 20-battery core.

[0029] F1-First direction. DETAILED DESCRIPTION

[0030] The technical solution of the present application will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments.

[0031] The components of the embodiments of the present application generally described and shown in the drawings herein may be arranged and designed in a variety of different configurations. Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the claimed application, but merely represents selected embodiments of the present application.

[0032] Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making any creative work shall fall within the scope of protection of this application.

[0033] In the description of this application, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are intended solely to facilitate the description of this application and simplify the description. They do not indicate or imply that the devices or components referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on this application. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0034] In the description of this application, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal connections between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on the specific circumstances.

[0035] Refer to the following Figure 1 and Figure 2 The heat dissipation assembly and battery pack according to some embodiments of the present application are described.

[0036] See also Figure 1 As shown, an embodiment of the present application provides a heat dissipation component for a battery pack, the battery pack including a plurality of battery cells 20 stacked along a first direction F1, and a heat dissipation component 10 is arranged between two adjacent battery cells 20. The heat dissipation component 10 includes a heat dissipation body 1, and the heat dissipation body 1 includes a first film layer 11, a second film layer 12, a liquid absorption portion 13 and a gas-liquid phase change portion. The first film layer 11 and the second film layer 12 are arranged to form a heat storage cavity. The liquid absorption portion 13 and the gas-liquid phase change portion are both sealed in the heat storage cavity. When the heat dissipation component 10 is in an environment not higher than a predetermined temperature, the gas-liquid phase change portion is liquid and is absorbed in the liquid absorption portion 13; when the temperature of the heat dissipation component 10 reaches a predetermined temperature, at least part of the gas-liquid phase change portion can vaporize.

[0037] According to the heat dissipation component provided by the above technical features, the first film layer 11 and the second film layer 12 are arranged opposite to each other to form a heat storage cavity, and the liquid absorption part 13 and the gas-liquid phase change part are sealed in the heat storage cavity. In this way, when the heat dissipation component 10 is set between two adjacent battery cells 20, once the temperature of the battery cell 20 reaches a predetermined temperature, the gas-liquid phase change part can undergo a vaporization reaction, absorb the heat of the battery cell 20, and thus achieve heat dissipation between the battery cells 20; when the temperature of the battery cell 20 returns to normal temperature, the gas-liquid phase change part can liquefy into liquid and be adsorbed in the liquid absorption part 13. On the one hand, setting the heat dissipation component 10 between the battery cells 20 not only improves the heat dissipation efficiency between the adjacent battery cells 20, but also enables the temperature to be transferred in the gas-liquid phase change part in the heat absorption part. It effectively improves the temperature uniformity of the battery core 20; on the other hand, the liquid absorption portion 13 can absorb the gas-liquid phase change portion in liquid state, so that the gas-liquid phase change portion is solidified, which not only facilitates the molding of the heat dissipation component 10 and the fixation of the battery pack at room temperature, but also realizes the recycling of the gas-liquid phase change portion through the vaporization / liquefaction characteristics of the gas-liquid phase change portion, that is, when the temperature of the battery core 20 exceeds the predetermined temperature, the gas-liquid phase change portion vaporizes and absorbs heat, and precipitates to the liquid absorption portion 13; when the temperature of the battery core 20 returns to room temperature, the gas-liquid phase change portion can be liquefied and absorbed by the liquid absorption portion 13.

[0038] Preferably, the gas-liquid phase change part may be a phase change material such as water, aqueous solution or mineral oil, which is liquid at room temperature and gaseous at high temperature.

[0039] Optionally, taking the gas-liquid phase change portion as water or an aqueous solution as an example, the liquid absorbing portion 13 may be a solid material capable of absorbing water, such as a water-absorbing resin, water-absorbing cotton or liquid-absorbing paper.

[0040] Optionally, taking the gas-liquid phase transition portion as mineral oil as an example, the liquid absorption portion 13 may be a solid material capable of absorbing mineral oil, such as oil-absorbing paper or sponge.

[0041] However, the present invention is not limited thereto. As long as the temperature of the heat dissipation component 10 is not higher than a predetermined temperature, the gas-liquid phase transition portion is in a liquid state. When the temperature of the heat dissipation component 10 reaches the predetermined temperature, the gas-liquid phase transition portion can undergo a vaporization reaction. The gas-liquid phase transition material is not limited to water, aqueous solutions, or mineral oil. Correspondingly, the liquid absorbing portion 13 is not limited to absorbent resin, absorbent cotton, or absorbent paper.

[0042] Preferably, the predetermined temperature can be 70°C to 150°C, for example, 100°C. In this way, when the heat dissipation component 10 is at room temperature, the gas-liquid phase change portion can be liquid and absorbed in the liquid absorption portion 13. In this way, at room temperature, the gas-liquid phase change portion can be solidified by the liquid absorption portion 13, thereby ensuring the convenience of assembly of the heat dissipation component 10 under the soft support structure of the first film layer 11 and the second film layer 12, and facilitating the molding of the heat dissipation component 10 and the fixation of the battery pack.

[0043] Preferably, if Figure 1 As shown, the first film layer 11 and the second film layer 12 can be arranged opposite to each other along the first direction F1, so as to fit with two adjacent battery cells 20, thereby improving the thermal conductivity and heat uniformity of the heat dissipation component 10.

[0044] Preferably, if Figure 1 As shown, the first membrane layer 11 and the second membrane layer 12 can be sealed and connected around the heat storage cavity for at least one circle to achieve sealing of the heat storage cavity and thereby prevent leakage of the gas-liquid phase change portion.

[0045] Optionally, the first film layer 11 and the second film layer 12 may be connected via hot pressing.

[0046] Optionally, the first film layer 11 and the second film layer 12 may be bonded together via hot melt adhesive.

[0047] In an embodiment, preferably, when the heat dissipation component 10 is in an environment not higher than a predetermined temperature, the air pressure in the heat storage cavity is negative pressure. In this way, on the one hand, the space occupied by the heat dissipation component 10 can be effectively compressed; on the other hand, a vaporization space can be reserved for the gas-liquid phase change part to prevent the gas-liquid phase change part from increasing in volume and bursting the heat storage cavity after vaporization.

[0048] Preferably, when the heat dissipation component 10 is in an environment not higher than a predetermined temperature, the air pressure in the heat storage chamber can be 10 2 ~10 5 Pa.

[0049] When the heat dissipation component 10 is in an environment not higher than a predetermined temperature, the volume of the heat storage chamber is defined as V, that is, the volume of the negative pressure chamber when the heat storage chamber is in a negative pressure state. Preferably, the maximum volume of the heat storage chamber is 0.1V to 3V. In other words, the maximum volume of the heat storage chamber can be understood as the maximum value of the sum of the volumes of the heat absorption part and the gas-liquid phase change part that can be accommodated in the heat storage chamber when the temperature of the heat dissipation component 10 exceeds the predetermined temperature. In this way, on the one hand, making the maximum volume of the heat storage chamber greater than or equal to 0.1V can reserve vaporization space in the heat storage chamber for the gas-liquid phase change part, preventing the gas-liquid phase change part from increasing in volume and bursting the heat storage chamber after vaporization; on the other hand, making the maximum volume of the heat storage chamber less than or equal to 3V can effectively limit the volume change of the heat dissipation component 10 with temperature changes, thereby reducing the impact of the heat dissipation component 10 on the volume of the battery pack.

[0050] It should be noted that the above-mentioned heat storage cavity is a flexible cavity formed by the first film layer 11 and the second film layer 12, and when the temperature of the heat dissipation component 10 is not higher than the predetermined temperature, the above-mentioned heat storage cavity is in a negative pressure state, that is, the heat storage cavity is in a compressed state; when the temperature of the heat dissipation component 10 exceeds the predetermined temperature, the vaporization volume of the gas-liquid phase change part increases, causing the heat storage cavity to expand. At this time, the volume of the heat storage cavity will exceed the volume V of the heat storage cavity in the negative pressure state.

[0051] In an embodiment, Figure 1 As shown, the above-mentioned heat dissipation assembly 10 includes a heat insulating portion 2 and two heat dissipation bodies 1. The two heat dissipation bodies 1 are stacked along the first direction F1, and a heat insulating portion 2 is provided between the two heat dissipation bodies 1. In this way, on the one hand, two adjacent battery cells 20 can be cooled and dissipated through the two heat dissipation bodies 1 respectively, further improving the heat dissipation and heat uniformity of the battery cells 20; on the other hand, providing the heat insulating portion 2 between the two adjacent heat dissipation bodies 1 can effectively reduce the heat transfer between the two adjacent battery cells 20, thereby reducing the thermal impact between the battery cells 20 of the battery pack.

[0052] Optionally, the thermal insulation part may be aerosol or other thermal insulation materials.

[0053] Optionally, both the first film layer 11 and the second film layer 12 are aluminum-plastic films.

[0054] Preferably, if Figure 1 As shown, the second film layers 12 of the two heat dissipation bodies 1 are arranged facing each other. Correspondingly, the first film layer 11 can be an aluminum-plastic film, and the second film layer 12 can be a plastic film. In this way, the outer surface of the heat dissipation component 10 is covered by the aluminum-plastic film (i.e., the first film layer 11), and the inner side of the heat dissipation component 10 is separated by the plastic film (i.e., the second film layer 12). While ensuring the protective strength of the outer surface of the heat dissipation component 10, it effectively saves the material cost of the second film layer 12 and reduces the space occupied by the second film layer 12.

[0055] However, it is not limited thereto. The number of the heat dissipation bodies 1 included in the heat dissipation assembly 10 is not limited to two, but may be multiple, for example, 3, 4, 5... or more.

[0056] See also Figure 2 As shown, an embodiment of the present application further provides a battery pack, comprising the heat dissipation assembly 10 and a plurality of the above-mentioned battery cells 20 as described in any of the above-mentioned embodiments, and thus having all the beneficial technical effects of the heat dissipation assembly 10, which will not be described in detail here.

[0057] Specifically, the battery pack includes a plurality of battery cells 20 stacked along a first direction F1 , and a heat dissipation assembly 10 is disposed between two adjacent battery cells 20 .

[0058] Preferably, the first direction F1 can be parallel to the thickness direction of the battery cell 20. In this way, the above-mentioned heat dissipation component 10 can be fitted with the large surface of the battery cell 20 (that is, the surface determined by both the length direction of the battery cell 20 and the width direction of the battery cell 20) to effectively increase the contact area between the heat dissipation component 10 and the battery cell 20, thereby improving the heat dissipation effect of the heat dissipation component 10.

[0059] Preferably, the heat dissipation assembly 10 is disposed between every two adjacent battery cells 20 .

[0060] Optionally, the multiple battery cells 20 stacked along the first direction F1 are sequentially divided into multiple battery cell groups of equal or unequal numbers, and the heat dissipation assembly 10 is disposed between every two adjacent battery cell groups.

[0061] Optionally, the number of battery cells 20 included in each battery cell group may be 1, 2, 3, 4... or more.

[0062] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some or all of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A heat dissipation component, characterized in that: Used in a battery pack, the battery pack comprising a plurality of battery cells stacked along a first direction, the heat dissipation assembly being arranged between two adjacent battery cells; The heat dissipation component includes a heat dissipation body, and the heat dissipation body includes a first film layer, a second film layer, a liquid absorption part and a gas-liquid phase change part; The first film layer and the second film layer are arranged to form a heat storage cavity; The liquid absorption part and the gas-liquid phase change part are both sealed in the heat storage cavity; When the temperature of the heat dissipation component is not higher than a predetermined temperature, the gas-liquid phase change portion is liquid and is absorbed in the liquid absorption portion; When the temperature of the heat dissipation component reaches the predetermined temperature, at least a portion of the gas-liquid phase change portion can be vaporized.

2. The heat dissipation assembly according to claim 1, wherein: When the temperature of the heat dissipation component is not higher than a predetermined temperature, the air pressure in the heat storage chamber is negative pressure.

3. The heat dissipation assembly according to claim 1, wherein: When the temperature of the heat dissipation component is not higher than the predetermined temperature, the pressure in the heat storage chamber is 10 2 ~10 5 Pa.

4. The heat dissipation assembly according to claim 1, wherein: The liquid absorbing part is water absorbing resin, water absorbing cotton or liquid absorbing paper.

5. The heat dissipation assembly according to claim 1, wherein: The gas-liquid phase change portion is water or mineral oil.

6. The heat dissipation assembly according to any one of claims 1 to 5, characterized in that: The heat dissipation assembly includes a heat insulating portion and at least two heat dissipation bodies. The at least two heat dissipation bodies are stacked along the first direction, and the heat insulating portion is provided between two adjacent heat dissipation bodies.

7. The heat dissipation assembly according to claim 6, wherein: There are two heat dissipation bodies, and the second film layers of the two heat dissipation bodies are arranged facing each other.

8. The heat dissipation assembly according to claim 7, wherein: The first film layer is an aluminum-plastic film; And / or, the second film layer is a plastic film.

9. The heat dissipation assembly according to claim 2 or 3, characterized in that: When the temperature of the heat dissipation component is not higher than a predetermined temperature, the volume of the heat storage cavity is defined as V; The maximum volume of the heat storage chamber is 0.1V to 3V.

10. A battery pack, characterized in that: The heat dissipation component comprises the heat dissipation component according to any one of claims 1 to 9 and a plurality of the battery cells.

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