Heat absorption device, battery pack and electric equipment

Abstract

The utility model discloses a heat absorption device, a battery pack and electric equipment, the battery pack comprises a shell, a plurality of battery cells arranged in the shell and the heat absorption device, and the heat absorption device is positioned between two adjacent battery cells, is in heat conduction connection with the shell and is used for absorbing heat of the thermal runaway battery cells. The heat absorption device comprises a beam structure and a heat conduction piece. The beam structure is provided with a channel, a heat exchange medium is arranged in the channel, and the heat conduction piece is arranged on the inner wall of the channel, makes heat conduction contact with the heat exchange medium and is used for conducting heat of the beam structure to the heat exchange medium. According to the heat absorption device, the battery pack and the electric equipment provided by the utility model, the heat transferred from the thermal runaway battery cell to the shell is conducted into the phase change material through the heat conduction piece, so that the probability that the thermal runaway battery cell transfers heat to the adjacent battery cell through the shell to cause heat diffusion is reduced, and the safety and the reliability of the performance of the battery pack are improved.

Description

Technical Field

[0001] The utility model relates to the technical field of batteries, and in particular to a heat absorption device, a battery pack and electrical equipment. Background Art

[0002] With the vigorous development of new energy vehicles, factors that cause thermal runaway include but are not limited to overtemperature, overcharging, overdischarging, short circuit, puncture, extrusion, etc. Since the operating environment of the battery pack is very complex, it is often impossible to completely avoid the occurrence of thermal runaway. Therefore, how to design thermal safety protection for the heat absorber so that the heat absorber has the ability to avoid or delay thermal runaway and spread heat to adjacent battery components, and minimize the risks and hazards of heat diffusion, is a problem that needs to be solved urgently.

[0003] Normally, heat insulation is set between adjacent battery elements to reduce heat diffusion. However, in the battery pack structure, the battery elements are set inside the battery pack shell, which will encapsulate the battery elements to protect them. If a battery element is in thermal runaway, its heat will be transferred to the battery pack shell, and the battery pack shell will transfer the heat to the adjacent battery elements. When the heat accumulation of the adjacent battery elements reaches the thermal runaway temperature, thermal diffusion and heat spread events will occur. Utility Model Content

[0004] The utility model aims to provide a heat absorption device, a battery pack and an electrical device, which are used to solve the technical problem in the prior art that thermal runaway of a battery cell easily leads to heat diffusion.

[0005] In order to achieve the purpose of the utility model, the utility model provides the following technical solutions:

[0006] In a first aspect, the utility model provides a heat absorption device, which is arranged between adjacent battery cells and is thermally connected to a shell accommodating the battery cells. The heat absorption device includes:

[0007] A beam structure, wherein the beam structure is provided with a channel, and a heat exchange medium is arranged in the channel,

[0008] A heat conducting member is arranged on the inner wall of the channel and is in thermal contact with the heat exchange medium to reduce the heat of the beam structure.

[0009] Optionally, the heat conducting member is a plurality of linearly arranged plates.

[0010] Optionally, the heat conducting members are arranged at intervals along the thickness direction of the beam structure.

[0011] Optionally, the heat conducting member is arranged on the upper end surface and / or the lower end surface of the channel, and the length of the heat conducting member along the height direction of the channel is smaller than the height of the channel.

[0012] Optionally, the heat conducting member extends along the height direction of the channel and contacts the upper end surface and the lower end.

[0013] Optionally, the heat exchange medium is a phase change material.

[0014] Optionally, the heat conductor is one of metal, graphite, graphene, aluminum oxide, and silicon carbide.

[0015] Optionally, the heat conducting member is arc-shaped or plate-shaped with grooves.

[0016] Optionally, the heat conductive member divides the channel into a number of cavities, and a through hole is provided on the heat conductive member for conducting the gas generated after the heat exchange medium inside the plurality of cavities absorbs heat. An exhaust port is provided on the beam structure, and an exhaust pipe is provided at the exhaust port for discharging the gas.

[0017] Optionally, the exhaust pipe is provided with a switch valve, and the switch valve is turned on when the gas pressure value of the gas reaches a threshold value, so as to guide the gas to the outside of the heat absorption device.

[0018] In a second aspect, the utility model provides a battery pack, the battery pack comprising:

[0019] case;

[0020] A plurality of battery cells, wherein the plurality of battery cells are accommodated in the housing;

[0021] The heat absorption device described in any of the above embodiments is arranged between two adjacent battery cells and is thermally connected to at least one end surface of the shell to absorb heat from the end surface of the shell.

[0022] Optionally, a heat conducting plate is provided between the heat absorbing device and the battery core, for conducting the heat of the battery core to the heat absorbing device to cool the battery core.

[0023] Optionally, there is an air gap between the beam structure and the battery cell to prevent heat transfer between adjacent battery cells.

[0024] Optionally, the shell includes an upper cover plate and a tray, and the upper cover plate and / or the tray are provided with a cooling structure, and the cooling structure is used to reduce the temperature of the end surface of the battery cell.

[0025] In a third aspect, the utility model provides an electrical device, comprising a battery pack and an electrical device provided in any one of the above embodiments, wherein the battery pack is used to supply power to the electrical device.

[0026] The utility model provides a heat absorption device, a battery pack and an electrical device, wherein the heat absorption device is arranged between adjacent battery cells and is thermally connected to a shell accommodating the battery cells; a channel is arranged in the beam structure to accommodate a heat exchange medium, and the heat exchange medium can cool the beam structure, thereby controlling the temperature of the battery cells within a normal range; in addition, in order to reduce the probability of heat from a thermal runaway battery cell being conducted to an adjacent battery cell through the shell and causing a heat diffusion event, a heat conductive member is arranged on the inner wall of the channel of the beam structure thermally connected to the shell, and the heat conductive member is thermally connected to the heat exchange medium, and is used to conduct the heat of the shell into the heat exchange medium, thereby timely reducing the temperature of the shell, which is beneficial to reducing the risk of heat diffusion and heat spread in the battery cells, and improving the safety and reliability of the battery pack. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the implementation methods of the utility model or the technical solutions in the prior art, the drawings required for use in the implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some implementation methods of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0028] Figure 1 It is an exploded diagram of the battery pack structure provided in this application;

[0029] Figure 2 is a three-dimensional diagram of the heat absorption device provided by the present application;

[0030] Figure 3 It is a schematic diagram of the structure of the heat absorption device provided in this application;

[0031] Figure 4 A schematic diagram of a heat conducting member of a heat absorbing device according to an embodiment Figure 1 ;

[0032] Figure 5 A schematic diagram of a heat conducting member of a heat absorbing device according to an embodiment Figure 2 ;

[0033] Figure 6 A schematic diagram of a heat conducting member of a heat absorbing device according to an embodiment Figure 3 ;

[0034] Figure 7 is a schematic diagram of a heat conducting member of a heat absorbing device according to an embodiment having air holes;

[0035] Figure 8 is a schematic structural diagram of an arc-shaped heat-conducting member of a heat-absorbing device according to an embodiment;

[0036] Fig. 9 is a schematic structural diagram of a heat-absorbing device with a stamped groove heat-conducting member according to an embodiment;

[0037] Description of reference numerals:

[0038] 1-heat absorbing device; 10-beam structure; 11-channel; 12-cavity; 20-heat conducting member; 21-through hole; 30-exhaust port; 31 exhaust pipe;

[0039] 4-battery pack; 40-battery cell; 51-upper cover; 52-tray; 53-cooling structure. DETAILED DESCRIPTION

[0040] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0041] It should be noted that when a component is said to be "fixed to" another component, it can be directly on the other component or there can be a central component. When a component is said to be "connected to" another component, it can be directly connected to the other component or there can be a central component at the same time.

[0042] Unless otherwise defined, all technical and scientific terms used in the present invention have the same meaning as those commonly understood by technicians in the technical field of the present invention. The terms used in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used in the present invention includes any and all combinations of one or more related listed items.

[0043] In the description of the embodiments of the present invention, it should be noted that the orientation or positional relationship of terms such as "upper", "lower", "vertical", "horizontal", "inside" and "outside" are based on the orientation or positional relationship described in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or component referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0044] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present utility model, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0045] In conjunction with the accompanying drawings, some embodiments of the present invention are described in detail below. In the absence of conflict, the following embodiments and features in the embodiments can be combined with each other.

[0046] The heat absorption device includes a beam structure and a heat conductor. A channel is opened in the beam structure, and the channel contains a phase change material. The phase change material absorbs the heat transferred from the battery cell to the beam structure during the phase change heat absorption process. The heat conductor is arranged on the upper end surface and / or the lower end surface of the inner wall of the channel. The heat conductor is at least partially immersed in the phase change material, and is used to conduct the heat from the upper end surface and the lower end surface of the beam structure to the phase change material.

[0047] The utility model provides an electric device, which comprises a battery pack and an electric device, and the electric device can be an electric car, an electric train, a golf cart and the like.

[0048] The utility model also provides a battery pack, such as Figure 1 As shown, normally, a battery pack includes a plurality of battery cells and a shell for accommodating the plurality of battery cells. The shell usually includes a tray and an upper cover plate. The upper cover plate is arranged on the upper part of the battery cell and cooperates with the tray to form a shell to protect the battery. In the case of thermal runaway of a battery cell, there are two paths for the thermal runaway battery cell to conduct heat to the adjacent battery cell. One is that the opposite surfaces between adjacent battery cells can transfer heat; the other is that the thermal runaway battery cell transfers heat to the shell, and the shell transfers heat to the adjacent battery cell. There is a heat absorption device between adjacent battery cells. The heat absorption device is thermally connected to at least one end face of the shell, and is used to absorb heat from the end face of the shell that is thermally connected to the heat absorption device, so as to reduce the risk of heat diffusion caused by the thermal runaway battery cell transferring heat to the adjacent battery cell through the shell.

[0049] In one embodiment, there are multiple heat absorption devices, which are arranged at intervals between multiple battery cells, and each heat absorption device is located between two battery cells, which can effectively reduce the probability of heat diffusion from the thermal runaway battery cell to the adjacent battery cell, resulting in heat spread.

[0050] In one embodiment, a heat conducting plate is provided between the battery cell and the heat absorbing device, and the heat conducting plate is used to quickly conduct the heat of the battery cell in thermal runaway to the heat absorbing device, thereby timely reducing the temperature of the battery cell in thermal runaway and reducing the occurrence of thermal runaway heat spread.

[0051] In one embodiment, there is an air gap between the battery cell and the heat absorption device. The air gap has a certain heat insulation effect and can effectively suppress the heat transfer in the heat conduction path between adjacent battery cells. The heat absorption device can absorb the heat of the upper cover plate and the tray in time to cool down, and can also effectively reduce the probability of heat spread.

[0052] like Figure 1As shown, in one embodiment, the upper cover plate and / or the tray are provided with a cooling structure, and the cooling structure is used to reduce the temperature of the end face of the battery cell. It can be understood that when the heat absorbing device is thermally connected to at least one end face of the shell, for example, the heat absorbing device is thermally connected to the tray, at this time, the upper cover plate is provided with a cold plate to reduce the temperature of the thermal runaway battery cell transferred to the upper cover plate, and the cold plate can be provided at the tray; when the heat absorbing device is thermally connected to the upper cover plate, the tray is provided with a cold plate to reduce the temperature of the thermal runaway battery cell transferred to the tray, and the upper cover plate can be provided with a cold plate.

[0053] The utility model also provides a heat absorbing device, such as Figure 2 As shown, the heat absorption device includes: a beam structure, a channel is opened, and a heat exchange medium is arranged in the channel; a heat conductor is arranged on the inner wall of the channel, and is in thermal contact with the heat exchange medium, and is used to reduce the heat of the beam structure. It can be understood that the heat conductor is arranged on the inner wall of the beam structure channel, and a heat exchange medium is arranged in the beam structure channel. The heat conductor is in thermal contact with the heat exchange medium, and the heat of the beam structure can be introduced into the heat exchange medium, thereby reducing the temperature of the beam structure. Specifically, in the case of thermal runaway of a battery cell, the heat exchange medium in the beam structure can quickly absorb the heat transferred from the thermal runaway battery, reduce the heat of the thermal runaway battery cell to other adjacent batteries, and effectively reduce the probability of heat diffusion. However, a simple beam structure cannot effectively suppress the transfer of heat from the tray and the upper cover. When the heat of the thermal runaway battery cell is transferred to the adjacent battery cell through the tray and the upper cover, and the heat of the adjacent battery cell reaches the temperature of thermal runaway, heat spread will occur.

[0054] On the other hand, the battery cell in thermal runaway fits tightly with the tray and the upper cover, and can transfer heat to the adjacent battery cell through the tray or the upper cover. When the heat accumulation of the adjacent battery cells through the upper cover and the tray reaches the temperature of thermal runaway, heat diffusion between the battery cells will occur. Therefore, the beam structure of the present application is thermally connected to the shell, and a heat conductor is provided on the upper end face of the inner wall of the channel in the beam structure, and / or the lower end face. The heat conductor is made of a material with a high thermal conductivity coefficient and is used to conduct the heat of the tray and the upper cover in the height direction of the battery pack into the heat exchange medium, thereby reducing the heat of the thermal runaway battery cell from being transferred to other battery cells through the upper cover and the tray, and reducing the probability of heat spread. It can effectively improve the safety performance of the battery pack.

[0055] In one embodiment, the heat conductor is a plurality of linearly arranged plates. It is understandable that the beam structure is usually a slender structure, and the heat conductors are arranged linearly along the length of the beam structure, and can be arranged at equal intervals or at non-equal intervals, for example, the heat conductors are arranged more densely in the part of the battery pack where it is difficult to dissipate heat, such as being arranged more densely in the middle area along the length of the battery cell. Optionally, the heat conductors can be arranged at intervals along the thickness direction of the beam structure, or can be arranged at intervals along the length direction of the beam structure.

[0056] Preferably, the heat conducting members are arranged at intervals along the thickness direction of the beam structure, where the thickness direction of the beam structure refers to the direction in which two adjacent battery cells are opposite to each other. The heat conducting members are arranged at intervals along the direction in which the battery cells are opposite to each other, which can effectively block the heat transfer between the battery cells.

[0057] In one embodiment, the length of the heat conducting member along the height direction of the beam structure channel is smaller than the height of the channel, and the heat conducting member is arranged on the upper end surface and / or the lower end surface of the inner wall of the channel.

[0058] Alternatively, if Figure 4 As shown, the heat conductive member is arranged on the lower end surface of the channel and extends toward the upper end surface. The length of the heat conductive member is smaller than the height of the channel. The heat conductive member can cool the lower end surface of the beam structure.

[0059] Optionally, the heat conductor is arranged on the upper end surface of the channel and extends toward the lower end surface, and its length is less than the height of the channel. The heat conductor can conduct away the heat on the upper end surface of the beam structure in time.

[0060] Alternatively, if Figure 5 As shown, the heat conductive part is arranged on the upper end face and the lower end face of the channel, and the heat conductive parts on the upper and lower end faces extend in opposite directions respectively. The length of the heat conductive part along the height direction of the beam structure channel is less than the height of the channel, and the heat conductive part on the upper end face and the heat conductive part on the lower end face are arranged alternately to reduce the temperature of the upper end face and the lower end face of the beam structure. The length of the heat conductive part is greater than half of the channel height and less than the channel height, and the heat conductive part on the upper end face and the heat conductive part on the lower end face are interlaced with each other; when the length of the heat conductive part is less than half of the channel length, the heat conductive part on the upper end face and the heat conductive part on the lower end face are separated from each other. The length of the heat conductive part is less than the height of the channel. In the case of the same heat conductive part preparation raw materials, a larger number of shorter heat conductive parts can be set. The more heat conductive parts there are on the end face, the better the heat conductive effect. Therefore, while ensuring the realization of the heat conductive function, it is beneficial to save the preparation cost.

[0061] In one embodiment, the heat conducting member is disposed between the upper end surface and the lower end surface, and the upper and lower end surfaces are in contact with each other. Figure 2 As shown, the heat conducting member is vertically arranged along the height direction of the channel, and the heat conducting member is connected to the upper and lower end surfaces, which can effectively enhance the strength of the beam structure.

[0062] like Figure 6 As shown, optionally, the heat conducting member may also be arranged at an angle, and the inclination angle of the heat conducting member to the vertical direction ranges from 1° to 45°, and the heat conducting member can improve the strength of the beam structure.

[0063] In one embodiment, the heat conducting member is one of metal, graphite, graphene, aluminum oxide, and silicon carbide, that is, the heat conducting member is made of a material with a high thermal conductivity coefficient and has excellent thermal conductivity.

[0064] In one embodiment, the heat conducting member is in an arc shape or a plate shape with grooves. Figure 8 As shown, optionally, the heat conducting member is arc-shaped; Fig. 9 As shown, optionally, the heat conducting member is a plate with a stamped groove. It is understandable that setting the heat conducting member to an arc-shaped or grooved plate can increase the heat exchange area between the heat conducting member and the heat absorbing material, improve the heat conduction rate and heat absorption efficiency, and the plate with grooves can be made by flat plate stamping.

[0065] In one embodiment, the heat exchange medium may be a phase change material or a cooling liquid. Optionally, the phase change material is one of hydrogel, paraffin, fatty acid, metal, crystalline hydrate, fatty alcohol, molten salt, and water.

[0066] When the heat conducting member is connected to the upper end surface and the lower end surface at the same time, the heat conducting member divides the channel into several independent cavities, and the phase change material absorbs heat to generate gas, such as Figure 7 As shown, it is necessary to set a through hole on the heat conductor to connect several cavities so that the gas generated by the phase change material after absorbing heat can be discharged through the through hole to avoid excessive gas pressure after the phase change in the beam structure after absorbing heat, which may cause danger. In addition, when the channel is divided into several independent cavities, the phase change material can be replenished through the through hole after the phase change material absorbs heat and volatilizes or sublimates.

[0067] Alternatively, if Figure 3 As shown, an exhaust port is provided on the beam structure, and an exhaust pipe is provided at the exhaust port, and the exhaust pipe is used to discharge the gas generated after the phase change material absorbs heat during phase change. If the phase change material is liquid at room temperature, the phase change material absorbs heat during phase change and becomes gaseous. At this time, it is necessary to set multiple through holes on the heat conducting member, or through holes with larger sizes, and it is also necessary to set an exhaust port and exhaust pipe with larger sizes to meet the exhaust needs.

[0068] Optionally, the exhaust duct can be directly connected to the exhaust channel or exhaust hole of the battery pack, and exhaust can be achieved with the help of the structure of the battery pack itself without adding other additional components, which helps to save costs and improve space utilization.

[0069] Optionally, a corresponding switch valve (not shown in the attached figure) is provided on the side of the exhaust duct away from the exhaust port, which can be opened when the air pressure inside the beam structure exceeds a threshold value, and the gas generated by the phase change heat absorption is discharged in time, effectively reducing the air pressure inside the beam structure, and reducing the probability of safety accidents caused by excessive air pressure generated by the phase change heat absorption. In addition, at room temperature or when the battery cell does not have thermal runaway, a switch valve is provided to provide a relatively closed space for the phase change material to prevent the volatilization of the phase change material or the entry of external dust.

[0070] Specifically, a diaphragm is provided on one side of the exhaust pipe away from the exhaust port, and the diaphragm may be made of metal material, polymer material, etc. When the phase change material in the channel absorbs heat and produces gas, the generated gas can flow through the pores. When the gas in the channel accumulates and the air pressure rises to a threshold value, such as 0.5 MPa, it reaches the detonation pressure of the diaphragm, the diaphragm ruptures, and the gas is directly discharged from the package through the exhaust port and the exhaust pipe. The diaphragm can automatically rupture when the air pressure reaches the threshold value to allow the gas to be discharged without the need for additional manual operation.

[0071] The above disclosure is only a preferred embodiment of the present invention, and certainly cannot be used to limit the scope of rights of the present invention. Ordinary technicians in this field can understand that all or part of the processes of the above embodiment and equivalent changes made according to the claims of the present invention still fall within the scope covered by the present invention.

Claims

1. A heat absorbing device, characterized in that: The heat absorption device is arranged between adjacent battery cells and is thermally connected to a shell accommodating the battery cells. The heat absorption device comprises: A beam structure, wherein the beam structure is provided with a channel, and a heat exchange medium is arranged in the channel, A heat conducting member is arranged on the inner wall of the channel and is in thermal contact with the heat exchange medium to reduce the heat of the beam structure.

2. The heat sink according to claim 1, characterized in that: The heat conducting member is a plurality of linearly arranged plates.

3. The heat sink according to claim 2, characterized in that: The heat conducting members are arranged at intervals along the thickness direction of the beam structure.

4. The heat sink according to claim 1 or 2, characterized in that: The heat conducting member is arranged on the upper end surface and / or the lower end surface of the channel, and the length of the heat conducting member along the height direction of the channel is smaller than the height of the channel.

5. The heat sink according to claim 4, characterized in that: The heat conducting member extends along the height direction of the channel and contacts the upper end surface and the lower end.

6. The heat sink according to claim 1, characterized in that: The heat exchange medium is a phase change material.

7. The heat sink according to claim 1, characterized in that: The heat conducting member is made of one of metal, graphite, graphene, aluminum oxide and silicon carbide.

8. The heat sink according to claim 1 or 7, characterized in that: The heat conducting member is in an arc shape or a plate shape with grooves.

9. The heat sink according to claim 5, characterized in that: The heat conducting member divides the channel into a plurality of cavities, and a through hole is provided on the heat conducting member for conducting the gas generated after the heat exchange medium absorbs heat in the plurality of cavities. An exhaust port is provided on the beam structure, and an exhaust pipe is provided at the exhaust port for discharging the gas.

10. The heat sink according to claim 9, characterized in that: The exhaust pipe is provided with a switch valve, and the switch valve is turned on when the gas pressure value of the gas reaches a threshold value, so as to guide the gas out of the heat absorption device.

11. A battery pack, characterized in that: include: case; A plurality of battery cells, wherein the plurality of battery cells are accommodated in the housing; The heat sink according to any one of claims 1 to 10, wherein the heat sink is disposed between two adjacent battery cells and is thermally connected to at least one end surface of the shell to absorb heat from the end surface of the shell.

12. The battery pack according to claim 11, characterized in that: A heat conducting plate is arranged between the heat absorbing device and the battery core, so as to conduct the heat of the battery core to the heat absorbing device and cool the battery core.

13. The battery pack according to claim 11, characterized in that: There is an air gap between the beam structure and the battery cell, which is used to block heat transfer between adjacent battery cells.

14. The battery pack according to claim 11, characterized in that: The shell includes an upper cover plate and a tray. The upper cover plate and / or the tray are provided with a cooling structure, and the cooling structure is used to reduce the temperature of the end surface of the battery cell.

15. An electrical equipment, characterized in that: It comprises the battery pack and the electrical appliance as described in any one of claims 11 to 14, wherein the battery pack is used to supply power to the electrical appliance.

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