Battery pack

Abstract

The utility model relates to power battery technical field especially relates to a battery pack. Include: shell has the accommodation cavity, the electric core group installs in the accommodation cavity, the fire extinguishing device installs in the accommodation cavity, and is suitable for spraying fire extinguishing medium when opening state, the thermosensitive wire installs in the accommodation cavity, the thermosensitive wire is connected with the fire extinguishing device, and is suitable for triggering the fire extinguishing device opening when the electric core group happens thermal runaway. The utility model has the beneficial effect: the fire extinguishing device installs in the accommodation cavity of shell, can make full use of the space inside the shell, need not extra occupy external space, based on this, set up the thermosensitive wire connected with the fire extinguishing device in the shell of battery pack, realize the start -up of fire extinguishing device through temperature change, need not set up controller, spare power supply and other detection control equipment, simplifyed the structure, also need not regular maintenance, reduced the cost.

Description

Technical Field

[0001] This utility model relates to the field of energy storage battery technology, and in particular to a battery pack. Background Technology

[0002] To prevent thermal runaway, fires, or explosions caused by misuse or abnormal conditions during the use of energy storage products, fire protection designs are often implemented at the product level. One type of fire protection design is at the battery pack level. This involves detecting a thermal safety event in a battery pack within a container, locating the specific battery pack, and implementing targeted fire protection measures, including spraying fire extinguishing agents and cooling.

[0003] Currently, a common fire-fighting measure at the battery pack level involves installing an interface on the battery pack, which connects to one end of an external pipe. The other end of the external pipe is connected to a fire-fighting medium container. The external pipe is controlled by an external valve to inject the medium from the external fire-fighting medium container into the battery pack to extinguish the fire. This method is complex, requires the placement of fire-fighting medium containers such as cylinders inside the container, occupies a large amount of container space, and requires regular maintenance, resulting in high costs. Summary of the Invention

[0004] This utility model provides a battery pack to solve the technical problems of low fire-fighting efficiency, complex structure, inconvenient maintenance, and high cost of battery packs, so as to improve fire-fighting efficiency and reduce costs.

[0005] To achieve the above and other related objectives, this utility model provides a battery pack, comprising:

[0006] The outer casing has an internal cavity for receiving the contents;

[0007] A battery cell assembly, wherein the battery cell assembly is installed within the receiving cavity;

[0008] A fire extinguishing device, which is installed in the receiving cavity and is adapted to spray a fire extinguishing medium when in the open state;

[0009] A thermal wire is installed inside the receiving cavity, the thermal wire is connected to the fire extinguishing device, and is adapted to trigger the fire extinguishing device to open when the battery pack experiences thermal runaway.

[0010] In one embodiment of the present invention, the outer shell includes a box body and a box cover, the box cover is connected to the box body to define the receiving cavity, and the thermal wire is installed on the box cover.

[0011] In one embodiment of the present invention, the battery cell assembly has a battery cell explosion-proof valve on the side facing the box cover, and at least a portion of the thermal wire is arranged corresponding to the battery cell explosion-proof valve.

[0012] In one embodiment of the present invention, there are multiple battery cell groups, and the multiple battery cell groups are arranged along a first direction to form a battery cell group unit. The fire extinguishing device is installed on the housing and located between two adjacent battery cell groups within the battery cell group unit.

[0013] In one embodiment of the present invention, the number of battery cell units is multiple, the multiple battery cell units are distributed along the second direction, the thermal wire extends along the first direction and bends back and forth to form multiple first sensing segments and second sensing segments distributed along the second direction, two adjacent first sensing segments are connected by the second sensing segment, and each battery cell unit corresponds to at least one first sensing segment and at least one second sensing segment.

[0014] In one embodiment of the present invention, two adjacent first sensing segments are connected in a U-shape by a second sensing segment.

[0015] In one embodiment of the present invention, each of the battery cell units corresponds to two first induction segments and one second induction segment.

[0016] In one embodiment of the present invention, the lid is sealed to the body to form a sealing surface, and at least a portion of the thermal wire corresponds to the sealing surface and extends along the inner circumference of the sealing surface.

[0017] In one embodiment of the present invention, the fire extinguishing device includes a housing, the housing contains the fire extinguishing medium, and the housing has a plurality of medium spray ports distributed circumferentially thereon.

[0018] In one embodiment of this utility model, the extinguishing medium includes aerosol, perfluorohexanone, or ultrafine dry powder.

[0019] The beneficial effects of this utility model are as follows: The battery pack proposed in this utility model has a fire extinguishing device installed in the housing cavity of the outer shell, which can make full use of the internal space of the outer shell without occupying additional external space; based on this, a thermal wire connected to the fire extinguishing device is set in the outer shell of the battery pack, and the fire extinguishing device is activated by temperature change, eliminating the need for a controller, backup power supply and other detection and control equipment, simplifying the structure, eliminating the need for regular maintenance, and reducing costs. Attached Figure Description

[0020] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application. It is obvious that the drawings described below are merely some embodiments of this application, and those skilled in the art can obtain other drawings based on these drawings without any inventive effort.

[0021] In the attached diagram:

[0022] Figure 1 An exploded view of a first embodiment of the battery pack provided by this utility model;

[0023] Figure 2 for Figure 1 Schematic diagram of the structure of the thermally sensitive wire, battery pack and enclosure;

[0024] Figure 3 for Figure 1 Bottom view of the heat-sensitive wire and the box cover;

[0025] Figure 4 for Figure 1 Explosion diagram of the battery pack, fire extinguishing device, and enclosure;

[0026] Figure 5 for Figure 1 Schematic diagram showing the connection between the fire extinguishing device and the enclosure;

[0027] Figure 6 for Figure 5 A magnified schematic diagram of part A in the middle;

[0028] Figure 7 A partial structural schematic diagram of a second embodiment of the battery pack provided by this utility model;

[0029] Figure 8 for Figure 7 Exploded view of a portion of the battery pack structure;

[0030] Figure 9 A bottom view of the thermal wire and the cover of the battery pack according to Embodiment 2 of this utility model.

[0031] The attached figures are labeled as follows:

[0032] 1. Outer shell, 11. Box body, 12. Battery cell assembly unit, 2. Battery cell assembly, 21. Fire extinguishing device, 3. Medium spray nozzle, 31. Thermal wire, 4. First sensing section, 41. Second sensing section, 42. Detailed Implementation

[0033] The following specific examples illustrate the implementation of this utility model. Those skilled in the art can easily understand other advantages and effects of this utility model from the content disclosed in this specification. This utility model can also be implemented or applied through other different specific embodiments. Various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of this utility model. In the absence of conflict, the following embodiments and features in the embodiments can be combined with each other.

[0034] It should be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of the present invention. The drawings only show the components related to the present invention and are not drawn according to the actual number, shape and size of the components. In actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0035] In the following description, numerous details are explored to provide a more thorough explanation of embodiments of the present invention. However, it will be apparent to those skilled in the art that embodiments of the present invention may be practiced without these specific details. In other embodiments, well-known structures and devices are shown in block diagram form rather than in detail to avoid obscuring embodiments of the present invention.

[0036] Please see Figure 1 , Figure 2 , Figure 7 and Figure 8 In some optional embodiments, this utility model provides a battery pack, including a shell 1, a battery cell assembly 21, a fire extinguishing device 3, and a thermal wire 4. The shell 1 has an internal cavity, in which the battery cell assembly 21 is installed. The fire extinguishing device 3 is also installed within the cavity and is adapted to spray a fire extinguishing medium when activated. The fire extinguishing medium sprayed by the fire extinguishing device 3 acts on the battery cell assembly 21, creating a flame-suppressing environment within the cavity or extinguishing open flames generated during thermal runaway. The thermal wire 4 is installed within the cavity and connected to the fire extinguishing device 3, adapted to trigger the fire extinguishing device 3 to activate when thermal runaway occurs in the battery cell assembly 21. Specifically, the thermal wire 4 is electrically connected to the fire extinguishing device 3. When thermal runaway is imminent or has already occurred in the battery cell assembly 21 within the cavity of the shell 1, and the temperature inside the shell 1 rises to a preset threshold, the resistance of the thermal wire 4 decreases with increasing temperature, causing the current to flow through the fire extinguishing device 3. The fire extinguishing device 3 then activates and sprays the fire extinguishing medium to create a flame-suppressing environment or extinguish a fire.

[0037] Optionally, the outer casing 1 includes a housing 11 and a cover 12. The cover 12 is connected to the housing 11 to define a receiving cavity. The thermal wire 4 is installed on the cover 12, which is easy to install.

[0038] Optionally, there may be multiple battery cell groups 21, arranged along a first direction to form a battery cell unit 2. A fire extinguishing device 3 is mounted on the housing 11 and located between adjacent battery cell groups 21 within the same battery cell unit 2. Further, a fire extinguishing device 3 is arranged between every two adjacent battery cell groups 21 within the same battery cell unit 2. Even further, each battery cell unit 2 includes two battery cell groups 21, with the fire extinguishing device 3 located between the two battery cell groups 21 within the same battery cell unit 2. That is, in the first direction, the fire extinguishing device 3 is positioned close to the center of the battery pack, which helps reduce differences in fire extinguishing efficiency. This structural layout facilitates the timely application of the extinguishing medium sprayed by the fire extinguishing device 3 to each cell group 21, enabling timely overall coverage of the internal space of the battery pack and reducing differences in extinguishing efficiency. In particular, compared to long battery packs, where space constraints limit the extinguishing medium to the outside of the battery pack and it can only be introduced into the battery pack from the front external interface, when a thermal safety accident occurs at the rear of the battery pack, the fire extinguishing medium at the front cannot diffuse to the rear in time, resulting in low fire extinguishing efficiency and the inability to eliminate safety risks in a timely manner. In this embodiment, the fire extinguishing device 3 is arranged between adjacent cell groups 21, which effectively solves the above problems.

[0039] Optionally, there may be multiple cell assembly units 2, arranged along the second direction. Further, there may be two cell assembly units 2.

[0040] In this utility model, the arrangement direction of multiple battery cell groups 21 within the same battery cell group unit 2 is the same as the first direction, i.e., the X direction in the figure; the arrangement direction of multiple battery cell group units 2 is the same as the second direction, i.e., the Y direction in the figure; the height direction of the battery cell group 21 is the third direction, i.e., the Z direction in the figure.

[0041] Optionally, the fire extinguishing device 3 includes a housing containing a fire extinguishing medium. The housing has multiple media spray nozzles 31 distributed circumferentially on it, which facilitates the uniform spraying of the fire extinguishing medium in all directions to fully cover the components inside the housing 1 and improve the fire extinguishing effect.

[0042] Optional extinguishing media include aerosols, perfluorohexanone, ultrafine dry powder, or other media.

[0043] In the above embodiment, the battery pack, fire extinguishing device 3 and thermal wire 4 are both installed in the receiving cavity of the outer shell 1. The arrangement is flexible and can make full use of the internal space of the outer shell 1. The thermal wire 4 is connected to the fire extinguishing device 3 to activate the fire extinguishing device 3 by temperature changes in the receiving cavity. The structure is simple, requires no maintenance, and helps to reduce costs. In addition, when the battery cell group 21 is about to experience thermal runaway or has experienced thermal runaway, the fire extinguishing device 3 can promptly spray the fire extinguishing medium, which helps to improve fire fighting efficiency.

[0044] See Figures 1 to 6 In some alternative embodiments, the battery cell assembly 21 has a battery cell explosion-proof valve on the side facing the cover 12, and at least a portion of the thermal wire 4 is arranged corresponding to the battery cell explosion-proof valve; wherein, the battery cell assembly 21 includes a plurality of stacked battery cells, and the battery cell explosion-proof valve is provided on the side of the battery cell facing the cover 12.

[0045] Optionally, at least a portion of the thermally sensitive wire 4 is arranged in the area of ​​the cover 12 near the cell explosion-proof valve; or, in the height direction of the cell assembly 21, the projection of at least a portion of the thermally sensitive wire 4 overlaps with the projection of the cell explosion-proof valve, so that the thermally sensitive wire 4 can promptly sense the temperature change around the cell explosion-proof valve and heat up to trigger the activation of the fire extinguishing device 3, so that the fire extinguishing medium can be sprayed in time to form a flame-suppressing environment before the cell assembly 21 experiences thermal runaway, which is beneficial to reduce risks and improve the efficiency of fire extinguishing.

[0046] Optionally, one end of the thermal wire 4 extends along a first direction and is repeatedly bent to form multiple first sensing segments 41 and second sensing segments 42 distributed along a second direction. Adjacent first sensing segments 41 are connected by second sensing segments 42. Each cell assembly unit 2 corresponds to at least one first sensing segment 41 and at least one second sensing segment 42. Further, each cell assembly unit 2 corresponds to two first sensing segments 41 and one second sensing segment 42.

[0047] Optionally, two adjacent first sensing segments 41 are connected in a U-shape via a second sensing segment 42.

[0048] In the battery pack of the above embodiment, the thermal wire 4 corresponds to the cell explosion-proof valve of the cell assembly 21. When the cell assembly 21 is about to experience thermal runaway, the temperature around the cell explosion-proof valve will rise significantly. The thermal wire 4 can sense the temperature change in time and heat up to activate the fire extinguishing device 3. This is beneficial for the fire extinguishing device 3 to start operating in time and spraying the fire extinguishing medium. It is also beneficial for forming a flame-suppressing environment in the housing cavity of the outer shell 1 before the cell assembly 21 completely experiences thermal runaway to prevent combustion, thereby improving safety.

[0049] See Figures 7 to 9 In some optional embodiments, the cover 12 is sealed to the body 11 to form a sealing surface. At least a portion of the thermal wire 4 corresponds to the sealing surface and extends along the inner circumference of the sealing surface. That is, the routing direction of at least a portion of the thermal wire 4 corresponds to the distribution direction of the sealing surface, so that the temperature of the open flame that appears near the sealing surface in the event of thermal runaway can be sensed by the thermal wire 4 near the sealing surface in a timely manner, and the thermal wire 4 can heat up in time to activate the fire extinguishing device 3 to spray the fire extinguishing medium.

[0050] The battery pack of this utility model has a thermal wire 4 and a fire extinguishing device 3 arranged in the receiving cavity of the outer shell 1 of the battery pack. When the ambient temperature in the receiving cavity rises, the thermal wire 4 will trigger the fire extinguishing device 3 to start in time. It is not only simple in structure and maintenance-free, but also flexible in arrangement. It can adapt to the usage needs of different scenarios before and during thermal runaway. It is beneficial to make full use of the internal space of the outer shell 1, reduce the occupation of the external space of the outer shell, reduce costs and improve safety.

[0051] The above embodiments are merely illustrative of the principles and effects of this utility model and are not intended to limit the scope of this utility model. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of this utility model. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in this utility model should still be covered by the claims of this utility model.

Claims

1. A battery pack, characterized in that, include: The outer casing has an internal cavity, and the outer casing includes a box body and a box cover, wherein the box cover is sealed to the box body to form a sealing surface and define the cavity; A battery cell assembly, wherein the battery cell assembly is installed within the receiving cavity; A fire extinguishing device, which is installed in the receiving cavity and is adapted to spray a fire extinguishing medium when in the open state; A thermal wire is installed inside the receiving cavity, the thermal wire is connected to the fire extinguishing device, and is adapted to trigger the fire extinguishing device to open when thermal runaway occurs in the battery pack, at least a portion of the thermal wire corresponds to the sealing surface and extends along the inner circumference of the sealing surface.

2. The battery pack according to claim 1, characterized in that, The thermal wire is installed on the box cover.

3. The battery pack according to claim 2, characterized in that, The battery cell assembly has a battery cell explosion-proof valve on the side facing the box cover, and at least a portion of the thermal wire is arranged corresponding to the battery cell explosion-proof valve.

4. The battery pack according to claim 2, characterized in that, The number of battery cells is multiple, and the multiple battery cells are arranged along a first direction to form a battery cell unit. The fire extinguishing device is installed on the housing and located between two adjacent battery cells within the battery cell unit.

5. The battery pack according to claim 4, characterized in that, The number of battery cell units is multiple, and the multiple battery cell units are distributed along the second direction. The thermal wire extends along the first direction and bends back and forth to form multiple first sensing segments and second sensing segments distributed along the second direction. Two adjacent first sensing segments are connected by the second sensing segments. Each battery cell unit corresponds to at least one first sensing segment and at least one second sensing segment.

6. The battery pack according to claim 5, characterized in that, The two adjacent first sensing segments are connected in a U-shape by the second sensing segment.

7. The battery pack according to claim 5, characterized in that, Each of the battery cell units corresponds to two first induction segments and one second induction segment.

8. The battery pack according to claim 1, characterized in that, The fire extinguishing device includes a housing containing the fire extinguishing medium, and the housing has multiple medium injection ports distributed circumferentially on it.

9. The battery pack according to claim 1 or 8, characterized in that, The extinguishing medium includes aerosol, perfluorohexanone, or ultrafine dry powder.

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