Battery pack and liquid storage plate thereof

Abstract

The utility model belongs to the field of cooling of secondary batteries, and particularly provides a battery pack and a liquid storage plate thereof. The battery pack comprises a box body, a battery cell is arranged in the box body, the battery pack further comprises a liquid storage plate located above the battery cell and connected with the box body, the liquid storage plate comprises a shell provided with a connecting structure used for being connected with the box body, the interior of the shell is a closed cavity, insulated phase change liquid is stored in the cavity, and the shell is configured to be molten through when the set temperature is reached. Therefore, the stored phase change liquid flows out. The liquid storage plate is used in the battery pack. According to the utility model, the liquid storage plate is additionally arranged above the battery cell in the battery pack, when the battery cell at a certain position is in thermal runaway, the instantaneous high temperature enables the shell to be melted through, the internal phase change liquid flows out, flows downwards under the action of self weight, and is subjected to phase change vaporization to take away heat, which is equivalent to active heat dissipation, so that an active heat suppression effect is achieved, and continuous spreading of the heat is avoided.

Description

Technical Field

[0001] This utility model belongs to the field of cooling for secondary batteries, and in particular relates to a battery pack and its liquid storage plate. Background Technology

[0002] The battery pack consists of a casing and several battery cells arranged and connected in a predetermined manner within the casing. The casing comprises a lower casing and a cover. During charging and discharging (e.g., overcharging, short circuits) or when subjected to mechanical damage, the internal temperature of some battery cells may rise abnormally for a short period, accelerating the internal chemical reactions and causing the explosion-proof valve to rupture, releasing high-temperature gases, electrolytes, and other high-temperature media. The thermal propagation of these high-temperature media within the casing can easily lead to thermal runaway in other battery cells, ultimately causing a major accident.

[0003] To address the above issues, existing technologies generally employ heat insulation to prevent the spread of heat from thermally runaway cells. For example, utility model patent CN214411404U discloses a lithium battery pack with a function to prevent the spread of thermal runaway. This battery pack includes a casing (i.e., a lower casing), a casing cover, a buffer layer, and a ceramic plate. The buffer layer is fixed to one side of the casing cover, and the ceramic plate is semi-fixed at the bottom of the buffer layer, directly above the cells. The heat resistance and insulation properties of the ceramic plate prevent the heat generated by the cells at the location of thermal runaway from spreading outwards.

[0004] While placing a heat insulation structure (such as a ceramic plate) above the battery cell can block heat transfer to some extent, the heat cannot dissipate quickly, and there is still a high risk of thermal runaway. Utility Model Content

[0005] The purpose of this invention is to provide a battery pack that solves the technical problem in existing battery packs where heat is difficult to dissipate when a cell experiences thermal runaway. Another purpose of this invention is to provide a liquid reservoir plate for the battery pack to solve the same technical problem.

[0006] To achieve the above objectives, the technical solution for the battery pack provided by this utility model is as follows:

[0007] A battery pack includes a housing containing battery cells, and a liquid storage plate located above the battery cells and connected to the housing. The liquid storage plate includes a housing with a connection structure for connecting to the housing. The housing has a sealed cavity inside, and the cavity stores an insulating phase change liquid. The housing is configured to melt through when a set temperature is reached, so that the stored phase change liquid can flow out.

[0008] As a further improvement, the outer shell is provided with an injection port for adding phase change liquid into the cavity, and the liquid storage plate is equipped with a sealing element to seal the injection port.

[0009] As a further improvement, the sealing component is a pressure relief valve.

[0010] As a further improvement, the box body includes a lower box body, an outer shell and a top sealing connection between the lower box body, and a liquid storage plate forming the box cover.

[0011] As a further improvement, the connection structure of the housing configuration includes mounting holes located around the perimeter of the housing for fastening screws to pass through, so as to secure and seal the housing to the lower housing by means of fastening screws.

[0012] As a further improvement, the housing includes a lower housing and a lid, with a liquid storage plate located between the housing and the lid.

[0013] This utility model is an improved invention, and its beneficial effects are: This utility model adds a liquid storage plate above the battery cell in the battery pack. When the battery cell experiences thermal runaway at a certain point, the instantaneous high temperature causes the outer shell to melt through, and the internal phase change liquid flows out. Under its own weight, it flows downward and undergoes phase change vaporization to carry away the heat, which is equivalent to active heat dissipation, achieving an active thermal suppression effect and preventing the heat from spreading continuously.

[0014] To achieve the above objectives, the technical solution for the electrolyte storage plate of the battery pack provided by this utility model is as follows:

[0015] A liquid storage plate for a battery pack includes a housing, the housing being configured with a connection structure for connection to the battery pack housing, the interior of the housing being a sealed cavity for storing an insulating phase change liquid, and the housing being configured to melt through upon reaching a set temperature to allow the stored phase change liquid to flow out.

[0016] As a further improvement, the outer shell is provided with an injection port for adding phase change liquid into the cavity, and the liquid storage plate is equipped with a sealing element to seal the injection port.

[0017] As a further improvement, the sealing component is a pressure relief valve.

[0018] As a further improvement, the connection structure of the housing configuration includes mounting holes located around the perimeter of the housing for fastening screws to pass through.

[0019] This invention is a pioneering creation, and its beneficial effects are as follows: The cavity inside the liquid storage plate of this invention can be used to store insulating phase change liquid. In use, it is connected to the battery pack housing through a connecting structure to form a battery pack with a liquid storage plate. When a cell in a certain part of the battery pack experiences thermal runaway, the instantaneous high temperature causes the outer shell to melt and break through, and the internal phase change liquid flows out. Under its own weight, it flows downward, undergoes phase change vaporization, and carries away the heat, which is equivalent to active heat dissipation, achieving an active thermal suppression effect and preventing the continuous spread of heat. Attached Figure Description

[0020] Figure 1This is an exploded view of the battery pack embodiment of this utility model.

[0021] Explanation of reference numerals in the attached figures:

[0022] 1. Lower casing; 2. Battery module; 3. Liquid reservoir plate; 4. Box cover; 301. Liquid filling port. Detailed Implementation

[0023] To better suppress thermal runaway in battery packs, the basic technical concept of this invention is to add a liquid reservoir plate inside the battery pack. The liquid reservoir plate stores an insulating phase change liquid. When thermal runaway occurs at a certain point in the battery cell, the resulting high temperature can cause the liquid reservoir plate to melt and break through, allowing the phase change liquid to flow out. The phase change liquid flows to the location of the thermal runaway and vaporizes, carrying away heat and actively suppressing heat propagation. The following detailed description of this invention, in conjunction with embodiments, further illustrates this invention.

[0024] Specific embodiments of the battery pack provided by this utility model:

[0025] As a most basic implementation example, such as Figure 1 As shown, the battery pack includes a housing, inside which are battery cells arranged and connected in a predetermined manner (series, parallel, etc.) to form a battery module 2. The battery pack also includes a liquid reservoir plate 3 located above the battery cells (explosion-proof valves are generally located on top of the battery cells), which is connected to the housing. The liquid reservoir plate 3 includes a shell with a connection structure for connecting to the housing; that is, the liquid reservoir plate 3 is connected to the housing via the connection structure on the shell. The shell is a hollow structure with a sealed cavity inside, which stores an insulating phase change liquid (e.g., fluorinated liquid). The shell is configured to melt through when a predetermined temperature is reached (or exceeded), allowing the stored phase change liquid to flow out from the melt-through point. The predetermined temperature is not limited here; it is related to the temperature of the medium ejected by the explosion-proof valve of the battery cell, ensuring that the temperature of the medium ejected by the explosion-proof valve is sufficient to melt through the shell. The shell can be made of plastic, which facilitates molding and melting through. Of course, the outer shell can also be made of metal, such as aluminum alloy, but in this case, the aluminum alloy should not be too thick to ensure that it can be melted through.

[0026] Analysis of the above structure shows that if thermal runaway occurs at a certain location in the battery cell, the ejected high-temperature medium can cause the outer casing to melt through. After melting through, the phase change liquid flows out, absorbs heat, and vaporizes, thereby achieving the effects of active cooling and thermal suppression. Moreover, the phase change liquid is stored in the liquid storage plate 3, and there is no need to connect it to a flow pipe, making the structure simple.

[0027] As a preferred embodiment for facilitating the manufacture and dispensing of phase change liquids, such as Figure 1As shown, the outer shell of the liquid storage plate 3 is provided with a liquid injection port 301, through which phase change liquid can be added to the cavity. Of course, to ensure the airtightness of the cavity, the liquid storage plate 3 is equipped with a sealing component to seal the liquid injection port 301. This allows the outer shell to be manufactured as a whole, and the phase change liquid to be added later.

[0028] It should be noted that in other embodiments, a separate injection port 301 may not be configured. Instead, an opening on one side can be pre-reserved during the manufacturing of the liquid storage plate 3, and the opening can be sealed after the phase change liquid is added. Clearly, the solution with the injection port 301 is more convenient.

[0029] Considering that the battery pack also dissipates heat during normal operation, and to prevent the phase change material from leaking out due to accidental thermal expansion and rupture of the outer casing, as a preferred embodiment, a pressure relief valve is preferably used as the sealing component for sealing the injection port 301. The specific structure of the pressure relief valve is existing technology. The pressure relief valve can release pressure and regulate the pressure difference between the inside and outside of the liquid reservoir plate 3.

[0030] Of course, in other embodiments, the sealing component may not use a pressure relief valve; for example, a threaded plug or a cover plate may be used.

[0031] Figure 1 In the illustrated embodiment, the housing includes a lower housing 1 and a housing cover 4, with the housing cover 4 connected to the lower housing 1. A liquid reservoir 3 is located between the housing cover 4 and the lower housing 1. In this configuration, the liquid reservoir 3 can be connected either to the lower housing 1 or to the inner side of the housing cover 4. Thus, the liquid reservoir 3 is located within a closed space inside the housing and is fully protected by the housing, making it suitable for applications with high vibration levels, such as for use as a vehicle power battery.

[0032] In other embodiments, the box body may not include a separate box cover 4, but rather the box cover 4 is formed by the liquid storage plate 3. Specifically, with Figure 1 For example, the outer shell of the liquid storage plate 3 is sealed to the top of the lower housing 1, which still ensures that the battery module 2 is in a sealed housing space, making the battery pack structure simpler. This type of battery pack is suitable for applications with low vibration, such as energy storage cabinets.

[0033] As a preferred embodiment that makes the connection between the liquid reservoir 3 and the lower housing 1 more reliable, the connection structure of the outer casing includes mounting holes located around the perimeter of the outer casing. These mounting holes allow fastening screws to pass through, enabling the outer casing and the lower housing 1 to be fastened and sealed together. Of course, sealing rings can be added if necessary. The number of mounting holes is not limited here, as long as a proper connection and seal are achieved.

[0034] In other embodiments, adhesive can be used to connect the lower housing 1 and the liquid storage plate 3, and the adhesive joint can serve as a seal.

[0035] Specific embodiments of the liquid storage plate of the battery pack in this utility model:

[0036] The embodiment of the liquid reservoir plate is the same as the liquid reservoir plate described in the embodiment of the battery pack above, and will not be described in detail here.

[0037] Finally, it should be noted that the above description is only a preferred embodiment of this utility model and is not intended to limit this utility model. Although this utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art can still make modifications to the technical solutions described in the foregoing embodiments without creative effort, or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A battery pack, comprising a housing, wherein battery cells are disposed inside the housing, characterized in that, It also includes a liquid storage plate located above the battery cell and connected to the housing. The liquid storage plate includes a housing with a connection structure for connecting to the housing. The interior of the housing is a sealed cavity containing an insulating phase change liquid. The housing is configured to melt through when a set temperature is reached, so that the stored phase change liquid can flow out.

2. The battery pack according to claim 1, characterized in that, The outer shell is provided with an injection port for adding phase change liquid into the cavity, and the liquid storage plate is equipped with a sealing element to seal the injection port.

3. The battery pack according to claim 2, characterized in that, The sealing component is a pressure relief valve.

4. The battery pack according to any one of claims 1-3, characterized in that, The enclosure includes a lower enclosure, an outer shell, and a sealed connection between the top of the lower enclosure and the liquid storage plate, which forms the enclosure cover.

5. The battery pack according to claim 4, characterized in that, The connection structure of the housing configuration includes mounting holes located around the perimeter of the housing for fastening screws to pass through, so as to secure and seal the housing to the lower housing by means of fastening screws.

6. The battery pack according to any one of claims 1-3, characterized in that, The tank consists of a lower tank and a cover, with a liquid storage plate located between the tank and the cover.

7. A liquid reservoir plate for a battery pack, characterized in that, The device includes an outer casing with a connection structure for connecting to the housing of a battery pack. The interior of the casing is a sealed cavity for storing an insulating phase change liquid. The casing is configured to melt through when a set temperature is reached, so that the stored phase change liquid can flow out.

8. The electrolyte reservoir plate of the battery pack according to claim 7, characterized in that, The outer shell is provided with an injection port for adding phase change liquid into the cavity, and the liquid storage plate is equipped with a sealing element to seal the injection port.

9. The electrolyte reservoir plate of the battery pack according to claim 8, characterized in that, The sealing component is a pressure relief valve.

10. The electrolyte reservoir of the battery pack according to any one of claims 7-9, characterized in that, The connection structure of the housing configuration includes mounting holes located around the perimeter of the housing for fastening screws to pass through.

Images