Battery pack upper cover, battery pack shell and battery pack

Abstract

The invention relates to the technical field of batteries, in particular to a battery pack upper cover, a battery pack shell and a battery pack. The battery pack upper cover comprises an upper cover plate, and a cooling pipeline and a buffer heat absorption piece which are arranged in the upper cover plate, the buffering heat absorption piece is provided with a plurality of micropores used for containing and buffering high-temperature substances, and the cooling pipeline makes contact with the buffering heat absorption piece so as to cool the buffering heat absorption piece. When the battery cell is in thermal runaway, the valve is opened, the wall effect and the cold wall effect of the micropores can cool and buffer the high-temperature combustible gas and the high-temperature electrolyte, and the high-temperature impact corrosion of the high-temperature combustible gas and the high-temperature electrolyte on the upper cover plate of the battery pack is relieved; therefore, the wall effect and the cold wall effect of the micropores can be further amplified, the cooling capacity and the high-temperature impact corrosion resistance of the micropores to high-temperature combustible gas and high-temperature electrolyte are improved, and continuous high-temperature baking of flames to the upper cover plate can be restrained.

Description

Technical Field

[0001] The present invention relates to the technical field of batteries, and in particular to a battery pack upper cover, a battery pack shell and a battery pack. Background Art

[0002] Nowadays, electrochemical energy storage related products are widely used in modern commerce, automobiles, industry and other fields. In addition to the normal chemical reactions of charging and discharging, lithium batteries have some side reactions that release heat. When the battery enters an uncontrollable self-heating runaway reaction, it may open the valve, burn or explode.

[0003] When a battery pack experiences thermal runaway, the cells will open valves and release a large amount of flammable gas. Due to the sealed structure of the battery pack, the high-temperature gas will accumulate in the pack and fill the entire box, which is equivalent to placing all the cells in the pack in a temperature box with a temperature of over 100 degrees. The heat cannot be discharged from the box in time, which will cause more cells to experience thermal runaway and cause more serious accidents. In addition, the large amount of flammable gas released by the cells or the flames caused will cause high-temperature impact on the battery pack, causing the pack to fail.

[0004] In order to bring the heat of the high-temperature gas in the battery pack out of the box in time, the current mainstream technical solution in the market is: opening a hole in the battery pack cover or box, installing a pressure relief valve on the hole, when the battery cell thermal runaway opens the valve to exhaust, the high-temperature gas in the box is discharged out of the box when the pressure reaches the critical opening pressure of the battery pack pressure relief valve.

[0005] However, after the valve of the battery cell is opened, high-temperature flammable gas and ungasified high-temperature electrolyte will be ejected from the valve port of the battery cell. The existing technology cannot avoid the high-temperature impact of high-temperature flammable gas and electrolyte on the upper cover of the battery pack. In addition, high-temperature flammable gas and high-temperature electrolyte are corrosive to a certain extent, which will cause deformation and corrosion of the battery pack, and thus cause more serious consequences. Therefore, it is necessary to prevent the impact and corrosion of flammable gas and high-temperature electrolyte on the battery pack box.

[0006] In addition, in extreme cases, battery packs may catch fire due to electrical failure, mechanical failure or overheating. Although existing technologies (such as full flooding firefighting technology) can extinguish the fire after it starts, the fire often starts suddenly and spreads very quickly, causing damage to the box before the firefighting technology is activated. Therefore, it is necessary to prevent the fire from continuously burning the battery pack shell at high temperature. Summary of the invention

[0007] The purpose of the present invention is to provide a battery pack cover to prevent the impact and corrosion of the battery pack shell by combustible gas and high-temperature electrolyte when the battery cell is thermally runaway, and to prevent the continuous high-temperature burning of the battery pack shell by the fire of the deflagration.

[0008] The present invention also provides a battery pack housing and a battery pack having the battery pack upper cover.

[0009] In order to solve the above technical problems, the present invention provides a battery pack cover.

[0010] The battery pack upper cover of the present invention comprises an upper cover plate and a cooling pipeline and a buffer heat absorbing member arranged in the upper cover plate;

[0011] The buffer heat absorbing component has a plurality of micropores for accommodating and buffering high-temperature substances, and the cooling pipeline contacts the buffer heat absorbing component to cool the buffer heat absorbing component.

[0012] Furthermore, one side of the cooling pipeline is fixedly connected to the upper cover plate, and the other side is in contact with the buffer heat absorption component for heat exchange.

[0013] Furthermore, the cooling pipeline includes metal fins and a medium delivery pipeline, the medium delivery pipeline is used to pass cooling medium, and the metal fins are arranged on the medium delivery pipeline and are in contact with the buffer heat absorption component.

[0014] Furthermore, the surface of the cooling pipeline in contact with the buffer heat absorbing component is coated with a thermally conductive structural adhesive.

[0015] Furthermore, the buffer heat absorption component is fixedly connected to the upper cover plate, and a receiving groove is provided in the buffer heat absorption component. The cooling pipeline is arranged in the receiving groove to perform heat exchange with the buffer heat absorption component.

[0016] Furthermore, the area of ​​the projection of the micropore on any plane perpendicular to the pore depth direction of the micropore is less than or equal to 5 mm 2 .

[0017] Furthermore, the buffer heat absorption component includes a plurality of porous plates stacked along the thickness direction, each of the porous plates is provided with a plurality of through holes, and the through holes on the plurality of porous plates are at least partially staggered so that the through holes between the plurality of porous plates overlap with each other to form the micropores.

[0018] Furthermore, the projection area of ​​the through hole on any plane perpendicular to the depth direction of the through hole is between 1 and 100 mm. 2 between.

[0019] Furthermore, the through hole has a shape of one or more of a polygon or a circle.

[0020] Furthermore, the buffer heat-absorbing component is made of a polyimide-type aromatic heterocyclic polymer compound.

[0021] The present invention also provides a battery pack housing, comprising a box body and a battery pack upper cover as described in any one of the above technical solutions for closing the box body.

[0022] The present invention also provides a battery pack, comprising a battery pack shell and a battery cell located in the battery pack shell, wherein the battery pack shell comprises a box body and a battery pack top cover as described in any one of the above technical solutions for closing the box body.

[0023] Compared with the prior art, the present invention has at least the following beneficial effects:

[0024] When the battery cell is thermally out of control, the valve will open, and the high-temperature combustible gas and unvaporized high-temperature electrolyte in the battery cell will be ejected from the battery cell valve port and enter the micropores of the buffer heat absorption component, reducing the amount of high-temperature combustible gas and high-temperature electrolyte falling back onto the battery cell. In addition, the wall effect and cold wall effect of the micropores can not only cool down and buffer the high-temperature combustible gas and high-temperature electrolyte, alleviate the high-temperature impact corrosion of the high-temperature combustible gas and high-temperature electrolyte on the upper cover of the battery pack, but also greatly reduce the risk of heat spread and heat accumulation. Because the cooling pipeline can cool the buffer heat absorption component, the wall effect and cold wall effect of the micropores can be further amplified, thereby improving the cooling capacity of the micropores for the high-temperature combustible gas and high-temperature electrolyte and the ability to resist high-temperature impact corrosion, and can also curb the continuous high-temperature baking of the upper cover by the flame. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 A schematic diagram of the structure of a battery pack in one embodiment of the present invention;

[0026] Figure 2 for Figure 1 A schematic diagram of the structure of a battery pack with a partial cutaway showing the cooling pipes;

[0027] Figure 3 for Figure 1 A schematic diagram of the structure of the battery pack after the upper cover hides the local structure;

[0028] Figure 4 for Figure 1 Exploded view of the parts of the battery pack cover;

[0029] Figure 5 for Figure 4 A schematic diagram of the structure of the upper cover plate of the battery pack upper cover;

[0030] Figure 6 for Figure 4 Schematic diagram of the coordination between the battery pack cover and the cooling pipe;

[0031] Figure 7 for Figure 1 A schematic diagram of the structure of the battery pack cover from another perspective;

[0032] Figure 8 for Figure 7 A partial schematic diagram of a partially cutaway upper cover of a battery pack;

[0033] Fig. 9 for Figure 1 A schematic diagram of the partial structure of the buffer heat absorbing member of the upper cover of the battery pack;

[0034] Fig.10 for Fig. 9 A partial cross-sectional view of the buffer heat absorbing member in FIG.

[0035] Fig.11 for Fig. 9 A partial cross-sectional view of another embodiment of the buffer heat absorbing member in FIG.

[0036] Reference numerals:

[0037] 100. Battery pack cover;

[0038] 110, upper cover plate; 111, opening; 112, fixing plate;

[0039] 120. Cooling pipeline;

[0040] 130. Buffer heat absorbing member; 131. Perforated plate; 132. Through hole;

[0041] 200, box body;

[0042] 300. Battery cell. DETAILED DESCRIPTION

[0043] The battery pack cover, battery pack housing and battery pack of the present invention will be described below in conjunction with schematic diagrams, wherein preferred embodiments of the present invention are shown. It should be understood that those skilled in the art may modify the present invention described herein while still achieving the advantageous effects of the present invention. Therefore, the following description should be understood as being widely known to those skilled in the art and not as a limitation of the present invention.

[0044] The serial numbers of the components herein, such as "first", "second", etc., are only used to distinguish the objects described and do not have any order or technical meaning. The "connection" and "coupling" mentioned in this application, unless otherwise specified, include direct and indirect connections (couplings). In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", etc. are based on the orientation or positional relationship shown in the accompanying drawings, which is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation to the present invention.

[0045] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0046] In this application, unless otherwise specified or limited, the term "connection" should be understood in a broad sense. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection or an indirect connection through an intermediate medium. In addition, the term "electrical connection" can be a direct electrical connection or an indirect electrical connection through an intermediate medium.

[0047] The present invention is described in more detail in the following paragraphs by way of example with reference to the accompanying drawings. The advantages and features of the present invention will become more apparent from the following description and claims. It should be noted that the drawings are in very simplified form and in non-precise proportions, and are only used to facilitate and clearly assist in illustrating the purpose of the embodiments of the present invention.

[0048] The following is attached to the instruction manual Figure 1 To Attachment Fig.10 , the battery pack cover, battery pack shell and battery pack of the present invention are introduced.

[0049] In one embodiment, if Figure 1 and Figure 2 As shown, the present invention provides a battery pack, which includes a battery pack shell and a battery cell 300 located in the battery pack shell. The battery pack shell includes a box body 200 and a battery pack cover 100 for closing the box body 200.

[0050] Since the battery cell 300 will generate heat during normal operation, in order to stabilize the battery cell 300 in the battery pack shell within a reasonable temperature range, a heat dissipation pipeline is provided in the box body 200, and a heat dissipation medium passes through the heat dissipation pipeline. The heat dissipation pipeline is preferably arranged at the bottom of the box body 200. In other embodiments, the heat dissipation pipeline can also be arranged on the side wall of the box body 200.

[0051] In order to prevent the combustible gas and high-temperature electrolyte from impacting and corroding the battery pack shell when the battery cell 300 is thermally runaway, and to prevent the fire from continuously burning the battery pack shell at high temperature, Figures 3 to 7 As shown, the battery pack upper cover 100 includes an upper cover plate 110 and a cooling pipeline 120 and a buffer heat absorption member 130 arranged in the upper cover plate 110 .

[0052] like Fig. 9 As shown, the buffer heat absorbing member 130 has a plurality of micropores for accommodating and buffering high-temperature substances, the cooling pipeline 120 contacts the buffer heat absorbing member 130 to cool the buffer heat absorbing member 130, and the inlet and outlet of the cooling pipeline 120 extend from the upper cover plate 110 for the cooling medium to flow in and out. The high-temperature substances include high-temperature combustible gas and ungasified high-temperature electrolyte.

[0053] When the battery cell 300 is in thermal runaway, the valve will open, and the high-temperature combustible gas and ungasified high-temperature electrolyte in the battery cell 300 will be ejected from the valve port of the battery cell 300 and enter the micropores of the buffer heat absorption component 130, reducing the amount of high-temperature combustible gas and high-temperature electrolyte falling back onto the battery cell 300. In addition, the wall effect and cold wall effect of the micropores can not only cool down and buffer the high-temperature combustible gas and high-temperature electrolyte, alleviate the high-temperature impact corrosion of the high-temperature combustible gas and high-temperature electrolyte on the battery pack cover 100, but also greatly reduce the risk of heat spread and heat accumulation. Because the cooling pipeline 120 can cool the buffer heat absorption component 130, the wall effect and cold wall effect of the micropores can be further amplified, thereby improving the cooling capacity of the micropores for the high-temperature combustible gas and high-temperature electrolyte and the ability to resist high-temperature impact corrosion, and can also curb the continuous high-temperature baking of the upper cover 110 by the flame.

[0054] Among them, the wall effect refers to reducing the flame propagation space, reducing the collision probability between flame free radicals and reaction molecules (such as oxygen molecules), increasing the collision between free radicals in the flame and the wall of the propagation channel, reducing the number of free radicals and thus increasing the heat loss of the flame, which prevents the spread of flame.

[0055] The cold wall effect refers to the fact that the presence of micropores increases the area of ​​the flame and the propagation channel, increasing the heat loss of the flame. Furthermore, when high-temperature combustible gas or high-temperature electrolyte splashes onto the micropores, the cold wall effect also plays a role, reducing the temperature of the combustible gas and electrolyte and reducing the risk of heat spread.

[0056] It should be noted that when the battery cell 300 is working normally, no cooling medium is passed into the cooling pipe 120 in the battery pack upper cover 100, and the heat dissipation pipe provided in the box 200 dissipates heat from the battery cell 300. The cooling pipe 120 is controlled by the battery management system. When the battery management system detects that the battery cell 300 has thermal runaway, a cooling medium is passed into the cooling pipe 120. The cooling medium can be liquid or gaseous.

[0057] The size of the micropores cannot be too large, otherwise it is difficult to give full play to the cold wall effect and the wall effect of the micropores. Preferably, the area of ​​the projection of the micropores on any plane perpendicular to the depth direction of the micropores is less than or equal to 5 mm. 2 .

[0058] In one embodiment, if Figure 4 , Fig. 9 , Fig.10 and Fig.11 As shown, in order to form the micropores, the buffer heat absorber 130 includes a plurality of porous plates 131 stacked in the thickness direction, each of the porous plates 131 is provided with a plurality of through holes 132, and the through holes 132 on the plurality of porous plates 131 are at least partially staggered so that the through holes 132 between the plurality of porous plates 131 overlap with each other to form the micropores. In this way, the processing difficulty of the buffer heat absorber 130 can be reduced, the production cost can be reduced, and mass production can be achieved.

[0059] For example, in this embodiment, if Fig.10 As shown, the projection area of ​​the micropore on any plane perpendicular to the pore depth direction of the micropore is 5 mm 2 In other embodiments, it can also be 1mm 2 or 3mm 2 .

[0060] In another embodiment, if Fig.11 As shown, the area of ​​the projection of the micropore on any plane perpendicular to the depth direction of the micropore is 0. At this time, the formed micropore is a completely tortuous channel. The flame or electrolyte cannot pass through the micropore along a straight path, but can move forward in the micropore through the tortuous channel. This structure can further amplify the wall effect and cold wall effect of the micropore, and improve the cooling capacity of the micropore for high-temperature combustible gas and high-temperature electrolyte and the ability to resist high-temperature impact corrosion.

[0061] Preferably, the projection area of ​​the through hole 132 on any plane perpendicular to the hole depth direction of the through hole 132 is 1-100 mm. 2 The through holes 132 of the plurality of porous plates 131 are stacked in an offset manner to form the micropores.

[0062] For example, in this embodiment, the projection area of ​​the through hole 132 on any plane perpendicular to the hole depth direction of the through hole 132 is 2, 3 or 6 mm. 2 .

[0063] The through hole 132 may be in a polygonal or circular shape or more. For example, the through hole 132 may be in a square, a triangle, a circle or other irregular shapes or more.

[0064] The buffer heat absorber 130 needs to have the characteristics of low unit density, high temperature resistance, acid and alkali corrosion resistance, and also needs to have certain mechanical properties. Preferably, a polyimide (PI) type aromatic heterocyclic polymer compound can be used, and its pyrolysis temperature is as high as 600°C, which is enough to meet the high temperature of the flame caused by thermal runaway and electrical short circuit of the battery cell 300. Of course, other materials that meet the characteristics of low unit density, high temperature resistance, and acid and alkali corrosion resistance can also be selected to make the buffer heat absorber 130.

[0065] In one embodiment, if Figure 7 As shown, the battery pack upper cover 100 also includes a fixing plate 112, on which a plurality of bolt holes are provided. The buffer heat absorption component 130 is fixed to the upper cover plate 110 through the fixing plate 112 and a portion of the bolt holes, and another portion of the bolt holes can also be used to install the cooling pipeline 120.

[0066] In one embodiment, if Figure 8 As shown, the side of the upper cover plate 110 is also provided with a plurality of openings 111, and a pressure relief valve is installed in the opening 111. When the air pressure in the battery pack is too high, the pressure relief valve opens to exhaust air to prevent the battery pack from exploding due to excessive air pressure.

[0067] In one embodiment, one side of the cooling pipeline 120 is fixedly connected to the upper cover plate 110 , and the other side is in contact with the buffer heat absorbing element 130 for heat exchange.

[0068] In this embodiment, the cooling pipeline 120 exchanges heat with the buffer heat absorbing component 130 through the side. The advantage of this installation method is that the installation is more convenient and the cost is lower.

[0069] Furthermore, in order to improve the heat exchange capacity, the cooling pipeline 120 includes metal fins and a medium delivery pipeline, the medium delivery pipeline is used to pass the cooling medium, and the metal fins are arranged on the medium delivery pipeline and in contact with the buffer heat absorbing member 130. The metal fins can increase the heat exchange area between the cooling pipeline 120 and the buffer heat absorbing member 130, thereby improving the heat exchange efficiency and improving the cooling capacity of the buffer heat absorbing member 130.

[0070] Furthermore, in one of the embodiments, a thermally conductive structural adhesive may be coated on the surface of the cooling pipeline 120 that contacts the buffer heat absorption component 130 , so as to further improve the cooling capacity of the cooling pipeline 120 on the buffer heat absorption component 130 .

[0071] In another embodiment, the buffer heat absorption member 130 is fixedly connected to the upper cover plate 110 , and a receiving groove is provided in the buffer heat absorption member 130 . The cooling pipeline 120 is provided in the receiving groove to perform heat exchange with the buffer heat absorption member 130 .

[0072] Specifically, the contour of the accommodating groove is the same as the contour of the cooling pipe 120, so that the cooling pipe 120 can be buried in the buffer heat absorption component 130 to increase the contact area with the buffer heat absorption component 130, thereby improving the heat exchange efficiency between the two and improving the cooling capacity of the cooling pipe 120 on the buffer heat absorption component 130.

[0073] The present invention further provides a battery pack shell, the structure of which is the same as that of the battery pack shell of the battery pack in the above embodiment, and will not be described in detail herein.

[0074] The present invention further provides a battery pack upper cover, the structure of which is the same as the structure of the battery pack upper cover of the battery pack shell in the above-mentioned embodiment, and will not be described in detail here.

[0075] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. A battery pack cover, characterized in that: It comprises an upper cover plate and a cooling pipeline and a buffer heat absorbing member arranged in the upper cover plate; The buffer heat absorbing component has a plurality of micropores for accommodating and buffering high-temperature substances, and the cooling pipeline contacts the buffer heat absorbing component to cool the buffer heat absorbing component.

2. The battery pack cover according to claim 1, characterized in that: One side of the cooling pipeline is fixedly connected to the upper cover plate, and the other side is in contact with the buffer heat absorbing component for heat exchange.

3. The battery pack cover according to claim 2, characterized in that: The cooling pipeline includes metal fins and a medium delivery pipeline, the medium delivery pipeline is used to pass cooling medium, and the metal fins are arranged on the medium delivery pipeline and are in contact with the buffer heat absorption component.

4. The battery pack cover according to claim 2, characterized in that: The surface of the cooling pipeline in contact with the buffer heat absorbing component is coated with heat conductive structural glue.

5. The battery pack cover according to claim 1, characterized in that: The buffer heat absorbing component is fixedly connected to the upper cover plate, and a receiving groove is arranged in the buffer heat absorbing component. The cooling pipeline is arranged in the receiving groove to perform heat exchange with the buffer heat absorbing component.

6. The battery pack cover according to claim 1, characterized in that: The projection area of ​​the micropore on any plane perpendicular to the depth direction of the micropore is less than or equal to 5 mm 2 .

7. The battery pack cover according to claim 1, characterized in that: The buffer heat absorber comprises a plurality of porous plates stacked in the thickness direction, each of the porous plates is provided with a plurality of through holes, and the through holes on the plurality of porous plates are at least partially staggered so that the through holes between the plurality of porous plates overlap with each other to form the micropores.

8. The battery pack cover according to claim 7, characterized in that: The projection area of ​​the through hole on any plane perpendicular to the depth direction of the through hole is 1-100 mm 2 between.

9. The battery pack cover according to claim 7, characterized in that: The through hole has a shape of one or more of a polygon or a circle.

10. The battery pack cover according to claim 1, characterized in that: The buffer heat absorbing component is made of a polyimide aromatic heterocyclic polymer compound.

11. A battery pack housing, characterized in that: A battery pack upper cover as claimed in any one of claims 1 to 10 comprising a box body and a box body for closing the box body.

12. A battery pack, characterized in that: The invention comprises a battery pack shell and a battery cell located in the battery pack shell, wherein the battery pack shell comprises a box body and a battery pack upper cover as claimed in any one of claims 1 to 10 for closing the box body.

Images