Battery pack

Abstract

A battery pack, comprising a case, a cell assembly, and a liquid cooling plate. The cell assembly is arranged in the case, and the liquid cooling plate is arranged in the case. The liquid cooling plate is provided with liquid cooling channels and first airflow channels, and each first airflow channel is provided with an air inlet and an air outlet. Liquid cooling sub-plates are in communication with a main plate by means of a liquid guide pipe, and a cooling liquid enters the liquid cooling channels by means of the liquid guide pipe. The liquid guide pipe comprises a liquid inlet end and a liquid outlet end. The liquid inlet end is in communication with the sub-plates, and the liquid outlet end comprises a first section and a second section. A liquid outlet of the first section is located in the liquid cooling channel of the main plate, and a liquid inlet of the second section is located in the liquid cooling channel of the main plate. The cooling liquid flows from the liquid outlet of the first section into the liquid cooling channel of the main plate, and is then directed out of the case by means of the liquid inlet of the second section. Therefore, in the present solution, when the cell assembly undergoes thermal runaway, the safety of the battery pack can be improved by cooling gas in the first airflow channels, and by means of the design of the first section and the second section, installation is facilitated, and later maintenance is facilitated.

Description

A battery pack

[0001] Cross Reference to Related Applications

[0002] The present application claims priority to the Chinese patent application No. 202422291346.3, filed on September 19, 2024, and entitled "A battery pack", the content of which is incorporated herein by reference in its entirety. TECHNICAL FIELD

[0003] The present application relates to the field of new energy materials, in particular to a battery pack. BACKGROUND

[0004] With the gradual strengthening of global environmental protection awareness and the gradual implementation of relevant regulations and policies, electric vehicles, as a green transportation tool, are gradually occupying a dominant position in the market. As the core power source of electric vehicles, the performance of lithium batteries directly affects the key performance indicators such as safety, range, and life of the whole vehicle. However, in actual application, lithium batteries will generate a large amount of heat during operation. If this heat cannot be effectively dissipated, it will cause the battery temperature to rise, thereby affecting the performance and life of the battery, and even may cause battery thermal runaway and other safety hazards.

[0005] When lithium batteries are working, the complex chemical reactions inside them will generate a large amount of heat. For example, the cells in the traditional battery pack are usually arranged in a close manner to reduce the volume and increase the energy density. However, this arrangement also leads to a longer heat conduction path between the cells, making it difficult for heat to be quickly dissipated, and the air flow in the battery pack is not smooth, forming a space for heat accumulation. If this heat cannot be effectively dissipated from the battery pack in time, the battery temperature will rise rapidly, which not only accelerates the aging process of the battery and shortens its service life, but also may cause serious safety problems such as battery thermal runaway. In addition, the temperature difference inside the battery pack will also cause uneven internal resistance and capacity between the cells, further reducing the overall performance of the battery. SUMMARY

[0006] The main purpose of the present application is to provide a battery pack that can improve the safety of the battery pack by cooling the gas in the first gas flow channel when the cell assembly experiences thermal runaway, and through the design of the first segment and the second segment, the battery pack of the present application is easy to install and maintain.

[0007] To achieve the above-mentioned purpose, some embodiments of the present application provide a battery pack, comprising:

[0008] a shell;

[0009] a cell assembly arranged in the shell;

[0010] The liquid cooling plate is arranged in the shell, and is attached to the battery cell assembly or is arranged at intervals between the liquid cooling plate and the battery cell assembly to cool the battery cell assembly. The liquid cooling plate is provided with a liquid cooling channel and a first airflow channel which are isolated from each other. The first airflow channel has an air inlet and an air outlet. The air inlet is used to obtain the gas generated after the battery cell assembly is in thermal runaway. The air outlet is used to discharge the gas in the first airflow channel from the shell. The liquid cooling plate further includes a mother plate and a daughter plate. The mother plate and the daughter plate are both provided with a liquid cooling channel and a first airflow channel. The battery pack includes a liquid guide pipe. The liquid cooling channel of the daughter plate is connected to the liquid cooling channel of the mother plate through the liquid guide pipe. The cooling liquid enters the liquid cooling channels of the daughter plate and the mother plate through the liquid guide pipe.

[0011] The liquid guide pipe includes an inlet end and an outlet end. The inlet end is connected to the daughter plate. The outlet end includes a first segment and a second segment. The first segment and the second segment are located on opposite sides of the mother plate. The outlet of the first segment is connected to the liquid cooling channel of the mother plate. The inlet of the second segment is connected to the liquid cooling channel of the mother plate. The cooling liquid flows into the liquid cooling channel of the mother plate through the outlet of the first segment, and then is guided out of the shell through the inlet of the second segment.

[0012] In some embodiments, in the vertical direction, the liquid cooling channel is located above the first airflow channel. The shell has a first direction. The liquid cooling channel and the first airflow channel both extend along the first direction. The first direction and the vertical direction intersect.

[0013] In some embodiments, the liquid cooling plate includes a plurality of daughter plates. The battery cell assembly includes a battery cell. The plurality of daughter plates are arranged at intervals along a second direction. The battery cell is located between adjacent two daughter plates in the plurality of daughter plates and / or between the daughter plate and the mother plate. The battery cell is adapted to be attached.

[0014] In some embodiments, only one battery cell can be arranged between adjacent liquid cooling plates, or a plurality of battery cells can be arranged side by side along the first direction.

[0015] In some embodiments, the shell is square. The width direction of the shell is configured as the first direction. The length direction of the shell is configured as the second direction. The height direction of the shell is configured as the vertical direction. The first direction, the second direction and the vertical direction are perpendicular to each other.

[0016] In some embodiments, the mother plate is located on one side of the plurality of daughter plates.

[0017] In some embodiments, the mother plate is located between each of the plurality of daughter plates.

[0018] In some embodiments, the liquid cooling plate includes a partition plate extending along the first direction. The partition plate divides the liquid cooling plate into an upper cavity and a lower cavity in the vertical direction. The upper cavity is configured as the liquid cooling channel. The lower cavity is configured as the first airflow channel.

[0019] In some embodiments, the mother board is located at one side of the battery pack, the daughter boards are arranged in the housing in the second direction at intervals, and surfaces of the daughter boards and the mother board are parallel to the first direction.

[0020] In some embodiments, the battery cell includes a first explosion-proof valve, the housing includes a mounting position, the mounting position includes a first opening, the battery cell is mounted in the mounting position, and the first explosion-proof valve covers the first opening.

[0021] The housing includes a second airflow channel, the second airflow channel is arranged on a bottom plate of the housing bearing the battery cell, the first opening is connected to the second airflow channel, the second airflow channel is connected to the first airflow channel, and the first opening is configured as an air inlet.

[0022] In some embodiments, the second airflow channel extends in the second direction, the mother board includes a second opening, and the second opening is connected to the first airflow channel and the second airflow channel; and / or,

[0023] The daughter board includes a second opening, and the second opening is connected to the first airflow channel and the second airflow channel.

[0024] In some embodiments, the second airflow channel extends through the liquid cooling plate in the second direction.

[0025] In some embodiments, in the second direction, a position of the first section close to the mother board is arc-shaped.

[0026] In some embodiments, the housing includes a third airflow channel, the liquid cooling plate includes a third opening, and the third opening is connected to the first airflow channel and the third airflow channel.

[0027] The battery pack includes a second explosion-proof valve, the housing includes a mounting hole, the second explosion-proof valve is mounted in the mounting hole, the mounting hole is connected to the third airflow channel, and the mounting hole is configured as an air outlet.

[0028] In some embodiments, the battery pack includes a gas guide pipe, the gas guide pipe is connected to the daughter boards and the mother board, the gas guide pipe includes an air outlet end, the air outlet end is located in the first airflow channel of the mother board, and the third opening is connected to the first airflow channel of the mother board and the third airflow channel.

[0029] In some embodiments, the third airflow channel surrounds a circumferential wall plate of the housing, and the third airflow channel is arranged in the circumferential wall plate.

[0030] In some embodiments, two ports of the gas guide pipe are oppositely arranged in the first airflow channel of the mother board in the first direction, and the two ports of the gas guide pipe are both configured as air outlet ends.

[0031] In some embodiments, part of a channel wall of the liquid cooling channel and part of a channel wall of the first airflow channel are the same wall body.

[0032] According to the above embodiments, the application has the following beneficial effects:

[0033] The battery pack of the present application comprises a shell, a battery cell assembly and a liquid cooling plate. The battery cell assembly and the liquid cooling plate are arranged in the shell, and the liquid cooling plate is provided with a liquid cooling channel and a first airflow channel isolated from each other. The liquid cooling plate is attached to the battery cell assembly or is arranged spaced apart from the battery cell assembly to cool the battery cell assembly. The first airflow channel has an air inlet and an air outlet, the air inlet is used to obtain the gas generated after the thermal runaway of the battery cell assembly, and the air outlet is used to discharge the gas in the first airflow channel out of the shell. The liquid cooling plate is provided with the liquid cooling channel and the first airflow channel at the same time. When the cooling liquid flows in the liquid cooling channel, it can not only directly cool the battery cell assembly, but also improve the safety of the battery pack by cooling the gas in the first airflow channel when the battery cell assembly has thermal runaway.

[0034] The liquid cooling plate further comprises a mother plate and a daughter plate, and the mother plate and the daughter plate are both provided with a liquid cooling channel and a first airflow channel. The battery pack comprises a liquid guide pipe, and the liquid cooling channel of the daughter plate is communicated with the liquid cooling channel of the mother plate through the liquid guide pipe. The cooling liquid enters the liquid cooling channels of the daughter plate and the mother plate through the liquid guide pipe. The liquid guide pipe comprises a liquid inlet end and a liquid outlet end. The liquid inlet end is communicated with the daughter plate, and the liquid outlet end comprises a first segment and a second segment. The liquid outlet of the first segment is located in the liquid cooling channel of the mother plate, and the liquid inlet of the second segment is located in the liquid cooling channel of the mother plate. The cooling liquid flows into the liquid cooling channel of the mother plate from the liquid outlet of the first segment, and then is guided out of the shell through the liquid inlet of the second segment. At this time, the cooling liquid from the liquid guide pipe enters the liquid cooling channel of the mother plate from the liquid outlet of the first segment. The cooling liquid continuously flows into the liquid cooling channel of the mother plate from the liquid outlet of the first segment. When the cooling liquid fills the liquid cooling channel of the mother plate, the cooling liquid is squeezed out of the liquid cooling channel of the mother plate to the outside of the shell through the liquid inlet of the second segment under pressure. Such a structure is simple, convenient to install and easy to maintain in later period, and enables the mother plate to fully participate in heat exchange with the battery cell.

[0035] Additional aspects and advantages of the present application will be made apparent from the following description. BRIEF DESCRIPTION OF DRAWINGS

[0036] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description only show some embodiments of the present application, and other drawings can also be obtained according to the structures shown in these drawings without any creative labor.

[0037] Fig. 1 is a schematic diagram of the overall structure of the battery pack in an embodiment of the present application;

[0038] Fig. 2 is a schematic diagram of the structure of the battery pack in Fig. 1 with the upper cover hidden;

[0039] Figure 3 is a structural schematic diagram of the battery pack in Figure 2 after hiding the cell assembly;

[0040] Figure 4 is a structural schematic diagram of a cell in an embodiment of the present application;

[0041] Figure 5 is a cross-sectional structural schematic diagram of the battery pack in an embodiment of the present application, viewed from a first perspective, and intended to show the relevant structure of the liquid guide pipe;

[0042] Figure 6 is an enlarged view of A in Figure 5;

[0043] Figure 7 is an enlarged view of B in Figure 5;

[0044] Figure 8 is a cross-sectional structural schematic diagram of the battery pack in an embodiment of the present application, viewed from a second perspective, and intended to show the relevant structure of the liquid guide pipe and the gas guide pipe;

[0045] Figure 9 is an enlarged view of C in Figure 8;

[0046] Figure 10 is a cross-sectional structural schematic diagram of the battery pack in an embodiment of the present application, viewed from a third perspective, and intended to show the relevant structure of the first opening;

[0047] Figure 11 is an enlarged view of D in Figure 10;

[0048] Figure 12 is a cross-sectional structural schematic diagram of the battery pack in an embodiment of the present application, viewed from a fourth perspective, and intended to show the relevant structure of the second opening;

[0049] Figure 13 is an enlarged view of E in Figure 12;

[0050] Figure 14 is a cross-sectional structural schematic diagram of the battery pack in an embodiment of the present application, viewed from a fifth perspective, and intended to show the relevant structure of the liquid cooling channel, the first gas flow channel, and the second gas flow channel;

[0051] Figure 15 is an enlarged view of F in Figure 14;

[0052] Figure 16 is a cross-sectional structural schematic diagram of the battery pack in an embodiment of the present application, viewed from a sixth perspective, and intended to show the relevant structure of the third gas flow channel;

[0053] Figure 17 is an enlarged view of G in Figure 16;

[0054] Figure 18 is a cross-sectional structural schematic diagram of the battery pack in an embodiment of the present application, viewed from a seventh perspective, and intended to show the relevant structure of the third opening;

[0055] Figure 19 is an enlarged view of H in Figure 18;

[0056] Figure 20 is the liquid flow direction of the liquid cooling structure in an embodiment of the present application;

[0057] FIG. 21 is a gas flow direction of the air cooling structure in an embodiment of the present application.

[0058] BRIEF DESCRIPTION OF DRAWINGS Shell 100; second air flow passage 110; first opening 111; third air flow passage 120; mounting position 112; bottom plate 113; peripheral wall plate 114; liquid cooling plate 200; mother plate 210; daughter plate 220; liquid cooling passage 230; first air flow passage 240; air inlet 241; air outlet 242; second opening 243; third opening 244; partition plate 250; upper cavity 251; lower cavity 252; battery cell assembly 3; battery cell 300; first explosion-proof valve 310; liquid guide pipe 400; liquid inlet end 410; liquid outlet end 420; first section 421; second section 422; liquid outlet 423; liquid inlet 424; air guide pipe 500; air outlet end 510; second explosion-proof valve 600; first direction X; second direction Y.

[0059] The implementation, functional features and advantages of the present application will be further described with reference to the accompanying drawings in conjunction with the embodiments. DETAILED DESCRIPTION

[0060] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all the other embodiments obtained by those skilled in the art without any creative work under the premise that the present application falls within the protection scope of the present application.

[0061] It should be noted that if the present application has directionality indication (such as up, down, left, right, front, back, etc.) in the embodiments, the directionality indication is only used to explain the relative position relationship, movement condition, etc. between the components in a certain posture, if the certain posture changes, the directionality indication also changes accordingly.

[0062] In addition, if the description of "first", "second", etc. is involved in the embodiments of the present application, the description of "first", "second", etc. is only for the purpose of description, and cannot be understood as indicating or implying the relative importance of the indicated technical features or implicitly indicating the number of the indicated technical features. Therefore, the features limited by "first", "second" can be explicitly or implicitly included at least one of the features. In addition, if "and / or", "and / or", or "and / or" appears throughout the text, it means that the three parallel schemes are included, for example, "A and / or B" includes A scheme, or B scheme, or A and B scheme. In addition, the technical solutions of each embodiment can be combined with each other, but it must be based on the realization of ordinary skilled in the art, when the combination of technical solutions appears contradictory or unachievable, it should be considered that the combination of technical solutions does not exist, nor within the scope of protection claimed in the present application.

[0063] In the related art, when the lithium battery is working, a large amount of heat will be generated due to the complex chemical reaction inside the battery. If these heat cannot be effectively discharged from the battery pack in time, the temperature of the battery will rise rapidly, which not only accelerates the aging process of the battery and shortens its service life, but also may cause serious safety problems such as thermal runaway of the battery. In addition, the temperature difference inside the battery pack will also cause uneven internal resistance and capacity between the cells, further reducing the overall performance of the battery.

[0064] The battery pack according to the embodiments of the present application will be described below with reference to FIGS. 1-21. Referring to FIGS. 1-4, in some embodiments, the battery pack of the present application includes a shell 100, a cell assembly 3 and a liquid cooling plate 200. The cell assembly 3 and the liquid cooling plate 200 are arranged in the shell 100, and the liquid cooling plate 200 is provided with a liquid cooling channel 230 and a first airflow channel 240 which are isolated from each other. The first airflow channel 240 has an air inlet 241 for obtaining the gas generated after the thermal runaway of the cell assembly 3, and an air outlet 242 for discharging the gas in the first airflow channel 240 out of the shell 100. The liquid cooling plate 200 is provided with the liquid cooling channel 230 and the first airflow channel 240 at the same time, and when the cooling liquid flows in the liquid cooling channel 230, it can not only directly cool the cell assembly 3, but also improve the safety of the battery pack by cooling the gas in the first airflow channel 240 when the cell assembly 3 occurs thermal runaway.

[0065] In some embodiments, the shell 100 is square, the width direction of the shell 100 is configured as a first direction X, the length direction of the shell 100 is configured as a second direction Y, and the height direction of the shell is configured as a vertical direction. The first direction X, the second direction Y and the vertical direction are perpendicular to each other.

[0066] It can be understood that in some embodiments, the liquid cooling plate 200 is hollow, and the liquid cooling plate 200 includes a partition plate 250 extending along the first direction X, the partition plate 250 divides the liquid cooling plate 200 into an upper cavity 251 and a lower cavity 252 in the vertical direction, wherein the upper cavity 251 is configured as the liquid cooling channel 230, and the lower cavity 252 is configured as the first airflow channel 240. It can be understood that of course, the liquid cooling channel 230 and the first airflow channel 240 can also be separately provided, and then connected to the side of the liquid cooling plate 200 facing the battery cell 300, as long as the liquid cooling channel 230 and the first airflow channel 240 are provided on one liquid cooling plate 200.

[0067] Referring to FIGS. 2 and 3, in some embodiments, the liquid cooling plate 200 includes a daughter plate 220 and a mother plate 210. The mother plate 210 is located on one side of the battery pack, and the daughter plates 220 are arranged in the housing 100 along the second direction Y, and the surfaces of the mother plate 210 and the daughter plates 220 are parallel to the first direction X. The battery pack includes a liquid guide pipe 400, and the daughter plates 220 are connected to the mother plate 210 through the liquid guide pipe 400. After the cooling liquid is injected into the liquid guide pipe 400, the cooling liquid enters the liquid cooling channel 230 of the mother plate 210 and the liquid cooling channel 230 of the daughter plate 220 through the liquid guide pipe 400 in sequence, so that the liquid cooling plate 200 has a cooling effect on the battery cell assembly 3. The liquid cooling channel 230 and the first airflow channel 240 extend along the first direction X. In the vertical direction, the liquid cooling channel 230 is located above the first airflow channel 240, the liquid cooling channel 230 and the first airflow channel 240 are arranged in a spaced manner, and the liquid cooling channel 230 and the first airflow channel 240 are adjacent, that is, part of the channel wall of the liquid cooling channel 230 and part of the channel wall of the first airflow channel 240 are the same wall. The channel wall shared by the liquid cooling channel 230 and the first airflow channel 240 is thin, so that the cooling liquid in the liquid cooling channel 230 has a more significant influence on the gas in the first airflow channel 240. The liquid cooling channel 230 is located above the first airflow channel 240, and the cooling liquid can also spread over the wall below the liquid cooling channel 230, that is, the channel wall shared by the liquid cooling channel 230 and the first airflow channel 240, without the cooling liquid completely filling the liquid cooling channel 230. Therefore, the arrangement facilitates the cooling liquid in the liquid cooling channel 230 to continuously cool the gas in the first airflow channel 240.

[0068] Referring to FIGS. 2-4, in some embodiments, the cell assembly 3 comprises a cell 300, the liquid cooling plate 200 comprises a plurality of sub-plates 220 arranged along the second direction Y, the cell 300 is located between the plurality of sub-plates 220 or between the sub-plate 220 and the mother plate 210, and the two surfaces of the cell 300 arranged oppositely along the second direction Y are both attached to the liquid cooling plate 200. In this way, on the one hand, the volume of the battery pack can be reduced and the energy density can be improved, and on the other hand, the two surfaces of the cell 300 arranged oppositely along the second direction Y can both be cooled by the liquid cooling plate 200.

[0069] It is of course understood that only one cell 300 can be arranged between adjacent liquid cooling plates 200, or a plurality of cells 300 can be arranged side by side along the first direction X.

[0070] It is of course understood that in some embodiments, the liquid cooling plate 200 does not have the mother plate 210 and the liquid guide pipe 400, and the cooling liquid directly flows into the liquid cooling channels 230 of the sub-plates 220 from the outside of the shell 100 along the first direction X, and the liquid cooling channels 230 of the sub-plates 220 are not connected to each other.

[0071] It is understood that in some embodiments, the mother plate 210 is located on one side of the sub-plate 220, and in some embodiments, the mother plate 210 is located between the sub-plates 220. The liquid guide pipe 400 extends along the second direction Y, the cooling liquid enters the liquid guide pipe 400 from the liquid inlet end 410 of the liquid guide pipe 400, and the cooling liquid continues to flow along the second direction Y, and in the process, flows in the opposite direction along the first direction X to fill the liquid cooling channels 230 of the sub-plates 220, and then the cooling liquid in the liquid cooling channels 230 of the sub-plates 220 flows out from the other side of the liquid cooling channels 230, converges on the other side of the liquid guide pipe 400, and then flows out from the liquid outlet end 420. The liquid outlet end 420 can be directly connected to the outside of the shell 100, or indirectly connected to the outside of the shell 100. The mother plate 210 is provided to facilitate the convergence, distribution and adjustment of the flow direction of the cooling liquid or gas.

[0072] With reference to FIGS. 5-9, in some embodiments, the liquid guide pipe 400 includes the liquid inlet end 410 and the liquid outlet end 420. The cooling liquid enters the liquid guide pipe 400 from the liquid inlet end 410, spreads to the liquid cooling channel 230, and then flows out of the liquid outlet end 420 after heat exchange with the battery cell 300. This arrangement enables circulation of the cooling liquid in the liquid cooling channel 230, so that new cooling liquid continuously enters the liquid cooling channel 230, thereby improving the heat exchange efficiency. Specifically, the liquid inlet end 410 penetrates the mother board 210 and directly communicates with the sub board 220. The cooling liquid directly flows into the liquid cooling channel 230 of the sub board 220 from the liquid inlet end 410 of the liquid guide pipe 400. The liquid outlet end 420 includes a first segment 421 and a second segment 422. The liquid outlet 423 of the first segment 421 is arranged in the liquid cooling channel 230 of the mother board 210. The cooling liquid flows into the liquid cooling channel 230 of the mother board 210 from the liquid cooling channel 230 of the sub board 220 through the liquid outlet 423 of the first segment 421. The liquid inlet 424 of the second segment 422 is arranged in the liquid cooling channel 230 of the mother board 210. After the cooling liquid fills the liquid cooling channel 230 of the mother board 210, the cooling liquid flows into the second segment 422 through the liquid inlet 424 of the second segment 422 and is guided out of the shell 100 through the second segment 422. In other words, the liquid outlet 423 of the first segment 421 is arranged in the liquid cooling channel 230 of the mother board 210, and the liquid inlet 424 of the second segment 422 is arranged in the liquid cooling channel 230 of the mother board 210. The other side of the second segment 422 communicates with the outside of the shell 100. At this time, the cooling liquid from the liquid guide pipe 400 enters the liquid cooling channel 230 of the mother board 210 from the liquid outlet 423 of the first segment 421. The cooling liquid continuously flows into the liquid cooling channel 230 of the mother board 210 from the liquid outlet 423 of the first segment 421. After the cooling liquid fills the liquid cooling channel 230 of the mother board 210, the cooling liquid is squeezed out of the liquid cooling channel 230 of the mother board 210 to the outside of the shell 100 through the liquid inlet 424 of the second segment 422 due to the pressure. This arrangement is simple in structure, convenient to install, and easy to maintain in the later period. In addition, the mother board 210 can fully participate in the heat exchange with the battery cell 300.

[0073] Referring to FIGS. 4, 10 and 11, in some embodiments, the shell 100 comprises a mounting position 112 for mounting the battery cell 300. The battery cell 300 comprises a first explosion-proof valve 310, and the mounting position 112 of the shell 100 comprises a first opening 111, and the first explosion-proof valve 310 covers the first opening 111, i.e. the first explosion-proof valve 310 is seated on the first opening 111. The shell 100 comprises a second airflow channel 110, which is provided on a bottom plate 113 of the shell 100 that carries the battery cell 300, the first opening 111 is in communication with the second airflow channel 110, and the second airflow channel 110 is in communication with the first airflow channel 240, and the first opening 111 is configured as the air inlet 241. Specifically, the hot gas generated by the battery cell 300 due to heat generation enters the second airflow channel 110 from the first opening 111, and then enters the first airflow channel 240 from the second airflow channel 110, and exchanges heat with the gas in the first airflow channel 240. In this way, the gas in the first airflow channel 240 can exchange heat with the gas in the second airflow channel 110, so as to exchange heat with the battery cell 300 at the first opening 111, and thus this arrangement can increase the area of the battery cell 300 for heat exchange. The gas in the first airflow channel 240 is kept at a low temperature by the cooling liquid in the liquid cooling channel 230, and the gas in the first airflow channel 240 exchanges heat with the gas in the second airflow channel 110, so that the gas in the entire airflow channel of the battery pack has a relatively low temperature. Since the battery cell 300 is directly seated at the first opening 111, the gas in the second airflow channel 110 can directly exchange heat with the battery cell 300 at the first opening 111, without the need for heat conduction through the surface of the liquid cooling plate 200.

[0074] Of course, it can be understood that in some embodiments, a first sealing ring is provided at the first opening 111 to ensure that the first explosion-proof valve 310 of the battery cell 300 is sealingly connected to the second airflow channel 110, so as to ensure the sealing of the second airflow channel 110.

[0075] Referring to FIGS. 12 and 13, in some embodiments, a sealing ring is provided to improve the sealing of the airflow channel of the battery pack. Specifically, a second sealing ring is provided at the second opening 243, and the second sealing ring is used to seal the first airflow channel 240 and the second airflow channel 110, and the gas in the second airflow channel 110 enters the first airflow channel 240 through the second sealing ring.

[0076] Referring to FIGS. 14 and 15, in some embodiments, the second airflow channel 110 extends along the second direction Y and penetrates through each liquid cooling plate 200 along the second direction Y. The liquid cooling plate 200 includes a second opening 243. In some embodiments, the mother plate 210 includes the second opening 243. In some embodiments, the daughter plate 220 includes the second opening 243. The second opening 243 communicates the first airflow channel 240 and the second airflow channel 110 to enable the gas in the second airflow channel 110 to exchange with the gas in the first airflow channel 240.

[0077] Referring to FIG. 9, in some embodiments, the liquid guide pipe 400 is arc-shaped near the position of the mother plate 210. This design enables the liquid guide pipe 400 to better adapt to the shape of the mother plate 210 when connected to the mother plate 210, and reduces stress concentration caused by the angle mutation at the connection, thereby improving the durability and sealing performance of the connection site. The arc-shaped design of the liquid guide pipe 400 helps to reduce the resistance loss during the flow of the cooling liquid, ensuring smooth flow of the cooling liquid into the liquid cooling channel 230, thereby improving the cooling efficiency.

[0078] It can be understood that, in some embodiments, the liquid guide pipe 400 is arc-shaped near the position of the mother plate 210. The arc-shaped design can optimize the connection between the liquid guide pipe 400 and the mother plate 210 by adjusting the size of the arc, further improving the connection strength and stability. In addition, by selecting a suitable arc, the liquid guide pipe 400 can be more compact in spatial layout, which is beneficial to save the internal space of the battery pack. The arc-shaped design also helps to improve the flow state of the cooling liquid, reducing the occurrence of turbulent flow, thereby reducing the flow noise and enhancing the quiet performance of the entire system. In this way, the overall structure of the battery pack is more reasonable, improving its reliability and user satisfaction in actual use.

[0079] Referring to FIGS. 16 and 17, in some embodiments, the shell 100 includes a third airflow passage 120, the third airflow passage 120 encircles the peripheral wall plate 114 of the shell 100, and the third airflow passage 120 is arranged in the peripheral wall plate 114. The liquid cooling plate 200 includes a third opening 244, the third opening 244 communicates the first airflow passage 240 and the third airflow passage 120. Specifically, the third opening 244 is arranged on the surface wall of the mother plate 210 arranged in the first direction X, the shell 100 has a circumferentially encircling hollow cavity configured as the third airflow passage 120, the third opening 244 communicates the hollow cavity of the shell 100, so that the first airflow passage 240 communicates the third airflow passage 120 through the third opening 244. Wherein, the battery pack includes a second explosion-proof valve 600, the shell 100 includes a mounting hole, the second explosion-proof valve 600 is mounted in the mounting hole, the mounting hole communicates the third airflow passage 120, and the mounting hole is configured as the gas outlet 242. The gas generated after the thermal runaway of the battery cell assembly 3 flows into the second airflow passage 110 from the first opening 111, then flows into the first airflow passage 240 of the mother plate 210 from the second opening 243 of the second airflow passage 110, and then flows into the third airflow passage 120 from the third opening 244. When the gas generated after the thermal runaway of the battery cell assembly 3 is excessive, the gas in the third airflow passage 120 will rush open the second explosion-proof valve 600, so as to improve the safety of the battery pack.

[0080] Referring to FIGS. 18, 19 and 9, in some embodiments, the battery pack includes a gas guide pipe 500, the gas guide pipe 500 communicates the sub-plate 220 and the mother plate 210. Specifically, the gas guide pipe 500 communicates the first airflow passage 240 of the sub-plate 220 and the first airflow passage 240 of the mother plate 210, the gas guide pipe 500 includes a gas outlet end 510, the gas outlet end 510 is located in the first airflow passage 240 of the mother plate 210, part of the gas generated after the thermal runaway of the battery cell assembly 3 enters the second airflow passage 110 from the first opening 111, then enters the first airflow passage 240 of the sub-plate 220 from the second opening 243, and the gas in the first airflow passage 240 of the sub-plate 220 enters the first airflow passage 240 of the mother plate 210 through the gas guide pipe 500; another part of the gas generated after the thermal runaway of the battery cell assembly 3 enters the second airflow passage 110 from the first opening 111, then enters the first airflow passage 240 of the mother plate 210 from the second opening 243 of the mother plate 210. The third opening 244 communicates the first airflow passage 240 of the mother plate 210 and the third airflow passage 120 of the shell 100, so that the gas in the first airflow passage 240 of the mother plate 210 enters the third airflow passage 120 from the third opening 244. When the gas generated after the thermal runaway of the battery cell assembly 3 is excessive, the gas in the third airflow passage 120 will rush open the second explosion-proof valve 600, so as to improve the safety of the battery pack.

[0081] Referring to FIG. 12 and FIG. 19, in some embodiments, both ends of the gas guide pipe 500 are configured as gas outlet ends 510, and the two gas outlet ends 510 are oppositely arranged in the first direction X in the first airflow channel 240 of the mother plate 210. This arrangement improves the flow efficiency of the gas, on the one hand, so that the gas in the first airflow channel 240 can quickly flow to other positions after being affected by the cooling liquid, and on the other hand, so that when the gas generated after the thermal runaway of the battery cell assembly 3 is too much, the gas can quickly flow to the mounting hole of the third airflow channel 120, open the second explosion-proof valve 600, and reduce the risk.

[0082] The flow direction of the liquid or gas in the liquid cooling structure and the gas cooling structure of the battery pack of the present application is described below.

[0083] Regarding the flow direction of the liquid in the liquid cooling structure, referring to FIG. 8 and FIG. 20, specifically, the cooling liquid flows into the liquid guide pipe 400 from the liquid inlet end 410 of the liquid guide pipe 400 and is divided into two branches. The first branch is that the cooling liquid flows in the liquid guide pipe 400 in the second direction Y, and the second branch is that the cooling liquid in the liquid guide pipe 400 fills the liquid cooling channel 230 of the daughter plate 220 in the opposite direction of the first direction X. At this point, the cooling liquid is distributed in the liquid cooling channel 230 of each daughter plate 220. The cooling liquid continues to flow in, so the cooling liquid in the liquid cooling channel 230 of each daughter plate 220 flows out from the other side and collects in the liquid guide pipe 400 on the other side. The liquid guide pipe 400 on this side includes a liquid outlet end 420, which includes a first segment 421 and a second segment 422. The first segment 421 and the second segment 422 are located on opposite sides of the mother plate 210, respectively. The liquid outlet 423 of the first segment 421 communicates with the liquid cooling channel 230 of the mother plate 210, and the liquid inlet 424 of the second segment 422 communicates with the liquid cooling channel 230 of the mother plate 210. The other end of the second segment 422 communicates with the outside of the housing 100. The cooling liquid continuously flows into the liquid cooling channel 230 of the mother plate 210 from the liquid outlet end 420, and after filling the liquid cooling channel 230 of the mother plate 210 in the first direction X, it is squeezed out from the liquid inlet 424 of the second segment 422 and flows to the outside of the housing 100. This cycle constitutes the liquid cooling structure of the battery pack of the present application.

[0084] With reference to the flow direction of the gas in the air cooling structure, with reference to FIG. 21, specifically, the gas generated by the thermal runaway of the battery cell assembly 3 enters the second airflow channel 110 from the first opening 111, and the airflow is divided into two branches. The first branch is that the gas flows along the second airflow channel 110 to the second opening 243 of the mother plate 210, and flows into the first airflow channel 240 of the mother plate 210 through the second opening 243 of the mother plate 210. The second branch is that the gas flows along the second airflow channel 110 to the second opening 243 of the daughter plate 220, and flows into the first airflow channel 240 of the daughter plate 220 from the second opening 243 of the daughter plate 220. The gas in the first airflow channel 240 of the daughter plate 220 enters the gas guide pipe 500 from both ends of the daughter plate 220 in the first direction X, the gas outlet end 510 of the gas guide pipe 500 is located in the first airflow channel 240 of the mother plate 210, and the gas in the gas guide pipe 500 enters the first airflow channel 240 of the mother plate 210 from the gas outlet end 510. The mother plate 210 and the daughter plate 220 each include a liquid cooling channel 230, the liquid cooling channel 230 and the first airflow channel 240 are adjacent, the channel wall of the liquid cooling channel 230 facing the first airflow channel 240 and the channel wall of the first airflow channel 240 facing the liquid cooling channel 230 are the same wall body, so that the cooling liquid passing through the channel wall affects the temperature of the gas in the first airflow channel 240. Therefore, the battery pack of the present application can improve the safety of the battery pack by cooling the gas in the first airflow channel 240 when the battery cell assembly 3 is in thermal runaway.

[0085] In addition, the gas generated by the thermal runaway of the battery cell assembly 3 flows into the first airflow channel 240 of the mother plate 210 through two branches, the first airflow channel 240 of the mother plate 210 is communicated with the third airflow channel 120 of the shell 100 through the third opening 244, the channel wall of the third airflow channel 120 of the shell 100 is provided with a mounting hole for mounting the second explosion-proof valve 600, when the gas generated by the thermal runaway of the battery cell assembly 3 is too much, the gas in the third airflow channel 120 will rush open the second explosion-proof valve 600 to prevent the explosion of the battery pack, so that the safety of the battery pack of the present application is guaranteed. The above is only the preferred embodiment of the present application, and does not limit the patent scope of the present application, any equivalent structural transformation made by using the contents of the present application specification and drawings, or direct / indirect application in other related technical fields is included in the patent protection scope of the present application.

Claims

1. A battery pack, comprising a housing (100); a cell assembly (3) arranged in the housing (100); a liquid cooling plate (200) arranged in the housing (100), the liquid cooling plate (200) being attached to or spaced apart from the cell assembly (3) to cool the cell assembly (3), the liquid cooling plate (200) being provided with a liquid cooling channel (230) and a first airflow channel (240) isolated from each other, the first airflow channel (240) having an air inlet (241) for obtaining gas generated after thermal runaway of the cell assembly (3) and an air outlet (242) for discharging the gas in the first airflow channel (240) out of the housing (100); the liquid cooling plate (200) further comprising a mother plate (210) and a daughter plate (220), the mother plate (210) and the daughter plate (220) being provided with the liquid cooling channel (230) and the first airflow channel (240), the battery pack comprising a liquid guide duct (400), the liquid cooling channel (230) of the daughter plate (220) being communicated with the liquid cooling channel (230) of the mother plate (210) through the liquid guide duct (400), and cooling liquid entering the liquid cooling channel (230) of the daughter plate (220) and the mother plate (210) through the liquid guide duct (400). The liquid guide duct (400) comprises a liquid inlet end (410) and a liquid outlet end (420), the liquid inlet end (410) being communicated with the daughter plate (220), and the liquid outlet end (420) comprising a first segment (421) and a second segment (422), the first segment (421) and the second segment (422) being located at opposite sides of the mother plate (210) respectively, an outlet (423) of the first segment (421) being communicated with the liquid cooling channel (230) of the mother plate (210), and an inlet (424) of the second segment (422) being communicated with the liquid cooling channel (230) of the mother plate (210), the cooling liquid flowing into the liquid cooling channel (230) of the mother plate (210) from the outlet (423) of the first segment (421) and then being guided out of the housing (100) through the inlet (424) of the second segment (422).

2. The battery pack of claim 1, wherein, In a vertical direction, the liquid cooling channel (230) is located above the first airflow channel (240), the housing (100) has a first direction (X), the liquid cooling channel (230) and the first airflow channel (240) both extend along the first direction (X), and the first direction (X) and the vertical direction intersect.

3. The battery pack of claim 2, wherein, The liquid cooling plate (200) comprises a plurality of sub-plates (220), the battery cell assembly (3) comprises a battery cell (300), the plurality of sub-plates (220) are arranged at intervals along the second direction (Y), the battery cell (300) is located between adjacent two of the plurality of sub-plates (220) and / or the battery cell (300) is located between the sub-plate (220) and the mother plate (210), and the battery cell (300) is adapted to be attached.

4. The battery pack of claim 3, wherein, One battery cell (300) can be arranged between adjacent liquid cooling plates (200), or a plurality of battery cells (300) can be arranged side by side along the first direction (X).

5. The battery pack of claim 3, wherein, The shell (100) is square, the width direction of the shell (100) is configured as the first direction (X), the length direction of the shell (100) is configured as the second direction (Y), and the height direction of the shell (100) is configured as the vertical direction, and the first direction (X), the second direction (Y) and the vertical direction are perpendicular to each other.

6. The battery pack of claim 3, wherein, The mother plate (210) is located on one side of the plurality of sub-plates (220).

7. The battery pack of claim 3, wherein, The mother plate (210) is located between each of the plurality of sub-plates (220).

8. The battery pack of claim 2, wherein, The liquid cooling plate (200) comprises a partition plate (250) extending along the first direction (X), the partition plate (250) divides the liquid cooling plate (200) into an upper cavity (251) and a lower cavity (252) in the vertical direction, the upper cavity (251) is configured as the liquid cooling channel (230), and the lower cavity (252) is configured as the first air flow channel (240).

9. The battery pack of claim 5, wherein, The mother plate (210) is located on one side of the battery pack, the sub-plates (220) are arranged at intervals along the second direction (Y) in the shell (100), and the surfaces of the sub-plates (220) and the mother plate (210) are parallel to the first direction (X).

10. The battery pack of claim 3, wherein, The battery cell (300) comprises a first explosion-proof valve (310), the shell (100) comprises a mounting position (112), the mounting position (112) comprises a first opening (111), the battery cell (300) is mounted in the mounting position (112), and the first explosion-proof valve (310) covers the first opening (111). The shell (100) comprises a second air flow channel (110), the second air flow channel (110) is provided on a bottom plate (113) of the shell (100) carrying the battery cell (300), the first opening (111) communicates with the second air flow channel (110), the second air flow channel (110) communicates with the first air flow channel (240), and the first opening (111) is configured as the air inlet (241).

11. The battery pack of claim 10, wherein, The second air flow channel (110) extends along the second direction (Y), the mother plate (210) comprises a second opening (243), and the second opening (243) communicates the first air flow channel (240) and the second air flow channel (110); and / or, The sub-plate (220) comprises the second opening (243) which communicates the first airflow channel (240) and the second airflow channel (110).

12. The battery pack of claim 11, wherein, The second airflow channel (110) penetrates the liquid cooling plate (200) along the second direction (Y).

13. The battery pack of claim 11, wherein, Along the second direction (Y), the first segment (421) is arc-shaped near the position of the parent plate (210).

14. The battery pack of claim 2, wherein, The shell (100) comprises a third airflow channel (120), and the liquid cooling plate (200) comprises a third opening (244) which communicates the first airflow channel (240) and the third airflow channel (120). The battery pack comprises a second explosion-proof valve (600), and the shell (100) comprises a mounting hole, the second explosion-proof valve (600) is mounted in the mounting hole, the mounting hole communicates the third airflow channel (120), and the mounting hole is configured as the air outlet (242).

15. The battery pack of claim 14, wherein, The battery pack comprises a gas guide pipe (500) which communicates the sub-plate (220) and the parent plate (210), the gas guide pipe (500) comprises an air outlet end (510) which is located in the first airflow channel (240) of the parent plate (210), and the third opening (244) communicates the first airflow channel (240) of the parent plate (210) and the third airflow channel (120).

16. The battery pack of claim 15, wherein, The third airflow channel (120) surrounds the peripheral wall plate (114) of the shell (100), and the third airflow channel (120) is arranged in the peripheral wall plate (114).

17. The battery pack of claim 15, wherein, The two ports of the gas guide pipe (500) are oppositely arranged in the first airflow channel (240) of the parent plate (210) along the first direction (X), and the two ports of the gas guide pipe (500) are configured as air outlet ends (510).

18. The battery pack of claim 1, wherein, Part of the channel wall of the liquid cooling channel (230) and part of the channel wall of the first airflow channel (240) are the same wall body.

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