A battery pack

Abstract

The application discloses a battery pack, comprising: a battery cell module comprising a plurality of battery cells arranged in sequence along a first direction, a plurality of battery cell modules arranged side by side along a second direction; a side cold plate arranged on at least one side of the battery cell module, a plurality of side cold plates arranged at intervals along the second direction, and a first flow channel arranged in the side cold plate; the first flow channel comprises at least three sub-flow channels connected in sequence, and a first communication port and a second communication port respectively located at two ends of the first flow channel, wherein, the extension directions of at least two sub-flow channels have an included angle, and the first communication port and the second communication port are respectively located at two ends of the side cold plate in the first direction; a first liquid inlet pipe and a second liquid inlet pipe are located at one end of the side cold plate close to the first communication port, and the first liquid inlet pipe and the second liquid inlet pipe are respectively connected to a plurality of first communication ports; a first liquid outlet pipe and a second liquid outlet pipe are located at one end of the side cold plate close to the second communication port, and the first liquid outlet pipe and the second liquid outlet pipe are respectively connected to a plurality of second communication ports.

Description

Technical Field

[0001] This application relates to the field of battery heat exchange technology, and in particular to a battery pack. Background Technology

[0002] During fast charging, the cells of new energy power batteries generate significant heat. If the heat generated by the cells cannot be dissipated in time, it may cause the cell temperature to become too high, affecting the cell performance and lifespan, and even causing thermal runaway, which may lead to vehicle fire and a series of serious consequences. Therefore, efficient thermal management technology is needed to protect the cells during fast charging.

[0003] Currently, the most common thermal management method for battery cells is bottom cooling, which has limited heat dissipation capacity and efficiency. To improve heat dissipation, some technologies use large-area cooling for the battery cells, but this often faces a problem: when there are many large-area cold plates, it is difficult to ensure the uniformity of flow between multiple parallel cold plates, resulting in poor temperature uniformity between battery cells, which will have a significant negative impact on the consistency of the battery cells.

[0004] Therefore, in view of the above situation, how to make the flow distribution among multiple parallel cold plates more uniform is a technical problem that needs to be solved by those skilled in the art. Utility Model Content

[0005] The purpose of this application is to provide a battery pack that matches the pressure drop ratio of the inlet and outlet liquid pipes with that of the side cold plates, so that the fluid state flowing through different side cold plates is consistent, thereby making the flow distribution among multiple parallel cold plates more uniform.

[0006] To achieve the above objectives, this application provides a battery pack, comprising:

[0007] A battery cell module includes multiple battery cells arranged sequentially along a first direction, and multiple battery cell modules are arranged side by side sequentially along a second direction;

[0008] A side cooling plate is disposed on at least one side of the battery cell module, and a plurality of the side cooling plates are arranged at intervals along a second direction, and a first flow channel is provided in the side cooling plate;

[0009] The first flow channel includes at least three sequentially connected sub-flow channels, and a first connecting port and a second connecting port located at both ends of the first flow channel, wherein at least two of the sub-flow channels extend at an angle, and the first connecting port and the second connecting port are located at both ends of the side cold plate in a first direction.

[0010] The first liquid inlet pipe is located at one end of the side cold plate near the first communication port, and the first liquid inlet pipe is connected to multiple first communication ports;

[0011] The second liquid inlet pipe is located at one end of the side cold plate near the first communication port, and the second liquid inlet pipe is connected to multiple first communication ports;

[0012] The first liquid outlet pipe is located at one end of the side cold plate near the second communication port, and the first liquid outlet pipe is connected to multiple second communication ports;

[0013] The second liquid outlet pipe is located at one end of the side cold plate near the second communication port, and the second liquid outlet pipe is connected to multiple second communication ports.

[0014] Preferably, the first flow channel includes a first sub-flow channel, a second sub-flow channel, ..., an Nth sub-flow channel connected in sequence, where N is an odd number greater than or equal to five;

[0015] Along a third direction, the first sub-channel is located near the electrode post of the battery cell, the first connection port is located at the first end of the first sub-channel, and the second end of the first sub-channel extends toward the second connection port.

[0016] Along a third direction, the Nth sub-channel is located on the side near the bottom of the cell, the second connection port is located at the second end of the Nth sub-channel, and the first end of the Nth sub-channel extends toward the first connection port;

[0017] The second sub-channel to the (N-1)th sub-channel is located between the first sub-channel and the Nth sub-channel, and among the third sub-channel to the (N-1)th sub-channel, at least two sub-channels are located between the first sub-channel and the second sub-channel.

[0018] Preferably, the Nth sub-channel is the fifth sub-channel;

[0019] The first end of the second sub-channel is connected to the second end of the first sub-channel, and the second end of the second sub-channel extends toward the first connection port.

[0020] The first end of the third sub-channel is connected to the second end of the second sub-channel. The third sub-channel is located between the first sub-channel and the second sub-channel, and the second end of the third sub-channel extends toward the second connection port.

[0021] The first end of the fourth sub-channel is connected to the second end of the third sub-channel. The fourth sub-channel is located between the first sub-channel and the third sub-channel, and the second end of the fourth sub-channel extends toward the first connection port.

[0022] The first end of the fifth sub-channel is connected to the second end of the fourth sub-channel.

[0023] Preferably, the side cooling plate is a rectangular plate, and the side cooling plate has clearance portions at both ends in the first direction, and the two clearance portions located at the same end of the side cooling plate are distributed along the third direction;

[0024] Along the third direction, the first liquid inlet pipe and the second liquid inlet pipe are respectively located at the two clearance portions at one end of the side cold plate, and the projections of the first liquid inlet pipe and the second liquid inlet pipe in the first direction and the second direction respectively overlap with the side cold plate at least partially.

[0025] Along a third direction, the first liquid outlet pipe and the second liquid outlet pipe are respectively located at the two clearance portions at the other end of the side cold plate, and the projections of the first liquid outlet pipe and the second liquid outlet pipe in the first direction and the second direction both at least partially overlap with the side cold plate;

[0026] Preferably, the avoidance part is a triangular structure, a rectangular structure, or an arc-shaped structure.

[0027] Preferably, the first inlet pipe, the second inlet pipe, the first outlet pipe, and the second outlet pipe are each provided with multiple tees. The first and second ports of the tees are connected to the inlet pipe or the outlet pipe, and the third port of the tees is connected to the first or second connecting port through an arc-shaped pipe.

[0028] The first liquid inlet pipe, the second liquid inlet pipe, the first liquid outlet pipe, and the second liquid outlet pipe each include multiple corrugated pipe sections, and the first port and the second port are connected to the corrugated pipe sections;

[0029] In one of the two adjacent side cold plates, the arc-shaped tube on either side cold plate is located on the side of the side cold plate opposite to the other side cold plate in the second direction.

[0030] Preferably, the first liquid inlet pipe and the second liquid inlet pipe are arranged in parallel and distributed along a third direction, and the two first connecting ports of the adjacent side cold plates are respectively connected to the first liquid inlet pipe and the second liquid inlet pipe; the first liquid outlet pipe and the second liquid outlet pipe are arranged in parallel and distributed along a third direction, and the two second connecting ports of the adjacent side cold plates are respectively connected to the first liquid outlet pipe and the second liquid outlet pipe.

[0031] Preferably, an arc-shaped transition section is provided between two adjacent sub-channels, and the included angle between two adjacent sub-channels is B, where B satisfies: 0°≤B≤45°;

[0032] Preferably, B satisfies: 0°≤B≤15°.

[0033] Preferably, the assembly further includes a bottom cooling plate disposed on the bottom surface of the battery cell module. The bottom cooling plate has a plurality of bottom flow channels extending along a first direction. The bottom flow channels are arranged in parallel. One end of the bottom flow channels converges and communicates with the liquid inlet on the bottom cooling plate, and the other end of the bottom flow channels converges and communicates with the liquid outlet on the bottom cooling plate.

[0034] Preferably, the liquid inlet is also connected to the first liquid inlet pipe and the second liquid inlet pipe, and the liquid outlet is also connected to the first liquid outlet pipe and the second liquid outlet pipe.

[0035] Preferably, in the second direction, the liquid inlet and the liquid outlet are located on the same side of the battery cell module. The bottom flow channel includes a first bottom flow channel and a second bottom flow channel. The first end of the first bottom flow channel is connected to the liquid inlet, and the second end of the first bottom flow channel extends away from the liquid inlet. The first end of the second bottom flow channel is connected to the second end of the first bottom flow channel, and the second end of the second bottom flow channel extends towards the liquid outlet.

[0036] Preferably, the side cooling plate and the bottom cooling plate are fixedly connected to the side and bottom surfaces of the battery cell respectively via heat conductors.

[0037] This application provides a first flow channel within the side cooling plate, comprising at least three sequentially connected sub-flow channels to increase the flow length of the fluid within the side cooling plate, thereby increasing the pressure drop of the first flow channel inside the side cooling plate. Furthermore, at least two of the sub-flow channels extend at an angle, which will also cause a change in pressure drop when the fluid flow direction changes, thus further increasing the pressure drop of the first flow channel. Consequently, the proportion of the pressure drop of the side cooling plate in the total pressure drop of the side cooling plate and the liquid inlet pipe increases, thereby reducing the impact of the pressure drop of the liquid inlet pipe on the fluid pressure change and ensuring that the fluid state flowing through different side cooling plates is consistent.

[0038] Furthermore, compared to a single inlet pipe, this application adopts a dual inlet pipe configuration with a first inlet pipe and a second inlet pipe. Based on the same flow cross-sectional area (liquid flow rate), the inner diameter and cross-sectional area of ​​the first and second inlet pipes can be reduced. On the one hand, this can increase the flow velocity in the first and second inlet pipes, making the liquid distribution at multiple side cold plate inlets more uniform and ensuring a more uniform flow rate of fluid into each side cold plate. On the other hand, compared to a single inlet pipe, this can increase the overall liquid flow rate and ensure the cooling effect of the side cold plates.

[0039] Compared to the aforementioned background technology, this application, under a reasonable pressure drop ratio matching, ensures that the pressure drop of the side cold plate accounts for a larger proportion of the total pressure drop of the side cold plate and the liquid inlet pipe, while the pressure drop of the liquid inlet pipe accounts for a smaller proportion. This reduces the impact of the pressure drop of the liquid inlet pipe on fluid pressure changes, ensuring that the fluid state flowing through different side cold plates is consistent. When the fluid pressure at the inlet and outlet of different side cold plates is consistent, the flow velocity of different side cold plates remains consistent under the same differential pressure, which means that the flow rate is the same, thereby achieving a more uniform flow distribution among different side cold plates.

[0040] Specifically, to reduce the pressure drop in the inlet pipe, it can be configured as a dual inlet pipe. Furthermore, by increasing the inlet pipe diameter and reducing its length, the impact of inlet pipe resistance loss on the consistency of inlet pressure across different side cold plates can be reduced, ensuring consistent fluid pressure as it enters each side cold plate. To increase the pressure drop in the side cold plates, the flow path length within the side cold plates is increased through the first flow channel, thereby increasing flow resistance and improving the overall pressure drop. By employing these methods, a larger proportion of pressure drop in the side cold plates (i.e., a smaller proportion of pressure drop in the inlet pipe), and a smaller proportion of pressure drop in the inlet pipe (i.e., a smaller relative pressure loss in the inlet pipe), the closer the fluid inlet pressures of the different side cold plates before and after the inlet pipe become, resulting in a more uniform flow rate into each side cold plate. Attached Figure Description

[0041] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of this application. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0042] Figure 1 This is a schematic diagram of the battery pack structure provided in an embodiment of this application;

[0043] Figure 2 This is a schematic diagram of the first flow channel structure inside the side cooling plate provided in an embodiment of this application;

[0044] Figure 3 for Figure 2 Enlarged structural diagram at point A in the middle;

[0045] Figure 4 This is a schematic diagram of the fluid flow direction in the inlet and outlet pipes provided in the embodiments of this application;

[0046] Figure 5 This is a schematic diagram of the bottom flow channel and fluid flow direction inside the bottom cooling plate provided in an embodiment of this application;

[0047] Figure 6 This is a schematic diagram of thermal management of multiple battery cells provided in an embodiment of this application.

[0048] In the diagram: 1-bottom cooling plate; 2-battery cell; 3-side cooling plate; 4-inlet pipe; 5-outlet pipe; 6-corrugated pipe section; 7-tee; 8-foam; 9-aerogel;

[0049] 11-Inlet; 12-Outlet; 13-First bottom channel; 14-Second bottom channel;

[0050] 31-First connecting port; 32-Second connecting port; 33-First sub-channel; 34-Second sub-channel; 35-Third sub-channel; 36-Fourth sub-channel; 37-Fifth sub-channel; 38-Alignment section;

[0051] 41-First inlet pipe; 42-Second inlet pipe;

[0052] 51 - First outlet pipe; 52 - Second outlet pipe. Detailed Implementation

[0053] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0054] It should be noted that in this embodiment, the orientation or positional relationship indicated by terms such as "upper," "lower," "front," and "rear" is based on the orientation or positional relationship shown in the accompanying drawings. It is used only for the convenience of describing this application and for simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation of this application. Furthermore, "first," "second," "third," and "fourth" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0055] To enable those skilled in the art to better understand the present application, the present application will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0056] like Figure 1 As shown, in this embodiment, a battery pack is provided, which includes a cell module and a side cooling plate 3. The cell module includes a plurality of cells 2 arranged sequentially along a first direction, and the plurality of cell modules are arranged side by side sequentially along a second direction. The battery pack includes at least two cell modules, and the number of cells 2 in each cell module is at least two.

[0057] It should be noted that, in this embodiment, the first direction is as follows: Figure 1 In the XYZ three-axis coordinate system, the X direction and the second direction are as follows: Figure 1The Y-axis of the XYZ three-axis coordinate system is such that the first direction, the second direction, and the third direction are mutually perpendicular, i.e., the Cartesian coordinate system; further, the length direction of the side cold plate 3 is the first direction, and the thickness direction of the side cold plate 3 is the second direction.

[0058] A side cooling plate 3 is disposed on at least one side of the battery cell module. Each battery cell module contains multiple battery cells 2, and the sides of the multiple battery cells 2 are on the same plane, so that the side cooling plate 3 can contact the sides of the multiple battery cells 2 to achieve the purpose of cooling and heat dissipation. Among them, the side that contacts the side cooling plate 3 is the side with a larger area of ​​the battery cell 2. That is, in a battery cell 2, there are two opposite large sides and two opposite small sides, and the side cooling plate 3 is disposed at the corresponding position of the large side to ensure that the battery cell 2 has a sufficiently large heat dissipation area and improve the heat dissipation effect of the battery cell 2.

[0059] Furthermore, a first flow channel is provided within the side cooling plate 3. The first flow channel includes at least three sequentially connected sub-flow channels and a first connecting port 31 and a second connecting port 32 located at both ends of the first flow channel. The first connecting port 31 and the second connecting port 32 are located at both ends of the side cooling plate 3 in a first direction, and the two ends of the side cooling plate 3 in the first direction extend beyond the two ends of the cell module, ensuring that each cell 2 within the cell module corresponds to the side cooling plate 3, thereby ensuring the heat dissipation effect of each cell 2. Based on this, since multiple cell modules are arranged side-by-side along a second direction, when the side cooling plate 3 is located on the large side of the cell 2, the multiple side cooling plates 3 can be spaced apart along the second direction, thereby ensuring that each cell module has at least one side cooling plate 3 to dissipate heat from its cell 2.

[0060] Among them, at least two sub-channels have an angle between their extension directions, and the extension direction is the flow direction of the fluid in the sub-channel. This causes the fluid flow direction to change when the fluid flows in multiple sub-channels, thereby increasing the resistance to fluid flow and resulting in an increase in pressure drop.

[0061] In this design, the first connecting port 31 and the second connecting port 32 of the first flow channel can be the flow channel inlet and the flow channel outlet, respectively; no specific distinction is made here, and they can be interchanged. Correspondingly, an inlet pipe 4 connected to the first connecting port 31 and an outlet pipe 5 connected to the second connecting port 32 should be provided to ensure that the coolant can circulate within the first flow channel. In some embodiments, since multiple side cooling plates 3 are distributed along the second direction, the inlet pipe 4 and the outlet pipe 5 can also extend along the second direction to accommodate the distribution positions of the first connecting port 31 and the second connecting port 32.

[0062] Further, please refer to Figure 1 and Figure 4Both the inlet pipe 4 and the outlet pipe 5 are configured with two paths. The inlet pipe 4 includes a first inlet pipe 41 and a second inlet pipe 42. The first inlet pipe 41 is located at the end of the side cooling plate 3 near the first connecting port 31 and connects to multiple first connecting ports 31. The second inlet pipe 42 is also located at the end of the side cooling plate 3 near the first connecting port 31 and connects to multiple first connecting ports 31. Similarly, the outlet pipe 5 includes a first outlet pipe 51 and a second outlet pipe 52. The first outlet pipe 51 is located at the end of the side cooling plate 3 near the second connecting port 32 and connects to multiple second connecting ports 32. The second outlet pipe 52 is also located at the end of the side cooling plate 3 near the second connecting port 32 and connects to multiple second connecting ports 32.

[0063] As can be seen, on multiple side cooling plates 3, some of the first connecting ports 31 are connected to the first liquid inlet pipe 41, and another part of the first connecting ports 31 are connected to the second liquid inlet pipe 42; some of the second connecting ports 32 are connected to the first liquid outlet pipe 51, and another part of the second connecting ports 32 are connected to the second liquid outlet pipe 52; this avoids the problem of concentrated flow in a single pipeline and provides greater flexibility and versatility.

[0064] Furthermore, the first connecting port 31 of adjacent side cold plates 3 can be connected to the first liquid inlet pipe 41 and the second liquid inlet pipe 42 respectively, and the second connecting port 32 of adjacent side cold plates 3 can be connected to the first liquid outlet pipe 51 and the second liquid outlet pipe 52 respectively, so that the first liquid inlet pipe 41 and the second liquid inlet pipe 42 correspond to half of the side cold plates 3 respectively. Similarly, the first liquid outlet pipe 51 and the second liquid outlet pipe 52 also correspond to half of the side cold plates 3 respectively, ensuring that the fluid flow can be evenly distributed between the first liquid inlet pipe 41 and the second liquid inlet pipe 42, thereby allowing the fluid to be evenly distributed to each side cold plate 3, and the fluid is the cooling medium.

[0065] Nozzles can be installed at the first connecting port 31 and the second connecting port 32 of each side cooling plate 3. The nozzles can be connected to the corresponding liquid inlet pipe 4 or liquid outlet pipe 5 via tee 7. It should be noted that, in order to ensure a more uniform fluid flow rate distributed to each side cooling plate 3, the specifications of the first liquid inlet pipe 41, the second liquid inlet pipe 42, the first liquid outlet pipe 51, and the second liquid outlet pipe 52 should be the same, and the specifications of each tee 7 and the corresponding distribution pipe connecting the tee 7 to the nozzle should also be the same.

[0066] In summary, this application provides a first flow channel within the side cooling plate 3, which includes at least three sequentially connected sub-flow channels to increase the flow length of the fluid within the side cooling plate 3, thereby increasing the pressure drop of the first flow channel inside the side cooling plate 3. Furthermore, at least two of the sub-flow channels extend at an angle, which will also cause a change in pressure drop when the fluid flow direction changes, thus further increasing the pressure drop of the first flow channel. As a result, the proportion of the pressure drop of the side cooling plate 3 in the total pressure drop of the side cooling plate 3 and the liquid inlet pipe 4 increases, thereby reducing the influence of the pressure drop of the liquid inlet pipe 4 on the fluid pressure change and ensuring that the fluid state flowing through different side cooling plates 3 is consistent.

[0067] Furthermore, compared to a single inlet pipe 4, this application adopts a dual inlet pipe configuration with a first inlet pipe 41 and a second inlet pipe 42. Based on the same flow cross-sectional area (liquid flow rate), the inner diameter and cross-sectional area of ​​the first inlet pipe 41 and the second inlet pipe 42 can be reduced. On the one hand, this can increase the flow velocity in the first inlet pipe 41 and the second inlet pipe 42, making the liquid distribution in the first inlet pipe 41 and the second inlet pipe 42 at the first connecting ports 31 of the multiple side cooling plates 3 more uniform, ensuring that the flow rate of fluid entering each side cooling plate 3 is more uniform. On the other hand, compared to a single inlet pipe 4, this can increase the overall liquid flow rate, ensuring the cooling effect of the side cooling plate 3.

[0068] It should be noted that this application utilizes pressure drop ratio matching. Under reasonable pressure drop ratio matching, the pressure drop of the side cooling plate 3 accounts for a relatively large proportion of the total pressure drop of the side cooling plate 3 plus the liquid inlet pipe 4, while the proportion of the liquid inlet pipe 4 in the total pressure drop is relatively small. For example, the pressure drop of the side cooling plate 3 accounts for more than 70% of the total pressure drop, which can ensure the flow uniformity among different side cooling plates 3. It should be explained that to ensure the flow uniformity among different side cooling plates 3, the fluid state flowing through different side cooling plates 3 must be consistent. For example, the fluid pressure at the inlet and outlet of different side cooling plates 3 must be consistent. Then, under the same pressure differential, the flow velocity of different side cooling plates 3 will be consistent, which means the flow rate is the same, thus achieving flow uniformity.

[0069] Therefore, in order to achieve the above-mentioned goal of uniform flow distribution, it is necessary to ensure that the inlet and outlet pressure parameters of different side cold plates 3 are close to or consistent. That is, when the fluid enters the first channel port 31 on different side cold plates 3, the pressure is close to or consistent, and when the fluid flows into the second channel port 32 on different side cold plates 3, the pressure is close to or consistent.

[0070] Therefore, this application can also design a pressure drop in the inlet pipe 4, for example, by increasing the diameter of the inlet pipe 4 or reducing the length of the inlet pipe 4, to reduce the impact of the resistance loss of the inlet pipe 4 on the consistency of the inlet pressure of the different side cold plates 3, that is, to ensure that the fluid pressure is consistent when the fluid enters the different side cold plates 3.

[0071] However, there is still a pressure drop along the fluid flow direction in the inlet pipe 4. Therefore, a pressure drop matching design is adopted for the side cold plate 3. Pressure drop matching involves matching the pressure drop distribution and the proportion of pressure drop. By using multiple sub-channels in the first flow channel, the flow channel length of the fluid in the side cold plate 3 is increased, and the included angle design between the sub-channels is used to increase the flow channel resistance and improve the overall pressure drop of the side cold plate 3. The larger the proportion of pressure drop in the side cold plate 3, the smaller the corresponding proportion of pressure drop in the inlet pipe 4. A small proportion of pressure drop in the inlet pipe 4 means a small relative pressure loss in the inlet pipe 4. Therefore, the fluid inlet pressures of different side cold plates 3 before and after the inlet pipe 4 are closer, and the flow rate is more uniform. Conversely, a large proportion of pressure drop in the inlet pipe 4 means a large relative pressure loss in the inlet pipe 4, which will lead to a large difference in the fluid state at the inlet and outlet of different cold plates before and after the inlet pipe 4, and thus a large difference in flow rate.

[0072] In some embodiments, the side cold plate 3 can be selected as a stamped and brazed cold plate, which can effectively control the required pressure drop and pressure drop ratio, and achieve the requirement of controlling the flow uniformity between different side cold plates 3.

[0073] The first flow channel includes a first sub-flow channel 33, a second sub-flow channel 34, ..., an Nth sub-flow channel connected in sequence, where N is an odd number greater than or equal to five. It should be noted that since the first connecting port 31 and the second connecting port 32 are located at the two ends of the side cold plate 3 along the first direction, and the first flow channel is set along the direction from the first connecting port 31 to the second connecting port 32, an odd number of sub-flow channels are required to meet the above conditions for the first flow channel. Furthermore, the first flow channel has a U-shaped structure, so two sub-flow channels need to turn back to the other two sub-flow channels. Therefore, at least four sub-flow channels are required to realize the U-shaped structure of the first flow channel. In conjunction with the above conditions, the total number of sub-flow channels is an odd number greater than or equal to five.

[0074] Based on the above embodiments, along a third direction, the first sub-channel 33 is located near the electrode post of the cell 2, and the third direction is... Figure 2 In the Z-axis of the XYZ three-axis coordinate system, the width direction of the side cooling plate 3 is the third direction. Generally speaking, the terminal of the battery cell 2 is located at the upper end of the battery cell 2. Therefore, the first sub-channel 33 is located on the upper side of the side cooling plate 3, which helps to solve the problem of large heat generation and difficult heat dissipation of the terminal under fast charging. The first connecting port 31 is located at the first end of the first sub-channel 33, and the second end of the first sub-channel 33 extends towards the second connecting port 32. The Nth sub-channel is located near the bottom of the battery cell 2. The second connecting port 32 is located at the second end of the Nth sub-channel, and the first end of the Nth sub-channel extends towards the first connecting port 31.

[0075] Among them, the second sub-channel 34 to the (N-1)th sub-channel is located between the first sub-channel 33 and the Nth sub-channel, and in the third sub-channel 35 to the (N-1)th sub-channel, at least two sub-channels turn back to the first sub-channel 33 and the second sub-channel 34, thereby forming the first channel.

[0076] Furthermore, the Nth sub-channel is the fifth sub-channel 37, please refer to... Figure 2 The first end of the second sub-channel 34 is connected to the second end of the first sub-channel 33, and the second end of the second sub-channel 34 extends toward the first connecting port 31. Based on the five sub-channels, the second sub-channel 34 can be located on the lower middle side of the side cooling plate 3, that is, corresponding to the lower middle part of the battery cell 2. Since the first connecting port 31 is located on the first sub-channel 33, the heat exchange capacity of the fluid in the first sub-channel 33 is the strongest, and the heat exchange capacity of the fluid in the second sub-channel 34 to the fifth sub-channel 37 decreases in sequence. Therefore, the second sub-channel can effectively improve the heat exchange capacity of the lower middle part of the battery cell 2, ensure that the temperature difference between the upper and lower ends of the battery cell 2 is small, and ensure the performance of the battery cell 2.

[0077] The first end of the third sub-channel 35 is connected to the second end of the second sub-channel 34. The third sub-channel 35 is located between the first sub-channel 33 and the second sub-channel 34, and the second end of the third sub-channel 35 extends towards the second connecting port 32. The first end of the fourth sub-channel 36 is connected to the second end of the third sub-channel 35. The fourth sub-channel 36 is located between the first sub-channel 33 and the third sub-channel 35, and the second end of the fourth sub-channel 36 extends towards the first connecting port 31. That is, the third sub-channel 35 and the fourth sub-channel 36 are two sub-channels that turn back to the area between the first sub-channel 33 and the second sub-channel 34. The heat transfer energy of the fluid in the third sub-channel 35 and the fourth sub-channel 36 will be reduced, which can dissipate heat in the middle and upper middle parts of the battery cell 2, ensuring the heat dissipation effect of the battery cell 2.

[0078] The first end of the fifth sub-channel 37 is connected to the second end of the fourth sub-channel 36. The heat exchange capacity of the fluid in the fifth sub-channel 37 is the worst, but due to the presence of the bottom cooling plate 1, the bottom of the cell 2 still has a good heat dissipation effect, so that the entire cell 2 can maintain a stable and efficient heat exchange efficiency, and make the temperature of all cells 2 under a side cooling plate 3 more uniform.

[0079] Please refer to Figure 3The side cooling plate 3 is provided with a clearance portion 38 at both ends in the first direction, and the two clearance portions 38 located at the same end of the side cooling plate 3 are distributed along the third direction. The first connecting port 31 and the second connecting port 32 are provided on the side cooling plate 3 corresponding to the clearance portion 38. The clearance portion 38 is provided to avoid the liquid inlet pipe 4 and the liquid outlet pipe 5 along the third direction. That is, the first liquid inlet pipe 41 and the second liquid inlet pipe 42 are respectively located at one end of the two clearance portions 38 of the side cooling plate 3. The projections of the first liquid inlet pipe 41 and the second liquid inlet pipe 42 in the first direction and the second direction overlap with the side cooling plate 3 at least partially, thereby reducing the space occupied by the liquid inlet pipe 4 in the first direction and the second direction, making the layout of the side cooling plate 3 and the liquid inlet pipe 4 more compact and reducing the overall size of the battery pack. Similarly, along the third direction, the first liquid outlet pipe 51 and the second liquid outlet pipe 52 are located at the two clearance portions 38 at the other end of the side cold plate 3, respectively. The projections of the first liquid outlet pipe 51 and the second liquid outlet pipe 52 in the first and second directions respectively overlap with the side cold plate 3 at least partially. The effect can be referred to the liquid inlet pipe 4, which will not be elaborated here.

[0080] The side cooling plate 3 can be a rectangular plate, and the clearance portion 38 can be a chamfer, notch, or through hole at the four corners of the rectangular plate. Furthermore, the clearance portion 38 can be a triangular structure, a rectangular structure, or an arc-shaped structure. That is, regardless of whether the clearance portion 38 adopts any of the chamfer, notch, or through hole methods, the shape of the two ends of the side cooling plate 3 can be triangular, arc-shaped, or other irregular shapes to accommodate the liquid inlet pipe 4 and / or the liquid outlet pipe 5. No further restrictions are imposed here, and all of them fall within the protection scope of this application.

[0081] Furthermore, multiple tees 7 are provided on the first liquid inlet pipe 41, the second liquid inlet pipe 42, the first liquid outlet pipe 51, and the second liquid outlet pipe 52. The first and second ports of the tees 7 are connected to the liquid inlet pipe 4 or the liquid outlet pipe 5, and the third port of the tees 7 is connected to the first connecting port 31 or the second connecting port 32 through an arc-shaped pipe. The first liquid inlet pipe 41, the second liquid inlet pipe 42, the first liquid outlet pipe 51, and the second liquid outlet pipe 52 all include multiple corrugated pipe sections 6. The first and second ports are connected to the corrugated pipe sections 6. The corrugated pipe sections 6 are flexible hoses that are axially expandable and contractible. The corrugated pipe sections 6 are used to absorb the displacement of the side cold plate 3 caused by the expansion and contraction of the battery cell 2 and to accommodate assembly tolerances.

[0082] Furthermore, in the same side cold plate 3, the first connecting port 31 and the second connecting port 32 are located on the same side wall of the side cold plate 3, that is, the arc-shaped tubes on the same side cold plate 3 are located on the same side of the side cold plate 3 in the second direction. In adjacent side cold plates 3, the arc-shaped tubes on either side cold plate 3 are located on the side of the side cold plate 3 away from the other side cold plate in the second direction; that is, the arc-shaped tubes in adjacent side cold plates 3 are located on different sides of the corresponding side cold plate 3 in the second direction, thereby avoiding interference between the arc-shaped tubes on two adjacent side cold plates 3 and affecting the normal arrangement of the arc-shaped tubes.

[0083] In some embodiments, the first inlet pipe 41 and the second inlet pipe 42 are arranged in parallel and distributed along a third direction. Compared with a series connection, the parallel connection can shorten the length of the first inlet pipe 41 and the second inlet pipe 42, thereby reducing the pressure drop and temperature difference before and after the first inlet pipe 41 and the second inlet pipe 42. The two first connecting ports 31 of adjacent side cold plates 3 are respectively connected to the first inlet pipe 41 and the second inlet pipe 42, so that the fluid of the first inlet pipe 41 and the second inlet pipe 42 can be alternately distributed to the two adjacent side cold plates 3, improving the uniformity of the fluid distributed to each side cold plate 3. Similarly, the arrangement of the first outlet pipe 51 and the second outlet pipe 52 can refer to the arrangement of the first inlet pipe 41 and the second inlet pipe 42, and will not be described again here.

[0084] Furthermore, an arc-shaped transition section is provided between two adjacent sub-channels, allowing fluid to flow from one sub-channel into the other after passing through the arc-shaped transition section. The included angle between two adjacent sub-channels is B, which satisfies: 0° ≤ B ≤ 45°. It should be noted that when the fluid flow direction changes (the fluid turning angle increases), fluid separation intensifies, the vortex range expands, and the local drag coefficient increases significantly. When B = 45°, the fluid turning angle between two adjacent sub-channels is 135°. The larger the turning angle, the greater the drag coefficient and pressure drop at the arc-shaped transition section. As B gradually decreases, when B = 0°, the two adjacent sub-channels are parallel to each other, but the fluid flow direction is opposite, i.e., the fluid turning angle between two adjacent sub-channels is 180°. At this point, the drag coefficient and pressure drop at the arc-shaped transition section reach their maximum. Furthermore, B satisfies: 0°≤B≤15°, corresponding to a steering angle between 165° and 180°. This allows for a larger steering angle, resulting in a larger drag coefficient at the arc-shaped transition section and a greater pressure drop.

[0085] The battery pack of this application also includes a bottom cooling plate 1 disposed on the bottom surface of the cell module, please refer to Figure 1 and Figure 4 The bottom cooling plate 1 has multiple bottom flow channels extending along a second direction. These bottom flow channels are arranged in parallel. One end of each bottom flow channel converges and connects to the liquid inlet 11 on the bottom cooling plate 1, while the other end of each bottom flow channel converges and connects to the liquid outlet 12 on the bottom cooling plate 1. In some embodiments, the liquid inlet 11 and the liquid outlet 12 can be respectively located on both sides of the bottom cooling plate 1 in the second direction, thereby forming a straight channel. Multiple bottom flow channels can be arranged in parallel to dissipate heat from each battery cell 2 in the battery cell module.

[0086] In other embodiments, in the second direction, the liquid inlet 11 and the liquid outlet 12 may also be located on one side of the bottom cooling plate 1, that is, the liquid inlet 11 and the liquid outlet 12 are located on the same side of the cell module. Please refer to [reference needed]. Figure 5The bottom flow channel includes a first bottom flow channel 13 and a second bottom flow channel 14. The first end of the first bottom flow channel 13 is connected to the liquid inlet 11, and the second end of the first bottom flow channel 13 extends away from the liquid inlet 11. The first end of the second bottom flow channel 14 is connected to the second end of the first bottom flow channel 13, and the second end of the second bottom flow channel 14 extends towards the liquid outlet 12, thus forming a U-shaped flow channel structure. Of course, both the first bottom flow channel 13 and the second bottom flow channel 14 can be multiple parallel flow channels to increase the heat exchange area.

[0087] Based on this embodiment, since the liquid inlet 11 and the liquid outlet 12 are located on one side of the bottom cooling plate 1, the liquid inlet 11 can also be connected to the first liquid inlet pipe 41 and the second liquid inlet pipe 42, and the liquid outlet 12 can also be connected to the first liquid outlet pipe 51 and the second liquid outlet pipe 52. After the fluid enters the bottom cooling plate 1 through the liquid inlet 11, it is divided in the internal flow channel of the bottom cooling plate 1. Part of the fluid flows to the bottom flow channel (bottom surface thermal management system), and the other part of the fluid flows into the first liquid inlet pipe 41 and the second liquid inlet pipe 42 after passing through a short section of the flow channel, and enters the first flow channel of the side cooling plate 3 (side surface thermal management system).

[0088] For the bottom-mounted thermal management system, the fluid flow direction is as follows: Figure 5 As shown, the fluid is first divided into multiple parallel regions (first bottom flow channel 13). Each parallel region corresponds to one of the cells 2 in multiple modules. After the fluid flows to the side away from the inlet 11, it turns back. When turning back, it enters multiple parallel branches (second bottom flow channel 14), merges near the outlet 12, and then merges with the fluid of the side thermal management system before reaching the outlet 12.

[0089] For the side thermal management subsystem, the fluid is diverted in parallel into the first inlet pipe 41 and the second inlet pipe 42. The first inlet pipe 41 and the second inlet pipe 42 are connected to the nozzles of the side cooling plate 3 through a tee 7. Each nozzle of the side cooling plate 3 corresponds to a tee 7. Similarly, the connection between the first outlet pipe 51 and the second outlet pipe 52 and the side cooling plate 3 can refer to the above scheme.

[0090] In addition, both the bottom cooling plate 1 and the side cooling plate 3 are stamped and brazed cold plates made of aluminum. The flow channel can be easily adjusted through the processing technology to control the pressure drop of the side cooling plate 3. After the pressure drop matching design between the side cooling plate 3 and the liquid inlet pipe 4, the flow uniformity between different side cooling plates 3 under the side thermal management system is consistent. It is not necessary to adjust the liquid inlet pipe 4, the three-way valve 7, or one or several side cooling plates 3 separately to achieve the flow uniformity, thereby ensuring the temperature uniformity among all cells 2 in the battery pack.

[0091] In some embodiments, the side cooling plate 3 and the bottom cooling plate 1 are fixedly connected to the side and bottom surfaces of the battery cell 2 respectively via a thermally conductive material. The thermally conductive material can be a thermally conductive structural adhesive, thereby transferring heat from the side and bottom surfaces of the battery cell 2. The thermally conductive structural adhesive can achieve balanced heat dissipation between the battery cells 2 and between the battery cell and the cooling plate, significantly reducing the temperature and temperature difference of the battery cell 2 and optimizing the battery thermal management system. Furthermore, a heat insulation layer is provided between the opposite surfaces of the battery cells 2 to ensure effective heat insulation between the four sides of the battery cell 2. After one battery cell 2 experiences thermal runaway, it will not cause thermal runaway of adjacent battery cells 2, achieving no heat diffusion and heat propagation. For the side surface of the battery cell 2 with the side cooling plate 3, its heat insulation layer can be provided on the side of the side cooling plate 3 away from the battery cell 2. If both opposite sides of two adjacent battery cells 2 are provided with side cooling plates 3, then the heat insulation layer can be provided between the two side cooling plates 3.

[0092] Furthermore, the insulation layer includes aerogel 9 and foam 8, please refer to... Figure 6 Aerogel 9 is filled between the opposite sides of adjacent cells 2 that do not have side cooling plates 3. Aerogel 9 can meet the thermal insulation performance and mechanical strength requirements between cells 2. Foam 8 is filled between the opposite sides of adjacent cells 2 that have side cooling plates 3. Foam 8 can provide thermal insulation while also providing some support and buffering for the side cooling plates 3, thus meeting the compression caused by the expansion of cells 2.

[0093] It should be noted that in this specification, relational terms such as first and second are used only to distinguish one entity from several other entities, and do not necessarily require or imply any such actual relationship or order between these entities.

[0094] This document uses specific examples to illustrate the principles and implementation methods of this application. The descriptions of the embodiments above are only for the purpose of helping to understand the method and core ideas of this application. It should be noted that those skilled in the art can make various improvements and modifications to this application without departing from the principles of this application, and these improvements and modifications also fall within the protection scope of the claims of this application.

Claims

1. A battery pack, characterized in that, include: A battery cell module includes multiple battery cells (2) arranged sequentially along a first direction, and the multiple battery cell modules are arranged side by side sequentially along a second direction; A side cooling plate (3) is disposed on at least one side of the battery cell module, and a plurality of the side cooling plates (3) are arranged at intervals along a second direction, and a first flow channel is provided in the side cooling plate (3); The first flow channel includes at least three sequentially connected sub-flow channels, and a first connecting port (31) and a second connecting port (32) located at both ends of the first flow channel, wherein at least two of the sub-flow channels have an angle between their extending directions, and the first connecting port (31) and the second connecting port (32) are located at both ends of the side cold plate (3) in a first direction. The first liquid inlet pipe (41) is located at one end of the side cold plate (3) near the first communication port (31), and the first liquid inlet pipe (41) connects to multiple first communication ports (31). The second liquid inlet pipe (42) is located at one end of the side cold plate (3) near the first connecting port (31), and the second liquid inlet pipe (42) connects to multiple first connecting ports (31). The first liquid outlet pipe (51) is located at one end of the side cold plate (3) near the second connecting port (32), and the first liquid outlet pipe (51) is connected to a plurality of second connecting ports (32). The second liquid outlet pipe (52) is located at one end of the side cold plate (3) near the second connecting port (32), and the second liquid outlet pipe (52) connects to multiple second connecting ports (32).

2. The battery pack according to claim 1, characterized in that, The first flow channel includes a first sub-flow channel (33), a second sub-flow channel (34), ..., an Nth sub-flow channel connected in sequence, where N is an odd number greater than or equal to five; Along a third direction, the first sub-channel (33) is close to the electrode post side of the cell (2), the first connection port (31) is located at the first end of the first sub-channel (33), and the second end of the first sub-channel (33) extends toward the second connection port (32); Along a third direction, the Nth sub-channel is located near the bottom side of the cell (2), the second connection port (32) is located at the second end of the Nth sub-channel, and the first end of the Nth sub-channel extends toward the first connection port (31); The second sub-channel (34) to the (N-1)th sub-channel are located between the first sub-channel (33) and the Nth sub-channel, and among the third sub-channel (35) to the (N-1)th sub-channel, at least two sub-channels are located between the first sub-channel (33) and the second sub-channel (34).

3. The battery pack according to claim 2, characterized in that, The Nth sub-channel is the fifth sub-channel (37); The first end of the second sub-channel (34) is connected to the second end of the first sub-channel (33), and the second end of the second sub-channel (34) extends toward the first connecting port (31); The first end of the third sub-channel (35) is connected to the second end of the second sub-channel (34). The third sub-channel (35) is located between the first sub-channel (33) and the second sub-channel (34), and the second end of the third sub-channel (35) extends toward the second connecting port (32). The first end of the fourth sub-channel (36) is connected to the second end of the third sub-channel (35). The fourth sub-channel (36) is located between the first sub-channel (33) and the third sub-channel (35), and the second end of the fourth sub-channel (36) extends toward the first connecting port (31). The first end of the fifth sub-channel (37) is connected to the second end of the fourth sub-channel (36).

4. The battery pack according to claim 1, characterized in that, The side cooling plate (3) is a rectangular plate, and the side cooling plate (3) has a clearance part (38) at both ends in the first direction. The two clearance parts (38) located at the same end of the side cooling plate (3) are distributed along the third direction. Along the third direction, the first liquid inlet pipe (41) and the second liquid inlet pipe (42) are respectively located at the two clearance portions (38) at one end of the side cold plate (3). The projections of the first liquid inlet pipe (41) and the second liquid inlet pipe (42) in the first direction and the second direction respectively overlap with the side cold plate (3) at least partially. Along the third direction, the first liquid outlet pipe (51) and the second liquid outlet pipe (52) are respectively located at the two clearance portions (38) at the other end of the side cold plate (3). The projections of the first liquid outlet pipe (51) and the second liquid outlet pipe (52) in the first direction and the second direction respectively overlap with the side cold plate (3) at least partially. Preferably, the avoidance part (38) is a triangular structure, a rectangular structure, or an arc-shaped structure.

5. The battery pack according to claim 1, characterized in that, The first liquid inlet pipe (41), the second liquid inlet pipe (42), the first liquid outlet pipe (51) and the second liquid outlet pipe (52) are each provided with multiple tees (7). The first and second ports of the tees (7) are connected to the liquid inlet pipe or the liquid outlet pipe, and the third port of the tees (7) is connected to the first connecting port (31) or the second connecting port (32) through an arc-shaped pipe. The first liquid inlet pipe (41), the second liquid inlet pipe (42), the first liquid outlet pipe (51) and the second liquid outlet pipe (52) each include multiple corrugated pipe sections (6), and the first port and the second port are connected to the corrugated pipe sections (6); In one of the two adjacent side cold plates (3), the arc-shaped tube on any one of the side cold plates (3) is located on the side of the side cold plate (3) away from the other side cold plate (3) in the second direction.

6. The battery pack according to claim 1, characterized in that, The first liquid inlet pipe (41) and the second liquid inlet pipe (42) are arranged in parallel and distributed along a third direction. The two first connecting ports (31) of the adjacent side cold plate (3) are respectively connected to the first liquid inlet pipe (41) and the second liquid inlet pipe (42); the first liquid outlet pipe (51) and the second liquid outlet pipe (52) are arranged in parallel and distributed along a third direction. The two second connecting ports (32) of the adjacent side cold plate (3) are respectively connected to the first liquid outlet pipe (51) and the second liquid outlet pipe (52).

7. The battery pack according to claim 1, characterized in that, An arc-shaped transition section is provided between two adjacent sub-channels, and the included angle between two adjacent sub-channels is B, wherein B satisfies: 0°≤B≤45°.

8. The battery pack according to claim 7, characterized in that, The condition B satisfies: 0°≤B≤15°.

9. The battery pack according to claim 1, characterized in that, It also includes a bottom cooling plate (1) disposed on the bottom surface of the battery cell module. The bottom cooling plate (1) is provided with a plurality of bottom flow channels extending along the first direction. The bottom flow channels are arranged in parallel. One end of the bottom flow channels is connected to the liquid inlet (11) on the bottom cooling plate (1), and the other end of the bottom flow channels is connected to the liquid outlet (12) on the bottom cooling plate (1). The inlet (11) is also connected to the first inlet pipe (41) and the second inlet pipe (42), and the outlet (12) is also connected to the first outlet pipe (51) and the second outlet pipe (52).

10. The battery pack according to claim 9, characterized in that, In the second direction, the liquid inlet (11) and the liquid outlet (12) are located on the same side of the battery cell module. The bottom flow channel includes a first bottom flow channel (13) and a second bottom flow channel (14). The first end of the first bottom flow channel (13) is connected to the liquid inlet (11), and the second end of the first bottom flow channel (13) extends away from the liquid inlet (11). The first end of the second bottom flow channel (14) is connected to the second end of the first bottom flow channel (13), and the second end of the second bottom flow channel (14) extends towards the liquid outlet (12).

11. The battery pack according to claim 9, characterized in that, The side cooling plate (3) and the bottom cooling plate (1) are fixedly connected to the side and bottom surfaces of the battery cell (2) respectively through heat conductors.

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