Battery module, and battery cell liquid-cooling method

Abstract

A battery module and a battery cell liquid-cooling method. The battery module comprises: battery cells (1) and a case (2), wherein a cavity (21) is formed in the case (2); a plurality of battery cells (1) arranged side by side are placed in the cavity (21); the cavity (21) is filled with a coolant; the bottom surface and top surface of the case (2) are respectively provided with a first flow channel (5) and a second flow channel (4); and the first flow channel (5) and the second flow channel (4) are in communication with the cavity (21), such that the coolant is fed into the cavity (21). By means of the provision of the cavity, the first flow channel and the second flow channel, which are used in cooperation in the battery module of the present application, the battery cells can be fully immersed in the cyclically flowing coolant for heat dissipation, which can ensure uniform heat dissipation of different parts of the battery cells, such that a good liquid-cooling effect is achieved; and the costs are relatively low.

Description

Battery module and battery cell liquid cooling method

[0001] This application claims priority to Chinese patent applications filed with the China Patent Office on July 29, 2024, with application numbers 202411025235.6 and 202421819503.7. The entire contents of the above applications are incorporated by reference into this application.

[0002] Technical Field

[0003] The present application relates to the field of battery technology, for example, to a battery module and a battery cell liquid cooling method.

[0004] Background Art

[0005] In a battery module, liquid cooling of battery cells is usually performed by direct contact between a liquid cooling tube or a liquid cooling plate and the battery cells. This liquid cooling method requires the installation of a liquid cooling tube or a liquid cooling plate.

[0006] Technical issues

[0007] In the related art, the method of cooling the battery by providing a liquid cooling tube or a liquid cooling plate makes the cost of the battery module higher, and the liquid cooling effect on the battery cell is poor due to the limited contact area between the liquid cooling tube or the liquid cooling plate and the battery cell.

[0008] Technical Solutions

[0009] The present application provides a battery module, comprising:

[0010] battery cells;

[0011] A box body is formed with a cavity, a plurality of battery cells arranged in parallel are placed in the cavity, the cavity is filled with coolant, and a first flow channel and a second flow channel are respectively provided on the bottom and top surfaces of the box body, and the first flow channel and the second flow channel are respectively connected to the cavity to fill the cavity with coolant.

[0012] The present application also provides a cell liquid cooling method, which is applied to a cell in a battery module, comprising:

[0013] Fill the cavity with coolant so that the battery cell is immersed in the coolant;

[0014] Cooling liquid is respectively filled into the second flow channel located on the top surface and the first flow channel located on the bottom surface so that cooling liquid flows at the top and bottom ends of the battery core respectively, and the cooling liquid in the second flow channel and the first flow channel flows back into the cavity.

[0015] Beneficial effects

[0016] The battery module and battery cell liquid cooling method provided by the present application are achieved by filling the cavity of the box body with coolant so that the battery cell is immersed in the coolant; and filling the second flow channel located on the top surface and the first flow channel located on the bottom surface with coolant so that coolant flows at the top and bottom ends of the battery cell, and the coolant in the second flow channel and the first flow channel flows back into the cavity; that is, the battery cell can be completely immersed in the coolant by the coolant in the cavity, the coolant in the second flow channel, and the coolant in the first flow channel, so that the battery cell can be completely immersed in the circulating coolant for cooling, ensuring uniform heat dissipation to different parts of the battery cell, and the liquid cooling effect is better, thereby improving the heat dissipation efficiency of the battery cell; there is no need to use liquid cooling tubes or liquid cooling plates, saving costs; and the second flow channel and the first flow channel are integrated on the box body, and there is no need to add other structures for setting the flow channels, so that the cost of the entire battery module is lower.

[0017] BRIEF DESCRIPTION OF THE DRAWINGS

[0018] FIG1 is a schematic diagram of the exploded structure of a battery module provided by some implementations of the present application;

[0019] FIG2 is a schematic structural diagram of a battery module (excluding battery cells, insulating brackets, integrated copper busbars, and a third side plate) provided in some implementations of the present application;

[0020] FIG3 is a schematic diagram of the assembly structure between the first side plate, the second side plate, and the lower flow channel plate provided by some implementations of the present application;

[0021] FIG4 is a schematic structural diagram of a second side plate provided by some implementations of the present application;

[0022] FIG5 is a schematic diagram of the exploded structure of a top cover assembly provided in some implementations of the present application;

[0023] FIG6 is a schematic diagram of the exploded structure of the bottom surface of the base plate assembly (with the lower cover plate located on top) provided in some implementations of the present application;

[0024] FIG7 is a schematic diagram of the bottom structure of a box (excluding the lower cover) provided in some implementations of the present application;

[0025] FIG8 is a schematic structural diagram of a downflow plate provided by some implementations of the present application;

[0026] FIG9 is a flow chart of a battery cell liquid cooling method provided by some implementations of the present application.

[0027] Description of reference numerals:

[0028] 1-battery cell;

[0029] 2-Box body; 21-Cavity; 22-Box body; 221-First side panel; 222-Second side panel; 223-Third side panel; 224-Glue groove; 23-Top cover assembly; 231-Upper flow channel plate; 2311-Liquid injection hole; 232-Upper cover plate; 2321-Window; 2322-Block plate; 24-Bottom plate assembly; 241-Lower flow channel plate; 2411-Pressure relief hole; 2412-Insulation seal; 242-Lower cover plate; 2421-Third through hole;

[0030] 3-third flow channel; 32-liquid inlet nozzle; 33-liquid inlet;

[0031] 4-second flow channel; 41-upper main flow channel; 42-upper branch flow channel; 43-first through hole;

[0032] 5-first flow channel; 51-lower main flow channel; 52-lower branch flow channel; 53-second through hole;

[0033] 61- liquid outlet; 62- liquid outlet nozzle; 64- outlet hole; 65- liquid outlet main channel;

[0034] 7-Integrated copper busbar; 8-Insulation bracket; 81-Mounting hole; 9-Output pole.

[0035] Modes for Carrying Out the Invention

[0036] Example 1

[0037] This embodiment provides a battery module that has high heat dissipation efficiency, a simple structure, and low cost. The battery module in this embodiment can be a lithium battery module, and the specific type of the battery module is not limited here.

[0038] As shown in Figures 1 to 8, the battery module includes a housing 2 and multiple battery cells 1. A cavity 21 is formed in the housing 2. Multiple battery cells 1 are placed in the cavity 21 and arranged in parallel. The cavity 21 is filled with coolant. A first flow channel 5 and a second flow channel 4 are provided on the bottom and top surfaces of the housing 2, respectively. The second flow channel 4 and the first flow channel 5 are respectively connected to the cavity 21 to fill the cavity 21 with coolant. The cavity 21 is filled with coolant.

[0039] The battery module in this embodiment changes the liquid cooling method for the battery cell 1; by filling the cooling liquid into the cavity 21 of the box body 2, the battery cell 1 is immersed in the cooling liquid; and filling the second flow channel 4 on the top surface and the first flow channel 5 on the bottom surface with cooling liquid, so that the top and bottom ends of the battery cell 1 are both filled with cooling liquid, and the cooling liquid in the second flow channel 4 and the first flow channel 5 flows back to the cavity 21; that is, through the cooling liquid in the cavity 21, the cooling liquid in the second flow channel 4, and the cooling liquid in the first flow channel 5, the cooling liquid in the second flow channel 4 and the cooling liquid in the first flow channel 5 are cooled. The liquid can completely immerse the battery cell 1 in the coolant, so that the battery cell 1 can be completely immersed in the circulating coolant for cooling, ensuring uniform heat dissipation of different parts of the battery cell 1, and the liquid cooling effect is better, thereby improving the heat dissipation efficiency of the battery cell 1; there is no need to use liquid cooling tubes or liquid cooling plates, the structure is simple, and the cost is saved; and the second flow channel 4 and the first flow channel 5 are integrated on the box body 2, and there is no need to add other additional structures for setting the flow channels, so that the structure of the entire battery module is simpler and the cost is lower.

[0040] The battery cell 1 in this embodiment is a cylindrical battery cell, and the two axial ends of the battery cell 1 face the top surface and the bottom surface of the box body 2 respectively, and the radial side walls of adjacent battery cells 1 abut against each other to ensure heat dissipation while improving the energy density of the battery module.

[0041] As shown in Figures 1 to 3, a third flow channel 3 is provided on the side of the box body 2, and the third flow channel 3 is connected to the second flow channel 4 and the first flow channel 5 respectively, so that the coolant in the third flow channel 3 flows into the second flow channel 4 and the first flow channel 5 respectively.

[0042] As shown in Figures 1 to 3, the box body 2 includes a box body main body 22, and the box body 22 includes a first side plate 221 located on the side of the box body 2. A third flow channel 3 is arranged in the first side plate 221, and the third flow channel 3 passes through the first side plate 221 along the Z axis, and a liquid inlet 33 connected to the third flow channel 3 is arranged on one side of the first side plate 221.

[0043] As shown in Figures 1 and 2, the box body 22 also includes a second side panel 222 and two third side panels 223 respectively located on the side surfaces of the box body 2. The second side panel 222 is arranged opposite to the first side panel 221, and the two third side panels 223 are arranged opposite to each other. The first side panel 221, the second side panel 222 and the two third side panels 223 are connected to each other to form a square structure. That is, the box body 22 is a square structure with an opening, and the box body 22 has a top opening and a bottom opening that are connected.

[0044] As shown in Figures 1 and 3, the liquid inlet 33 is connected to a liquid inlet nozzle 32. That is, the liquid inlet nozzle 32 passes through one of the third side plates 223 and is connected to the liquid inlet 33, so that the coolant can be transported to the liquid inlet 33 and the third flow channel 3 through the liquid inlet nozzle 32. The coolant in this embodiment can be silicone oil.

[0045] As shown in Figures 1 to 4, a fourth flow channel connected to the cavity body 21 is provided in the second side plate 222, and a liquid outlet 61 connected to the fourth flow channel is provided on one side of the second side plate 222. The fourth flow channel is configured to discharge the cooling liquid in the cavity body 21 to the liquid outlet 61.

[0046] As shown in Figures 1 and 4, a liquid outlet nozzle 62 is connected to the liquid outlet 61, and the liquid outlet nozzle 62 and the liquid inlet nozzle 32 are located on the same side, that is, the liquid outlet nozzle 62 connected to the liquid outlet 61 passes through one of the third side panels 223 to the outside of the box body 22 so that the coolant can be transported to the outside of the box body 22 through the liquid outlet nozzle 62.

[0047] As shown in Figures 3 and 4, the fourth flow channel includes a main liquid outlet channel 65 and a plurality of outlet holes 64. The main liquid outlet channel 65 extends along the Y-axis, and the plurality of outlet holes 64 are evenly and spaced apart along the Y-axis. Each outlet hole 64 is respectively connected to the cavity body 21 and the main liquid outlet channel 65, and the first end of the main liquid outlet channel 65 is located inside the second side plate 222, and the second end of the main liquid outlet channel 65 opposite to the first end of the main liquid outlet channel 65 is connected to the liquid outlet port 61, that is, the main liquid outlet channel 65 does not pass through the entire second side plate 222 along the Y-axis.

[0048] As shown in Figures 3 and 4, on the Y-axis and in the direction close to the liquid outlet 61, the apertures of the multiple outlet holes 64 gradually decrease to ensure that the flow rate of the coolant entering each outlet hole 64 is relatively uniform, thereby ensuring the uniformity of the flow of the coolant in the entire box 2, ensuring the uniformity of liquid cooling of the battery cells 1 located at different positions, and avoiding overcooling of some battery cells 1 and overheating of other battery cells 1.

[0049] As shown in FIG2 , the first side panel 221, the second side panel 222, and the two third side panels 223 are sealed together to ensure the overall sealing of the box body 22. Glue grooves 224 are provided on the first side panel 221, the second side panel 222, and the third side panel 223. Sealant is first applied to the glue grooves 224, and then the first side panel 221, the second side panel 222, and the two third side panels 223 are connected to each other to ensure the sealing connection between the first side panel 221, the second side panel 222, and the two third side panels 223. In order to ensure the connection stability of the entire box body 22, bolts are used to connect the first side panel 221, the second side panel 222, and the two third side panels 223 while sealing them together.

[0050] As shown in Figures 1 and 5, the box body 2 also includes a top cover assembly 23, which is located on the top surface of the box body 2 and is sealed to the top end opening of the box body 22 to ensure the sealing between the top cover assembly 23 and the box body 22; the top cover assembly 23 includes an upper flow channel plate 231, and a second flow channel 4 is provided on the top surface of the upper flow channel plate 231, and a first through hole 43 communicating with the cavity body 21 is provided in the second flow channel 4, so that the communication between the second flow channel 4 and the cavity body 21 can be ensured through the first through hole 43.

[0051] As shown in Figures 1 and 5, the upper flow channel plate 231 is arranged horizontally and is sealed and connected to the top of the first side plate 221, the second side plate 222, and the two third side plates 223. In addition, an integrated copper busbar 7 is arranged below the upper flow channel plate 231. The integrated copper busbar 7 is electrically connected to multiple battery cells 1 so that multiple battery cells 1 can be connected in series or in parallel. Among them, two output poles 9 are connected to the two output ends of the integrated copper busbar 7. The two output poles 9 are located on the same side and are both installed on the third side plate 223. That is, the two output poles 9 are located on one of the third side plates 223, and the liquid inlet nozzle 32 / liquid outlet nozzle 62 is located on the other third side plate 223. Among them, the sealed connection between the upper flow channel plate 231 and the top of the first side plate 221, the second side plate 222, and the two third side plates 223 can be sealed by a glue groove 224. Here, the specific sealing method is not limited.

[0052] As shown in Figure 5, the second flow channel 4 includes an upper main channel 41 and multiple upper branch flow channels 42; wherein, the upper main channel 41 extends along the Y axis, and the first end of the upper main channel 41 is connected to the third flow channel 3; the upper branch flow channel 42 extends along the X axis, and the multiple upper branch flow channels 42 are respectively connected to the second end opposite to the first end of the upper main channel 41, and the multiple upper branch flow channels 42 are arranged side by side at intervals along the Y axis, and each upper branch flow channel 42 is provided with multiple first through holes 43 at intervals, so that the cooling liquid in the upper branch flow channel 42 can flow to the cavity 21 through the multiple first through holes 43.

[0053] By providing multiple upper branch flow channels 42 spaced and arranged side by side along the Y-axis, the tops of the multiple battery cells 1 within the cavity 21 can be covered by the multiple upper branch flow channels 42, ensuring that coolant flows on the top of each battery cell 1, thereby ensuring uniform liquid cooling of the multiple battery cells 1. In this embodiment, there are five upper branch flow channels 42, and each upper branch flow channel 42 is provided with seven first through holes 43. Here, the number of upper branch flow channels 42 and first through holes 43 provided is not limited.

[0054] Among them, the X-axis, Y-axis and Z-axis are perpendicular to each other.

[0055] As shown in Figures 1 and 5, the top cover assembly 23 also includes an upper cover plate 232. The upper cover plate 232 is provided as a sealing cover on one side of the upper flow channel plate 231 where the second flow channel 4 is provided. This seals the second flow channel 4, ensuring that the coolant flows only along the second flow channel 4 and preventing the coolant from overflowing outside the upper flow channel plate 231. The upper cover plate 232 and the upper flow channel plate 231 can be sealed by welding or gluing, which is not specifically limited here.

[0056] As shown in Figure 5, a window 2321 is provided on the upper cover plate 232 for injecting coolant into the cavity body 21, and a baffle 2322 is removably covered at the window 2321. When it is necessary to inject coolant into the cavity body 21 through the window 2321, the baffle 2322 is removed to open the window 2321; when the injection is completed, the baffle 2322 is covered on the window 2321 to close the window 2321 to prevent dust and other impurities from entering the cavity body 21 through the window 2321.

[0057] As shown in Figure 5, an injection hole 2311 is also provided on the upper flow channel plate 231, and the injection hole 2311 is correspondingly arranged below the window 2321, so that the coolant can be injected into the cavity body 21 through the window 2321 and the injection hole 2311 in sequence; and the shielding plate 2322 can cover the injection hole 2311 while shielding the window 2321.

[0058] As shown in Figures 1, 6 and 7, the box body 2 also includes a bottom plate assembly 24, which is located on the bottom surface of the box body 2 and is sealed to the bottom end opening of the box body 22 to ensure a sealed connection between the box body 22 and the bottom plate assembly 24; and the bottom plate assembly 24 includes a lower flow channel plate 241, and a first flow channel 5 is provided on the bottom surface of the lower flow channel plate 241. A second through hole 53 that communicates with the cavity body 21 is provided in the first flow channel 5, so that the communication between the first flow channel 5 and the cavity body 21 can be ensured through the second through hole 53.

[0059] As shown in Figures 1 and 6, the lower flow channel plate 241 is arranged horizontally and is sealed to the bottom ends of the first side plate 221, the second side plate 222, and the two third side plates 223. The sealed connections between the lower flow channel plate 241 and the bottom ends of the first side plate 221, the second side plate 222, and the two third side plates 223 can be sealed using a glue groove 224, and the specific sealing method is not limited here.

[0060] As shown in Figures 6 and 7, the first flow channel 5 includes a lower main channel 51 and multiple lower branch flow channels 52; wherein, the lower main channel 51 extends along the Y axis, and the first end of the lower main channel 51 is connected to the third flow channel 3; the lower branch flow channel 52 extends along the X axis, and the multiple lower branch flow channels 52 are respectively connected to the second end opposite to the first end of the lower main channel 51, and the multiple lower branch flow channels 52 are arranged side by side at intervals along the Y axis, and each lower branch flow channel 52 is provided with multiple second through holes 53 at intervals, so that the cooling liquid in the lower branch flow channel 52 can flow to the cavity 21 through the multiple second through holes 53.

[0061] By providing multiple lower branch flow channels 52 spaced and arranged side by side along the Y-axis, the bottoms of the multiple battery cells 1 within the cavity 21 can be covered by the multiple lower branch flow channels 52, ensuring that coolant flows at the bottom of each battery cell 1, thereby ensuring uniform liquid cooling of the multiple battery cells 1. In this embodiment, there are five lower branch flow channels 52, and each lower branch flow channel 52 is provided with seven second through holes 53. The number of lower branch flow channels 52 and second through holes 53 provided is not limited here.

[0062] As shown in Figures 1 and 6, the bottom plate assembly 24 also includes a lower cover plate 242. The lower cover plate 242 is provided as a sealing cover on one side of the lower flow channel plate 241 where the first flow channel 5 is provided. This seals the first flow channel 5, ensuring that the coolant flows only along the first flow channel 5 and preventing the coolant from overflowing outside the lower flow channel plate 241. The lower cover plate 242 and the lower flow channel plate 241 can be sealed by welding or gluing, which is not specifically limited here.

[0063] As shown in Figures 6 to 8, a plurality of pressure relief through holes 2411 are provided on the lower flow channel plate 241, and one battery cell 1 is corresponding to one pressure relief through hole 2411, so that when thermal runaway occurs in the battery cell 1, the high-temperature and high-pressure gas generated can be discharged to the outside of the battery module through the corresponding pressure relief through hole 2411, thereby ensuring the safety of the battery module during thermal runaway; correspondingly, a third through hole 2421 matching the pressure relief through hole 2411 is provided on the lower cover plate 242, that is, a pressure relief through hole 2411 is aligned with a third through hole 2421, so as to ensure that the high-temperature and high-pressure gas in the pressure relief through hole 2411 can be discharged to the outside of the battery module through the third through hole 2421, thereby avoiding interference of the lower cover plate 242 with the pressure relief operation.

[0064] The diameter of the pressure relief hole 2411 is slightly smaller than the diameter of the battery cell 1 to ensure that the pressure relief valve of the battery cell 1 is arranged opposite to the pressure relief hole 2411, and to ensure that the high-temperature and high-pressure gas discharged by the pressure relief valve can be discharged in a direction through the pressure relief hole 2411.

[0065] Since a plurality of lower branch channels 52 and a plurality of pressure relief holes 2411 are respectively provided on the lower flow channel plate 241, each lower branch channel 52 is bent on the X-axis. As shown in FIG6 and FIG7 , the lower branch channel 52 is not a straight channel parallel to the X-axis, but a wavy curved channel. Thus, the lower branch channel 52 and the pressure relief hole 2411 can be avoided by the bending setting, thereby preventing the lower branch channel 52 from being connected to the pressure relief hole 2411, thereby ensuring that the pressure relief work and the liquid cooling work of the battery module do not interfere with each other. Here, there is no limitation on the specific bending angle and bending amplitude of the lower branch channel 52, as long as the lower branch channel 52 is not connected to the pressure relief hole 2411.

[0066] As shown in Figures 3 and 8, an insulating seal 2412 is connected between the battery cell 1 and the pressure relief through hole 2411. The insulating seal 2412 can be an annular insulating sealing ring; wherein, an annular groove is provided on the top surface of the downflow plate 241 close to the cavity body 21, and an annular groove is provided on the outer ring of a pressure relief through hole 2411, and the annular insulating sealing ring is installed in the annular groove; when the battery cell 1 is installed in the cavity body 21, the battery cell 1 abuts against the annular insulating sealing ring so that the pressure relief valve of the battery cell 1 is located in the pressure relief through hole 2411.

[0067] By providing the insulating seal 2412, on the one hand, direct contact between the battery cell 1 and the downstream flow plate 241 can be avoided, so that the battery cell 1 and the downstream flow plate 241 are insulated from each other; on the other hand, the gap between the battery cell 1 and the pressure relief through hole 2411 can be sealed to prevent the coolant in the cavity 21 from flowing out through the gap between the pressure relief through hole 2411 and the battery cell 1.

[0068] As shown in FIG1 , the battery module further includes an insulating bracket 8, which is mounted in the cavity 21. A plurality of battery cells 1 are mounted on the insulating bracket 8. Specifically, a plurality of mounting holes 81 are provided on the insulating bracket 8. A battery cell 1 is clamped into each mounting hole 81. Specifically, the diameter of the mounting hole 81 is slightly smaller than the diameter of the battery cell 1, so that the battery cell 1 can be clamped and fixed in the mounting hole 81, thereby fixing the battery cell 1 in the cavity 21. The insulating bracket 8 is adhered to the cavity 21 by glue, i.e., the insulating bracket 8 is adhered to the inner wall surfaces of the two third side plates 223 by glue.

[0069] The insulating bracket 8 can be provided to fix the battery cell 1, ensuring that the battery cell 1 is supported and installed in the cavity 21. On the other hand, it can insulate the battery cell 1 from the downstream flow channel plate 241, ensuring better insulation between the battery cell 1 and the downstream flow channel plate 241. In this embodiment, the insulating bracket 8 can be a plastic bracket.

[0070] The battery module in this embodiment adopts a method of liquid inlet and liquid outlet simultaneously along the Z axis, which can shorten the flow path of the coolant in the box 2, ensure that the coolant can cool the battery cell 1 in time, so as to have a better liquid cooling effect on the battery cell 1. At the same time, it can ensure that the number of flow channels is small, reduce the processing cost of the flow channels, and ensure that the entire battery module has good heat dissipation efficiency while being low in cost.

[0071] Example 2

[0072] In this embodiment, a cell liquid cooling method is proposed. The cell 1 in the battery module is liquid-cooled using the cell liquid cooling method. As shown in FIG9 , the cell liquid cooling method includes the following steps:

[0073] S1: Fill the cavity 21 with coolant so that the battery cell 1 is immersed in the coolant;

[0074] S2: Cooling liquid is respectively filled into the second flow channel 4 located on the top surface of the box body 22 and the first flow channel 5 located on the bottom surface of the box body 22, so that cooling liquid flows at the top and bottom ends of the battery cell 1, and the cooling liquid in the second flow channel 4 and the first flow channel 5 flows back into the cavity 21.

[0075] The specific liquid cooling process of the battery cell liquid cooling method in this embodiment is as follows:

[0076] Cooling liquid is injected into the cavity 21 through the window 2321 on the upper cover plate 232 and the injection hole 2311 on the upper flow channel plate 231 so that the cooling liquid fills the entire cavity 21 . At this time, the battery cell 1 is immersed in the cooling liquid.

[0077] Then, the coolant is transported to the liquid inlet 33 and the third flow channel 3 through the liquid inlet nozzle 32, and the coolant in the third flow channel 3 flows up and down along the Z axis, so that the coolant in the third flow channel 3 flows upward along the Z axis to the upper main channel 41, and flows through the upper main channel 41 to the multiple upper branch flow channels 42 respectively, so that the coolant flows on the top surface of the battery cell 1; at the same time, the coolant in the upper branch flow channel 42 flows into the cavity 21 through the multiple first through holes 43.

[0078] At the same time, the coolant in the third flow channel 3 flows downward along the Z-axis into the lower main channel 51, and flows into the multiple lower branch flow channels 52 through the lower main channel 51, so that the coolant flows on the bottom surface of the battery cell 1; at the same time, the coolant in the lower branch flow channel 52 flows into the cavity 21 through the multiple second through holes 53.

[0079] The coolant in the cavity 21 after passing through the liquid-cooled battery cell 1 is then made to flow into the liquid outlet main channel 65 through multiple outlet holes 64, so that the coolant in the liquid outlet main channel 65 flows out of the battery module through the liquid outlet port 61 and the liquid outlet nozzle 62 in turn, thereby realizing the circulation of the coolant, so that the battery cell 1 is always completely immersed in the coolant, ensuring the liquid cooling effect of the battery cell 1.

[0080] The battery cell liquid cooling method in this embodiment has a short cooling path for the battery cell 1, a simple cooling method, and can ensure uniform heat dissipation to different parts of the battery cell 1. The liquid cooling effect is good, ensuring that the battery cell 1 has high heat dissipation efficiency.

Claims

1. A battery module, comprising: Battery cell (1); A box (2), wherein a cavity (21) is formed in the box (2), wherein a plurality of the battery cells (1) arranged in parallel are placed in the cavity (21), wherein the cavity (21) is filled with a cooling liquid, wherein a first flow channel (5) and a second flow channel (4) are respectively provided on the bottom surface and the top surface of the box (2), and wherein the first flow channel (5) and the second flow channel (4) are respectively connected to the cavity (21) so as to fill the cavity (21) with the cooling liquid.

2. The battery module according to claim 1, wherein: A third flow channel (3) is provided on the side of the box body (2), and the third flow channel (3) is respectively connected to the second flow channel (4) and the first flow channel (5), so that the coolant in the third flow channel (3) flows to the second flow channel (4) and the first flow channel (5) respectively.

3. The battery module according to claim 2, wherein: The box (2) comprises: The box body (22) comprises a first side plate (221) located on a side of the box body (2), the third flow channel (3) being arranged in the first side plate (221), the third flow channel (3) penetrating the first side plate (221) along the Z axis, and a liquid inlet (33) communicating with the third flow channel (3) being arranged on one side of the first side plate (221).

4. The battery module according to claim 3, wherein: The box body (22) further comprises a second side plate (222) located on a side of the box body (2), the second side plate (222) being arranged opposite to the first side plate (221), a fourth flow channel being arranged in the second side plate (222) and being connected to the cavity (21), and a liquid outlet (61) being arranged on one side of the second side plate (222) and being connected to the fourth flow channel, the fourth flow channel being arranged to transport the cooling liquid in the cavity (21) to the liquid outlet (61).

5. The battery module according to claim 3 or 4, wherein: The box (2) also includes: A top cover assembly (23) is located on the top surface of the box body (2) and is sealed to the top end opening of the box body main body (22), the top cover assembly (23) comprising an upper flow channel plate (231), the top surface of the upper flow channel plate (231) being provided with the second flow channel (4), and the second flow channel (4) being provided with a first through hole (43) communicating with the cavity (21).

6. The battery module according to claim 5, wherein: The second flow channel (4) comprises: An upper main flow channel (41) extends along the Y axis, and a first end of the upper main flow channel (41) is connected to the third flow channel (3); a plurality of upper branch flow channels (42), the upper branch flow channels (42) extending along the X-axis, the plurality of upper branch flow channels (42) being respectively connected to the second end of the upper main flow channel (41), the plurality of upper branch flow channels (42) being arranged side by side at intervals along the Y-axis, and a plurality of the first through holes (43) being arranged at intervals in each of the upper branch flow channels (42); The X-axis, the Y-axis and the Z-axis are perpendicular to each other.

7. The battery module according to claim 5, wherein: The top cover assembly (23) further comprises: An upper cover plate (232), a sealing cover is arranged on a side of the upper flow channel plate (231) on which the second flow channel (4) is arranged, and a window (2321) is arranged on the upper cover plate (232) for injecting cooling liquid into the cavity (21).

8. The battery module according to claim 3 or 4, wherein: The box (2) also includes: A bottom plate assembly (24) is located on the bottom surface of the box body (2) and is sealed to the bottom opening of the box body main body (22), the bottom plate assembly (24) comprising a lower flow channel plate (241), the lower surface of the lower flow channel plate (241) being provided with the first flow channel (5), and the first flow channel (5) being provided with a second through hole (53) communicating with the cavity (21).

9. The battery module according to claim 8, wherein: The first flow channel (5) comprises: A lower main flow channel (51) extending along the Y axis, wherein a first end of the lower main flow channel (51) is connected to the third flow channel (3); A plurality of lower branch flow channels (52), the lower branch flow channels (52) extending along the X-axis, the plurality of lower branch flow channels (52) respectively communicating with the second end of the lower main flow channel (51), the plurality of lower branch flow channels (52) being arranged side by side at intervals along the Y-axis, and a plurality of the second through holes (53) being arranged at intervals in each of the lower branch flow channels (52).

10. The battery module according to claim 8, wherein: A plurality of pressure relief through holes (2411) are provided on the lower flow channel plate (241), one of the battery cells (1) is provided corresponding to one of the pressure relief through holes (2411), and an insulating sealing member (2412) is connected between the battery cell (1) and the pressure relief through hole (2411).

11. The battery module according to claim 8, wherein: The base plate assembly (24) further comprises: A lower cover plate (242), the lower cover plate (242) being a sealing cover and being arranged on a side surface of the lower flow channel plate (241) on which the first flow channel (5) is arranged.

12. The battery module according to any one of claims 1 to 4, wherein: The battery core (1) is a cylindrical battery core, and two ends of the battery core (1) along the axial direction face the top surface of the box body (2) and the bottom surface of the box body (2) respectively, and the radial side walls of adjacent battery cores (1) abut against each other.

13. A battery cell liquid cooling method, applied to the battery cell (1) in the battery module according to any one of claims 1 to 12, the method comprising: Filling the cavity (21) with coolant so that the battery core (1) is immersed in the coolant; Cooling liquid is respectively filled into the second flow channel (4) located on the top surface and the first flow channel (5) located on the bottom surface, so that cooling liquid flows at the top end and the bottom end of the battery cell (1), respectively, and the cooling liquid in the second flow channel (4) and the first flow channel (5) flows back into the cavity (21).

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