Square battery pack

Abstract

The utility model provides a square battery pack which comprises a box body, a battery cell module, a first liquid cooling structure and a second liquid cooling structure, and the box body is provided with an accommodating cavity; the battery cell module is arranged in the accommodating cavity; the first liquid cooling structure is arranged in the accommodating cavity and is positioned at the bottom of the battery cell module; the second liquid cooling structure is arranged in the accommodating cavity and is positioned at the top of the battery cell module; the second liquid cooling structure is provided with a plurality of liquid cooling channels, at least one liquid cooling channel in the plurality of liquid cooling channels is directly communicated with the liquid inlet, and at least one liquid cooling channel in the rest liquid cooling channels is directly communicated with the liquid outlet; each liquid cooling channel comprises a plurality of sub liquid cooling flow channels, and the flow channel width of each sub liquid cooling flow channel in the liquid cooling channel which is at least directly communicated with the liquid inlet is different from the flow channel width of each sub liquid cooling flow channel in the other liquid cooling channels. According to the square battery pack, the problem that a top liquid cooling plate of the square battery pack in the prior art cannot effectively and uniformly dissipate heat of a battery cell due to a small space is solved.

Description

Technical Field

[0001] This utility model relates to the field of liquid cooling technology for batteries, and more specifically, to a square battery pack. Background Technology

[0002] Based on the shape of the square battery pack, in order to solve the problem of fast charging, it is not enough to just set a liquid cooling plate at the bottom of the square battery pack. Therefore, some existing square battery packs use liquid cooling plates at both the top and bottom to dissipate heat. However, due to the structural characteristics of the square battery pack, the liquid cooling plate at the top can only utilize the limited vertical height of the square battery pack, resulting in poor heat dissipation capacity of the liquid cooling plate at the top and failing to effectively and evenly dissipate heat from the square battery pack. Utility Model Content

[0003] The main objective of this invention is to provide a square battery pack to solve the problem that the top liquid cooling plate of the existing square battery pack cannot effectively and evenly dissipate heat from the battery cells due to the small space.

[0004] To achieve the above objectives, this utility model provides a square battery pack, including a housing, a cell module, a first liquid cooling structure, and a second liquid cooling structure. The housing has a receiving cavity; the cell module is disposed within the receiving cavity; the first liquid cooling structure is disposed within the receiving cavity and located at the bottom of the cell module to dissipate heat from the bottom of the cell module; the second liquid cooling structure is disposed within the receiving cavity and located at the top of the cell module to dissipate heat from the top of the cell module. The second liquid cooling structure has multiple liquid cooling channels, at least one of which is directly connected to an inlet, and at least one of the remaining liquid cooling channels is directly connected to an outlet. Each liquid cooling channel includes multiple sub-liquid cooling channels, and the channel width of each sub-liquid cooling channel in at least the liquid cooling channel directly connected to the inlet is different from the channel width of each sub-liquid cooling channel in the other liquid cooling channels.

[0005] Furthermore, the width of each sub-liquid cooling channel in the liquid cooling channel that is directly connected to the liquid inlet is smaller than the width of each sub-liquid cooling channel in the other liquid cooling channels.

[0006] Furthermore, the width of each sub-liquid cooling channel in the same liquid cooling channel is equal.

[0007] Furthermore, the second liquid cooling structure includes a liquid cooling plate body, which has a liquid inlet, a liquid outlet, and multiple liquid cooling channels; each liquid cooling channel extends along the length direction of the liquid cooling plate body, and the multiple liquid cooling channels are spaced apart along the width direction of the liquid cooling plate body; the second liquid cooling structure also has multiple liquid cooling branches, each of which extends along the width direction of the liquid cooling plate body, so that the multiple liquid cooling channels are interconnected through the multiple liquid cooling branches; there is one liquid inlet and one liquid outlet, and the liquid inlet and the liquid outlet are both located on the same side of the liquid cooling plate body.

[0008] Furthermore, at least two of the multiple liquid cooling channels have different numbers of sub-liquid cooling channels.

[0009] Furthermore, the second liquid cooling structure includes a liquid cooling plate body, which has a liquid inlet, a liquid outlet, and multiple liquid cooling channels; the number of sub-liquid cooling channels in two liquid cooling channels located at the two edges in the width direction of the liquid cooling plate body is less than the number of sub-liquid cooling channels in the remaining liquid cooling channels; and / or, at least the number of sub-liquid cooling channels in the liquid cooling channel directly connected to the liquid inlet is not less than the number of sub-liquid cooling channels in the remaining liquid cooling channels; and / or, at least the number of sub-liquid cooling channels in the liquid cooling channel directly connected to the liquid outlet is not less than the number of sub-liquid cooling channels in the remaining liquid cooling channels.

[0010] Furthermore, the second liquid cooling structure includes a liquid cooling plate body and multiple sets of spacer strips. The liquid cooling plate body has a liquid inlet, a liquid outlet, and multiple liquid cooling channels. The multiple sets of spacer strips correspond one-to-one with the multiple liquid cooling channels, and each set of spacer strips includes multiple spacer strips. One set of spacer strips is provided for each liquid cooling channel. Each spacer strip in the same set of spacer strips extends along the length direction of the liquid cooling plate body. The multiple spacer strips divide the corresponding liquid cooling channel into multiple sub-liquid cooling channels.

[0011] Furthermore, the second liquid cooling structure includes a liquid cooling plate body and multiple sets of spacer blocks. The liquid cooling plate body has a liquid inlet, a liquid outlet, and multiple liquid cooling channels. The multiple sets of spacer blocks correspond one-to-one with the multiple liquid cooling channels, and each set of spacer blocks includes multiple spacer blocks. One set of spacer blocks is provided for each liquid cooling channel. Multiple spacer blocks in the same set of spacer blocks are spaced apart along the length and width directions of the liquid cooling plate body to divide the corresponding liquid cooling channel into multiple sets of interconnected sub-liquid cooling channels.

[0012] Furthermore, at least two turbulence protrusions are provided at the liquid inlet; and / or, at least two turbulence protrusions are provided at the inlet of each liquid cooling channel; and / or, at least two turbulence protrusions are provided at the pipe diameter change points of the liquid cooling branches used to connect each liquid cooling channel.

[0013] Furthermore, the square battery pack includes a supporting foam and a top cover structure, wherein the supporting foam is disposed on the bottom surface of the receiving cavity, the first liquid cooling structure is disposed on the supporting foam and located between the supporting foam and the battery cell module; the top cover structure is disposed at the opening of the receiving cavity.

[0014] The present invention provides a square battery pack, comprising a housing, a cell module, a first liquid cooling structure, and a second liquid cooling structure. The housing has a receiving cavity; the cell module is disposed within the receiving cavity; the first liquid cooling structure is disposed within the receiving cavity and located at the bottom of the cell module to dissipate heat from the bottom of the cell module; the second liquid cooling structure is disposed within the receiving cavity and located at the top of the cell module to dissipate heat from the top of the cell module. The second liquid cooling structure has multiple liquid cooling channels, at least one of which is directly connected to an inlet, and at least one of the remaining liquid cooling channels is directly connected to an outlet. Each liquid cooling channel includes multiple sub-liquid cooling channels, and the channel width of each sub-liquid cooling channel in at least the liquid cooling channel directly connected to the inlet is different from the channel width of each sub-liquid cooling channel in the other liquid cooling channels. In this way, by using a structural form in which the flow width of each sub-liquid cooling channel in the liquid cooling channel that is directly connected to the liquid inlet is different from the flow width of each sub-liquid cooling channel in the other liquid cooling channels, it is beneficial to adjust the flow rate of each sub-liquid cooling channel. This ensures that the coolant can dissipate heat evenly to the top of the cell module after flowing through each sub-liquid cooling channel, thus ensuring the uniformity and reliability of heat dissipation of the cell module and the operational reliability of the cell module. Attached Figure Description

[0015] The accompanying drawings, which form part of this application, are used to provide a further understanding of the present invention. The illustrative embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an undue limitation of the present invention. In the drawings:

[0016] Figure 1 An exploded structural diagram of a square battery pack according to an alternative embodiment of the present invention is shown;

[0017] Figure 2 It shows Figure 1 A schematic diagram of the second liquid cooling structure of the square battery pack in the diagram;

[0018] Figure 3 It shows Figure 2 A magnified structural diagram at point A in the diagram;

[0019] Figure 4 It shows Figure 2 A magnified structural diagram at point B in the diagram;

[0020] Figure 5 It shows Figure 1Schematic diagrams of different embodiments of the second liquid cooling structure of the square battery pack in the diagram;

[0021] Figure 6 It shows Figure 5 A comparison diagram of the flow rates of each sub-liquid cooling channel after width adjustment and the addition of turbulence protrusions in different embodiments.

[0022] The above figures include the following reference numerals:

[0023] 10. Box body; 11. Receiving cavity;

[0024] 20. Battery cell module; 30. First liquid cooling structure;

[0025] 40. Second liquid cooling structure; 41. Liquid cooling channel; 411. Sub-liquid cooling flow channel; 42. Liquid inlet; 43. Liquid outlet; 44. Liquid cooling plate body; 45. Liquid cooling branch; 46. Spacer bar; 47. Spacer block; 48. Turbulence protrusion;

[0026] 50. Supporting foam; 60. Top cover structure; 70. Liquid flow pipeline; 80. BDU liquid cooling plate. Detailed Implementation

[0027] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the present utility model or its application or use. All other embodiments obtained by those skilled in the art based on the embodiments of the present utility model without creative effort are within the scope of protection of the present utility model.

[0028] To address the problem that the top liquid cooling plate of the existing square battery pack cannot effectively and evenly dissipate heat from the battery cells due to its small size, this invention provides a square battery pack.

[0029] like Figures 1 to 5As shown, the square battery pack includes a housing 10, a cell module 20, a first liquid cooling structure 30, and a second liquid cooling structure 40. The housing 10 has a receiving cavity 11; the cell module 20 is disposed within the receiving cavity 11; the first liquid cooling structure 30 is disposed within the receiving cavity 11 and located at the bottom of the cell module 20 to dissipate heat from the bottom of the cell module 20; the second liquid cooling structure 40 is disposed within the receiving cavity 11 and located at the top of the cell module 20 to dissipate heat from the top of the cell module 20. The second liquid cooling structure 40 has multiple liquid cooling channels 41. At least one of the multiple liquid cooling channels 41 is directly connected to the liquid inlet 42, and at least one of the remaining liquid cooling channels 41 is directly connected to the liquid outlet 43. Each liquid cooling channel 41 includes multiple sub-liquid cooling channels 411. The channel width of each sub-liquid cooling channel 411 in the liquid cooling channel 41 that is directly connected to the liquid inlet 42 is different from the channel width of each sub-liquid cooling channel 411 in the remaining liquid cooling channels 41.

[0030] By using a structural form in which the flow width of each sub-liquid cooling channel 411 in the liquid cooling channel 41 that is directly connected to the liquid inlet 42 is different from the flow width of each sub-liquid cooling channel 411 in the other liquid cooling channels 41, it is beneficial to adjust the flow rate of each sub-liquid cooling channel 411, thereby ensuring that the coolant can be evenly cooled to the top of the cell module 20 after flowing through each sub-liquid cooling channel 411, ensuring the uniformity and reliability of heat dissipation of the cell module 20, and thus ensuring the operational reliability of the cell module 20.

[0031] like Figure 2 As shown, the width of each sub-liquid cooling channel 411 in the liquid cooling channel 41 that is directly connected to the liquid inlet 42 is smaller than the width of each sub-liquid cooling channel 411 in the other liquid cooling channels 41. This helps to prevent excessive coolant from flowing from the liquid cooling channel 41 that is directly connected to the liquid inlet 42 to the liquid outlet 43.

[0032] It should be noted that in this application, the width of each sub-liquid cooling channel 411 in the same liquid cooling channel 41 is equal. This ensures the uniformity of coolant flow, thereby ensuring the reliability of cooling the battery cell module 20.

[0033] Specifically, such as Figure 2 As shown, from top to bottom, the channel widths of the sub-liquid cooling channels 411 of each liquid cooling channel 41 are C, D, E, F, and G, respectively, where C is 21 mm, D is 20 mm, E is 20 mm, F is 15 mm, and G is 20 mm.

[0034] like Figure 2As shown, the second liquid cooling structure 40 includes a liquid cooling plate body 44, which has a liquid inlet 42, a liquid outlet 43, and multiple liquid cooling channels 41. Each liquid cooling channel 41 extends along the length of the liquid cooling plate body 44, and the multiple liquid cooling channels 41 are spaced apart along the width of the liquid cooling plate body 44. The second liquid cooling structure 40 also has multiple liquid cooling branches 45, each of which extends along the width of the liquid cooling plate body 44, so that the multiple liquid cooling channels 41 are interconnected through the multiple liquid cooling branches 45. There is one liquid inlet 42 and one liquid outlet 43, and both the liquid inlet 42 and the liquid outlet 43 are located on the same side of the liquid cooling plate body 44. In this way, the coolant flowing through each sub-liquid cooling channel 411 can be as uniform as possible, thereby achieving effective and uniform heat dissipation for the battery cell module.

[0035] It should be noted that, in this application, in order to ensure the uniform distribution of flow rate, volume, etc., in each sub-liquid cooling channel 411, such as Figure 2 As shown, at least two of the multiple liquid cooling channels 41 have a different number of sub-liquid cooling channels 411. This ensures that the coolant flowing through each sub-liquid cooling channel 411 is as uniform as possible.

[0036] like Figures 2 to 4 As shown, the second liquid cooling structure 40 includes a liquid cooling plate body 44, which has a liquid inlet 42, a liquid outlet 43, and a plurality of liquid cooling channels 41. The number of sub-liquid cooling channels 411 in the two liquid cooling channels 41 located at the two sides of the liquid cooling plate body 44 in the width direction is less than the number of sub-liquid cooling channels 411 in the remaining liquid cooling channels 41. And / or, the number of sub-liquid cooling channels 411 in the liquid cooling channel 41 that is directly connected to the liquid inlet 42 is not less than the number of sub-liquid cooling channels 411 in the remaining liquid cooling channels 41. And / or, the number of sub-liquid cooling channels 411 in the liquid cooling channel 41 that is directly connected to the liquid outlet 43 is not less than the number of sub-liquid cooling channels 411 in the remaining liquid cooling channels 41.

[0037] like Figures 2 to 4 As shown, the second liquid cooling structure 40 includes a liquid cooling plate body 44 and multiple sets of spacer strips. The liquid cooling plate body 44 has a liquid inlet 42, a liquid outlet 43, and multiple liquid cooling channels 41. The multiple sets of spacer strips correspond one-to-one with the multiple liquid cooling channels 41, and each set of spacer strips includes multiple spacer strips 46. Each liquid cooling channel 41 is provided with a set of spacer strips. Each spacer strip 46 in the same set of spacer strips extends along the length direction of the liquid cooling plate body 44. The multiple spacer strips 46 divide the corresponding liquid cooling channel 41 into multiple sub-liquid cooling channels 411. In this way, it is ensured that each liquid cooling channel 41 can have as many sub-liquid cooling channels 411 as possible, and the multiple sub-liquid cooling channels 411 are spaced apart along the width direction of the liquid cooling plate body 44 to ensure effective heat dissipation of the entire top of the cell module 20.

[0038] like Figures 2 to 4 As shown, the second liquid cooling structure 40 includes a liquid cooling plate body 44 and multiple sets of spacer blocks. The liquid cooling plate body 44 has a liquid inlet 42, a liquid outlet 43, and multiple liquid cooling channels 41. The multiple sets of spacer blocks correspond one-to-one with the multiple liquid cooling channels 41, and each set of spacer blocks includes multiple spacer blocks 47. Each liquid cooling channel 41 is provided with a set of spacer blocks. The multiple spacer blocks 47 in the same set of spacer blocks are spaced apart along the length and width directions of the liquid cooling plate body 44 to divide the corresponding liquid cooling channel 41 into multiple interconnected sub-liquid cooling channels 411. In this way, it is ensured that each liquid cooling channel 41 can have as many sub-liquid cooling channels 411 as possible, and the multiple sub-liquid cooling channels 411 are spaced apart along the width direction of the liquid cooling plate body 44 to ensure effective heat dissipation of the entire top of the cell module 20.

[0039] like Figures 2 to 4 As shown, at least two turbulence protrusions 48 are provided at the liquid inlet 42; and / or, at least two turbulence protrusions 48 are provided at the inlet of each liquid cooling channel 41; and / or, at least two turbulence protrusions 48 are provided at the pipe diameter changes of the liquid cooling branch 45 connecting each liquid cooling channel 41. Thus, the turbulence protrusions 48 control the flow rate of the coolant, ensuring that the coolant is distributed as evenly as possible in each sub-liquid cooling channel 411, thereby ensuring that heat dissipation to the top of the cell module 20 is as even as possible.

[0040] like Figure 1 As shown, the square battery pack includes a supporting foam 50 and a top cover structure 60. The supporting foam 50 is disposed on the bottom surface of the receiving cavity 11, and the first liquid cooling structure 30 is disposed on the supporting foam 50 and located between the supporting foam 50 and the cell module 20. The top cover structure 60 covers the opening of the receiving cavity 11. In this way, the top cover structure 60 protects the cell module 20, the first liquid cooling structure 30, and the second liquid cooling structure 40 inside the receiving cavity 11.

[0041] like Figure 2 As shown, the square battery pack also includes a liquid inlet pipe 70 and a BDU liquid cooling plate 80. The liquid inlet pipe 70 has a liquid inlet that is connected to an external coolant source. The liquid inlet pipe 70 also has two branch pipes. One of the branch pipes is connected to the liquid inlet 42 of the second liquid cooling structure 40, and the other branch pipe is connected to the inlet of the BDU liquid cooling plate 80, so as to introduce external coolant into the second liquid cooling structure 40 and the BDU liquid cooling plate 80. The BDU liquid cooling plate 80 is used to dissipate heat for other structural components of the square battery pack.

[0042] like Figure 5 and Figure 6 As shown, Figure 5 The figure shows four different second liquid cooling structures 40. Figure a indicates no turbulence protrusion 48, figure b indicates the addition of turbulence protrusion 48 compared to a, figure c indicates the addition of turbulence protrusion 48 at the liquid inlet 42 and at the width change position of the liquid cooling branch 45 compared to figure b, and figure d indicates a structural form with turbulence protrusion 48 at the liquid inlet 42 in a different state compared to figure c. Figure 5 a, b, c, and d in the text correspond to respectively Figure 6 The horizontal coordinates 1, 2, 3, and 4 (also representing Scheme 1, Scheme 2, Scheme 3, and Scheme 4) represent the four second liquid cooling structures 40. Each of the four second liquid cooling structures 40, except for the liquid cooling channel 41 (corresponding to number 3) directly connected to the liquid outlet 43, has sub-liquid cooling channels 411 with different widths from top to bottom in each of the remaining liquid cooling channels 411. The specific impact of the four different channel widths on the flow rate is shown in the table below:

[0043] Option 1 Option 2 Option 3 Option 4 Flow channel cross-sectional area 1 0.024348 0.027127 0.028532 0.034223 Flow channel cross-sectional area 2 0.086132 0.080508 0.077429 0.066847 Flow channel cross-sectional area 4 0.118752 0.125775 0.126742 0.122846 Flow channel cross-sectional area 5 0.022658 0.023596 0.023904 0.027521

[0044] It should be noted that, in this application, the values ​​in the table above are flow rate values ​​corresponding to different flow channel cross-sections, in kg / s. Figure 6 The horizontal axis in the diagram represents 1, 2, 3, and 4 (which are also Scheme 1, Scheme 2, Scheme 3, and Scheme 4). Figure 6 The vertical axis in the graph represents a comparison of flow rate values ​​corresponding to different flow channel cross-sections. Figure 6 Analysis shows that after changing the flow channel width and adding the turbulence protrusion 48, the flow rate of Scheme 4 is relatively stable.

[0045] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0046] Unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps described in these embodiments do not limit the scope of this invention. It should also be understood that, for ease of description, the dimensions of the various parts shown in the drawings are not drawn to actual scale. Techniques, methods, and devices known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and devices should be considered part of the specification. In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters in the following drawings denote similar items; therefore, once an item is defined in one drawing, it need not be further discussed in subsequent drawings.

[0047] For ease of description, spatial relative terms such as "above," "on top of," "on the upper surface of," "above," etc., are used herein to describe the spatial positional relationship of a device or feature as shown in the figures to other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation beyond the orientation of the device as described in the figures. For example, if the device in the figures were inverted, a device described as "above" or "on top of" other devices or structures would subsequently be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below." The device may also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein will be interpreted accordingly.

[0048] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0049] It should be noted that the terms "first," "second," etc., used in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented in sequences other than those illustrated or described herein.

[0050] The above description is merely a preferred embodiment of this utility model and is not intended to limit the utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A square battery pack, characterized by, The square battery pack comprises: a box body (10) having a containing cavity (11); an electric core module (20) arranged in the containing cavity (11); a first liquid cooling structure (30) arranged in the containing cavity (11) and located at the bottom of the electric core module (20) to dissipate heat from the bottom of the electric core module (20); a second liquid cooling structure (40) arranged in the containing cavity (11) and located at the top of the electric core module (20) to dissipate heat from the top of the electric core module (20); wherein the second liquid cooling structure (40) has a plurality of liquid cooling channels (41), at least one of the plurality of liquid cooling channels (41) directly communicates with a liquid inlet (42), and at least one of the remaining liquid cooling channels (41) directly communicates with a liquid outlet (43); each of the liquid cooling channels (41) comprises a plurality of sub-liquid cooling flow channels (411), and the flow channel width of each of the sub-liquid cooling flow channels (411) in the liquid cooling channel (41) directly communicating with the liquid inlet (42) is different from the flow channel width of each of the sub-liquid cooling flow channels (411) in the remaining liquid cooling channels (41).

2. The square battery pack of claim 1, wherein, The flow channel width of each of the sub-liquid cooling flow channels (411) in the liquid cooling channel (41) directly communicating with the liquid inlet (42) is smaller than the flow channel width of each of the sub-liquid cooling flow channels (411) in the remaining liquid cooling channels (41).

3. The square battery pack of claim 1, wherein, The flow channel width of each of the sub-liquid cooling flow channels (411) in the same liquid cooling channel (41) is equal.

4. The square battery pack according to claim 1, wherein the second liquid cooling structure (40) comprises a liquid cooling plate body (44) having the liquid inlet (42), the liquid outlet (43) and the plurality of liquid cooling channels (41); each of the liquid cooling channels (41) extends along the length direction of the liquid cooling plate body (44), and the plurality of liquid cooling channels (41) are arranged in the width direction of the liquid cooling plate body (44) at intervals; the second liquid cooling structure (40) further has a plurality of liquid cooling branches (45), each of the liquid cooling branches (45) extends along the width direction of the liquid cooling plate body (44) to make the plurality of liquid cooling channels (41) communicate with each other through the plurality of liquid cooling branches (45); the liquid inlet (42) and the liquid outlet (43) are one, and the liquid inlet (42) and the liquid outlet (43) are located on the same side of the liquid cooling plate body (44).

5. The square battery pack of claim 1, wherein, The number of the sub-liquid cooling flow channels (411) in at least two of the plurality of liquid cooling channels (41) is different.

6. The square battery pack according to claim 1, wherein the second liquid cooling structure (40) comprises a liquid cooling plate body (44) having the liquid inlet (42), the liquid outlet (43) and the plurality of liquid cooling channels (41); The number of the sub-liquid cooling flow channels (411) in the two liquid cooling channels (41) located at the two side edges of the liquid cooling plate body (44) in the width direction is less than the number of the sub-liquid cooling flow channels (411) in the remaining liquid cooling channels (41); and / or, The number of the sub-liquid cooling flow channels (411) in at least the liquid cooling channels (41) directly communicating with the liquid inlet (42) is not less than the number of the sub-liquid cooling flow channels (411) in the remaining liquid cooling channels (41); and / or, The number of the sub-liquid cooling flow channels (411) in at least the liquid cooling channels (41) directly communicating with the liquid outlet (43) is not less than the number of the sub-liquid cooling flow channels (411) in the remaining liquid cooling channels (41).

7. The square battery pack according to any one of claims 1 to 6, characterized in that, The second liquid cooling structure (40) comprises a liquid cooling plate body (44) and a plurality of groups of spacing strips, the liquid cooling plate body (44) has the liquid inlet (42), the liquid outlet (43) and a plurality of liquid cooling channels (41), each group of spacing strips corresponds to one of the liquid cooling channels (41), and each group of spacing strips comprises a plurality of spacing strips (46); Each liquid cooling channel (41) is provided with one group of spacing strips, and each spacing strip (46) in the same group of spacing strips extends along the length direction of the liquid cooling plate body (44), and the plurality of spacing strips (46) divide the corresponding liquid cooling channel (41) into a plurality of sub-liquid cooling flow channels (411).

8. The square battery pack according to any one of claims 1 to 6, characterized in that, The second liquid cooling structure (40) comprises a liquid cooling plate body (44) and a plurality of groups of spacing blocks, the liquid cooling plate body (44) has the liquid inlet (42), the liquid outlet (43) and a plurality of liquid cooling channels (41), each group of spacing blocks corresponds to one of the liquid cooling channels (41), and each group of spacing blocks comprises a plurality of spacing blocks (47); Each liquid cooling channel (41) is provided with one group of spacing blocks, and the plurality of spacing blocks (47) in the same group of spacing blocks are arranged in the length direction and the width direction of the liquid cooling plate body (44) to divide the corresponding liquid cooling channel (41) into a plurality of groups of sub-liquid cooling flow channels (411) that communicate with each other.

9. The square battery pack according to any one of claims 1 to 6, characterized in that, At least two turbulence protrusions (48) are arranged at the liquid inlet (42); and / or, At least two turbulence protrusions (48) are arranged at the channel inlet of each liquid cooling channel (41); and / or, At least two turbulence protrusions (48) are arranged at the pipe diameter change of the liquid cooling branch (45) for communicating each liquid cooling channel (41).

10. The square battery pack according to any one of claims 1 to 6, characterized by, The square battery pack comprises: Supporting foam (50) arranged at the bottom surface of the accommodating cavity (11), the first liquid cooling structure (30) is arranged on the supporting foam (50) and located between the supporting foam (50) and the battery cell module (20); Upper cover structure (60) covering the cavity opening of the accommodating cavity (11).

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