Battery structure and liquid-cooled battery module
By adopting a vertical stacked battery cell group structure and liquid cooling system in lithium-ion batteries, the problem of module length changes caused by cell expansion is solved, the safety and service life of the battery module are improved, and uniform Heat dissipation effect.
Patent Information
- Application Number
- CN202311622084.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2023-11-30
- Publication Date
- 2024-12-20
AI Technical Summary
The battery cell expansion caused by chemical reactions during the charge and discharge cycle of lithium-ion batteries, causing changes in the length of the battery module, affecting safety and service life, especially the harm caused by expansion increases under high battery life demand.
A battery structure is adopted, wherein the first battery cell group and the second battery cell group are stacked in a vertical direction, and the number of the second battery cell group is less than the first battery cell group, and the cooling is reduced in combination with the liquid cooling system and passed through the rectangular groove body. It dissipates heat evenly with the multi-layer cold plate structure to reduce expansion of the battery cell.
It effectively reduces the harm of battery cell expansion to the battery module, improves the service life of the battery module, and improves the cooling efficiency through uniform heat dissipation.
Smart Images
Figure CN119170846A_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the technical field of lithium batteries, and in particular to a battery structure and a liquid-cooled battery module. Background Art
[0002] As a carrier of electrochemical energy storage, lithium-ion batteries undergo chemical reactions all the time when in use, causing changes in the internal structure and external shape of lithium-ion batteries. During multiple charge and discharge cycles of lithium-ion batteries, a series of physical and chemical changes will form pressure inside the lithium battery. Over time, lithium batteries will expand significantly, causing significant pressure changes between battery cells, thus affecting battery performance. The cells of traditional battery modules are usually stacked in one direction. During use, the cells will heat up, and uneven cooling will cause temperature differences in the cells, which makes the cells easy to expand. The expansion of the cells is all transferred to the end of the battery module, and the length of the battery module changes greatly, reducing the safety of the battery module. Especially now that high battery life is pursued, the number of cells in the battery module has further increased, and the harm caused by the expansion of the cells has also greatly increased. Summary of the invention
[0003] Based on this, on the one hand, the present application provides a battery structure that can reduce the change in battery module length caused by battery cell expansion, thereby reducing the harm of battery cell expansion to the battery module and increasing the service life of the battery module.
[0004] On the other hand, the present application provides a liquid-cooled battery module, which cools the battery structure by setting up a liquid cooling system, reduces the expansion of the battery cell, and increases the service life of the battery module.
[0005] In order to achieve the above objectives, this application adopts the following technical solutions:
[0006] The present application provides a battery structure, including a first battery cell group and a second battery cell group, the first battery cell group including a plurality of battery cells stacked in sequence along a first direction, the second battery cell group including a plurality of battery cells stacked in sequence along a second direction, the first direction and the second direction are perpendicular to each other on a plane, a second battery cell group is respectively arranged on both sides of the battery cell width direction of the first battery cell group, the length of the first battery cell group along the first direction is smaller than the width of the battery cell, and the number of battery cells in the second battery cell group is less than the number of battery cells in the first battery cell group.
[0007] Furthermore, the number of battery cells in the first battery cell group is twice the number of battery cells in the second battery cell group.
[0008] Compared with the traditional battery arrangement structure, the above-mentioned battery structure has lower expansion force, stress and module length change under the same number of battery cells, thereby reducing the harm of battery cell expansion to the battery module and increasing the service life of the battery module.
[0009] The present application provides a liquid-cooled battery module, comprising a battery structure as described above and a liquid cooling system for cooling the battery structure, the liquid cooling system comprising two end cold plates, two side cold plates and a bottom cold plate, and flow channel groups are arranged on the end cold plates, the side cold plates and the bottom cold plates; the two end cold plates are respectively connected to two opposite ends of the bottom cold plate and are perpendicular to the bottom cold plate, and the two side cold plates are respectively connected to the other opposite sides of the bottom cold plate and are perpendicular to the bottom cold plate, so that the two end cold plates, the two side cold plates and the bottom cold plate form a rectangular trough body with an open upper end, the battery structure is placed in the rectangular trough body and the positive and negative end points of the battery cells in the battery structure are facing the opening of the rectangular trough body, and the end cold plates, the side cold plates and the bottom cold plate are attached to the outer surface of the battery structure.
[0010] Furthermore, the two end cold plates are respectively attached to the end surfaces of the two second battery cell groups away from the first battery cell group, the two side cold plates are respectively attached to the two end surfaces of the first battery cell group in the first direction, and the bottom cold plate is attached to the lower end surfaces of the first battery cell group and the second battery cell group.
[0011] Furthermore, a coolant joint and a first flow channel group are provided on the end cold plate, the first flow channel group includes a plurality of flow channels a, and the flow channels a are connected to the coolant joint; a second flow channel group is provided on the side cold plate, the second flow channel group includes a plurality of flow channels b; a third flow channel group is provided on the bottom cold plate, the third flow channel group is provided with four and distributed in the four corners of a rectangle, and the third flow channel group includes a plurality of flow channels c; the plurality of flow channels a of the end cold plate are connected one-to-one to the plurality of flow channels c of the two third flow channel groups on the bottom cold plate close to the end cold plate, the plurality of flow channels b of the side cold plate are connected one-to-one to the plurality of flow channels c of the two third flow channel groups on the bottom cold plate close to the side cold plate, and the two ports of the flow channel b are connected to the flow channels c of different third flow channel groups.
[0012] Furthermore, on the end cold plate, the flow channel a is in the shape of a straight line perpendicular to the bottom cold plate, and a plurality of the flow channels a are evenly spaced along the length direction of the end cold plate; on the side cold plate, the flow channel b is in the shape of a semi-rectangular edge line, and a plurality of the flow channels b are evenly spaced inside and outside, and gradually approach the lower surface of the side cold plate as they are evenly spaced inwardly; on the bottom cold plate, the flow channel c is in the shape of a right-angled edge line, and a plurality of the flow channels c are evenly spaced inside and outside, and gradually approach the corner of the bottom cold plate as they are evenly spaced inwardly.
[0013] Furthermore, the end cold plate and the side cold plate are fixedly connected to the bottom cold plate by screws.
[0014] Furthermore, a plurality of through holes are evenly spaced apart on the end cold plate, and the through holes penetrate the upper surface and the lower surface of the end cold plate in a direction perpendicular to the bottom cold plate.
[0015] Furthermore, the liquid-cooled battery module also includes a binding strap, which is circumferentially bound around a side of the two end cold plates and the two side cold plates away from the battery structure.
[0016] Furthermore, limiting grooves for limiting the binding belt are provided on both side edges of the end cold plate which are perpendicular to the bottom cold plate.
[0017] The above-mentioned liquid-cooled battery module includes cold plates at both ends, cold plates on both sides and a bottom cold plate, which form a rectangular trough body. The battery structure is placed in the rectangular trough body. The five surfaces of the battery structure can dissipate heat at the same time, making the heat dissipation more uniform and the heat dissipation effect better, thereby reducing the expansion of the battery cell and increasing the service life of the battery module; the flow channels on the cold plates at both ends, the cold plates on both sides and the bottom cold plate are connected, and only one coolant inlet and outlet need to be set to connect the external infusion tube; the flow channel a of the end cold plate is in a straight line shape perpendicular to the bottom cold plate, the flow channel b is in a semi-rectangular side line shape, and the flow channel c is in a right-angle side line shape. The coolant passes through a large range, which can also improve the space utilization of the cold plate, and more flow channels are set to enhance the heat dissipation effect. BRIEF DESCRIPTION OF THE DRAWINGS
[0018] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.
[0019] Figure 1 This is a schematic diagram of the structure of an embodiment of a battery structure in this application;
[0020] Figure 2 This is a schematic diagram of the structure of the traditional battery arrangement in this application;
[0021] Figure 3 for Figure 1 The battery structure embodiment shown is Figure 2 The test comparison results of the traditional battery arrangement structure at different charging rates are shown, (a) is the expansion force comparison, (b) is the stress comparison, and (c) is the module length comparison;
[0022] Figure 4 This is a schematic diagram of another embodiment of the battery structure in this application;
[0023] Figure 5 This is a schematic diagram of the structure of an embodiment of a liquid-cooled battery module in this application;
[0024] Figure 6 for Figure 5 A schematic diagram of the structure of the liquid cooling system in the illustrated embodiment;
[0025] Figure 7 for Figure 6 Schematic diagram of the structure of the middle cold plate, (a) is a three-dimensional schematic diagram of the end cold plate, (b) is a bottom view of the end cold plate, and (c) is a cross-sectional schematic diagram of the end cold plate;
[0026] Figure 8 for Figure 6 Schematic diagram of the cross section of the middle side cold plate;
[0027] Fig. 9 for Figure 6 Schematic diagram of the structure of the bottom cold plate, (a) is a three-dimensional schematic diagram of the bottom cold plate, and (b) is a cross-sectional schematic diagram of the bottom cold plate.
[0028] Description of reference numerals:
[0029] 100, battery cell; 200, battery structure; 210, first battery cell group; 220, second battery cell group; 300, liquid cooling system; 310, end cold plate; 311, coolant connector; 312, delivery channel; 313, channel a; 314, first threaded hole; 315, first bolt positioning hole; 316, through hole; 317, limit groove; 320, side cold plate; 321, channel b; 322, third threaded hole; 330, bottom cold plate; 331, channel c; 332, second threaded hole; 333, fourth threaded hole; 334, second bolt positioning hole; 335, channel connector; 400, binding strap. DETAILED DESCRIPTION
[0030] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are described in detail below with reference to the accompanying drawings. The present application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present application, so the present application is not limited by the specific embodiments disclosed below.
[0031] In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.
[0032] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of this application, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.
[0033] In this application, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.
[0034] In the present application, unless otherwise clearly specified and limited, a first feature being “above” or “below” a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being “above”, “above”, and “above” a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being “below”, “below”, and “below” a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.
[0035] In one embodiment, if Figure 1 As shown, the battery structure 200 provided in the present application includes a first battery cell group 210 and a second battery cell group 220, the first battery cell group 210 includes a plurality of battery cells 100 stacked in sequence along a first direction, the second battery cell group 220 includes a plurality of battery cells 100 stacked in sequence along a second direction, the first direction and the second direction are perpendicular to each other on a plane, a second battery cell group 220 is respectively arranged on both sides of the width direction of the battery cells 100 of the first battery cell group 210, the length of the first battery cell group 210 along the first direction is less than the width of the battery cell 100, and the number of battery cells 100 in the second battery cell group 220 is less than the number of battery cells 100 in the first battery cell group 210.
[0036] It should be noted that Figure 1In the marking, the direction represented by the X-axis is the first direction, the direction represented by the Y-axis is the second direction, L represents the width of the battery cell 100, and W represents the thickness of the battery cell 100. The "multiple battery cells 100 stacked in sequence" mentioned above refers to the stacking of multiple battery cells 100 in thickness, and the battery cells 100 of the first battery cell group 210 and the battery cells 100 of the second battery cell group 220 are placed perpendicular to each other.
[0037] It should be noted that the positive and negative terminal points of all the battery cells 100 of the first battery cell group 210 and the second battery cell group 220 are located on the same end surface of the battery structure 200 .
[0038] Preferably, the number of 100 battery cells in the first battery cell group 210 is twice the number of 100 battery cells in the second battery cell group 220 .
[0039] For specific settings, refer to Figure 1 The first battery cell group 210 includes 6 battery cells 100, and the second battery cell group 220 includes 3 battery cells 100. The width of the battery cell 100 is between the thickness of 6 to 7 battery cells 100 stacked in sequence.
[0040] The arrangement is similar to the conventional battery arrangement structure (eg Figure 2 The expansion force, stress and module length change of the battery structure 200 at different charging rates are tested, and the results are as follows Figure 3 The comparison results shown in the figure show that the expansion force, stress and module length change of the battery structure 200 of the present application are all lower than those of the traditional battery arrangement structure.
[0041] In other embodiments, the battery structure 200 can be expanded horizontally and / or vertically to accommodate battery boxes of different sizes. The horizontal expansion is to continuously arrange the battery structures 200 along the second direction, and only one second battery group 220 is arranged between the first battery groups 210 of two adjacent battery structures 200. The vertical expansion is to continuously arrange the battery structures 200 along the first direction, and the second battery groups 220 of two adjacent battery structures 200 are abutted. For example, in another embodiment, Figure 4 As shown, the battery structures 200 are distributed in a 2*2 array.
[0042] The battery structure 200 of the present application has lower expansion force, stress and module length change than the traditional battery arrangement structure under the same number of battery cells 100, thereby reducing the damage caused by the expansion of the battery cells 100 to the battery module and increasing the service life of the battery module.
[0043] The present application also provides a liquid-cooled battery module. In one embodiment, Figure 5 and Figure 6As shown, the liquid-cooled battery module includes the battery structure 200 and a liquid cooling system 300 for cooling the battery structure 200. The liquid cooling system 300 includes two end cold plates 310, two side cold plates 320 and a bottom cold plate 330. The end cold plates 310, the side cold plates 320 and the bottom cold plate 330 are all provided with flow channel groups. The two end cold plates 310 are respectively connected to two opposite ends of the bottom cold plate 330 and are perpendicular to the bottom cold plate 330. The two side cold plates 320 are respectively connected to the two opposite ends of the bottom cold plate 330 and are perpendicular to the bottom cold plate 330. The other two opposite sides of the bottom cold plate 330 are respectively connected and perpendicular to the bottom cold plate 330, so that the two end cold plates 310, the two side cold plates 320 and the bottom cold plate 330 form a rectangular trough with an open upper end, the battery structure 200 is placed in the rectangular trough and the positive and negative end points of the battery cells 100 in the battery structure 200 face the opening of the rectangular trough, and the end cold plates 310, the side cold plates 320 and the bottom cold plate 330 are in contact with the outer surface of the battery structure 200.
[0044] The liquid-cooled battery module evenly removes the heat of the battery structure 200 through the cold plates 310 at both ends, the cold plates 320 at both sides and the bottom cold plate 330 , thereby evenly cooling the battery structure 200 , reducing the expansion of the battery cell 100 and increasing the service life of the battery module.
[0045] Specifically, the two end cold plates 310 are respectively attached to the end surfaces of the two second battery cell groups 220 away from the first battery cell group 210, the two side cold plates 320 are respectively attached to the two end surfaces of the first battery cell group 210 in the first direction, and the bottom cold plate 330 is attached to the lower end surfaces of the first battery cell group 210 and the second battery cell group 220.
[0046] Specifically, thermal pads are provided on the end cold plate 310, the side cold plate 320 and the bottom cold plate 330. The end cold plate 310 is bonded to the end surface of the second battery cell group 220 through the thermal pad, the side cold plate 320 is bonded to the end surface of the first battery cell group 210 through the thermal pad, and the bottom cold plate 330 is bonded to the lower end surfaces of the first battery cell group 210 and the second battery cell group 220 through the thermal pad.
[0047] Specifically, insulating sheets are provided between adjacent battery cells 100 on the first battery cell group 210 and the second battery cell group 220 .
[0048] refer to Figure 7 A coolant connector 311 is provided at the upper end of the end cold plate 310, and a delivery channel 312 and a first channel group are provided inside the end cold plate 310. The lower end of the coolant connector 311 is connected to the delivery channel 312, and the delivery channel 312 is arranged parallel to the upper end surface of the end cold plate 310. The first channel group includes a plurality of linear channels a313 arranged at even intervals and perpendicular to the bottom cold plate 330. The lower end of the channel a313 passes through the lower surface of the end cold plate 310, and the upper end of the channel a313 is connected to the delivery channel 312.
[0049] refer to Figure 8 A second flow channel group is provided inside the side cold plate 320, and the second flow channel group includes a plurality of flow channels b321 which are equidistantly arranged inside and outside and have a semi-rectangular edge line. The plurality of flow channels b321 gradually approach the lower surface of the side cold plate 320 as they are equidistantly arranged inwardly. The two ports of the flow channels b321 penetrate the lower surface of the side cold plate 320, and the number of the flow channels b321 is half the number of the flow channels a313.
[0050] refer to Fig. 9 A third flow channel group is provided inside the bottom cold plate 330. The third flow channel group is provided with four third flow channel groups, and the four third flow channel groups are distributed in the shape of a rectangle at the four corners of the bottom cold plate 330. The third flow channel group includes a plurality of flow channels c331 which are arranged equidistantly inside and outside and are in the shape of right-angled edges. The plurality of flow channels c331 gradually approach the corners of the bottom cold plate 330 as they are arranged equidistantly inward. The two ports of the flow channel c331 penetrate the upper surface of the bottom cold plate 330 upward, and the number of the flow channels c331 is half the number of the flow channels a313.
[0051] The lower surface of the end cold plate 310 and the lower surface of the side cold plate 320 are both attached to the upper surface of the bottom cold plate 330, and the plurality of flow channels a313 of the end cold plate 310 are connected to the plurality of flow channels c331 of the two third flow channel groups on the bottom cold plate 330 close to the end cold plate 310 in a one-to-one correspondence, and the plurality of flow channels b321 of the side cold plate 320 are connected to the plurality of flow channels c331 of the two third flow channel groups on the bottom cold plate 330 close to the side cold plate 320 in a one-to-one correspondence, and the two ports of the flow channel b321 are connected to the flow channels c331 of different third flow channel groups. The flow channels a313 and the flow channels c331, and the flow channels b321 and the flow channels c331 are all connected through the flow channel connector 335.
[0052] It can be understood that the coolant joint 311 on the cold plate 310 at one end is the coolant inlet, and the coolant joint 311 on the cold plate 310 at the other end is the coolant outlet, and the flow direction of the coolant is: first pass through the coolant joint 311, the delivery channel 312 and each channel a313 of the cold plate 310 at one end in sequence, then pass through each channel c331 of the two third channel groups on the bottom cold plate 330, then pass through each channel b321 of the cold plates 320 on both sides, then pass through each channel c331 of the other two third channel groups on the bottom cold plate 330, and finally pass through each channel a313, the delivery channel 312 and the coolant joint 311 of the cold plate 310 at the other end in sequence.
[0053] The liquid cooling system 300 of the liquid-cooled battery module includes cold plates 310 at both ends, cold plates 320 at both sides and a bottom cold plate 330, which form a rectangular trough. The battery structure 200 is placed in the rectangular trough. The five surfaces of the battery structure 200 can dissipate heat at the same time, making the heat dissipation more uniform and the heat dissipation effect better, thereby reducing the expansion of the battery cell and improving the service life of the battery module; the flow channels on the cold plates 310 at both ends, the cold plates 320 at both sides and the bottom cold plate 330 are connected, and only one coolant inlet and outlet need to be set to connect the external infusion tube; the flow channel a313 of the end cold plate 310 is in a straight line perpendicular to the bottom cold plate 330, the flow channel b321 is in a semi-rectangular side line shape, and the flow channel c331 is in a right-angle side line shape. The coolant passes through a large range, which can also improve the space utilization of each cold plate, and more flow channels are set to enhance the heat dissipation effect.
[0054] Specifically, the end cold plate 310 and the side cold plate 320 are fixedly connected to the bottom cold plate 330 by screws. Figure 7 , Figure 8 and Fig. 9 A first threaded hole 314 is provided on the lower surface of the end cold plate 310 toward the upper surface of the end cold plate 310, and a plurality of the first threaded holes 314 are provided at intervals along the length direction of the end cold plate 310. A plurality of second threaded holes 332 are provided on the bottom cold plate 330 below the end cold plate 310, and the plurality of second threaded holes 332 are provided one-to-one correspondingly to the plurality of first threaded holes 314. The first threaded holes 314 and the second threaded holes 332 are threadedly connected by screws to fix the end cold plate 310 to the bottom cold plate 330; A third threaded hole 322 is provided on the lower surface of the side cold plate 320 toward the upper surface of the side cold plate 320, and a plurality of the third threaded holes 322 are provided at intervals along the length direction of the side cold plate 320. A plurality of fourth threaded holes 333 are provided on the bottom cold plate 330 below the side cold plate 320, and the plurality of fourth threaded holes 333 are provided in one-to-one correspondence with the plurality of third threaded holes 322. The third threaded holes 322 and the fourth threaded holes 333 are screwed together to fix the side cold plate 320 to the bottom cold plate 330. Such a configuration can enhance the reliability of the connection between the cold plates and avoid coolant leakage.
[0055] Optionally, refer to Figure 7 and Fig. 9 First bolt positioning holes 315 are respectively provided at both ends of the end cold plate 310 along the length direction, and second bolt positioning holes 334 are provided on the bottom cold plate 330 corresponding to the first bolt positioning holes 315. Bolts are passed through the first bolt positioning holes 315 and the second bolt positioning holes 334 and then tightened with nuts. Such an arrangement can further enhance the connection reliability between the end cold plate 310 and the bottom cold plate 330.
[0056] Specifically, refer to Figure 7 A plurality of through holes 316 are evenly spaced on the end cold plate 310, and the through holes 316 penetrate the upper surface and the lower surface of the end cold plate 310 in a direction perpendicular to the bottom cold plate 330. The through holes 316 are arranged beside the flow channel a313 and on the side of the end cold plate 310 away from the battery structure 200, and the through holes 316 are not covered by the bottom cold plate 330. The through holes 316 are used to increase the heat dissipation area.
[0057] Specifically, refer to Figure 1 The liquid-cooled battery module further includes a binding band 400, which is circumferentially bound around the two end cold plates 310 and the two side cold plates 320 on a side away from the battery structure 200. The binding band 400 binds the first battery cell group 210, the second battery cell group 220 and the cooling system together through a pre-tightening force.
[0058] For further reference, Figure 7 The end cold plate 310 is provided with limiting grooves 317 on both side edges perpendicular to the bottom cold plate 330, and the strap 400 passes through the limiting grooves 317. The limiting grooves 317 limit the strap 400 to prevent the strap 400 from moving, tilting, and not being tied tightly.
[0059] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.
[0060] The above-described embodiments only express several implementation methods of the present application and should not be construed as limiting the scope of the patent application. It should be noted that, for a person of ordinary skill in the art, several modifications and improvements can be made without departing from the concept of the present application, and these all fall within the scope of protection of the present application. Therefore, the scope of protection of the patent application shall be subject to the attached claims.
Claims
1. A battery structure, characterized in that: It includes a first battery cell group and a second battery cell group, the first battery cell group includes a plurality of battery cells stacked in sequence along a first direction, the second battery cell group includes a plurality of battery cells stacked in sequence along a second direction, the first direction and the second direction are perpendicular to each other on a plane, a second battery cell group is respectively arranged on both sides of the battery cell width direction of the first battery cell group, the length of the first battery cell group along the first direction is smaller than the width of the battery cell, and the number of battery cells in the second battery cell group is less than the number of battery cells in the first battery cell group.
2. The battery structure according to claim 1, characterized in that: The number of battery cells in the first battery cell group is twice the number of battery cells in the second battery cell group.
3. A liquid-cooled battery module, characterized in that: It includes a battery structure as described in any one of claims 1 to 2 and a liquid cooling system for cooling the battery structure, the liquid cooling system includes two end cold plates, two side cold plates and a bottom cold plate, and flow channel groups are arranged on the end cold plates, the side cold plates and the bottom cold plate; the two end cold plates are respectively connected to two opposite ends of the bottom cold plate and are perpendicular to the bottom cold plate, and the two side cold plates are respectively connected to the other opposite sides of the bottom cold plate and are perpendicular to the bottom cold plate, so that the two end cold plates, the two side cold plates and the bottom cold plate form a rectangular trough body with an open upper end, the battery structure is placed in the rectangular trough body and the positive and negative end points of the battery cells in the battery structure are facing the opening of the rectangular trough body, and the end cold plates, the side cold plates and the bottom cold plate are attached to the outer surface of the battery structure.
4. The liquid-cooled battery module according to claim 3, characterized in that: The two end cold plates are respectively attached to the end surfaces of the two second battery cell groups away from the first battery cell group, the two side cold plates are respectively attached to the two end surfaces of the first battery cell group in the first direction, and the bottom cold plate is attached to the lower end surfaces of the first battery cell group and the second battery cell group.
5. The liquid-cooled battery module according to claim 3, characterized in that: A coolant joint and a first flow channel group are provided on the end cold plate, wherein the first flow channel group includes a plurality of flow channels a, and the flow channels a are connected to the coolant joint; A second flow channel group is provided on the side cold plate, and the second flow channel group includes a plurality of flow channels b; A third flow channel group is provided on the bottom cold plate, and the third flow channel group is provided with four and distributed in the four corners of a rectangle, and the third flow channel group includes a plurality of flow channels c; The several flow channels a of the end cold plate are connected one-to-one to the several flow channels c of the two third flow channel groups on the bottom cold plate close to the end cold plate, the several flow channels b of the side cold plate are connected one-to-one to the several flow channels c of the two third flow channel groups on the bottom cold plate close to the side cold plate, and the two ports of the flow channels b are connected to the flow channels c of different third flow channel groups.
6. The liquid-cooled battery module according to claim 5, characterized in that: On the end cold plate, the flow channel a is in a straight line perpendicular to the bottom cold plate, and a plurality of the flow channels a are evenly spaced along the length direction of the end cold plate; On the side cold plate, the flow channel b is in a semi-rectangular shape, and a plurality of the flow channels b are arranged at equal intervals inside and outside, and gradually approach the lower surface of the side cold plate as they are arranged at equal intervals inward; On the bottom cold plate, the flow channel c is in the shape of a right-angled edge line, and a plurality of the flow channels c are arranged at equal intervals inside and outside, and gradually approach the corner of the bottom cold plate as they are arranged at equal intervals inward.
7. The liquid-cooled battery module according to claim 3, characterized in that: The end cold plate and the side cold plate are fixedly connected to the bottom cold plate by screws.
8. The liquid-cooled battery module according to claim 3, characterized in that: A plurality of through holes are evenly spaced apart on the end cold plate, and the through holes penetrate the upper surface and the lower surface of the end cold plate in a direction perpendicular to the bottom cold plate.
9. The liquid-cooled battery module according to claim 3, characterized in that: The liquid-cooled battery module further includes a binding strap, which is circumferentially bound around a side of the two end cold plates and the two side cold plates away from the battery structure.
10. The liquid-cooled battery module according to claim 9, characterized in that: Limiting grooves for limiting the binding belt are provided on both side edges of the end cold plate which are perpendicular to the bottom cold plate.