Cylindrical battery cell module

Abstract

The utility model discloses a cylindrical battery cell module. The cylindrical battery cell module sequentially comprises a cover plate from top to bottom in the vertical direction of the battery cell module, a flexible water cooling belt is attached to the side wall of each cylindrical battery cell, and a gap between every two adjacent rows of cylindrical battery cells is filled with polystyrene foam; and a limiting contour for fixing the cylindrical battery cell is arranged on the contact surface of the bottom plate and the cylindrical battery cell. By adopting the flexible water-cooling belt, on one hand, the material thickness of the flexible water-cooling belt is only one half of that of an aluminum water-cooling device, the energy density of the battery module is effectively improved, on the other hand, the flexible water-cooling belt is tightly attached to the cylindrical battery cell under the liquid pressure, a heat-conducting structural adhesive is not needed, the cost is reduced, and the production takt is accelerated; and meanwhile, the position of the battery cell is fixed through the matched use of the limiting contour and the battery cell bracket, so that the welding quality of the battery cell and the busbar sheet is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of batteries, in particular to a cylindrical battery core module. Background Art

[0002] With the popularity of electric vehicles, the market has higher and higher requirements for battery performance. Among them, the energy density of a battery pack refers to the ratio of how much energy a battery can store to its weight or volume; the volume utilization of a battery pack refers to the proportion of effective space in the battery pack. High energy density allows electric vehicles to travel farther, and high volume utilization helps to install more battery cells in a limited space. The increase in energy density causes the heat generated by the battery under different working conditions to increase sharply, which brings more challenges to battery thermal management. At the same time, the volume utilization of the battery pack is also closely related to the thermal management method, that is, the increase in the volume and weight of thermal management components will reduce the volume utilization and energy density of the battery pack. In this way, although there is better temperature control, the overall energy density and volume utilization of the battery pack are reduced.

[0003] At present, aluminum water cooling devices are mainly used for cooling cylindrical batteries. However, the shortcomings of this method are also obvious. Relatively speaking, it occupies a large space and is not light in weight, which has an adverse effect on the improvement of volume utilization and energy density. In addition, when the aluminum water cooling device contacts the cylindrical battery cell, it is necessary to fill the contact interface with thermal conductive structural adhesive, which increases the manufacturing cost on the one hand, and on the other hand, the relative position of the battery cell and the aluminum water cooling device is fixed. When the cylindrical battery cell is welded to the busbar in the later stage, serious problems such as misalignment, cold soldering and desoldering are prone to occur. Utility Model Content

[0004] In order to solve the above technical problems, the utility model provides a cylindrical battery module, which includes the following components from top to bottom along the vertical direction of the battery module:

[0005] Cover plate;

[0006] Cylindrical battery cells, a flexible water cooling belt is arranged in contact with the side wall of the cylindrical battery cells, and the gap between two adjacent rows of the cylindrical battery cells is filled with foam glue; and

[0007] The bottom plate has a contact surface with the cylindrical battery core and is provided with a limiting contour for fixing the cylindrical battery core.

[0008] Furthermore, a busbar piece is integrated on the cover plate; a cell holder for fixing the cylindrical cell is provided at one end of the cylindrical cell away from the limiting contour, and the cell holder cooperates with the limiting contour to fix the position of the cylindrical cell so as to align the pole of the cylindrical cell with the busbar piece.

[0009] Furthermore, the battery cell support is a planar mesh structure, comprising staggered circular holes and a small hole in the middle of the mesh structure, the circular holes are sleeved on the ends of the corresponding single cylindrical battery cells, and the small holes are inlets for injecting the foam glue.

[0010] Furthermore, a uniformly arranged hole structure is provided on the bottom edge of the flexible water-cooling belt, and the hole structure forms a flow channel for the foam glue.

[0011] Furthermore, the flexible water-cooling belts are connected through pipelines.

[0012] Furthermore, side plates and end plates are arranged around the edge of the bottom plate, and the side plates are arranged along the length direction of the cylindrical battery cell module; and the end plates are arranged along the width direction of the cylindrical battery cell module.

[0013] Furthermore, the gap between the end plate and the end of the flexible water-cooling belt is filled with sponge.

[0014] Furthermore, a waist-shaped hole is provided at the connection between the busbar sheet and the positive electrode of the cylindrical battery cell; and a forked structure is present at the connection between the busbar sheet and the negative electrode of the cylindrical battery cell.

[0015] Furthermore, a through hole is provided between the contact surface between the bottom plate and the cylindrical battery cell for discharging ejected matter when the cylindrical battery cell thermally runs away.

[0016] Furthermore, the gap between two adjacent rows of the cylindrical battery cells is 2.2 mm-2.5 mm.

[0017] Compared with the prior art, the utility model has the following beneficial effects:

[0018] Compared with the existing aluminum water-cooling device, the utility model adopts a flexible water-cooling belt. On the one hand, its material thickness is only half of that of the aluminum water-cooling device, which effectively improves the energy density of the battery module. On the other hand, the flexible water-cooling belt fits tightly with the cylindrical battery cell under liquid pressure, and does not require thermal conductive structural adhesive, thereby reducing costs and speeding up production cycles. At the same time, the battery cell position is fixed by the coordinated use of the limiting contour and the battery cell bracket, thereby improving the welding quality of the battery cell and the busbar sheet. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is an exploded view of the overall structure of an embodiment of the utility model;

[0020] Figure 2 This is a schematic diagram of the cover plate structure of an embodiment of the utility model, showing that a plurality of busbar plates are integrated on the cover plate;

[0021] Figure 3It is a partial enlarged view of the busbar piece of the embodiment of the utility model;

[0022] Figure 4 It is a front view of the battery cell support of an embodiment of the utility model;

[0023] Figure 5 An axonometric view of a base plate of an embodiment of the utility model;

[0024] Figure 6 It is an axonometric view of the flexible water cooling belt of the embodiment of the utility model;

[0025] Figure 7 It is a front view of the flexible water cooling belt of the embodiment of the utility model;

[0026] Figure 8 A side view of a flexible water cooling belt according to an embodiment of the utility model;

[0027] Fig. 9 This is an enlarged view of the bottom of the flexible water-cooling belt according to an embodiment of the utility model.

[0028] In the figure:

[0029] 10. Cover plate; 11. Busbar plate; 110. Waist-shaped hole;

[0030] 20. Cylindrical battery cell; 21. Flexible water cooling belt; 22. Battery cell bracket; 220. Round hole; 221. Small hole;

[0031] 30. Bottom plate; 31. Limiting profile; 310. Through hole; 32. Side plate; 33. End plate. DETAILED DESCRIPTION

[0032] In order to make the technical scheme and technical effect of the utility model clearer, the technical scheme in the embodiment of the utility model will be clearly and completely described below in conjunction with the drawings in the embodiment. Obviously, the described embodiment is only a part of the embodiment of the utility model, not all of the embodiments.

[0033] The utility model aims to provide a cylindrical battery cell module, which has the advantages of improving the energy density of the battery cell module, increasing the volume utilization rate and improving the welding quality.

[0034] like Figure 1 As shown, the battery module includes a cover plate 10, a cylindrical battery cell 20 and a bottom plate 30 from top to bottom in the vertical direction. The gap between two adjacent rows of cylindrical battery cells 20 is 2.2mm-2.5mm, which reduces the gap between the battery cells and improves the volume utilization of the battery module. The gap between two adjacent rows of cylindrical battery cells 20 is filled with foam.

[0035] like Figure 2The cover plate 10 shown in the figure has a plurality of busbar sheets 11 integrated thereon. The busbar sheets 11 are designed with a specific structure to achieve a stable connection between the cells, ensuring that the current can be effectively transmitted. Figure 3 As shown, a waist-shaped hole 110 is provided at the connection between the busbar piece 11 and the positive electrode of the cylindrical battery cell 20; the connection between the busbar piece 11 and the negative electrode of the cylindrical battery cell 20 is a forked structure. Such a design can reduce the stress inside the solder joint after the busbar piece 11 and the battery cell are welded, further avoid the desoldering problem, and effectively improve the welding quality between the busbar piece 11 and the battery cell.

[0036] like Figure 5 As shown, the contact surface between the bottom plate 30 and the cylindrical battery cell 20 is provided with a limiting contour 31 for fixing the cylindrical battery cell 20, and a through hole 310 is provided at the center position of the limiting contour 31. The through hole 310 has a certain diameter for discharging the ejected matter when the cylindrical battery cell 20 thermally runs away.

[0037] Side plates 32 and end plates 33 are arranged around the edge of the bottom plate. The side plates 32 are arranged along the length direction of the cylindrical battery module; and the end plates 33 are arranged along the width direction of the cylindrical battery module.

[0038] like Figure 4 As shown, a cell holder 22 for fixing the cylindrical cell 20 is provided at one end of the cylindrical cell 20 away from the limiting contour 31. The cell holder 22 cooperates with the limiting contour 31 to fix the position of the cylindrical cell 20 so as to align the pole of the cylindrical cell 20 with the busbar sheet 11. The cell holder 22 is a planar mesh structure. The cell holder 22 includes staggered circular holes 220 and a small hole 221 located in the middle of the mesh structure. The circular hole 220 is sleeved on the corresponding end of a single cylindrical cell, and the small hole 221 is the entrance for injecting the foam glue. The potting foam glue is injected from these small holes 221 to enhance the strength of the module and prevent the heat diffusion of the cell. By limiting the upper and lower positions, the position of the cell can be accurately fixed, that is, the cell pole and the upper busbar sheet 11 can be effectively aligned, which is beneficial to improve the welding quality of the cell and the busbar sheet 11.

[0039] like Figure 6-9As shown, the utility model cools the battery module by using a flexible water-cooling belt 21 with low density. The flexible water-cooling belt 21 is composed of four single belts, and the flexible water-cooling belts 21 are connected by nylon or rubber pipes, and the pipes and the flexible water-cooling belts 21 are hard-connected or laser-welded by clamps. The material thickness of the flexible water-cooling belt 21 is only half of that of the aluminum water-cooling device, which can effectively improve the energy density. Without the need for thermal conductive structural adhesive, the flexible water-cooling belt 21 can fit well with the side wall of the cylindrical battery cell 20 under liquid pressure. The bottom edge of the flexible water-cooling belt 21 is provided with a uniformly arranged hole structure, which forms a flow channel for the foam glue, allowing the potting glue liquid to flow from one side of the flexible water-cooling belt 21 to the other side, which can effectively increase the uniformity of the foam glue, avoid excessive foaming of the glue liquid in one place and less foaming in other areas, and effectively avoid problems such as uneven module strength or thermal runaway spread.

[0040] The gap between the end plate 33 and the end of the flexible water-cooling belt 21 is filled with sponge. Specifically, a sponge with a certain thickness and a certain compression rate is glued to the end of the flexible water-cooling belt 21 and then the end plate 33 is inserted to prevent the glue from flowing out during the later filling of the foam glue.

[0041] During production, after the cover plate 10 with integrated busbar piece 11 is welded to the cylindrical battery cell 20, compressed air of about 2 atmospheres is filled into the flexible water-cooling belt 21 to maintain the close fit between the cylindrical battery cell 20 and the flexible water-cooling belt 21, and then the foaming glue liquid is injected into the module, and the encapsulated foaming glue should be able to completely wrap the cover plate 10 after foaming. This design is because the foaming glue has extremely low thermal conductivity and insulation ability, so this can not only avoid heat diffusion of the battery cell, but also effectively prevent the busbar piece 11 from being short-circuited by the ejecta or other conductive particles during thermal runaway of the battery cell, thereby ensuring the safety of the battery cell module.

[0042] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A cylindrical battery module, characterized in that: From top to bottom along the vertical direction of the battery module, it includes: Cover plate (10); A cylindrical battery cell (20), wherein a flexible water cooling belt (21) is arranged in contact with the side wall of the cylindrical battery cell (20), and the gap between two adjacent rows of the cylindrical battery cells (20) is filled with foam glue; and The bottom plate (30) is provided with a limiting contour (31) for fixing the cylindrical battery core (20) on its contact surface with the cylindrical battery core (20).

2. The cylindrical battery module according to claim 1, characterized in that: A busbar sheet (11) is integrated on the cover plate (10); a cell support (22) for fixing the cylindrical cell (20) is provided at one end of the cylindrical cell (20) away from the limiting contour (31); the cell support (22) cooperates with the limiting contour (31) to fix the position of the cylindrical cell (20) so as to align the pole of the cylindrical cell (20) with the busbar sheet (11).

3. The cylindrical battery cell module according to claim 2, characterized in that: The cell support (22) is a planar mesh structure, comprising staggered circular holes (220) and a small hole (221) located in the middle of the mesh structure, the circular hole (220) being sleeved on the end of a corresponding single cylindrical cell, and the small hole (221) being an inlet for injecting the foam glue.

4. The cylindrical battery cell module according to claim 1, characterized in that: The bottom edge of the flexible water-cooling belt (21) is provided with a uniformly arranged hole structure, and the hole structure forms a flow channel for the foam glue.

5. The cylindrical battery cell module according to claim 4, characterized in that: The flexible water cooling belts (21) are connected via pipelines.

6. The cylindrical battery cell module according to claim 4, characterized in that: Side plates (32) and end plates (33) are arranged around the edge of the bottom plate (30); the side plates (32) are arranged along the length direction of the cylindrical battery module; and the end plates (33) are arranged along the width direction of the cylindrical battery module.

7. The cylindrical battery cell module according to claim 6, characterized in that: The gap between the end plate (33) and the end of the flexible water-cooling belt (21) is filled with sponge.

8. The cylindrical battery cell module according to claim 2, characterized in that: A waist-shaped hole (110) is provided at a connection point between the busbar sheet (11) and the positive electrode of the cylindrical battery cell (20); and a connection point between the busbar sheet (11) and the negative electrode of the cylindrical battery cell (20) is in a bifurcated structure.

9. The cylindrical battery cell module according to claim 1, characterized in that: A through hole (310) is provided on a contact surface between the bottom plate (30) and the cylindrical battery core (20) for discharging ejected matter when the cylindrical battery core (20) experiences thermal runaway.

10. The cylindrical battery cell module according to claim 1, characterized in that: The gap between two adjacent rows of cylindrical battery cells (20) is 2.2 mm to 2.5 mm.

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