Plug-in battery cell, battery cell module and battery pack

Abstract

The utility model discloses a plug-in battery cell, a battery cell module and a battery pack. The plug-in cell comprises a first pole and a second pole, the polarity of the first pole is opposite to that of the second pole, the first pole and the second pole are located at one end of the cell, the first pole comprises a first connecting structure, and the second pole comprises a second connecting structure; and the battery cells which are oppositely arranged on the pole side can be inserted and connected in series by virtue of the first connecting structure and the second connecting structure. According to the plug-in battery cell disclosed by the utility model, the first pole comprises the first connecting structure, the second pole comprises the second connecting structure, and the at least two battery cells of which the pole sides are oppositely arranged can be plugged and connected in series by virtue of the first connecting structure and the second connecting structure, so that effective plug-in between the battery cells is realized; the grouping space during the connection of the battery cell poles is saved, and the energy density of the power supply system is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of batteries, in particular to a plug-in battery cell, a battery cell module and a battery pack. Background Art

[0002] With the rapid development of the new energy industry, the application of power battery systems is becoming more and more extensive. A battery cell is a basic component of a battery pack, and the arrangement and connection methods of battery cells directly affect the performance and efficiency of the battery system. In traditional battery packs, battery cells are usually connected in series and parallel by welding aluminum bars. Although this method can realize the connection of battery cells, it will occupy a large amount of grouping space, reduce the energy density of the power system, and require a large number of aluminum bars, increasing the production cost. Further, this connection method also requires the use of welding equipment and labor, further increasing the production cost. At the same time, the requirements for fast charging and high power cause the battery heat generation to increase. Therefore, how to make the battery dissipate heat efficiently has become an important research topic. Summary of the Utility Model

[0003] The purpose of the utility model is to overcome the deficiencies and defects of the prior art, and provide a plug-in battery cell, a battery cell module and a battery pack.

[0004] In the first aspect of the utility model, a plug-in battery cell is provided, which includes a first pole column and a second pole column. The polarities of the first pole column and the second pole column are opposite and are located at one end of the battery cell. The first pole column includes a first connection structure, and the second pole column includes a second connection structure; the battery cells with opposite sides of the pole columns can be plugged and connected in series by means of the first connection structure and the second connection structure.

[0005] Wherein, the first connection structure is a groove on the surface of the pole column, and the second connection structure is a convex part that can be plugged together with the groove; the upper end of the groove has a limiting structure and there is an insertion opening on the peripheral side of the limiting structure. The second connection structure is inserted into the groove through the insertion opening for plugging and assembling with the groove.

[0006] Wherein, the convex part includes an upper part with a large diameter and a lower part with a small diameter, and the inner diameter of the limiting structure at the upper end of the groove is matched with the lower part with a small diameter.

[0007] Wherein, the first pole column is a negative pole column, and the second pole column is a positive pole column.

[0008] Wherein, the first pole column is a positive pole column, and the second pole column is a negative pole column.

[0009] Wherein, the plug-in battery cell is a square battery cell.

[0010] In a second aspect of the present utility model, a battery cell module is provided, which includes a battery cell module unit formed by plugging and assembling a plurality of the plug-in battery cells according to the first aspect of the present utility model.

[0011] Among them, the battery cell module includes a flexible printed circuit board disposed between the plug-in battery cells of the battery cell module unit. The flexible printed circuit board includes a plurality of buckles for snap-connecting with the poles of the plug-in battery cells.

[0012] Among them, the battery cell module includes an exhaust passage between the plug-in battery cells of the battery cell module unit. The exhaust passage includes a main passage and an explosion-proof valve docking passage communicating with the main passage. The explosion-proof valve docking passage includes exhaust holes corresponding to the explosion-proof valves of each plug-in battery cell. One end of the exhaust passage is closed, and the other end is of an open structure.

[0013] In a third aspect of the present utility model, a battery pack is provided, which includes the battery module according to the second aspect of the present utility model. The battery module includes at least two battery cell module units. A liquid cooling plate is arranged between the large surfaces of the battery cells of the two battery cell module units. Elastic fillers are arranged on the inner surfaces of the upper cover and the lower box body of the battery pack, and the elastic fillers are in contact with the large surfaces of the battery cells of the battery cell module unit;

[0014] The liquid cooling plate is connected to the battery cell module unit through a thermally conductive structural adhesive;

[0015] The liquid cooling plate includes a plurality of independently circulating liquid cooling circulation units. The upper and lower surfaces of each liquid cooling circulation unit respectively correspond to a battery cell module unit. Each liquid cooling circulation unit is provided with a liquid inlet and a liquid outlet, and the liquid inlet and the liquid outlet are arranged on the same side;

[0016] It further includes a bus bar for connecting the battery cell module units in series; the bus bar includes a plug-in structure for cooperating with the first pole and the second pole of the plug-in battery cell.

[0017] For the plug-in battery cell of the present utility model, the first pole includes a first connection structure, the second pole includes a second connection structure, and at least two battery cells with opposite pole sides can be plugged and connected in series by means of the first connection structure and the second connection structure to achieve effective plugging between the battery cells, save the group space during the connection of the battery cell poles, and improve the energy density of the power system.

[0018] In addition, by adopting the method of plugging the battery cell poles, the space and materials of the bus bar can be saved, and the production cost can be reduced. After the battery cells form a battery cell module unit, they can be arranged in two layers, and a liquid cooling plate can be placed between the two layers of battery cell modules for liquid cooling, which can effectively cool the battery cells and improve the service life of the battery cells. Description of the Drawings

[0019] Figure 1 It is a schematic structural diagram of the plug-in battery cell according to an embodiment of the present utility model.

[0020] Figure 2 It is a schematic cross-sectional view of the plug-in battery cell according to an embodiment of the present utility model.

[0021] Figure 3 It is a schematic diagram of the battery cell plug-in according to an embodiment of the present utility model.

[0022] Figure 4 It is an exploded view of the battery cell module unit formed by the plug-in battery cell according to an embodiment of the present utility model.

[0023] Figure 5 It is a schematic diagram of the exhaust passage according to an embodiment of the present utility model.

[0024] Figure 6 It is an exploded view of the battery pack according to an embodiment of the present utility model.

[0025] Figure 7 It is a schematic diagram of the liquid cooling plate according to an embodiment of the present utility model.

[0026] Figure 8 It is a schematic diagram of the first series connection row according to an embodiment of the present utility model.

[0027] Description of reference numerals:

[0028] 1 - Battery cell;

[0029] 11 - Positive electrode terminal, 12 - Negative electrode terminal, 111 - Upper large diameter part, 112 - Lower small diameter part, 121 - Groove, 122 - Limiting structure;

[0030] 2 - Flexible printed circuit board;

[0031] 21 - Buckle;

[0032] 3 - Exhaust passage;

[0033] 31 - Main passage, 32 - Explosion-proof valve docking passage, 33 - Exhaust hole;

[0034] 4 - Elastic filler;

[0035] 5 - Lower box body;

[0036] 6 - Upper box cover;

[0037] 7 - Liquid cooling plate:

[0038] 71 - Liquid inlet, 72 - Liquid outlet;

[0039] 8 - First series connection row;

[0040] 81 - First plug-in structure, 82 - Second plug-in structure;

[0041] 9 - Second series row. Specific embodiments

[0042] The following further describes the present utility model in detail with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present utility model and are not used to limit the present utility model.

[0043] The plug-in battery cell of the embodiment of the present utility model includes a first pole column and a second pole column. The polarities of the first pole column and the second pole column are opposite and are located at one end of the battery cell. The first pole column includes a first connection structure, and the second pole column includes a second connection structure; the battery cells with opposite pole column sides can be plugged and connected in series by means of the first connection structure and the second connection structure.

[0044] Among them, the first pole column can be the positive pole column 11 or the negative pole column 12, and the second pole column can be the positive pole column 11 or the negative pole column 12. The inserted battery cell is preferably a battery cell with a square structure, that is, a square battery cell.

[0045] Next, for the convenience of description, the positive pole column 11 and the negative pole column 12 are taken as examples to illustrate the structure and connection method of the plug-in battery cell.

[0046] As Figure 1 and Figure 2 shown, the plug-in battery cell 1 of the embodiment of the present utility model has a positive pole column 11 and a negative pole column 12. The negative pole column 12 has a first connection structure, and the first connection structure is a groove structure, that is, the negative pole column is an inner concave pole column. The positive pole column has a second connection structure, and the connection structure is an outer convex structure, that is, the positive pole column is an outer convex pole column. The shape and size of the outer convex structure are adapted to the groove structure. When forming a battery cell module unit, the pole column sides of two plug-in battery cells are opposite, and the negative pole column of one plug-in battery cell is plugged into the positive pole column of another plug-in battery cell to realize the connection of the two plug-in battery cells. As Figure 3 shown, through the cooperation of the inner concave pole column and the outer convex structure, it can be ensured that the plugging is in place and the cooperation is good.

[0047] In some embodiments, the positive pole column 12 has a lower small diameter portion 112 and an upper large diameter portion 121. The negative pole column 11 has a matching structure. For example, the upper end of the groove structure of the negative pole column has a limiting structure, and there is an insertion opening on the circumferential side of the limiting structure. The second connection structure is inserted into the groove through the insertion opening for plugging and assembling with the groove.

[0048] Through the design of the plugging structure of the battery cell pole column described above, effective plugging between battery cells can be realized, saving the grouping space and improving the energy density of the power system.

[0049] In the second aspect of the embodiments of the present utility model, a battery cell module is provided. Refer to Figure 4 As shown, it includes a battery cell module unit formed by plugging and assembling a plurality of the plug-in battery cells in the first aspect of the embodiments of the present utility model.

[0050] In some embodiments, the battery cell module, as Figure 4 shown, includes a flexible printed circuit board 2 for collecting the voltage and temperature of the battery cells, which is placed between the plug-in battery cells of each battery cell module unit. The flexible printed circuit board includes a plurality of buckles 21 for snap-connecting with the poles of the plug-in battery cells. Refer to Figure 4 As shown, the flexible printed circuit board 21 is strip-shaped and adapted to the length of the connected battery cell module unit. The plurality of buckles 21 cooperate with the poles of the battery cells and can be snap-connected to the outside of the battery cell poles. In the prior art, the flexible printed circuit board of the battery cell module is welded to the bus bar. In this application, the connection method of the flexible printed circuit board is set as a buckle, replacing welding with a snap-connection form, which can save the cost of welding equipment and labor cost. The buckle can be made of a metal material, such as aluminum, copper, nickel, etc., and preferably nickel.

[0051] In some embodiments, refer to Figure 4 、 Figure 5 As shown, the battery cell module includes an exhaust channel 3 for discharging high-temperature gas during thermal runaway of the battery cells. Between the plug-in battery cells of each battery cell module unit, the exhaust channel includes a main channel 31 and an explosion-proof valve docking channel 32 communicating with the main channel. The explosion-proof valve docking channel 32 includes exhaust holes 33 corresponding to the explosion-proof valves of each plug-in battery cell. One end of the exhaust channel is closed and the other end is an open structure. In this way, the gas discharged from the battery cells can be discharged from one end of the main channel. Preferably, the open structure can be arranged on the side where the battery pack explosion-proof valve is located at the tail of the battery pack. In this way, once a battery cell undergoes thermal runaway, the high-temperature gas discharged from the battery cell breaks through the battery cell explosion-proof valve, enters the exhaust channel, surges to the tail of the battery pack, and is discharged by the battery pack explosion-proof valve at the tail of the battery pack, avoiding the influence of high-temperature smoke on the front-end connector and information collection components of the battery pack.

[0052] In some embodiments, the material of the exhaust channel can be a metal material, such as iron, aluminum, etc., and its thickness is preferably 0.1 mm - 1 mm, and the outer surface is sprayed with an insulating material. When installing the exhaust channel, first apply a thin layer of glue on the non-surface of the exhaust channel, insert it into the gap between two rows of battery cells of the battery cell module unit, and wait for the glue layer to cure to complete the connection. More preferably, the exhaust channel 3 and the flexible printed circuit board 2 can be arranged on the opposite sides of the plug-in battery cells of the battery cell module unit, and of course, they can also be arranged on the same side.

[0053] In the third aspect of the embodiments of the present utility model, a battery pack is provided. Refer to Figure 6 As shown, it includes the battery module of the second aspect of the embodiments of the present utility model. The battery module includes at least two cell module units. A liquid cooling plate 7 is arranged between the large surfaces of the cells of the two cell module units. Elastic fillers 4 are arranged on the inner surface of the upper cover of the battery pack and the inner surface of the lower box body. The elastic fillers are in contact with the large surfaces of the cells of the cell module units. The liquid cooling plate is connected to the cell module unit through a thermally conductive structural adhesive. The liquid cooling plate 7 includes a plurality of independently circulating liquid cooling circulation units. The upper and lower surfaces of each liquid cooling circulation unit respectively correspond to one cell module unit. Each liquid cooling circulation unit is provided with a liquid inlet 71 and a liquid outlet 72. The liquid inlet and the liquid outlet are arranged on the same side. It also includes a bus bar for connecting the cell module units in series. The bus bar includes a plug-in structure that cooperates with the first pole and the second pole of the plug-in cell.

[0054] As Figure 7 shown, Figure 7 As shown in the figure, it is a schematic diagram of the liquid cooling plate 7. The black arrows in the figure indicate the flow direction of the coolant. The liquid inlet 71 and the liquid outlet 72 are both concentrated at the front of the battery pack, saving the space at the tail. The liquid inlet 71 can be connected to the liquid inlet of the battery pack box body through a pipeline, and the liquid outlet 72 can be connected to the liquid outlet of the battery pack box body through a pipeline (not shown in the figure). Among them, each coolant circulation path in the liquid cooling plate corresponds to the cell unit in contact with its upper and lower surfaces. In this application, the coolant in the liquid cooling plate is shunted through a plurality of liquid cooling circulation units, which can shorten the coolant circulation path, accelerate the coolant circulation, and at the same time make the coolant temperature difference smaller, improving the consistency of the cell temperature. Since the heat generated by the large surface of the cell is the highest, the cooling efficiency of the large surface of the cell is the highest. In this application, the large surface of the cell is pasted on the liquid cooling plate with a thermally conductive structural adhesive, with high heat dissipation efficiency and good effect. At the same time, different from the single-sided utilization of the liquid cooling plate, there are cells on both the upper and lower surfaces of this liquid cooling plate, and the liquid cooling plate can take away more heat and has a high utilization rate.

[0055] During the use of the cell, due to the change of the internal structure, the cell will undergo a certain degree of deformation. The bulging deformation will cause the pressure borne by the cell to change. Therefore, in some embodiments, a layer of elastic filler 4 is pasted between the cell and the lower box body and between the cell and the upper cover, so that one side of the large surface of each cell is evenly provided with an elastic filler, which can absorb the expansion and improve the cycle life of the cell. By using the elastic filler 4, the expansion force of the cell can be effectively absorbed, and the service life of the cell can be improved. The elastic filler 4 can be made of microporous foamed polypropylene MPP, PU foam, rubber, etc., and is in a sheet structure, and its size is adapted to the cell module in the battery pack.

[0056] In this application, the bus bar used to connect the battery cell module units adopts a series connection bar and also adopts a plug-in form to connect with the battery cells. It includes a first series connection bar 8 and a second series connection bar 9. The second series connection bar 9 is used for connecting the battery cell modules on the same layer, and the first series connection bar 8 is used for connecting the battery cell module units on different upper and lower layers. As Figure 8 shown, this Figure 8 shows the structure of the first series connection bar. When connecting the first series connection bar, only the first connection structure 81 and the second connection structure 82 of the bus bar need to be respectively plugged into the negative electrode posts 12 and the positive electrode posts 11 of two battery cells, and then the plug-in connection between the battery cell units can be completed. The structures of the first series connection bar 8 and the second series connection bar 9 are similar, except for the length and bending method, and the structure will not be elaborated here.

[0057] Among them, through the first plug-in structure 81 and the second plug-in structure 82, the connection with the electrode posts of the plugged-in battery cells is realized, forming a series structure of the battery cell module units. The structures of the first plug-in structure and the second plug-in structure are similar or the same as the first connection structure and the second connection structure of the aforementioned battery cell electrode posts, and are connected to the positive electrode post and the negative electrode post of the corresponding battery cell to be connected, which will not be elaborated here.

[0058] In this application, the bus bar in series between the battery cell module units adopts a plug-in form to connect with the battery cells, which can save welding costs, can save the investment in welding equipment and welding space, and can further reduce production costs and improve production efficiency.

[0059] The assembly process of the battery pack of this application is as follows:

[0060] When multiple assembled battery cell module units are connected to form a battery pack, first paste an elastic filler 4 on the lower box body, then stack the assembled battery cell module units on the first layer of the battery pack, apply a thermal conductive structural adhesive on the top of the battery cells of the module units on the first layer, then place the liquid cooling plate, and then apply a thermal conductive structural adhesive on the top of the liquid cooling plate, stack the upper layer of battery cell units, use the first series connection bar 8 and the second series connection bar 9 to connect the battery cell units in series to form a complete circuit path, then paste a layer of elastic filler 4 on the top of the upper layer of battery cell units, and finally install the upper cover.

[0061] The battery pack of the present utility model adopts the method of plugging the battery cell electrode posts, which saves the grouping space and improves the energy density of the power system; at the same time, since the connection between the battery cells and the connection of the flexible printed circuit board are not in the form of welding, the investment in welding equipment and welding labor is saved, and the production cost is further reduced.

[0062] The foregoing has shown and described the basic principles, main features and advantages of the present utility model. For those skilled in the art, it is obvious that the present utility model is not limited to the details of the above-mentioned exemplary embodiments, and without departing from the spirit or basic features of the present utility model, the present utility model can be implemented in other specific forms;

[0063] Therefore, from any point of view, the embodiments should be regarded as exemplary and non-restrictive. The scope of the present utility model is defined by the appended claims rather than the above description. Therefore, all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be embraced by the present utility model.

[0064] In addition, it should be understood that although this specification is described according to the embodiments, not every embodiment only contains an independent technical solution. This narrative way of the specification is only for clarity. Those skilled in the art should regard the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A plug-in battery cell, comprising a first pole and a second pole, wherein the first pole and the second pole have opposite polarities and are located at one end of the battery cell, characterized in that: The first pole and the second pole are both protrudingly arranged at one end of the battery cell, the first pole includes a first connection structure, and the second pole includes a second connection structure; the battery cells arranged relatively to each other on the pole sides can be plugged in and connected in series with the help of the first connection structure and the second connection structure; the first connection structure is a groove on the surface of the pole, and the second connection structure is a convex portion that can be plugged together and cooperates with the groove; when forming a battery cell module unit, the pole sides of the two plug-in battery cells are opposite, and the negative pole of one plug-in battery cell is plugged into the positive pole of the other plug-in battery cell to achieve the connection between the two plug-in battery cells.

2. The plug-in battery cell according to claim 1, characterized in that: The upper end of the groove has a limiting structure and the peripheral side of the limiting structure has an insertion opening. The second connecting structure is inserted into the groove through the insertion opening and is plug-assembled with the groove.

3. The plug-in battery cell according to claim 2, characterized in that: The convex portion includes a large-diameter upper portion and a small-diameter lower portion, and the inner diameter of the limiting structure at the upper end of the groove matches the small-diameter lower portion.

4. The plug-in battery cell according to claim 1, characterized in that: The first pole is a negative pole, and the second pole is a positive pole.

5. The plug-in battery cell according to claim 1, characterized in that: The first pole is a positive pole, and the second pole is a negative pole.

6. The plug-in battery cell according to claim 1, characterized in that: The plug-in battery cell is a square battery cell.

7. A battery cell module, characterized in that: A battery module unit comprising a plurality of plug-in battery cells as described in any one of claims 1 to 6 formed by plugging and assembling.

8. The battery cell module according to claim 7, characterized in that: It comprises a flexible printed circuit board, which is placed between the plug-in cells of the cell module unit, and the flexible printed circuit board comprises a plurality of buckles for being connected with the plug-in cell poles.

9. The battery cell module according to claim 8, characterized in that: It includes an exhaust channel between the plug-in cells of the battery module unit. The exhaust channel includes a main channel and an explosion-proof valve docking channel connected to the main channel. The explosion-proof valve docking channel includes exhaust holes that can correspond to the explosion-proof valve of each plug-in cell. One end of the exhaust channel is closed and the other end is an open structure.

10. A battery pack, characterized in that: The battery cell module comprises the battery cell module of any one of claims 7 to 9, wherein the battery cell module comprises at least two battery cell module units, a liquid cooling plate is arranged between the large surfaces of the batteries of the two battery cell module units, and elastic fillers are arranged on the inner surfaces of the upper cover and the lower box of the battery pack, and the elastic fillers are in contact with the large surfaces of the batteries of the battery cell module units; The liquid cooling plate and the battery module unit are connected via a heat-conducting structural adhesive; The liquid cooling plate includes a plurality of independently circulating liquid cooling circulation units, the upper and lower surfaces of each liquid cooling circulation unit respectively correspond to a battery module unit, each of the liquid cooling circulation units is arranged with a liquid inlet and a liquid outlet, and the plurality of liquid inlets and liquid outlets are arranged on the same side; It also includes a busbar that connects the battery module units in series; the busbar includes a plug-in structure that cooperates with the first pole and the second pole of the plug-in battery cell.

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