CN218334206U

CN218334206U - Connecting device, battery module and electric vehicle

Info

Publication number: CN218334206U
Application number: CN202222397497.8U
Authority: CN
Inventors: 阮祖云; 曾勇; 许炳; 华超; 李德壮
Original assignee: GAC Aion New Energy Automobile Co Ltd
Current assignee: GAC Aion New Energy Automobile Co Ltd
Priority date: 2022-09-08
Filing date: 2022-09-08
Publication date: 2023-01-17
Anticipated expiration: 2032-09-08

Abstract

The application relates to a connecting device, a battery module and an electric vehicle. Connecting device is laminated structure spare for the first electric core of series connection and second electric core, connecting device includes: the conductive electrode column comprises a first cover plate, a first insulating layer and a second cover plate which are arranged in a stacked mode; the conductive electrode column sequentially penetrates through the first cover plate, the first insulating layer and the second cover plate, so that the first end of the conductive electrode column is located on the first cover plate, and the second end of the conductive electrode column is located on the second cover plate; the first end is used for being electrically connected with a positive lug of the first battery cell, and the first cover plate is electrically connected with the conductive pole column; the second end of the second cover plate is electrically connected with a negative pole lug of a second battery cell, and the second cover plate is in insulated connection with the conductive pole column; the first cover plate is used for being connected with a shell of a first battery cell, and the second cover plate is used for being connected with a shell of a second battery cell. In the connection device provided by the above technical scheme, the conductive electrode column is used for realizing the electrical connection between the positive electrode lug and the negative electrode lug in the two battery cells, and realizing the series connection of the first battery cell and the second battery cell.

Description

Connecting device, battery module and electric vehicle

Technical Field

The application relates to a battery structure, in particular to a connecting device, a battery module and an electric vehicle.

Background

The blade batteries used at present include long blade batteries up to 1m in length and short blade batteries of type L600, which are only about 0.6m in length.

The short blade battery is shorter than the long blade battery, and the number of the short blade batteries arranged in the vehicle body is larger, and accordingly, the number of the bus bars used for connection is increased, and the bus bars occupy the space of the vehicle body, resulting in a reduction in space utilization. But the short-knife battery has smaller length, small production difficulty and low manufacturing cost.

SUMMERY OF THE UTILITY MODEL

It is an object of the present application to provide a connection device that can be used to connect a short blade battery.

Another object of the present application is to provide a battery module, which can reduce the production cost of the battery.

It is another object of the present application to provide an electric vehicle for reducing the production cost of the electric vehicle.

The technical scheme adopted by the application for realizing one purpose is as follows:

a connection device, the connection device being a layered structure for connecting a first cell in series with a second cell, the connection device comprising: the conductive electrode column comprises a first cover plate, a first insulating layer and a second cover plate which are arranged in a stacked mode; the conductive electrode column sequentially penetrates through the first cover plate, the first insulating layer and the second cover plate, so that the first end of the conductive electrode column is located on the first cover plate, and the second end of the conductive electrode column is located on the second cover plate; the first end is used for being electrically connected with a positive lug of the first battery cell, and the first cover plate is electrically connected with the conductive pole column; the second end is used for being electrically connected with a negative electrode tab of the second battery cell, and the second cover plate is in insulation connection with the conductive electrode post; the first cover plate is used for being connected with a shell of the first battery cell, and the second cover plate is used for being connected with a shell of the second battery cell.

In the connection device provided by the above technical scheme, the conductive pole column is used for realizing the electrical connection between the positive pole lug and the negative pole lug in the two battery cells, and realizing the series connection of the first battery cell and the second battery cell. The connecting device provided by the technical scheme can realize the connection of the short battery cell to the long battery cell. And because the first cover plate is connected with the positive lug of the battery cell and is connected with the shell of the battery cell, the shell of the battery cell can have a certain potential, and the shell is prevented from being corroded.

Furthermore, the first cover plate and the second cover plate are both metal structural members, and gaps are formed between the first cover plate and the conductive electrode column and between the second cover plate and the conductive electrode column;

the connecting device also comprises a positive pole column cover plate and a negative pole column cover plate which are both metal structural parts;

the positive pole cover plate is positioned on one side, away from the second cover plate, of the first cover plate and is in contact connection with the first end of the conductive pole; a conductive plastic layer is arranged between the positive post cover plate and the first cover plate;

the negative pole column cover plate is located one side, far away from the first cover plate, of the second cover plate and is in contact connection with the second end of the conducting electrode column, and a second insulating layer is arranged between the negative pole column cover plate and the second cover plate.

Among the above-mentioned technical scheme, can reduce the electric potential with the casing of first apron connection through setting up electrically conductive plastic layer, avoid leading to electrolyte to decompose because of the electric potential of casing is too high. Through setting up the second insulating layer, can avoid conductive electrode post and second apron to be connected. Through setting up anodal post apron and negative pole post apron, can improve connecting device surface conducting material's area, be convenient for realize being connected with the electricity of electricity core.

Furthermore, one end of the conductive pole penetrates through the positive pole cover plate, and the other end of the pole penetrates through the negative pole cover plate;

and the two ends of the conductive electrode post are respectively provided with a flange structure, and the outer side surface of the positive electrode post cover plate and the outer side surface of the negative electrode post cover plate are respectively provided with a groove structure matched with the flange structures.

The positioning and fixing of the conductive electrode column in the thickness direction of the connecting device can be realized through the flange structures at the two ends of the conductive electrode column and the groove structures on the outer side surfaces of the cover plates of the positive electrode column and the negative electrode column.

Further, the conductive plastic layer is provided with a first positioning structure for positioning the positive pole cover plate; the second insulating layer is provided with a second positioning structure for positioning the negative pole column cover plate.

Furthermore, sealing rings are arranged between the conductive plastic layer and the conductive electrode posts and between the second insulating layer and the conductive electrode posts.

The water can be prevented from passing through by arranging the sealing ring.

Furthermore, the first insulating layer is a plastic structural member, bosses are arranged on the upper side and the lower side of the first insulating layer, flanges are arranged at the tops of the bosses, and the first cover plate and the second cover plate are provided with groove structures matched with the bosses.

Furthermore, the positive pole cover plate and the negative pole cover plate are both connected with a patch, the patch is a metal structural member, and the patch is used for being electrically connected with a pole lug.

The second purpose of the application is realized by adopting the following technical scheme:

a battery module comprises a first battery cell, a second battery cell and the connecting device arranged between the first battery cell and the second battery cell, wherein the first battery cell comprises a first shell and a first electrode assembly positioned in the first shell, and the first electrode assembly is provided with a positive electrode lug; the second cell comprises a second casing and a second electrode assembly positioned in the second casing, wherein the second electrode assembly is provided with a negative electrode lug;

one end of the first shell, which is close to the positive lug, is connected with the first cover plate, and the positive lug is electrically connected with the first end of the conductive pole; one end of the second shell, close to the negative electrode lug, is connected with the second cover plate, and the negative electrode lug is electrically connected with the second end of the conductive electrode post.

By adopting the technical scheme, the two short-knife batteries can be connected into the long-knife battery by adopting the connecting device, so that the cost for producing the long-knife battery is reduced.

Further, an explosion-proof valve is arranged on the first shell and/or the second shell.

The technical scheme adopted by the application to achieve the third purpose is as follows:

an electric vehicle comprises the battery module.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings that are required to be used in the embodiments will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present application and therefore should not be considered as limiting the scope, and for those skilled in the art, other related drawings can be obtained from the drawings without inventive effort.

Fig. 1 is a schematic structural diagram of a connection device according to an embodiment of the present disclosure;

FIG. 2 is a top view of FIG. 1;

FIG. 3 isbase:Sub>A cross-sectional view A-A of FIG. 2;

FIG. 4 is one of the schematic views illustrating the installation of the first cover plate, the second cover plate and the first insulating layer;

FIG. 5 is a cross-sectional view taken along line B-B of FIG. 4;

fig. 6 is a schematic structural diagram of a first insulating layer according to an embodiment of the present disclosure;

fig. 7 is a schematic structural diagram of an interposer provided in an embodiment of the present application;

fig. 8 is a schematic view illustrating an electrical connection between a connection device and a battery cell according to an embodiment of the present disclosure;

fig. 9 is a schematic view illustrating a connection between the connection device and an electrical housing according to an embodiment of the disclosure.

Icon: 100-a connecting means; 110-conducting electrode pillars; 120-a first cover plate; 130-a first insulating layer; 140-a second cover plate; 150-positive post cover plate; 160-negative pole post cover plate; 170-conductive plastic layer; 180-a second insulating layer; 190-sealing ring; 200-an adaptor sheet; 310-a first cell; 320-second cell.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. It is to be understood that the embodiments described are only a few embodiments of the present application and not all embodiments. The components of the embodiments of the present application, generally described and illustrated in the figures herein, can be arranged and designed in a wide variety of different configurations.

In the description of the present application, it should be noted that the terms "inside", "outside", and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings or orientations or positional relationships that the products of the application usually place when using, and are only used for convenience in describing the present application and simplifying the description, but do not indicate or imply that the devices or elements that are referred to must have a specific orientation, be constructed in a specific orientation, and operate, and thus, should not be construed as limiting the present application. Furthermore, the terms "first," "second," and the like are used solely to distinguish one from another, and are not to be construed as indicating or implying relative importance.

In the description of the present application, it is also to be noted that, unless otherwise explicitly specified or limited, the terms "disposed" and "connected" are to be interpreted broadly, e.g., as being either fixedly connected, detachably connected, or integrally connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meaning of the above terms in this application will be understood to be a specific case for those of ordinary skill in the art.

At present, in practical application, the short-blade batteries are connected in the vehicle through the bus bars, and the occupied space is large, so that the inventor of the application provides the connecting device 100 which can be used for connecting the short-blade batteries more compactly, and the space is saved; by adopting the connecting device 100 provided by the technical scheme, the existing short-knife batteries can be connected into the long-knife batteries, so that the manufacturing cost of the long-knife batteries is reduced.

The connecting device 100 provided by the present application is a layered structure, as shown in fig. 1 to fig. 3, and includes a conductive electrode pillar 110, the conductive electrode pillar 110 may be a metal structure, and a first cover plate 120, a first insulating layer 130 and a second cover plate 140 which are stacked, wherein the first insulating layer 130 is disposed between the first cover plate 120 and the second cover plate 140. The first cover plate 120 and the second cover plate 140 are respectively used for connecting with the casings of the first battery cell 310 and the second battery cell 320. The conductive electrode pillar 110 sequentially penetrates through the first cover plate 120, the first insulating layer 130 and the second cover plate 140 in the thickness direction of the connecting device 100. One end of the conductive electrode pillar 110 located on the first cover plate 120 is a first end, and the first end is used for electrically connecting with the positive tab of the first battery cell 310; one end of the conductive electrode pillar 110 located on the second cover plate 140 is a second end, and the second end is used for electrically connecting with the negative electrode tab of the second battery cell 320. The electrically conductive electrode posts 110 in the above technical solution can realize the electrical connection between the first battery cell 310 and the second battery cell 320, and the first cover plate 120 and the second cover plate 140 can realize the structural connection between the first battery cell 310 and the second battery cell 320.

In practical use, the casing of the battery cell is often provided with a positive potential to prevent the casing from being corroded, and therefore, in the embodiment of the present application, the first cover plate 120 is a conductive structural member, and the first cover plate 120 is electrically connected to the first end of the conductive electrode pillar 110, so that after the connection device 100 provided by the present application is connected to the first battery cell 310, the casing of the first battery cell 310 has a positive potential; of course, the positive potential of the housing cannot be too high, otherwise oxidative decomposition of the electrolyte would result. Therefore, in the embodiment of the present application, a conductive plastic layer 170 is further disposed between the conductive electrode post 110 and the first cover plate 120, and the conductive plastic layer 170 is a plastic structural member added with a conductive material, and has a relatively large resistance, so that the positive potential on the surface of the casing of the first battery cell 310 can be reduced.

Since the first cover plate 120 is a metal structural member, the first cover plate 120 and the first battery cell 310 may be connected by welding, so as to ensure the reliability of the connection and the sealing performance of the first battery cell 310.

In other embodiments, if the first cover plate 120 is made of a conductive plastic structure, the first cover plate 120 and the first battery cell 310 may be connected by a snap-fit connection, and a sealing measure is preferably applied to the connection.

Correspondingly, in practical applications, the housing of the second battery cell 320 should also have a certain positive potential, and after the connection device 100 provided in the present application is installed on the second battery cell 320, conduction between the positive electrode and the negative electrode of the second battery cell 320 should be avoided. In some embodiments, the second cover plate 140 is made of a metal material, and insulation processing is performed between the second cover plate 140 and the conductive electrode column 110, so that electrical connection between the conductive electrode column 110 and the casing of the second battery cell 320 can be avoided, and further, mutual conduction between the positive electrode and the negative electrode of the second battery cell 320 and short circuit can be avoided. The specific method includes disposing the second insulating layer 180 between the second cover plate 140 and the conductive post 110, or providing a gap between the second cover plate 140 and the conductive post 110 to prevent the second cover plate 140 and the conductive post 110 from being electrically connected. The second cover plate 140 made of metal can facilitate the welding connection with the casing of the second battery cell 320, and improve the reliability of the connection and the sealing performance of the second battery cell 320.

In other embodiments, the second cover plate 140 may also be made of an insulating material, so as to prevent conduction between the positive electrode and the negative electrode of the second battery cell 320. Likewise, the second cover plate 140 may be connected to the housing by means of a snap-fit connection or the like, and a sealing measure may be applied thereto.

In a preferred embodiment of the present application, an interposer 200 electrically connected to the conductive electrode pillar 110 is disposed on both a side of the first cover plate 120 away from the second cover plate 140 and a side of the second cover plate 140 away from the first cover plate 120, and the interposer 200 is a conductive structural member. Specifically, the conductive plastic layer 170 is located between the interposer 200 and the first cover plate 120; the second insulating layer 180 is located between the interposer 200 and the second cover plate 140. Interposer 200 may be a metal structure, and interposer 200 is welded to conductive post 110. Exemplarily, as shown in fig. 7, the interposer 200 includes a bottom plate and two side plates that are vertically disposed on the same side of the bottom plate and are parallel to each other, and the two side plates and the bottom plate form a slot body adapted to the battery cell tabs, so that the tabs of the first battery cell 310 and the second battery cell 320 can contact with the two side plates of the interposer 200 when located in the slot body, thereby implementing the electrical connection between the positive tab of the first battery cell 310 and the conductive electrode post 110, and the electrical connection between the negative tab of the second battery cell 320 and the conductive electrode post 110, that is, implementing the series connection between the first battery cell 310 and the second battery cell 320 through the connection device 100 provided in the present application.

Because the conductive electrode post 110 is limited in size, the welding operation of the conductive electrode post 110 and the adaptor sheet 200 is inconvenient, and the reliability after welding is low, in order to provide a positive electrode post cover plate 150 made of a metal material between the conductive plastic layer 170 and the first adaptor sheet 200 (not shown in the figure) in some embodiments, as shown in fig. 3, the positive electrode post cover plate 150 is electrically connected to the first end of the conductive electrode post 110, and the positive electrode post cover plate 150 is welded to the first adaptor sheet 200; a negative pole cover plate 160 made of a metal material is disposed between the second insulating layer 180 and the second interposer 200 (not shown in the figure), the negative pole cover plate 160 is electrically connected to the second end of the conductive pole 110, and the negative pole cover plate 160 is welded to the second interposer 200. The first interposer 200 is an interposer 200 located on one side of the first cover plate 120, and the second interposer 200 is an interposer 200 located on one side of the second cover plate 140. The positive post cover plate 150 and the negative post cover plate 160 are both welded to the conductive post 110.

In order to ensure the connection reliability, the positive post cover plate 150 and the negative post cover plate 160 are both welded to the conductive post 110, and for convenience of operation, a flange structure shown in fig. 3 may be formed at the first end and the second end of the conductive post 110 by riveting, so as to achieve the initial connection between the conductive post 110 and the positive post cover plate 150 and the negative post cover plate 160, and then welding is performed. Correspondingly, the positive pole cover plate 150 and the negative pole cover plate 160 are provided with groove structures matched with the flange structures for accommodating the flange structures, so as to avoid the interference between the flange structures on the conductive pole 110 and the adaptor plate 200.

In the present application, the structure of the conductive electrode column 110 is not limited, and when the conductive electrode column 110 has a cylindrical structure, the positive electrode column cover plate 150 and the negative electrode column cover plate 160 may rotate around the conductive electrode column 110 during the installation process. Accordingly, a positioning structure may be disposed on the conductive plastic layer 170 and the second insulating layer 180. For example, as shown in fig. 1 and fig. 2, the positioning structure may be a rib-shaped structure, and the positive post cover plate 150 and the negative post cover plate 160 are embedded in the positioning structure.

In the connection device 100 provided by the present application, the first insulating layer 130 mainly plays an insulating role between the first cover plate 120 and the second cover plate 140, and the first insulating layer 130 may be a plastic structural member, and is connected with the first cover plate 120 and the second cover plate 140 by adhesion, or may be only an insulating material for adhesion coated between the first cover plate 120 and the second cover plate 140.

Since the connection device 100 provided by the present application is used to connect electrical cores, one of application scenarios of the connected electrical cores is an electric vehicle, and there is a shake in the driving process of the vehicle, in order to improve the connection reliability of the first cover plate 120 and the second cover plate 140, the first insulation layer 130 which is a plastic structural member may be adopted, and two side surfaces of the first insulation layer 130, which are used to contact the first cover plate 120 and the second cover plate 140, are both provided with boss structures having flanges, as shown in fig. 5 and 6, correspondingly, the first cover plate 120 and the second cover plate 140 are provided with groove structures adapted to achieve a firmer connection. The connection manner may be implemented by using the first cover plate 120 and the second cover plate 140 made of metal materials and the first insulating layer 130 injection-molded between the first cover plate 120 and the second cover plate 140.

The present application further provides a battery module, which includes a first battery cell 310 and a second battery cell 320 connected by the above connection device 100, where the first battery cell 310 includes a first casing and a first electrode assembly, such as an electrode coil and an electrolyte, located inside the first casing; the second cell 320 includes a second casing and a second electrode assembly located inside the second casing. One end of the first casing close to the positive tab of the first electrical core 310 is connected to the first cover plate 120 in the connection device 100, and after the first cover plate 120 is covered on the first casing, the first cover plate 120 is welded to the first casing along a seam of the first cover plate 120. One end of the second casing close to the negative tab of the second cell 320 is connected to the second cover plate 140 in the connection device 100. The positive tab in the first cell 310 is electrically connected to the first end of the conductive pole 110 in the connection device 100; the negative tab of the second cell 320 is electrically connected to the second end of the conductive post 110 of the connection device 100.

In the battery module that this application provided, also can include the electric core of three and above quantity, connect through connecting device 100 between the two adjacent electric cores, the explosion-proof valve that is located middle electric core sets up on the casing.

For example, as shown in fig. 8, the connection device 100 is connected to the positive tab in the first battery cell 310 and the negative tab in the second battery cell 320 through two adapter sheets 200, as shown in fig. 9, the first cover plate 120 and the second cover plate 140 in the connection device 100 are connected to the casings of the first battery cell 310 and the second battery cell 320, respectively.

The application also provides an electric vehicle which comprises the battery module provided in the embodiment.

Example 1

A connecting device 100, as shown in fig. 1 to 7, includes a positive post cover plate 150, a conductive plastic layer 170, a first cover plate 120, a first insulating layer 130, a second cover plate 140, a second insulating layer 180, a negative post cover plate 160, and a conductive post 110 penetrating the above structure in a thickness direction. The positive post cover plate 150, the first cover plate 120, the second cover plate 140, the negative post cover plate 160, and the conductive post 110 are all metal structural members, and the first insulating layer 130 and the second insulating layer 180 are all plastic structural members.

The conductive plastic layer 170, the first cover plate 120, the first insulating layer 130, the second cover plate 140 and the second insulating layer 180 have a gap with the conductive electrode column 110 in the radial direction of the conductive electrode column 110. Sealing rings 190 are disposed between the conductive plastic layer 170 and the conductive electrode column 110, between the first cover plate 120 and the conductive electrode column 110, between the second insulating layer 180 and the conductive electrode column 110, and between the second cover plate 140 and the conductive electrode column 110, so as to prevent water from entering the battery cell through the plastic conductive plastic layer 170, the second insulating layer 180, and the first insulating layer 130.

The lateral surface of positive post apron 150 is provided with groove structure, the first end of leading electrode post 110 through form after the riveting with the flange structure of this groove structure adaptation, still carry out welded connection to leading electrode post 110 and positive post apron 150 through the mode of laser beam welding along this groove structure and the seam of this flange structure. Similarly, the negative electrode pillar cover 160 is also connected by a groove structure and a flange at the second end of the conductive electrode pillar 110, and is connected by laser welding.

The surface of the first cover plate 120 for contacting the conductive plastic layer 170 is provided with an annular protrusion, and the annular protrusion and the surface of the first cover plate 120 form a step surface for matching with the housing of the battery cell and a groove body for accommodating the conductive plastic layer 170. As shown in fig. 6, a bump structure having a flange at the top is provided on the upper and lower surfaces of the first insulating layer 130. A groove structure is disposed on a surface of the first cover plate 120, which is in contact with the first insulating layer 130, and the groove structure is adapted to the protrusion structure on the upper surface of the first insulating layer 130 and has a one-to-one position. Similarly, the second cover plate 140 is also provided with an annular protrusion, which forms a step surface adapted to the case of the battery cell and a groove for accommodating the second insulating layer 180 with the surface of the second cover plate 140.

The surfaces of the positive pole cover plate 150 and the negative pole cover plate 160 are respectively welded with a first adapter sheet 200 and a second adapter sheet 200 which have the same structure.

When the connecting device 100 provided in the above embodiment is used, the adaptor sheet 200 is welded to the tab of the battery cell, and then the first cover plate 120 and the second cover plate 140 are fitted to the casing of the battery cell and welded.

It should be noted that the features of the embodiments in the present application may be combined with each other without conflict.

The above description is only a preferred embodiment of the present application and is not intended to limit the present application, and various modifications and changes may be made to the present application by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A connecting device, wherein the connecting device is a layered structure configured to connect a first electrical core and a second electrical core in series, and the connecting device comprises: the conductive electrode column comprises a first cover plate, a first insulating layer and a second cover plate which are arranged in a stacked mode; the conductive electrode column sequentially penetrates through the first cover plate, the first insulating layer and the second cover plate, so that the first end of the conductive electrode column is located on the first cover plate, and the second end of the conductive electrode column is located on the second cover plate; the first end is used for being electrically connected with a positive lug of the first battery cell, and the first cover plate is electrically connected with the conductive pole column; the second end is used for being electrically connected with the negative electrode tab of the second battery cell, and the second cover plate is in insulation connection with the conductive electrode column; the first cover plate is used for being connected with a shell of the first battery cell, and the second cover plate is used for being connected with a shell of the second battery cell.

2. The connecting device according to claim 1, wherein the first cover plate and the second cover plate are both metal structural members, and gaps are provided between the first cover plate and the conductive electrode column and between the second cover plate and the conductive electrode column;

the connecting device also comprises a positive pole column cover plate and a negative pole column cover plate which are both metal structural members;

the positive pole cover plate is positioned on one side of the first cover plate, which is far away from the second cover plate, and is in contact connection with the first end of the conductive pole; a conductive plastic layer is arranged between the positive post cover plate and the first cover plate;

3. A connecting device according to claim 2, wherein one end of the conductive post extends through the positive post cover plate and the other end of the conductive post extends through the negative post cover plate;

4. A connecting device according to claim 3, wherein the conductive plastic layer is provided with a first positioning structure for positioning the positive post cover plate; the second insulating layer is provided with a second positioning structure for positioning the negative pole column cover plate.

5. A connecting device according to claim 2, wherein sealing rings are provided between the conductive plastic layer and the conductive electrode pillar and between the second insulating layer and the conductive electrode pillar.

6. The connecting device according to claim 2, wherein the first insulating layer is a plastic structural member, bosses are disposed on both upper and lower sides of the first insulating layer, a flange is disposed on a top of each boss, and the first cover plate and the second cover plate are each provided with a groove structure engaged with the boss.

7. A connecting device according to any one of claims 2 to 6, wherein the positive pole cover plate and the negative pole cover plate are both connected with an adapter plate, the adapter plate is a metal structural member, and the adapter plate is used for electrically connecting with a pole lug.

8. A battery module comprising a first cell, a second cell, and the connection device of any one of claims 1 to 7 disposed between the first cell and the second cell, wherein the first cell comprises a first housing and a first electrode assembly located in the first housing, and the first electrode assembly has a positive electrode tab; the second cell comprises a second casing and a second electrode assembly positioned in the second casing, wherein the second electrode assembly is provided with a negative electrode lug;

9. The battery module according to claim 8, wherein an explosion-proof valve is provided on the first housing and/or the second housing.

10. An electric vehicle comprising the battery module according to claim 8 or 9.