KR100658686B1 - Secondary battery module - Google Patents

Abstract

Provided is a secondary battery module which is reduced in the contact resistance between unit cells by improving the structure of a connection tool installed at an electrode terminal. The secondary battery module comprises a plurality of unit cells containing an electrode terminal(21); a connection tool(30) which connects the electrode terminals of the unit cells electrically and has a projected part(30a) formed on at least one surface; and a nut(26) which is connected with the electrode terminal to support the connection tool. Preferably the connection tool has a hole where the electrode terminal penetrates, at the front surface; and the projected part is formed at the surrounding of the hole.

Description

Secondary Battery Module {SECONDARY BATTERY MODULE}

1 is an exploded perspective view illustrating a configuration of a rechargeable battery module according to a first embodiment of the present invention.

2 is a cutaway perspective view illustrating a connector of a rechargeable battery module according to a first exemplary embodiment of the present invention.

3 is a partial cross-sectional view showing a state in which the connector is assembled in the unit cell according to the first embodiment of the present invention.

4 is a cutaway perspective view illustrating a connector of a rechargeable battery module according to a second exemplary embodiment of the present invention.

5 is a partial cross-sectional view showing a state in which the connector is assembled to the unit cell according to the second embodiment of the present invention.

6 is a perspective view illustrating a connector of a rechargeable battery module according to a third exemplary embodiment of the present invention.

The present invention relates to a secondary battery module. More particularly, the present invention relates to a secondary battery module capable of minimizing contact resistance in electrical connection between neighboring unit cells.

A secondary battery is a battery that can be charged and discharged unlike a primary battery that is not rechargeable. Low-capacity secondary batteries are used in portable electronic devices such as mobile phones, notebook computers, and camcorders, and large-capacity batteries are widely used as power sources for driving motors in hybrid vehicles.

Recently, a high output secondary battery using a high energy density nonaqueous electrolyte has been developed, and the high output secondary battery connects a plurality of batteries in series so as to be used for driving a motor such as an electric vehicle requiring a large power. It consists of a large capacity secondary battery.

In addition, one large-capacity secondary battery (hereinafter referred to as a battery module for convenience of description throughout) is composed of a plurality of secondary batteries (hereinafter referred to as unit cells for convenience of explanation throughout) in series.

Each of the unit cells has a case having an electrode group in which a positive electrode and a negative electrode are positioned with a separator interposed therebetween, and a case having a space in which the electrode group is built, and a cap having a through hole in which the case is sealed and an electrode terminal is inserted. A plate, an electrode terminal electrically connected to the electrode group and inserted into the through hole and including an anode terminal and a cathode terminal protruding out of the case, and a gasket inserted into the through hole to insulate the cap plate from the electrode terminal. do.

Here, the case is manufactured in various shapes, and typical shapes include cylindrical and rectangular shapes. And the rectangular battery is composed of a case of a hexahedral shape with one side opened, a cap plate blocking the opening and an electrode terminal provided on the cap plate. In addition, the positive electrode terminal and the negative electrode terminal are made of male threads, and nuts are fastened to the respective electrode terminals to fix the electrode terminals on the cap assembly.

Each of the unit cells is arranged so that the positive electrode terminal and the negative electrode terminal are crossed with the positive terminal and the negative terminal of the neighboring unit cell so as to be connected in series. The connector is inserted into the positive terminal of the unit cell of one side and the negative terminal of the neighboring unit cell, and the nut is fastened again on the connector so that the connector is stably fixed to the electrode terminal.

In addition, a washer is installed between the connector and the nut to improve the tightening force of the nut.

The electrode terminals of neighboring unit cells are electrically connected to neighboring unit cells through nuts, washers, and connectors.

However, this structure has a problem in that the contact resistance is increased by the non-uniform contact between the two members in contact with the washer and the connector. Although the surface is smoothly machined in appearance, microscopically there is a rugged surface, which causes both members to be in point contact. As such, when the washer and the connector make point contact, the contact area is small and the contact resistance is increased, and the output of the secondary battery module is lowered due to the resistance.

In particular, when the battery module is mounted on the device and used for a long time, the nut is loosened due to external vibration, and the contact resistance at the contact surface is further increased.

In addition, there is a problem that the contact resistance occurs as described above also in the contact with the nut and the washer.

In particular, in the case of a secondary battery module for a HEV (hybrid electric vehicle), the vibration of the battery module is continuously applied to the battery module as the vehicle travels, so that the nut is released, thereby increasing the contact resistance between the unit cells. In addition, in the HEV secondary battery module, since several tens of unit cells are connected in series, when a contact resistance occurs in a portion connecting the unit cells, there is a problem in that the output of the battery module is significantly reduced.

Therefore, the present invention has been made to solve the above problems, an object of the present invention is to provide a secondary battery module that can reduce the contact resistance by improving the structure of the connector installed in the electrode terminal.

In order to achieve the above object, a battery module according to the present invention includes a plurality of unit cells including an electrode terminal, a connector that electrically connects the electrode terminals of the unit cells and has a protrusion formed on at least one surface thereof, on the electrode terminal. It may include a nut that is fastened to support the connector.

The protrusion may be formed of a protrusion protruding outward from the surface of the connector, it may be formed by a groove formed inward on the surface of the connector.

Accordingly, when the connector is in contact with the nut, the protrusion formed on the connector is in contact with the nut with a smaller area, and when the same fastening pressure is applied, the contact pressure applied to the protrusion is increased, thereby reducing the contact resistance of both.

Here, the protrusion formed in the connector is preferably formed around the hole through which the electrode terminal passes.

The protrusion may be formed on one surface of the connector in contact with the nut, or may be formed on both sides of the connector.

The protruding portion may be formed with a sharp end in the form of a wedge.

In addition, the protrusion may be continuously formed along the hole of the connector.

In addition, the protrusion may be formed in a horn shape.

The protrusion may be pressed by the nut to be in close contact with the contact surface of the nut, and the protrusion may be further pressed by the nut to be installed to penetrate the surface of the nut.

In addition, the secondary battery module is an energy source for driving a motor of the device in a device that operates by using a motor such as a hybrid electric vehicle (HEV), an electric vehicle (EV), a wireless cleaner, an electric bicycle, an electric scooter, and the like. Can be used as

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is an exploded perspective view illustrating a rechargeable battery module according to a first embodiment of the present invention.

Referring to the drawings described above, the secondary battery module 100 according to the present embodiment includes a plurality of electrode terminals 21 and 22 including the positive terminal 21 and the negative terminal 22 protruding to the outside. The battery cell 11 and the electrode terminals 21 and 22 of the neighboring unit cell 10 are electrically disposed between the unit cell 10, the unit cells 10 to form a flow path of the heat transfer medium. It comprises a connector 30 for connecting, nuts 25 and 26 for fixing the connector 30.

The unit cell 10 according to the present embodiment has a rectangular shape and includes a case 15 accommodating an electrode group and a cap plate 17 enclosing the case 15. However, in the present embodiment, the rectangular battery is described as an example, but the present invention is not limited thereto, and the unit battery 10 may be formed in a cylindrical shape or other shape.

The cap plate 17 is provided with electrode terminals 21 and 22 protruding outwardly, and the electrode terminals 21 and 22 have threads formed on an outer circumferential surface thereof so that the nuts 25 and 26 can be fastened.

In addition, a gasket 23 is provided between the cap plate 17 and the electrode terminals 21 and 22 to insulate the cap plate 17 and the electrode terminals 21 and 22. The nut 25 is installed on the gasket 23 through the washers 31 so as to support the electrode terminals 21 and 22.

Each of the unit cells 10 constituting the battery module is arranged such that the positive electrode terminal 21 and the negative electrode terminal 22 of the neighboring unit cells 10 are crossed so that they can be connected in series. The connector 30 is provided between the positive electrode terminal 21 and the negative electrode terminal 22 of the unit cell 10 adjacent thereto.

And a nut 26 is installed on the upper portion of the connector 30 so that the connector 30 is fixed.

According to this embodiment, as shown in FIG. 2, at least one protrusion 30a is formed on a contact surface of the connection terminal 30 in contact with the nut 25.

The protrusion 30a according to the present embodiment is formed in a wedge shape so that when the nut 26 is tightened, it is pressed by the nut 26 to dig into the surface of the nut 25. However, the shape of the protrusion 30a is only one example of the present embodiment, and the present invention is not limited thereto.

Looking at the connector 30 in more detail, as shown in Figure 2, the connector 30 is formed with a hole (30b) formed in the center so that the electrode terminal 21 is fitted, the projection (30a) ) Is formed continuously in a circle around the hole (30b) to form a round band.

Such strip-shaped protrusions 30a are continuously arranged along the outer side of the hole 30b. The number of the protrusions may vary depending on the size of the protrusions, and is preferably formed only on the contact surface with the nut 25.

In addition, the protrusion (30a) is made of a triangular cross-section of the end pointed toward the outside so as to be able to more easily penetrate into the surface of the nut 25 when the nut 26 is pressed.

Accordingly, as shown in FIG. 3, when the connector 30 connects the electrode terminals 21 of the unit cells 11 through the nut 26, the connector 30 is pressurized by the nut 26. When it is in close contact with the nut 25, the pressure is concentrated in the projection 30a of the connector 30 to dig the surface of the nut 25. In this way, the nut 25 and the connector 30 is in a substantial and reliable contact. Therefore, the current can flow freely through the portion making the surface contact, the contact resistance can be minimized.

4 and 5 illustrate a state in which the connector and the connector of the secondary battery module according to the second embodiment are assembled to the unit cell.

According to the above drawings, the unit battery according to the present embodiment is the cap plate 47 which seals the case 44 and the case 44 in the same way as the unit cell of the first embodiment, and to the outside of the cap plate 47. It includes a protruding electrode terminal 21.

The electrode terminal 21 is provided with a connector 40 for electrically connecting the electrode terminals 21 of neighboring unit cells. And nuts 45 and 46 for supporting the connector 40 are installed on the upper and lower portions of the connector 40.

Here, the connector 40 has a hole 40b formed therein so that the electrode terminal 21 penetrates in the center thereof, and protrusions 40a are formed around both sides of the connector 40b.

The protrusion 40a is formed continuously in a circle around the hole 30b to form a round band.

Such strip-shaped protrusions 30a are continuously arranged along the outer side of the hole 30b. The number of the protrusions may vary depending on the size of the protrusions, and is preferably formed only at the contact surface with the nut 45.

In addition, the protrusion (30a) is made in the form of a triangular cross-section pointed toward the outside so that the nut 46 is easier to dig into the surface of the nut 45 when pressed.

Therefore, when the connector 40 is pressed by the nut 46, the protrusion 40a is in close contact with the nut 45. When the connector 40 is further pressed by the nut 46, pressure is concentrated on the protrusion 40a to dig into the surfaces of the nuts 45 and 46.

Therefore, in the portion in which the protrusion 40a is formed, the connector 40 is surely in contact with the nuts 45 and 46, thereby minimizing the contact resistance generated at the contact surface of these members.

5 is a perspective view showing a connector according to a third embodiment of the present invention.

In the secondary battery module according to the present embodiment, all of the structures except for the connector 50 have the same structure as that of the battery module according to the first or second embodiment.

In addition, the connector 50 has a hole 50b in which the electrode terminal 21 is inserted in the center thereof, and a minute protrusion 50a having a horn shape is formed on the surface of the connector 50 along the periphery of the hole 50b. do.

Although the protrusion 50a is illustrated as having a conical shape in FIG. 5, this is only an example of the present embodiment, and the present invention is not limited thereto. Therefore, the protrusion 50a may be formed in various forms such as cones, square pyramids, and triangular pyramids.

In addition, the protrusion 50a may be formed only on one surface of the connector 30 and may be formed on both surfaces.

As the minute projection 50a is formed in the connector 50 as described above, when the connector 50 is pressurized by a nut (see 26 in FIG. 1), the protrusions 50a have a higher pressure on the neighboring member. In close contact with each other, the intimate contact with the neighboring member is in surface contact with each other. In addition, when the connector 50 is further pressurized by a nut, the protrusion 50a penetrates the surface of the member which is in surface contact, and thus these members may be more in surface contact.

The secondary battery module of the present invention is an energy source for driving a motor of the device in a device that operates using a motor, such as a hybrid electric vehicle (HEV), an electric vehicle (EV), a wireless cleaner, an electric bicycle, an electric scooter, and the like. Can be used as.

Although the preferred embodiments of the present invention have been described above, the present invention is not limited thereto, and various modifications and changes can be made within the scope of the claims and the detailed description of the invention and the accompanying drawings. Naturally, it belongs to

As described above, according to the exemplary embodiment of the present invention, the electrical resistance between the unit cells may be reduced to maximize the performance of the battery module.

Claims (10)

A plurality of unit cells including electrode terminals; A connector electrically connecting electrode terminals of the unit cells and having protrusions formed on at least one surface thereof; A nut fastened to the electrode terminal to support the connector Secondary battery module comprising a. According to claim 1, The connector has a hole in the electrode terminal penetrates the front surface, the protrusion is formed around the hole secondary battery module. The method according to claim 1 or 2, The protrusion is a secondary battery module consisting of a protrusion protruding outward. The method according to claim 1 or 2, The protrusion is a secondary battery module formed by a groove formed in the connector. According to claim 1, The protrusion is formed on both sides of the connector. According to claim 1, The protrusion is a secondary battery module having a sharp end. According to claim 1, The protruding portion is continuously formed along the periphery of the electrode terminal through hole formed in the connector. According to claim 1, The protrusion is a secondary battery module is formed in a horn shape. According to claim 1, The protrusion is pressed by the nut to the secondary battery module to dig the surface of the nut. According to claim 1, The secondary battery module is a secondary battery module for driving a motor.

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