CN209981419U - Battery module - Google Patents

Abstract

The utility model provides a battery module, which can easily prevent unevenness of path resistance in each connection path. The path resistance is a plurality of connections that electrically connect electrode terminals of a plurality of stacked battery cells and a voltage detection portion Path resistance of the path. The battery module (1) includes: a plurality of stacked battery cells (2); and a voltage detection unit (5), which is arranged on the outer surface of the plurality of stacked battery cells (2) and is connected to electrodes of the battery cells (2) terminals (21, 22) for voltage detection of the battery cells (2), wherein the connection paths between the electrode terminals (21, 22) of some of the battery cells (2) and the voltage detection unit (5) include a fixed pattern In the connection circuit (6), the electrode terminals (21, 22) of all the battery cells (2) are electrically connected to the voltage detection part (5) using the connection circuit (6) of the same pattern.

Description

battery module

technical field

The utility model relates to a battery module stacked with a plurality of battery cells.

Background technique

A hybrid car or an electric car is equipped with a battery module formed by stacking a plurality of battery cells such as a lithium ion secondary battery. Conventionally, as such a battery module, it is known to detect the voltage of the battery cell by a voltage detection unit, monitor the remaining capacity of the battery cell, and control the charge and discharge of the battery cell (for example, refer to Patent Document 1).

[Prior Art Literature]

[Patent Literature]

Patent Document 1: Japanese Patent Laid-Open No. 2010-137807

Utility model content

[The problem to be solved by the utility model]

The voltage detection unit includes a plurality of electronic components, and adopts a housing structure in which these are accommodated in a single housing. Generally, such a voltage detection part is electrically connected to the electrode terminal of a battery cell through a wire harness. At this time, if there are the electrode terminals of the battery cells that are close to the voltage detection unit and the electrode terminals of the distant battery cells, the connection path between the electrode terminals and the voltage detection unit is electrically connected according to the distance between the electrode terminals and the voltage detection unit. The lengths of the (wiring harnesses) are different, so that there is a problem of uneven path resistance for each connection path. If the path resistances are not uniform, errors may occur in the detection values, resulting in a decrease in detection accuracy. In addition, when constructing a battery module, it is necessary to prepare a variety of wire harnesses with different lengths, so there is a problem that the number of parts to be managed is large, resulting in an increase in cost.

Therefore, an object of the present invention is to provide a battery module capable of preventing unevenness in each connection path of a path resistance that electrically connects electrode terminals of a plurality of stacked battery cells to a voltage detection unit The path resistance of multiple connection paths can be reduced, and the cost can be reduced.

[Technical means to solve the problem]

(1) A battery module (for example, a battery module described later) of the present invention includes: a plurality of stacked battery cells (for example, a battery cell described later); and a voltage detection unit (for example, a voltage detection unit described later), which is arranged in The outer surfaces of the plurality of stacked battery cells are connected to electrode terminals of the battery cells (for example, a positive electrode terminal and a negative electrode terminal to be described later), whereby the voltage detection of the battery cells is performed, and a part of the battery cells are detected. The connection path between the electrode terminals of the battery cells and the voltage detection unit includes a connection circuit having a fixed pattern (for example, a connection circuit to be described later), and the electrode terminals of all the battery cells use the same pattern. The circuit is connected to be electrically connected to the voltage detection unit.

According to the battery module according to (1), since all the electrode terminals of the plurality of stacked battery cells and the voltage detection unit are electrically connected by the connection circuit of the same pattern, it is possible to easily prevent path resistance from occurring in each connection path uneven. In addition, since a plurality of connection circuits are shared by the same pattern, the number of parts to be managed can be reduced, and cost reduction can be achieved.

(2) In the battery module according to (1), preferably, the voltage detection portion has a flat shape extending over the entire stacking direction of the battery cells.

According to the battery module according to the above (2), the protrusion amount of the voltage detection portion from the outer surface of the plurality of stacked battery cells is suppressed, so that the height dimension of the battery module is suppressed, and the electrode terminals of each battery cell can be The connection path with the voltage detection unit is shared by the shortest path.

(3) In the battery module according to (1) or (2), it is preferable that the battery cells have a plurality of terminal surfaces having the electrode terminals (for example, terminal surfaces described later) on the same surface. The voltage detection part is arranged on the terminal surface between the positive and negative electrode terminals of each battery cell, and the connection circuit spans the voltage detection part. The side surface (for example, the side surface mentioned later) which opposes the said electrode terminal is provided with the said electrode terminal.

According to the battery module according to (3), since the connection circuit is arranged from the side surface of the voltage detection portion toward each electrode terminal, the connection circuit does not protrude above the voltage detection portion, and the connection circuit is not connected to the voltage The height dimension of the battery module increases due to the detection portion.

(4) In the battery module according to (1) or (2), it is preferable that the connection circuit has a bus bar portion (for example, described later) that electrically connects the electrode terminals of the adjacent battery cells to each other. the busbar part), and a connection part (eg, a connection part described later) that electrically connects the busbar part and the voltage detection part, at least the connection part of the busbar part and the connection part is made of flexible A printed circuit board (for example, a flexible printed circuit board to be described later) is formed.

(5) In the battery module according to (3), it is preferable that the connection circuit has a bus bar portion (for example, a bus bar portion described later) that electrically connects the electrode terminals of the adjacent battery cells to each other. , and a connecting portion (for example, a connecting portion described later) that electrically connects the bus bar portion and the voltage detecting portion, at least the connecting portion of the bus bar portion and the connecting portion is a flexible printed circuit board (for example, a flexible printed circuit board). flexible printed circuit board to be described later).

According to the battery modules described in (4) and (5), the connection portion of each connection circuit can be made as thin as possible, and can be easily flexed and deformed, so that the connection portion does not affect the battery module. Height size affects. Furthermore, since the flexible printed circuit board is lightweight, the battery module can also be reduced in weight.

(6) In the battery module according to (4), preferably, the connection portion is electrically connected to the voltage detection portion in a detachable and detachable manner via a connector (eg, a connector described later).

(7) In the battery module according to (5), it is preferable that the connection portion is electrically detachably connected to the voltage detection portion via a connector (for example, a connector described later).

According to the battery modules described in (6) and (7), each connection circuit and the voltage detection portion can be easily connected without soldering or the like, and the battery module assembly workability is excellent. Furthermore, the connection between each connection circuit and the voltage detection unit can be easily released as needed.

[Effect of the utility model]

According to the present invention, it is possible to provide a battery module capable of preventing unevenness in path resistance, which is a plurality of paths electrically connecting electrode terminals of a plurality of stacked battery cells and a voltage detection portion, in each connection path. The path resistance of the connection path can be reduced, and the cost can be reduced.

Description of drawings

FIG. 1 is an overall perspective view of the battery module of the present invention.

2 is an exploded perspective view of the battery module of the present invention.

3 is a plan view of the battery module of the present invention.

4 is a perspective view showing one connection circuit of the battery module of the present invention.

5 is a side view of the battery module of the present invention.

Explanation of symbols

1: battery module

2: battery unit

2a: Terminal face

21: Positive terminal (electrode terminal)

22: Negative terminal (electrode terminal)

5: Voltage detection section

5a: Side (of the voltage detection unit)

6: Connect the circuit

61: Busbar part

62: Connection part

621: Flexible Printed Substrates

622: Connector

Detailed ways

Hereinafter, an example of embodiment of this invention is demonstrated in detail, referring drawings.

FIG. 1 is an overall perspective view of the battery module of the present invention. 2 is an exploded perspective view of the battery module of the present invention. 3 is a plan view of the battery module of the present invention.

The battery module 1 is configured by integrally fastening a plurality of stacked battery cells 2 together with a pair of end plates 3 by fastening members 4 . In addition, among the directions shown in the drawings, the D1 direction is a direction along the stacking direction of the plurality of battery cells 2 , and represents the longitudinal direction of the battery module 1 . The D2 direction is a direction orthogonal to the stacking direction of the plurality of battery cells 2 , and represents the width direction of the battery module 1 . The D3 direction is a direction orthogonal to the stacking direction of the plurality of battery cells 2 , and represents the height direction (up-down direction) of the battery module 1 . In the D3 direction, the upper side of the paper is referred to as "upper" and the lower side is referred to as "lower".

The battery cell 2 includes, for example, a lithium ion secondary battery, and an electrode body (not shown) is accommodated inside a rectangular parallelepiped-shaped cell case 20 including aluminum, an aluminum alloy, or the like. The upper surface of the battery cell 2 is covered to form a terminal surface 2a on which a pair of electrode terminals of a positive electrode terminal 21 and a negative electrode terminal 22 are arranged to protrude.

The battery cell 2 has a box-shaped shape whose thickness along the D1 direction is sufficiently small with respect to the width along the D2 direction. As shown in FIG. 2 , the plurality of battery cells 2 are stacked in the thickness direction so that the terminal surfaces 2a of the plurality of battery cells 2 are arranged on the same surface. When the adjacent battery cells 2 and 2 are viewed in the stacking direction, the positive electrode terminals 21 and the negative electrode terminals 22 are alternately arranged in a straight line. The adjacent battery cells 2 and 2 are respectively insulated by sandwiching insulating plates 23 called spacers, and are maintained at a constant interval.

The end plates 3 are formed of metal, resin, or a composite thereof, and are arranged at both ends of the plurality of stacked battery cells 2 in the stacking direction, respectively. The end plate 3 includes a rectangular plate-like member similar to the side surface 2 b facing in the stacking direction of the battery cells 2 . All the battery cells 2 are arranged so as to be sandwiched between the pair of end plates 3 and 3 and are integrally fastened by the pair of fastening members 4 and 4 . In addition, as shown in FIG. 2 , an insulating plate 23 is also sandwiched between the battery cells 2 arranged at both ends in the stacking direction and the end plates 3 .

The fastening member 4 is a metal connecting tape that binds the entirety of the plurality of stacked battery cells 2 and the pair of end plates 3 and 3 , and is formed in a long shape along the stacking direction of the battery cells 2 . The pair of fastening members 4 and 4 are arranged so as to sandwich the entirety of the plurality of stacked battery cells 2 and the pair of end plates 3 and 3 from both sides. At both ends of each of the fastening members 4 and 4 in the longitudinal direction (D1 direction), fixing pieces 41 and 41 which are bent at right angles toward the inner side (the side of the battery cell 2 ) are respectively provided. The fastening member 4 is fixed to the outer surface 3a of the end plate 3 by the respective fixing pieces 41 and 41 and using an appropriate number of fixing members 42 such as bolts. Thereby, the pair of fastening members 4 and 4 impart a binding force in the stacking direction between the end plates 3 and 3 for all the battery cells 2, thereby suppressing the expansion of the battery cells 2 due to charge and discharge.

In the battery module 1 , the voltage detection unit 5 is arranged on the outer surface of the plurality of stacked battery cells 2 . The voltage detection unit 5 accommodates a voltage detection circuit including a plurality of electronic components (not shown) inside a rectangular parallelepiped-shaped housing 50 . The voltage detection unit 5 detects the voltage of each battery cell 2 via the plurality of connection circuits 6 , and outputs the detection result to the outside of the battery module 1 via a signal line (not shown).

The voltage detection unit 5 shown in this embodiment is arranged on the upper surface 1 a of the battery module 1 including the terminal surface 2 a of each battery cell 2 . Specifically, the voltage detection unit 5 is disposed between the positive electrode terminal 21 and the negative electrode terminal 22 on each terminal surface 2 a on the upper surface 1 a of the battery module 1 . Therefore, without affecting the protruding heights of the positive electrode terminal 21 and the negative electrode terminal 22, the voltage detection unit 5 can be brought close to the positive electrode terminal 21 and the negative electrode terminal 22 in the plane direction (direction parallel to the upper surface 1a of the battery module 1). configuration. Since the voltage detection unit 5 is disposed in contact with or close to the terminal surface 2 a of each battery cell 2 , the size of the battery can be reduced compared to, for example, when the voltage detection unit 5 is placed above the positive electrode terminal 21 and the negative electrode terminal 22 . Height dimension of module 1.

As shown in FIGS. 1 and 3 , the voltage detection unit 5 shown in this embodiment extends over the entire stacking direction of the battery cells 2 . The voltage detection unit 5 is formed to be elongated in the plane direction with a higher height direction (D3 direction) by distributing the electronic components inside the casing 50 in the plane direction. Specifically, the plane direction is the stacking direction of the battery cells 2 . Therefore, the voltage detection portion 5 has a flat shape whose height (thickness) along the D3 direction is sufficiently smaller than the width along the D2 direction. Accordingly, even if the voltage detection portion 5 is disposed on the upper surface 1a of the battery module 1, the amount of protrusion of the voltage detection portion 5 from the upper surface 1a can be suppressed, so that the height dimension H of the battery module 1 is also suppressed as shown in FIG. 5 . . The voltage detection part 5 is fixed to the upper end surfaces 3b and 3b of the end plates 3 and 3 by fixing members 52 such as screws by using the attachment parts 51 and 51 integrally provided at both ends in the longitudinal direction.

As shown in FIG. 3 , the width of the voltage detection portion 5 is sufficiently smaller than the separation distance between the pair of electrode terminals (the positive terminal 21 and the negative terminal 22 ) protruding from the terminal surface 2 a of the battery cell 2 . Thus, a fixed distance L is provided between the voltage detection unit 5 and the positive electrode terminal 21 and the negative electrode terminal 22 of each battery cell 2 . In the voltage detection unit 5 , the two side surfaces 5 a and 5 a facing in the D2 direction are arranged to face the row of the positive electrode terminals 21 and the negative electrode terminals 22 arranged along the stacking direction of the battery cells 2 . Since the voltage detection unit 5 extends over the entire stacking direction of the battery cells 2 , the distance L between each positive electrode terminal 21 and each negative electrode terminal 22 and the side surfaces 5 a and 5 a of the voltage detection unit 5 is equal for all the positive electrode terminals 21 and the negative electrode terminals 22 . .

The voltage detection unit 5 is electrically connected to the positive electrode terminal 21 and the negative electrode terminal 22 of each battery cell 2 through a plurality of connection circuits 6 having the same pattern using the two side surfaces 5a and 5a. The connection circuit 6 constitutes a connection path between the positive electrode terminal 21 and the negative electrode terminal 22 of each battery cell 2 and the voltage detection unit 5 , respectively. The distance L between each positive electrode terminal 21 and each negative electrode terminal 22 and the side surfaces 5a and 5a of the voltage detection unit 5 is equal for all positive electrode terminals 21 and negative electrode terminals 22, so that the connection paths can be shared by the shortest path.

An example of the configuration of the connection circuit 6 will be described in further detail with reference to FIG. 4 . The connection circuit 6 has a bus bar portion 61 and a connection portion 62 . The bus bar portion 61 electrically connects two electrode terminals, the positive electrode terminal 21 and the negative electrode terminal 22 , which are adjacent in the stacking direction. The connection part 62 electrically connects the bus bar part 61 and the voltage detection part 5 . The connection circuit 6 is formed into a patterned circuit using the bus bar portion 61 and the connection portion 62, and the plurality of connection circuits 6 having the same pattern (same structure, same shape) are respectively applied to the positive terminals 21 and 21 of the other adjacent battery cells 2 and 2, respectively. The negative terminal 22 is electrically connected to the voltage detection unit 5 . Therefore, all the connection circuits 6 in the battery module 1 are common to one pattern, so that the path resistance does not vary among the connection circuits 6 . Furthermore, by commonizing the plurality of connection circuits 6 , the number of parts to be managed can also be reduced, and the cost of the battery module 1 can be reduced.

The bus bar part 61 shown in this embodiment consists of a rectangular plate-shaped thin metal plate material. The bus bar portion 61 has two through holes 611 and 611 through which the electrode terminals are inserted. The bus bar portion 61 is fixed by inserting the positive electrode terminal 21 and the negative electrode terminal 22 into the through holes 611 and 611 , respectively, and screwing a nut (not shown) to the positive electrode terminal 21 and the negative electrode terminal 22 . Thereby, the bus bar portion 61 is fixed across the positive electrode terminal 21 and the negative electrode terminal 22 , and electrically connects the positive electrode terminal 21 and the negative electrode terminal 22 .

In the bus bar portion 61 of the connection circuit 6 shown in this embodiment, the positive electrode terminal 21 and the negative electrode terminal 22 fitted in the two through holes 611 and 611 are shifted one by one on both sides of the voltage detection portion 5 . Therefore, the bus bar portion 61 of each connection circuit 6 does not include one of the pair of electrode terminals (in this embodiment, the positive electrode terminal 21A of the battery cell 2 at one end and the other electrode terminal) of the two battery cells 2 and 2 arranged at both ends. All the battery cells 2 are connected in series by electrically connecting all adjacent positive electrode terminals 21 and negative electrode terminals 22 except for the negative electrode terminal 22A) of the battery cell 2 at one end. However, in the battery module 1 , the positive electrode terminal 21 and the negative electrode terminal 22 of the adjacent battery cells 2 and 2 may be stacked on the same side, and all the battery cells 2 may be connected in parallel through the bus bar portion 61 .

The connection portion 62 shown in this embodiment includes a flexible printed circuit board 621 (hereinafter referred to as an FPC (Flexible Printed Circuit) 621 ) and a connector 622 . The FPC 621 is configured by laminating insulating layers 621B on both surfaces of a metal thin film layer 621A formed in a strip shape. On one surface of one end portion 621a of the FPC 621, a metal thin film layer 621A is exposed by removing a part of the insulating layer 621B. The exposed metal thin film layer 621A in the one end portion 621a of the FPC 621 is brought into contact with the surface of the bus bar portion 61, and is joined to the bus bar portion 61 by a fixing member (none of which is shown) such as conductive adhesive, solder, or screws.

The connector 622 is provided on the other end portion 621b of the FPC 621 . The connector 622 is fitted to the connector mounting portion 53 provided at intervals along the stacking direction on the side surface 5a of the voltage detecting portion 5, thereby electrically connecting the FPC 621 (metal thin film layer 621A) to the voltage detecting portion in a detachable manner. 5. The battery module 1 shown in this embodiment has six connector mounting portions 53 on one side surface 5 a of the voltage detection portion 5 and five connector mounting portions 53 on the other side surface 5 a. Therefore, as shown in FIG. 3 , the battery module 1 is provided with eleven connection circuits 6 corresponding to the connector attachment portions 53 so as to protrude laterally (D2 direction), respectively.

Since all the connection circuits 6 are connected by the side surface 5 a of the voltage detection unit 5 , they do not protrude upward from the voltage detection unit 5 . Therefore, as shown in FIG. 5 , the height dimension H of the battery module is not increased by connecting the connection circuit 6 to the voltage detection unit 5 . Since the connection circuit 6 is connected to the voltage detection unit 5 through the connector 622 , each connection circuit 6 can be easily connected to the voltage detection unit 5 without soldering, screws, or the like, so that the assembly workability of the battery module 1 is excellent. Furthermore, the connection between each connection circuit 6 and the voltage detection unit 5 can be easily released at the time of maintenance of the battery module 1, replacement of parts, and the like.

Furthermore, since the connection portion 62 of each connection circuit 6 is constituted with the FPC 621, the connection portion 62 can be made as thin as possible, and the connection portion 62 can be easily Flexurally deformed. Therefore, there is no possibility that the connection portion 62 affects the height dimension H of the battery module 1 . Furthermore, since the FPC 621 is lightweight, the battery module 1 can be reduced in weight.

In addition, the bus bar part 61 of the connection circuit 6 is not limited to a metal plate, For example, a metal wire (wire) may be included. Furthermore, in the connection circuit 6 , the portion of the bus bar portion 61 may be formed of the FPC integrated with the connection portion 62 . Since the entire FPC of the connection circuit 6 other than the connector 622 can be reduced, the connection circuit 6 can be simplified, the component cost can be suppressed, and the battery module 1 can be further reduced in weight. In addition, the connection part 62 of the connection circuit 6 is not limited to the one that can be detachably connected by the connector 622 , and may be connected to the voltage detection part 5 in a non-detachable manner.

Claims (7)

1. A battery module, comprising: a plurality of stacked battery cells; and a voltage detection unit disposed on an outer surface of the plurality of stacked battery cells and connected to electrode terminals of the battery cells to detect voltages of the battery cells, wherein the battery module is characterized in that,

a connection path of a part of the electrode terminals of the battery cells to the voltage detection part includes a connection circuit having a fixed pattern,

the electrode terminals of all the battery cells are electrically connected to the voltage detection unit using the connection circuit of the same pattern.

2. The battery module according to claim 1,

the voltage detection unit has a flat shape extending over the entire battery cell in the stacking direction.

3. The battery module according to claim 1 or 2,

a plurality of the battery cells are stacked with the terminal surfaces having the electrode terminals disposed on the same plane,

the voltage detection unit is disposed between the pair of electrode terminals of each of the battery cells on the terminal surface,

the connection circuit is provided across the electrode terminal and a side surface of the voltage detection unit that faces the electrode terminal.

4. The battery module according to claim 1 or 2,

the connection circuit includes bus bar portions electrically connecting the electrode terminals of the adjacent battery cells to each other, and a connection portion electrically connecting the bus bar portions and the voltage detection portion,

at least the connecting portion of the bus bar portion and the connecting portion is formed using a flexible printed circuit board.

5. The battery module according to claim 3,

the connection circuit includes bus bar portions electrically connecting the electrode terminals of the adjacent battery cells to each other, and a connection portion electrically connecting the bus bar portions and the voltage detection portion,

at least the connecting portion of the bus bar portion and the connecting portion is formed using a flexible printed circuit board.

6. The battery module according to claim 4,

the connection portion is detachably electrically connected to the voltage detection portion via a connector.

7. The battery module according to claim 5,

the connection portion is detachably electrically connected to the voltage detection portion via a connector.

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