JPH1145690A - Battery module - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a battery module capable of greatly improving the reliability of an inside connecting conductor while restricting the increasing weight and volume of the battery module. SOLUTION: To the terminals 10, 11 of element batteries 1, 2 in an exclosure case, a connecting conductor 12 with the deformable curves 12a is connected. The connecting conductor 12 as a thin tape conductor has the curve 12a in a zigzag-curved shape between positive electrode terminals 10, 11. In this way, the deformation of the exclosure case due to impact in falling on a floor, resulting in the element batteries 1, 2 to be relatively displaced with each other, or the relative displacement of the element batteries 1, 2 from a circuit board 6, thus applying strong force to the connecting conductor 12 connecting these in the longitudinal direction to prevent poor connection.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a battery
The present invention relates to a battery module formed by housing a plurality of battery modules.

[0002]

2. Description of the Related Art Japanese Patent Application Laid-Open No. Hei 7-20076 discloses that a plurality of cells connected to each other by connection conductors are housed in an outer case to form a battery module (battery pack). I have. In addition, there is also known an apparatus in which a circuit board is provided in an outer case to control charging and discharging of a unit cell.

[0003]

However, in the above battery module, when the battery module is dropped on a floor or the like or a certain impact is applied, a connecting conductor for connecting the unit cells, a unit cell, or the like. There is a possibility that the connection conductor connecting the circuit board and the circuit board may be disconnected or a connection failure may occur. More specifically, an outer casing supporting each unit cell.
The rigidity of the cell itself is limited, and the deformation of the surrounding case due to an impact or an external force applied thereto causes stress on the connection conductor through the displacement of the unit cell.

[0004] In addition, adjacent cells may expand with the progress of the charge / discharge cycle, and the distance between the cells may increase, whereby stress may occur in the connection conductor connecting the two. Of course, improving the rigidity and strength of each part of the battery module is one option, but it is not practical because the weight, volume, and cost of the battery module are significantly increased.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and a battery module in which the reliability of internal connection conductors is significantly improved while suppressing an increase in the weight and volume of the battery module. Providing is an issue to be solved.

[0006]

In the battery module according to the present invention, a deformable and flexible connection conductor is connected to a terminal of the unit cell in the outer case. In this way, the outer casing is dropped by impact such as dropping to the floor or the like.
Even if the cells are deformed and the cells are displaced relative to each other, or if the cells are displaced relative to the circuit board, the connection conductors that connect them can be deformed, preventing connection failures. Therefore, a highly reliable battery module can be realized with a simple configuration.

According to a second aspect of the present invention, in the battery module according to the first aspect, the connection conductor extends in the direction of lamination of the plates of the unit cell. Even when adjacent unit cells are displaced relative to each other, the connection conductors connecting them easily extend in the extending direction, so that disconnection of the connection conductors and poor connection at connection points can be prevented, and a simple structure can be achieved. High reliability can be obtained with the configuration.

According to a third aspect of the present invention, in the battery module according to the first or second aspect, the connection conductor is further formed of a wire having a concentrating structure. The wire may be a bare stranded wire structure or a covered cable. With such a configuration, the connection conductor unique to the battery module due to insufficient rigidity of the battery module, insufficient supporting strength of the battery module, or barrel expansion of the battery cell with a simple configuration. Connection failure can be solved.

According to a fourth aspect of the present invention, in the battery module according to the first or second aspect, the connection conductor is further formed of a tape-shaped conductor that is curved in a thickness direction. With such a configuration, the connection conductor unique to the battery module due to insufficient rigidity of the battery module, insufficient supporting strength of the battery module, or barrel expansion of the battery cell with a simple configuration. Connection failure can be solved.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION It is preferable that a lithium ion secondary battery, a nickel hydrogen storage alloy battery, or the like be used as the unit cell.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the drawings. (Embodiment 1) The battery module of Embodiment 1 will be described below with reference to an exploded perspective view shown in FIG. 1 and a longitudinal sectional view shown in FIG.

The battery module of this embodiment includes a pair of cells 1 and 2 having the same shape, spacers 3 to 5, a circuit board 6,
An outer case 7 for accommodating them is provided. The unit cells 1 and 2 are prismatic lithium ion secondary batteries, in which an electrode laminate (not shown) formed by laminating a negative electrode plate and a positive electrode plate with a separator interposed therebetween together with an electrolyte (not shown) It is housed in a rectangular container 8 made of nickel-plated steel plate or the like.

The spacers 3 to 5 are provided in contact with the side plates 8a of the rectangular containers 8 of the unit cells 1 and 2 in the direction of lamination of the plates. That is, the spacer 3 is a double-sided container 8, 8
The spacer 4 is in contact with the upper side plate 8a of the rectangular container 8 of the unit cell 1, and the spacer 5 is in contact with the lower side plate of the rectangular container 8 of the unit cell 2. . Spacers 3-5
Is formed by molding a metal plate or a resin plate, for example, has a rectangular shape in contact only with the peripheral edge of each side plate portion 8a of the rectangular container 8, and has a rectangular opening 9 in the center.

The cells 1 and 2 and the spacers 3 to 5
Are stacked and integrated in the electrode plate stacking direction as described above, and the spacer 5 is in contact with the periphery of the circuit board 6. Reference numeral 10 denotes a positive terminal of the unit cell 1 and 11 denotes a positive terminal of the unit cell 2, both of which are connected in parallel by a connecting conductor 12 and further connected to a predetermined portion of the circuit board 6. Reference numeral 13 denotes a connection conductor welded to the side plate portion of the rectangular container 8 of the unit cell 1, ie, the negative electrode terminal, and reference numeral 14 denotes a connection conductor welded to the side plate portion of the rectangular container 8 of the unit cell 2, ie, the negative electrode terminal. 13 and 14 are connected to predetermined portions of the circuit board 6. Connection conductors 15 and 16 connect the positive and negative terminals 17 and 18 fixed to the outer case 7 to predetermined portions of the circuit board 6.

The outer case 7 is composed of an upper case 7a, a lower case 7b and a terminal plate 7c which are fitted to each other to form a rectangular sealed case. Are formed in a thin rectangular box shape, and after the above-mentioned fitting, they are bonded and integrated. Terminal plate 7c
The positive and negative terminals 17 and 18 are fixed to the.
The flat main inner surface of the upper case 7a supports the rectangular container 8 of the unit cell 2 through the spacer 4, and the lower case 7b supports the circuit board 6, and as a result, The unit cells 1 and 2 and the circuit board 6 are supported so as not to move relative to the surrounding case 7.

Next, the connecting conductor 1 which characterizes this embodiment is described.
2 to 14 will be described with reference to FIGS. As shown in FIG. 2, the connection conductor 12 is welded at its end to the positive electrode terminal 10 of the unit cell 1, and is further extended downward, that is, in the electrode stacking direction of the unit cells 1 and 2, and It is welded to the positive terminal 11, further extended downward, and connected to a predetermined electrode portion of the circuit board 6.

The connecting conductor 12 is a thin tape-shaped conductor having a bent portion 12a bent in a serpentine shape between the positive terminals 10, 11, and a bent portion 12b having the same shape as the positive terminal 11 and the circuit board. 6 between. As a result, these cells 1 and 2 and the circuit board 6
Are relatively moved in the vertical direction, the bending portions 12a, 1
2b easily extends in the vertical direction and absorbs it, so that an excessive tensile stress acts on the welded portion between the positive electrode terminals 10, 11 and the connection conductor 12 and the connection portion of the connection conductor 12 on the circuit board 6. As a result, it is possible to prevent the occurrence of a connection failure at this portion or the like. In addition, even if the unit cells 1 and 2 and the circuit board 6 move relative to each other in the horizontal direction, the curved portions 12a and 12b absorb the same to some extent, so that the same effect of suppressing poor connection can be obtained.

Similarly to the connection conductors 12, the connection conductors 13 and 14 are located between the side plate portions of the unit cells 1 and 2, that is, the welded portion serving as the negative electrode terminal and the circuit board 6, and have a serpentine curved portion 13a. , 14a. As a result, even if an excessive force or impact is applied to the battery module, the connection conductors 13 and 14
No peeling occurs at the welded portion of No. 1, and the connection conductors 13 and 14 do not tear.

After all, the battery module of this embodiment can have high reliability by adding a simple configuration. (Embodiment 2) Another embodiment of the present invention will be described with reference to FIG. This embodiment is different from the first embodiment only in that connection conductors 120 and 121 are used instead of the tape-shaped connection conductor 12 used in the first embodiment.

The connecting conductor 120 is a stranded wire type insulated cable 120 having a large number of fine conductors and excellent flexibility.
a and 120b, and connection fittings 120c and 120d fixed to both ends of the insulated cable 120a. The connection metal 120c is welded to the positive electrode terminal 10, the connection metal 120d is welded to the positive electrode terminal 11, and the insulating coating cable 120b connects the connection metal 120d to the electrode portion of the circuit board 6. Insulated cable 120a, 120
The length “b” is made sufficiently longer than the linear distance between the connection fittings 120 b and 120 c and the linear distance between the connection fitting 120 c and the electrode portion of the circuit board 6.

The insulated cables 120a and 120b are
Since it has excellent flexibility despite its thickness, it is apparent that the same operation and effect as in the first embodiment can be obtained. Although the description has been omitted, it is needless to say that the connection conductors 13 and 14 of the first embodiment can also be replaced with an insulated cable in the same manner as above.

(Modification) In the above embodiment, the spacer 3
-5 are unit cells 1, 2 and circuit board 6 and upper case 7a
However, it is a matter of course that they may be adhered to each other, or may be adhered with a double-sided adhesive tape. Also, it goes without saying that they may be fixed to each other via an electrically insulating film or the like instead of the spacers 3 to 5.

[Brief description of the drawings]

FIG. 1 is a battery module (battery module) of Example 1.
FIG. 3 is an exploded perspective view of FIG.

FIG. 2 is an enlarged side view of a main part showing a wiring state of connection conductors 12 of the battery module of FIG.

FIG. 3 is a main part enlarged side view showing a wiring state of connection conductors 120 of the battery module according to the second embodiment.

[Description of References] 1, 2 are unit cells, 3 to 5 are spacers, 6 is a circuit board, 7
Is an outer case, 8 is a rectangular container for the cells 1 and 2, 12 to 1
4 is a connection conductor, 12a, 12b, 13a, and 14a are bent portions in a serpentine shape.

Claims (4)

[Claims] A plurality of unit cells, an outer case for accommodating each of said unit cells, and terminals between adjacent unit cells in said outer case or between said unit cells and a circuit board. A battery module comprising: a connection conductor connecting between the battery modules; wherein the connection conductor has deformable flexibility. 2. The battery module according to claim 1, wherein the connection conductor extends in the direction of stacking the plates of the unit cell to make the connection. 3. The battery module according to claim 1, wherein the connection conductor is formed of a wire having a concentrating structure. 4. The battery module according to claim 1, wherein the connection conductor is formed of a tape-shaped conductor that curves in a thickness direction.