JP4227762B2 - Assembled battery unit and connecting method of assembled battery unit - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an assembled battery unit and a method for connecting the assembled battery unit .
[0002]
[Prior art]
For example, when a high voltage battery is used as a power source, such as a hybrid vehicle or an electric vehicle, a plurality of battery cells are connected in series to form an assembled battery unit. In order to obtain a desired voltage or capacity, the assembled battery units are connected in series or in parallel.
[0003]
Japanese Patent Application Laid-Open No. 11-162443 discloses a structure of an assembled battery unit. This unit is formed by stacking a plurality of sheet-like battery cells. Each battery cell is provided with protruding electrode tabs, and the battery cells are connected in series by joining the electrode tabs having different polarities adjacent to each other. In this battery cell, the protruding portion of the electrode tab is thinner than the other portion, and the connecting portion between the electrode tabs is disposed in the space. Thereby, the stacking space of the battery cells is reduced and space saving is achieved.
[0004]
[Problems to be solved by the invention]
By the way, welding, screw connection, rivet connection, ultrasonic connection, etc. are mentioned as a joining method of an electrode tab. However, when a laminate cell that is a lithium ion battery is used for the battery cell, a technique such as welding is difficult because the electrode tab is formed of a thin metal plate. In addition, when connecting with screws or rivets, the connection parts between the electrode tabs are thickened by the screw heads or rivets, so it is not easy to ensure insulation between the adjacent electrode connection parts. Easy to invite.
[0005]
Therefore, the connection between such thin metal plates is generally performed by ultrasonic connection. However, in ultrasonic connection, each time one electrode tab is connected, the battery potential rises rapidly and electric shock is likely to occur. For this reason, it is necessary to improve the safety of connection work.
[0006]
This invention is made | formed in view of this situation, The objective is to perform the connection of battery cells efficiently, ensuring the insulation of an electrode, and aiming at the improvement of a connection workability | operativity. .
[0007]
[Means for Solving the Problems]
In order to solve this problem, the assembled battery unit according to the first invention has a plurality of battery cells stacked in one direction. The electrode tabs projecting from each of these stacked battery cells are arranged as a group of electrode tabs in one direction. A pair of adjacent positive electrode tabs and negative electrode tabs are sandwiched and connected in series by a pair of opposed surfaces of an insulating sheet having insulating properties in which a plurality of surfaces are connected in a bellows shape.
[0008]
Here, in 1st invention, it is preferable to provide the clamping member which clamps between the both ends of an insulating sheet.
[0009]
2nd invention provides the connection method of an assembled battery unit . In this connection method, first, a plurality of battery cells with protruding electrode tabs are overlapped in one direction, and the respective electrode tabs are arranged in one direction. Next, a pair of adjacent positive electrode tabs and negative electrode tabs are sandwiched and connected in series by a pair of opposed surfaces of an insulating sheet having insulating properties in which a plurality of surfaces are connected in a bellows shape. And in the state which clamped a pair of electrode tab with a pair of surface, between the both ends of an insulating sheet is clamped by the clamping member.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a schematic cross-sectional view of an assembled battery body that forms an assembled battery unit in the present embodiment. FIG. 2 is a perspective view of the battery cell. As shown in FIG. 1, the assembled battery body 1 has a structure in which a plurality of battery cells are stacked and stacked. As the battery cells, for example, a thin laminate cell 2 can be used. As shown in FIG. 2, these laminate cells 2 are formed of, for example, a lithium ion battery 3 and a laminate sheet 4 that covers the lithium ion battery 3. On the upper end side of the laminate cell 2, for example, a positive electrode tab (hereinafter referred to as a positive electrode tab) 5 formed of a thin metal such as aluminum is provided so as to protrude. On the other hand, on the lower end side of the laminate cell 2, for example, a negative electrode tab (hereinafter referred to as a negative electrode tab) 6 formed of a thin metal plate such as nickel is provided so as to protrude.
[0011]
The respective laminate cells 2 are alternately inverted and arranged so as to overlap each other, and the positive electrode tab 5 and the negative electrode tab 6 are arranged so as to face each other in one direction. Insulating sheets 7 and 9 having insulating properties are interposed between the positive electrode tab 5 and the negative electrode tab 6 in the laminate cells 2 adjacent to each other. These insulating sheets 7 and 9 have a bellows shape that can be expanded and folded in the parallel direction of the respective laminate cells 2. The first insulating sheet 7 sandwiches the electrode tab pairs 5 and 6 by a pair of facing surfaces 7a and 7b facing in a V shape or an inverted V shape. Similarly, the second insulating sheet 9 sandwiches the electrode tab pairs 5 and 6 by a pair of facing surfaces 9a and 9b facing each other in a V shape or an inverted V shape. Thereby, since the electrode tabs 5 and 6 of different polarity are joined together, the laminate cells 2 are connected in series.
[0012]
In addition, bolt holes 8 and 10 are formed in the facing surfaces 7a and 7b and 9a and 9b of the first and second insulating sheets 7 and 9 so as to penetrate in the parallel direction of the respective laminate cells 2 in the folded state. ing. The bolts 11 are inserted into the bolt holes 8 and 10 from one end side of the insulating sheets 7 and 9. Then, a nut 12 is screwed to the bolt 11 from the other end side of each of the insulating sheets 7 and 9. Due to the clamping force of these members 11 and 12, the respective electrode connection portions of the respective laminate cells 2 sandwiched between the insulating sheets 7 and 9 are clamped and fixed.
[0013]
3-5 is a figure for demonstrating the connection method of the battery cell in this embodiment. FIG. 3 is a partial perspective view of the arrangement state of the battery cells when the insulating sheet is unfolded. FIG. 4 is a schematic cross-sectional view of an arrangement state of battery cells when the insulating sheet is developed. FIG. 5 is a schematic cross-sectional view of a state in which the battery cell is held by an insulating sheet. In FIG. 3, only the lower half side of the arrangement state of the laminate cells 2 is shown, but the upper half side of the laminate cells 2 has a substantially similar configuration.
[0014]
That is, in order to connect between the electrode tab pairs 5 and 6 at the connection site in the adjacent laminate cells 2, as shown in FIG. 3 and FIG. 4, the plurality of laminate cells 2 are inverted so as to overlap each other alternately. Parallel. As a result, the positive electrode tab 5 and the negative electrode tab 6 face each other in one direction. Next, the insulating first and second insulating sheets 7 and 9 are interposed between the positive electrode tab 5 and the negative electrode tab 6 in the laminate cell 2 adjacent to each other. As described above, each of the insulating sheets 7 and 9 has a bellows-like shape that can be expanded and contracted in the arrangement direction of the respective laminate cells 2. Therefore, each laminate cell 2 is inserted between the facing surfaces 7a, 7b and 9a, 9b facing each other in a V shape or an inverted V shape when the insulating sheets 7, 9 are unfolded.
[0015]
In this inserted state, the respective insulating sheets 7 and 9 are folded in a reduction direction indicated by solid line arrows in FIG. Thereby, as shown in FIG. 5, the electrode tab pairs 5 and 6 in the laminate cells 2 adjacent to each other are sandwiched by the facing surfaces 7a and 7b and 9a and 9b of the insulating sheets 7 and 9, respectively.
[0016]
In such a folded state, the bolts 11 are inserted from the one end sides of the insulating sheets 7 and 9 into the bolt holes 8 and 10 provided in the facing surfaces 7a and 7b and the facing surfaces 9a and 9b, respectively. After inserting the bolt 11, the nut 12 is screwed to the bolt 11 from the other end side of the insulating sheets 7 and 9. Thereby, the electrode connection portion of the laminate cell 2 sandwiched between the insulating sheets 7 and 9 is fastened and fixed in a sandwiched state.
[0017]
In the above-described embodiment, the clamping force generated by the engagement between the bolt 11 and the nut 12 is used to sandwich the insulating sheets 7 and 9, but the present invention is limited to this. is not. For example, it is naturally possible to use a clamping member such as a clip or a spring in addition to this.
[0018]
【The invention's effect】
Thus, according to the present invention, the battery cells can be efficiently connected to each other, the insulation of the electrodes can be ensured, and the connection workability can be improved.
[Brief description of the drawings]
FIG. 1 is a schematic cross-sectional view of an assembled battery body forming an assembled battery unit in the present embodiment. FIG. 2 is a perspective view of a battery cell. FIG. 3 is a partial perspective view of an arrangement state of battery cells when an insulating sheet is unfolded. FIG. 4 is a schematic cross-sectional view of an arrangement state of battery cells when the insulating sheet is unfolded. FIG. 5 is a schematic cross-sectional view of a state in which battery cells are held by an insulating sheet.
1 Battery pack body 2 Battery cell (laminate cell)
3 Lithium ion battery 4 Laminate sheet 5 Positive electrode tab (positive electrode tab)
6 Negative electrode tab (negative electrode tab)
7 First insulating sheets 7a, 7b facing 8 bolt holes 9 Second insulating sheets 9a, 9b facing 10 bolt holes 11 bolts 12 nuts

Claims (3)

A plurality of battery cells stacked in one direction;
An electrode tab group in which electrode tabs provided to protrude from each of the stacked battery cells are arranged in one direction;
Insulating sheet, having a plurality of surfaces connected in a bellows shape, and having an insulating sheet that is connected in series with a pair of adjacent positive and negative electrode tabs sandwiched between a pair of opposing surfaces An assembled battery unit characterized by The assembled battery unit according to claim 1, further comprising a sandwiching member that sandwiches between both end portions of the insulating sheet. In the connection method of the assembled battery unit ,
Overlaying a plurality of battery cells from which electrode tabs protrude in one direction, and arranging each electrode tab in one direction;
Step of sandwiching a pair of adjacent positive electrode tabs and negative electrode tabs by a pair of surfaces facing each other in an insulating sheet having insulating properties in which a plurality of surfaces are connected in a bellows shape, and connecting in series
Said pair of electrode tabs while sandwiched by the pair of surfaces, the connection method of an assembled battery unit, characterized in that a step of sandwiching between both end portions of the insulating sheet by clamped members.

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