JP2007324004A - Battery pack and manufacturing method of battery pack - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a battery pack in which a plurality of unit cells are connected and which is simple and connects unit cells excellently, and to provide its manufacturing method. <P>SOLUTION: The secondary battery 10 has a plurality of battery modules 101 arranged in which a plurality of sealed batteries 120 are connected by a bus bar 160 in a row and in series. When the sealed batteries 120, 120 arranged adjacently are connected, the bus bar 160 is adhered to an external positive electrode terminal 131 of one of the sealed battery 120 and the external negative electrode terminal 151 of the other sealed battery 120, thereupon, a plastic deformation planned part 164 of the bus bar 160 is plastic deformed so that the positions of a first adhesion part 161 and a second adhesion part 162 may conform respectively to the positions of the external positive electrode terminal 131 and the external negative electrode terminal 151. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an assembled battery and a method for manufacturing the assembled battery.

  In recent years, various secondary batteries have been proposed as power sources for portable devices and portable devices, and as power sources for electric vehicles and hybrid vehicles. Such secondary batteries are configured by connecting a plurality of unit batteries.

  By the way, in the secondary battery, when two unit cells are arranged side by side when connecting adjacent unit cells, the interval between the electrode terminal of one unit cell and the electrode terminal of the other unit cell is usually Dimensional differences occur for each unit battery. This dimensional difference is caused by having individual dimensional tolerances in the shape and dimensions of the manufactured battery body and electrode terminals. For this reason, various ideas are made so that one electrode terminal and the other electrode terminal can be connected appropriately (for example, refer to patent documents 1 and patent documents 2).

JP-A-4-248254 JP-A-9-223494

  The sealed lead-acid battery disclosed in Patent Literature 1 is configured by connecting two unit cells (unit cells) having a plate-like anode terminal and a cathode terminal in series as electrode terminals of the battery. In this unit cell, the cathode terminal is made of a conductive material that can be bent, such as copper, and is longer than the anode terminal. The two unit cells are arranged at a position where the anode terminal of one unit cell and the cathode terminal of the other unit cell face each other, and each unit cell is bent by the cathode terminal and connected to the anode terminal of the adjacent unit cell. It is made to contact the upper end. Each unit cell is connected by fixing the contact portion between the cathode terminal and the anode terminal by welding or soldering.

  Moreover, in the battery disclosed in Patent Document 2, between adjacent unit cells, the positive terminal of one battery and the negative terminal of the other battery are connected in series by a connection terminal plate (inter-terminal connecting member), A plurality of single cells are connected. In the battery of Patent Document 2, each of the positive electrode terminal and the negative electrode terminal has a bolt shape in which a step portion is provided on the neck side of the male screw. The connection terminal plate has a flat plate shape, and has a positive side opening through which the positive terminal is inserted on one side and a negative side opening through which the negative terminal is inserted. In this connection terminal plate, the positive electrode side opening has a predetermined diameter through which the positive electrode terminal can be inserted with a margin. Similarly, the opening on the negative electrode side has a predetermined diameter through which the negative electrode terminal can be inserted with a margin.

  In the connection between unit cells, the connecting terminal plate is inserted into the positive electrode side through the positive terminal of one unit cell, the negative electrode side through the negative terminal of the other unit cell, and the step of the positive terminal It is placed on the step portion of the negative electrode terminal. As a result, gaps are formed between the inside of the positive electrode side opening and the outer periphery of the positive electrode terminal, and between the inside of the negative electrode side opening and the outer periphery of the negative electrode terminal. The paste is injected to fill the gaps in the gaps. In this way, the area of the contact portion that makes electrical contact between the connection terminal plate and the positive electrode terminal and the contact portion that makes electrical contact between the connection terminal plate and the negative electrode terminal are increased to connect with the positive electrode terminal and the negative electrode terminal. It tries to keep the connection resistance with the terminal board low. This connection terminal plate is between the fixed nut screwed into the male screw of the positive electrode terminal and the stepped portion of the positive electrode terminal, and between the fixed nut screwed into the male screw of the negative electrode terminal and the stepped portion of the negative electrode terminal. It is sandwiched and fixed to each unit cell.

  However, in particular, for secondary batteries for automobiles, there is a demand for a method that is simpler and that allows adjacent unit cells to be connected well.

  The present invention has been made in view of the current situation, and an assembled battery in which a plurality of unit cells are connected to each other, and an object thereof is to provide an assembled battery in which unit cells are well connected and a manufacturing method thereof. And

  The solution includes a plurality of unit batteries having electrode terminals, and the first unit battery and the second unit battery in which a relative position of the first unit battery is fixed among the plurality of unit batteries. An inter-terminal connecting member for electrically connecting the first electrode terminal of the first unit battery and the second electrode terminal of the second unit battery, wherein the first fixing portion is fixed to the first electrode terminal, An inter-terminal connection member comprising: a second fixing portion fixed to a two-electrode terminal; and a connecting portion connecting the first fixing portion and the second fixing portion. A plastic deformation planned portion, which is at least a part of the connecting portion of the inter-connection member, is plastically deformed to be a plastic deformation portion, and the inter-terminal connecting member is positioned at the first fixing portion and the second fixing portion. A shape that matches the position of the electrode terminal and the second electrode terminal. It is a manufacturing method of an assembled battery comprising a plastic deformation step of a.

When the first unit battery and the second unit battery are connected using the inter-terminal connecting member, the size of the unit battery and the position of the electrode terminal include dimensional tolerances, and the first and second fixed to each other. Among the unit cells, the position of the second electrode terminal of the second unit cell with respect to the first electrode terminal of the first unit cell may be displaced from the original position.
However, in the method for manufacturing an assembled battery of the present invention, in order to connect the first unit battery and the second unit battery, at least a part of the connecting portion connecting the first fixing portion and the second fixing portion is scheduled to be plastically deformed. An inter-terminal connecting member having a portion is used. In fixing the inter-terminal connecting member to the first electrode terminal and the second electrode terminal, in the plastic deformation step, the plastic deformation scheduled portion is located at the positions of the first fixed portion and the second fixed portion. Plastic deformation is performed so as to match the positions of the terminal and the second electrode terminal.
By doing in this way, even if the size of the unit cell and the position of the electrode terminal vary, the plastic deformation planned portion can be plastically deformed to be a plastic deformation portion according to the individual state. The positions of the first fixing portion and the second fixing portion can be adapted to the positions of the first electrode terminal and the second electrode terminal, respectively.
Accordingly, the first fixing portion can be fixed to the first electrode terminal and the second fixing portion can be fixed to the second electrode terminal in an appropriate position.

In addition, since the positions are adapted to each other, the deformation of the plastic deformation portion remaining in the inter-terminal connecting member in a state where the first fixing portion is fixed to the first electrode terminal and the second fixing portion is fixed to the second electrode terminal. Since the residual stress (elastic force) due to is not generated or becomes low, the residual stress continues to be applied to the first and second electrode terminals, thereby preventing deformation or breakage of these.
Therefore, it is possible to obtain an assembled battery in which unit cells are fixedly connected with high reliability by the inter-terminal connecting member.

As a unit battery, in addition to a battery composed of a single power generation element (cell) having one positive terminal and one negative terminal, a plurality of power generation elements (cells) are connected to form one module. A battery is mentioned.
In addition, as the fixing between the first fixing portion and the second fixing portion and the first electrode terminal and the second electrode terminal, for example, in addition to welding, fixing using an adhesive, caulking, fastening by screws, or the like may be used. Can be mentioned.

  Furthermore, in the above-described method for manufacturing an assembled battery, the inter-terminal connecting member may be configured such that, before the plastic deformation step, an interval between the first fixing portion and the second fixing portion is set to be different from that of the first electrode terminal. A first adhering step of adhering the first adhering part to the first electrode terminal in a state in which the second adhering part is brought closer to the second electrode terminal; A plastic deformation step in which the second fixing portion is disposed at a position where the second fixing portion can be fixed to the second electrode terminal; and after the plastic deformation step, the second fixing portion is used as the second electrode terminal. It is good to set it as the manufacturing method of an assembled battery provided with the 2nd adhering process to adhere.

In the assembled battery manufacturing method of the present invention, in the first fixing step, the first fixing portion is moved to the first electrode terminal of the first unit battery while the second fixing portion is brought close to the second electrode terminal of the second unit battery. It sticks to. Next, in the plastic deformation step, the second fixing portion is disposed at a position where it can be fixed to the second electrode terminal. Further, after the plastic deformation step, the second fixing portion is fixed to the second electrode terminal in the second fixing step.
By doing so, the first fixed portion is fixed to the first electrode terminal and then the plastic deformation scheduled portion is deformed. Therefore, only the position of the second fixed portion is deformed to fit the second electrode terminal. Sufficient and easy to determine the size of deformation. There is also an advantage that the second fixing portion can be fixed immediately after the deformation.

  Furthermore, in any of the above-described assembled battery manufacturing methods, the planned plastic deformation portion is a bent portion formed by bending a part of the flat plate-like connecting portion having a predetermined thickness and a predetermined width. It is good to use this manufacturing method.

In the method for manufacturing an assembled battery of the present invention, the bent portion, which is the plastic deformation scheduled portion, is formed by bending a part of the flat plate-like connecting portion.
By doing so, the bent portion, which is the plastic deformation scheduled portion, is easily deformed. Therefore, in the plastic deformation step, when a force is applied to change the relative positions of the first fixed portion and the second fixed portion. Since the bent portion is easily plastically deformed, a desired amount of deformation can be easily obtained.
Even if residual stress remains, the magnitude of the residual stress can be reduced by elastic deformation of the bent portion.

Further, since the connecting portion is a flat plate having a predetermined thickness and a predetermined width, there is no significant difference in cross-sectional area at each portion of the connecting portion including the plastic deformation portion (plastic deformation scheduled portion).
Accordingly, since the cross-sectional area of the connecting portion is particularly small compared to other portions, it is possible to prevent the portion from generating heat due to a partial increase in conduction resistance, and thus the deterioration of the characteristics of the assembled battery. Can also be prevented.

  In another solution, a plurality of unit batteries having electrode terminals, and a second unit battery having a fixed relative position between the first unit battery and the first unit battery among the plurality of unit batteries. An inter-terminal connecting member electrically connecting the first electrode terminal of the first unit cell and the second electrode terminal of the second unit cell, wherein the first fixing part is fixed to the first electrode terminal; An inter-terminal connecting member having a second fixing part fixed to the second electrode terminal and a connecting part connecting the first fixing part and the second fixing part, and the connecting part of the inter-terminal connecting member In fixing at least a part of the inter-terminal connecting member to the first electrode terminal and the second electrode terminal, the positions of the first fixing part and the second fixing part are the first electrode terminal and the second electrode terminal. The plastic deformation is applied to fit the position of 2 electrode terminals. Was a battery assembly having a plastically deformed portion.

In the assembled battery of the present invention, the position of the first fixing portion and the second fixing portion is determined when fixing the inter-terminal connecting member to the first electrode terminal and the second electrode terminal on at least a part of the connecting portion of the inter-terminal connecting member. However, it has the plastic deformation part plastically deformed so that it may each fit in the position of the 1st electrode terminal and the 2nd electrode terminal.
Therefore, in this assembled battery, the residual stress (elastic force) applied to the first and second electrode terminals does not occur or can be reduced by plastic deformation of the plastic deformation portion of the inter-terminal connecting member. This keeps on the two-electrode terminals, thereby preventing these deformations and damages.
For this reason, the unit cells are assembled batteries that are firmly connected to each other by the inter-terminal connecting member.

  Furthermore, in the assembled battery described above, the plastic deformation portion is formed by bending a part of the flat plate-like connecting portion having a predetermined thickness and a predetermined width, and the inter-terminal connecting member is connected to the first electrode terminal and In fixing to the second electrode terminal, an assembled battery which is a bent portion further plastically deformed is preferable.

In the assembled battery of the present invention, the bent portion formed in advance in a part of the connecting portion is further plastically deformed.
For this reason, even if residual stress remains, the magnitude of the residual stress can be further reduced by elastic deformation of the bent portion.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(Example)
The assembled battery 100 (see FIG. 1) according to the present embodiment is a secondary battery such as a nickel-hydrogen secondary storage battery or a lithium ion battery, which is used as a drive power source for an electric vehicle or a hybrid vehicle. The assembled battery 100 has a configuration in which a plurality of battery modules 101 in which a plurality of sealed batteries 120 are connected in series by a bus bar 160 in a line are arranged. As shown in FIG. 3, the sealed battery 120 included in the assembled battery 100 is a rectangular unit battery having a substantially rectangular parallelepiped shape. The sealed battery 120 includes a battery case 111 including a battery container 111 having a rectangular parallelepiped shape and a sealing lid 112 for closing the battery container 111, and a power generation element (not shown) housed in the battery container 111. Yes. The sealed battery 120 includes an external positive terminal 131 and an external negative terminal 151 that protrude to the outside of the battery case 110. In the sealed battery 120, an electrolytic solution is injected into the battery container 111.

  In the battery case 110, the battery container 111 is made of a conductive material such as metal, and as shown in FIG. 3, the first container side surface 111a having a flat and rectangular shape and the first container side surface 111a positioned in parallel with the first container side surface 111a. The second container side surface 111b having the same shape as the first container side surface, the short side of the first container side surface 111a (the vertical side in FIG. 3 (b)) and the short side of the second container side surface 111b are rectangular and rectangular. A flat and rectangular shape connecting the three container side surfaces 111c and the fourth container side surface 111d, the long side of the first container side surface 111a (the side in the horizontal direction in FIG. 3B) and the long side of the second container side surface 111b. And a container lower surface 111e. The battery container 111 has an opening (not shown) on the insertion side (the upper side in FIG. 3B), and the power generation element can be accommodated inside the battery container 111 from this opening.

  The sealing lid 112 is made of a conductive material such as metal, and as shown in FIG. 3, the long side along the first container side surface 111 a and the second container side surface 111 b in the battery container 111, the third container side surface 111 c, It is a rectangular flat plate having short sides (vertical direction in FIG. 3A) along the four container side surfaces 111d. The sealing lid 112 is spaced at predetermined intervals in the longitudinal direction along the long side of the first container side surface 111a, and terminal insertion holes (see FIG. 5) through which the external positive terminal 131 and the external negative terminal 151 described below can be respectively inserted. 2) (not shown) are perforated. The sealing lid 112 liquid-tightly closes the opening of the battery container 111 after the power generation element is accommodated in the battery container 111.

Next, the sealed battery 120 will be described.
The sealed battery 120 is connected to the positive electrode of the power generation element inside the battery case 111, and has an external positive electrode terminal 131 protruding outside through one terminal insertion hole of the sealing lid 112 (right side in FIG. 3). The external negative electrode terminal 151 is connected to the negative electrode and protrudes to the outside through the terminal insertion hole on the other side (left side in FIG. 3) of the sealing lid 112.
In the sealed battery 120, the external positive electrode terminal 131 is fixed inside the battery container 111 and is liquid-tight by the first seal member 113 fitted in the terminal insertion hole of the sealing lid 112. In a state of being electrically insulated, the shape protrudes toward the outside of the sealing lid 112. The external positive terminal 131 is made of aluminum, and is a flat electrode terminal having a terminal first welding surface 131a and a terminal second welding surface 131b on the opposite side. The terminal first welding surface 131a is parallel to the first container side surface 111a of the battery container 111, and the terminal second welding surface 131b is parallel to the second container side surface 111b. In the present embodiment, the external positive terminal 131 has a plate width (dimension in the left-right direction in FIG. 3A) W = 8 mm and a plate thickness (dimension in the vertical direction in FIG. 3A) t = 1.5 mm. Has been.

On the other hand, the external negative electrode terminal 151 is fixed inside the battery container 111 and is liquid-tight and electrically insulated from the sealing lid 112 by the second sealing member 114 fitted into the terminal insertion hole of the sealing lid 112. In this state, it protrudes toward the outside of the sealing lid 112. The external negative electrode terminal 151 is made of copper, and is a plate-like electrode terminal having a terminal first welding surface 151a and a terminal second contact surface 151b which is a surface opposite to the terminal first welding surface 151a. The terminal first welding surface 151a is parallel to the first container side surface 151a of the battery container 111, and the terminal second welding surface 151b is parallel to the second container side surface 111b. In this embodiment, the external negative electrode terminal 151 has a plate width (dimension in the left-right direction in FIG. 3A) W = 8 mm and a plate thickness (dimension in the vertical direction in FIG. 3A) t = 1.0 mm. Has been.
The sealed battery 120 corresponds to the unit battery of the present invention, the external positive electrode terminal 131 corresponds to the first electrode terminal, and the external negative electrode terminal 151 corresponds to the second electrode terminal.

Next, the battery module 101 including the sealed battery 120 will be described with reference to FIGS. 1 and 2.
In this embodiment, one battery module 101 (101A, 101B) is formed by arranging ten sealed batteries 120 in a row. As shown in FIGS. 1 and 2, the sealed batteries 120 and 120 included in the battery module 101 include a positive electrode (external positive terminal 131) and a negative electrode (external positive electrode) of the sealed batteries 120 and 120 arranged adjacent to each other. The negative terminals 151) are alternately arranged on the opposite side and arranged in parallel with each other.

  Specifically, in the battery module 101, the sealed batteries 120 and 120 are, as shown in FIG. 1, the first container side surfaces 111a and 111a of the battery container 111 and the second container side surfaces 111b and 111b. Are arranged so as to face each other alternately. And among the sealed batteries 120, 120 arranged adjacent to each other, by connecting the external positive terminal 131 of one sealed battery 120 and the external negative terminal 151 of another sealed battery 120 by the bus bar 160, Ten sealed batteries 120 (120Aa to 120Aj, 120Ba to 120Bj) are connected to each other in series.

  In the battery module 101 (101A, 101B), between the sealed batteries 120, 120 arranged adjacent to each other, the terminal first welding surface 131a of the external positive terminal 131 included in one sealed battery 120 and the other The distance between the external negative electrode terminal 151 of the sealed battery 120 and the terminal first welding surface 151a is a predetermined distance Lt between terminal welding surfaces (see FIG. 1). Further, the distance between the terminal second welding surface 131b of the external positive electrode terminal 131 included in one sealed battery 120 and the terminal second welding surface 151b of the external negative electrode terminal 151 included in the other sealed battery 120 is also a predetermined terminal welding. The distance between surfaces Lt.

  As shown in FIGS. 1 and 2, the bus bar 160 is another sealed battery in which the position relative to one sealed battery 120 is fixed among the 10 sealed batteries 120 constituting the battery module 101. This is a member that electrically connects the external positive electrode terminal 131 of one sealed battery 120 and the external negative electrode terminal 151 of another sealed battery 120 in 120 (battery adjacent in this embodiment). As shown in FIG. 4, the bus bar 160 is made of copper. As shown in FIG. 4, the first fixing portion 161, the second fixing portion 162 parallel to the first fixing portion 161, and the connecting portion connecting the first fixing portion 161 and the second fixing portion 162. This is a U-shaped member having a predetermined thickness. In the bus bar 160, a part of the connecting portion 163 is a plastic deformation scheduled portion 164. The bus bar 160 corresponds to the inter-terminal connecting member of the present invention.

Of the bus bar 160, the first fixing portion 161 is a portion that is fixed to the external positive terminal 131 of the sealed battery 120 by welding and is electrically connected to the external positive terminal 131. As shown in FIG. 4, the first fixing portion 161 is parallel to the bus bar first welding surface 161a and the bus bar first welding surface 161a disposed at a position facing the second fixing portion 162. And a bus bar first pressing surface 161b on the opposite side.
On the other hand, the second fixing portion 162 is a portion that is fixed to the external negative electrode terminal 151 of the sealed battery 120 by welding and is electrically connected to the external negative electrode terminal 151. The second fixing portion 162 is a bus bar second welding surface 162a opposite to the bus bar first welding surface 161a of the first fixing portion 161, and is parallel to the bus bar first welding surface 162a and on the opposite side. And a bus bar second pressing surface 162b.

  Of the bus bar 160, the connecting portion 163 has a flat plate shape having a predetermined thickness and a predetermined width, and the interval between the bus bar first welding surface 161a and the bus bar second welding surface 162a is a predetermined bus bar welding surface distance Lb. In addition, the first fixing portion 161 and the second fixing portion 162 are connected. Moreover, this connection part 163 has the plastic deformation scheduled part 165 formed by bending the part so that it may mention later. The distance Lb between the bus bar welding surfaces is larger than the maximum possible value of the distance Lt between the terminal welding surfaces in consideration of the dimensional tolerance of each part of the sealed battery 120, the tolerance of the arrangement position of the sealed batteries 120, 120, and the like. It is getting bigger.

In the battery module 101 (101A, 101B), when the sealed batteries 120, 120 arranged adjacent to each other are connected to each other, the bus bar 160 has a fixing portion 161 and a second fixing portion as shown in FIGS. 162 is disposed across the sealed batteries 120, 120. The first fixing part 161 of the bus bar 160 is fixed to the external positive terminal 131 of one sealed battery 120, and the second fixing part 162 is fixed to the external negative terminal 151 of another sealed battery 120 by welding.
Specifically, when one sealed battery 120 and another sealed battery 120 adjacent thereto are arranged so that the second container side surfaces 111b and 111b of both battery containers 111 face each other. The bus bar first welding surface 161a of the first fixing part 161 is brought into contact with the terminal first welding surface 131a of the external positive electrode terminal 131 of the sealed battery 120, and the first welding portion 181 is welded to the external positive electrode terminal 131. . On the other hand, the bus bar second welding surface 162a of the second fixing portion 162 is brought into contact with the terminal first welding surface 151a of the external negative electrode terminal 151 of another sealed battery 120, and the second welding portion 182 is welded to the external negative electrode terminal 151. To do.

  In addition, when one sealed battery 120 and another sealed battery 120 adjacent thereto are arranged so that the first container side surfaces 111a and 111a of both battery containers 111 face each other, the first The bus bar first welding surface 161 a of the fixing portion 161 is brought into contact with the terminal second welding surface 131 b of the external positive electrode terminal 131 of one sealed battery 120, and the first welding portion 181 is welded to the external positive electrode terminal 131. On the other hand, the bus bar second welding surface 162a of the second fixing part 162 is brought into contact with the terminal second welding surface 151b of the external negative electrode terminal 151 of another sealed battery 120, and the second welding portion 182 is welded to the external negative electrode terminal 151. To do.

  As will be described in detail later, in the bus bar 160, the plastic deformation scheduled portion 164 includes the first fixing portion 161 and the external positive electrode terminal 131 in contact with each other, and the second fixing portion 162 and the external negative electrode terminal 151 being in contact with each other. When it comes into contact, the plastic deformation portion 165 is plastically deformed.

Next, the assembled battery 100 comprised by the battery module 101 is demonstrated using FIG.1 and FIG.2.
As shown in FIG. 1, the assembled battery 100 according to the present embodiment includes two battery modules 101 </ b> A and 101 </ b> B (101) arranged side by side. Specifically, in this assembled battery 100, one sealed battery 120 belonging to the battery module 101A and the other sealed battery 120 belonging to the battery module 101B include a third container side surface 111c of both battery containers 111, 111c and 4th container side surface 111d and 111d are arrange | positioned so that it may oppose alternately.

Among the battery modules 101 (101A, 101B) constituting the assembled battery 100, the total negative terminal 151Sa (151) of the sealed battery 120 (120Aa to 120Aj) belonging to the battery module 101A and the sealed type belonging to the battery module 101B. The total positive terminal 131Sa (131) of the battery 120 (120Ba to 120Bj) is coupled by the inter-module connection member 170.
Specifically, among the sealed batteries 120 (120Aa to 120Aj) belonging to the battery module 101A, the total negative terminal 151Sa of the sealed battery 120Aa located at the end (frontmost in FIG. 1) and the battery module 101B belong. Among the sealed batteries 120 (120Ba to 120Bj), the total positive electrode terminal 131Sa of the sealed battery 120Ba located at the end (frontmost in FIG. 1) is connected by the inter-module connection member 170.

As a result, among the sealed batteries 120 (120Aa to 120Aj) belonging to the battery module 101A, the external positive electrode terminal 131Tj of the sealed battery 120Aj located at the end opposite to the sealed battery 120Aa (the back side in FIG. 1) ( 131) serves as a total positive terminal of the assembled battery 100, and is used for connection to the outside of the assembled battery.
Similarly, the external negative electrode terminal 151Tj (151) of the sealed battery 120Bj located at the end opposite to the sealed battery 120Ba serves as a total negative electrode terminal of the assembled battery 100 and is used for connection to the outside of the assembled battery.

  Although not shown in FIGS. 1 and 2, in the assembled battery 100, an insulating sheet is disposed between the battery modules 101 </ b> A and 101 </ b> B (101), and the battery modules 101 </ b> A and 101 </ b> B (101) are insulated from each other. Has been. Further, end plates (not shown) are arranged on both sides of the assembled battery 100 (both sides in the row direction of the battery modules 101), and the entire assembled battery is restrained by a restraining band.

Next, the manufacturing method of the assembled battery 100 is demonstrated using FIG.2 and FIG.5. However, in this assembled battery 100, other than the connection of the sealed batteries 120, 120 by the bus bar 160, any known method may be used. Therefore, the bus bar 160 is sealed with the external positive terminal 131Pa (131) of the sealed battery 120Aa. The description will focus on the bus bar connection step of fixing to the external negative electrode terminal 151Pb (151) of the battery 120Ab, and the rest will be described briefly.
Hereinafter, as the sealed batteries 120 and 120 to be connected, the sealed battery 120Aa belonging to the battery module 101A and the sealed battery 120Ab adjacent thereto will be described as a representative.
That is, the bus bar 160 fixes the first fixing portion 161 to the external positive electrode terminal 131Pa (131) of the sealed battery 120Aa, and then the second fixing portion 162 contacts the external negative electrode terminal 151Pa (151) of the sealed battery 120Ab. In this way, the plastic deformation planned portion 164 is plastically deformed.

  First, the sealed battery 120 shown in FIG. 3 is manufactured by a known method. Next, the sealed batteries 120Aa and 120Ab are arranged in a state where the second container side surfaces 111b and 111b of the battery containers 111 face each other. Thereby, the terminal first welding surface 131Paa (131a) of the external positive electrode terminal 131Pa (131) and the terminal second welding surface 151Paa (151a) of the external negative electrode terminal 151Pa (151) face each other.

  Next, a bus bar connecting step for fixing the bus bar 160 to the external positive electrode terminal 131Pa (131) of the sealed battery 120Aa and the external negative electrode terminal 151Pa (151) of the sealed battery 120Ab will be described. The bus bar connecting step further includes four steps: (1) a bus bar arranging step, (2) a first fixing step, (3) a plastic deformation step, and (4) a second fixing step.

5A to 5D show the first fixed portion 161 of the bus bar 160 on the external positive terminal 131Pa (131) of the sealed battery 120Aa in FIG. 2, and the external negative terminal 151Pa (151 of the sealed battery 120Ab. ) Is an explanatory diagram for explaining a bus bar connecting step until the second fixing portions 162 of the bus bar 160 are fixed to each other.
In FIG. 5, the left-right direction is the X axis, the right is the + X direction, and the left is the -X direction. Also, the vertical direction in the figure is the Y axis, the upper direction is the + Y direction, and the lower direction is the -Y direction.

In the bus bar arrangement step, the bus bar 160 is arranged so that the plastic deformation scheduled portion 164 faces the container third side surface 111c of the sealed battery 120Aa and the container fourth side surface 111d of the sealed battery 120Ab, and the first fixing portion 161 and the first The external positive electrode terminal 131Pa (131) and the external negative electrode terminal 151Pa (151) are positioned between the two fixing portions 162, and are disposed so as to straddle the sealed batteries 120Aa and 120Ab (see FIG. 5A).
Specifically, the first fixing portion 161 of the bus bar 160 is arranged on the external positive electrode terminal 131Pa (131) side, and the second fixing portion 162 is arranged on the external negative electrode terminal 151Pa (151) side. As a result, the bus bar first welding surface 161a of the first fixing portion 161 and the terminal first welding surface 131Paa (131a) of the external positive terminal 131Pa (131) face each other, and the bus bar second welding surface of the second fixing portion 162. 162a and the terminal first welding surface 151Paa (151a) of the external negative electrode terminal 151Pa (151) face each other.

Next, in the first fixing step shown in FIG. 5B, the first fixing portion 161 of the bus bar 160 is fixed to the external positive electrode terminal 131Pa (131).
Specifically, the first support surface 230a of the welding support member 230 is brought into contact with the terminal second welding surface 131Pab (131b) of the external positive electrode terminal 131Pa (131). On the other hand, the pressing surface 210 a of the first welding pressing member 210 is brought into contact with the bus bar first contact surface 161 b of the first fixing portion 161 of the bus bar 160. In this state, the first welding pressing member 210 is moved in the + Y direction until the bus bar first welding surface 161a of the first fixing portion 161 and the terminal first welding surface 131Paa (131a) of the external positive electrode terminal 131Pa (131) contact each other. Move. As a result, the external positive electrode terminal 131Pa (131) and the first fixing portion 161 are sandwiched between the first welding pressing member 210 and the welding support member 230. Next, in this state, the interface between the bus bar first welding surface 161a and the terminal first welding surface 131Paa (131a) is joined by ultrasonic welding to form the first welding portion 181. As a result, the first fixing portion 161 of the bus bar 160 and the external positive terminal 131Pa (131) are fixed to each other.

Next, in the plastic deformation step shown in FIG. 5C, the plastic deformation planned portion 164 of the bus bar 160 is plastically deformed so that the position of the second fixing portion 162 matches the position of the external negative electrode terminal 151Pa (151).
Specifically, the second support surface 230b of the welding support member 230 is brought into contact with the terminal second welding surface 151Pab (151b) of the external negative electrode terminal 151Pa (151). The first pressing member 240 is arranged so that the connecting portion 163 of the bus bar 160 is positioned substantially in the center in the X-axis direction of the first pressing member 240, and the pressing surface 240 a of the first pressing member 240 is the first fixing portion 161. The bus bar is brought into contact with the first welding surface 161a. Separately, the second pressing member 250 is arranged so that the connecting portion 163 is positioned at the center in the X-axis direction of the second pressing member 250, and the pressing surface 250 a of the second pressing member 250 is a bus bar of the second fixing portion 162. It abuts on the second abutment surface 162b. Thereby, the connection part 163 of the bus bar 160 is sandwiched between the first pressing member 240 and the second pressing member 250.

Next, in a state where the first pressing member 240 supports the first fixing portion 161 of the bus bar 160 and the welding support member 230 supports the external negative electrode terminal 151Pa, the bus bar second welding surface 162a of the second fixing portion 162 is the external negative electrode terminal. The second pressing member 250 is moved in the -Y direction to a position where it comes into contact with the first welding surface 151Paa (151a) of 151 Pa and can be fixed by welding in the second fixing step described below. The second fixing portion 162 of 160 is pressed.
Specifically, the second pressing member 250 is pressed until the distance between the bus bar first welding surface 161a and the bus bar second welding surface 162a is reduced from the bus bar welding surface distance Lb to the bus bar welding surface distance Lb. The bus bar second welding surface 162a and the terminal first welding surface 151Paa (151a) are brought into contact with each other. As a result, the plastic deformation planned portion 164 of the connecting portion 163 of the bus bar 160 mainly undergoes plastic deformation to become a plastic deformation portion 165 (see FIG. 5C).

In this embodiment, since the plastic deformation planned portion 164 is provided in the connecting portion 163, the plastic deformation planned portion 164 is easily and greatly plastically deformed. For this reason, even when the first pressing member 240 and the second pressing member 250 are removed, the spring back is small and the bus bar second welding surface 162a can be kept close to the terminal first welding surface 151Paa (151a). .
Further, since the plastic deformation scheduled portion 164 is deformed after the first fixing portion 161 is fixed to the external positive electrode terminal 131Pa (131), the position of the second fixing portion 162 is adapted to the external negative electrode terminal 151Pa (151). It is sufficient to make the deformation, and the size of the deformation can be easily determined. There is also an advantage that the second fixing portion 162 can be fixed immediately after the deformation.

Next, as shown in FIG. 5 (d), the second fixing portion 162 of the bus bar 160 and the external negative terminal 151Pa (151) are fixed in the second fixing step.
Specifically, the second fixing portion 162 is in a state where the bus bar second welding surface 162a and the first welding surface 151Paa (151a) are sandwiched between the second welding pressing member 220 and the welding support member 230. Next, in this state, the interface between the bus bar second welding surface 162a and the terminal first welding surface 151Paa (151a) is joined by ultrasonic welding to form the second welding portion 182. As a result, the second fixing portion 162 of the bus bar 160 and the external negative terminal 151Pa (151) are fixed to each other.

Thus, the sealed battery 120Aa belonging to the battery module 101A and the adjacent sealed battery 120Ab are connected to the external positive terminal 131Pa of the sealed battery 120Aa and the external negative terminal 151Pa of the sealed battery 120Ab by the bus bar 160. Are connected in series.
The sealed battery 120Aa corresponds to the first unit battery of the present invention, and the sealed battery 120Ab corresponds to the second unit battery.

  Further, in the battery module 101 (101A, 101B) constituting the assembled battery 100, the sealed batteries 120, 120 other than the sealed batteries 120Aa, 120Ab are also similar to the above-described connection between the sealed batteries 120Aa, 120Ab. The bus bar 160 is plastically deformed and connected through the bus bar connecting step. Thus, the battery module 101 (101A, 101B) shown in FIG. 1 is formed.

Then, the manufacturing method of the assembled battery 100 is demonstrated.
After the battery modules 101A and 101B (101) are manufactured, the battery modules 101A and 101B are arranged in a row with an insulating sheet (not shown) interposed therebetween, and are connected by a connecting member 170.
Specifically, among the sealed batteries 120 (120Aa to 120Aj) belonging to the battery module 101A, the external negative electrode terminal 151Sa (151) of the sealed battery 120Aa and the sealed batteries 120 (120Ba to 120Bj) belonging to the battery module 101B. Of these, the external positive terminal 131Sa (131) is coupled by the connecting member 170. Thereafter, the battery modules 101A and 101B arranged in a row are restrained by an end plate and a restraining band (not shown). Thus, the assembled battery 100 is completed.

In the assembled battery 100 according to the present embodiment, among the sealed batteries 120 belonging to one battery module 101, the sealed batteries 120 and 120 arranged adjacent to each other are connected to each other by a bus bar including a plastic deformation scheduled portion 165. 160 was used. In fixing the bus bar 160 to the external positive terminal 131 of one sealed battery 120 and the external negative terminal 151 of another sealed battery 120 adjacent to the sealed battery 120, the first fixing portion 161 and the second fixing portion 161 The plastic deformation planned portion 164 of the bus bar 160 is plastically deformed so that the position of the fixing portion 162 matches the position of the external positive electrode terminal 131 and the external negative electrode terminal 151, respectively.
Moreover, in the bus bar 160, the distance Lb between the bus bar weld surfaces, which is the distance between the bus bar first weld surface 161a and the bus bar second weld surface 162a, is the dimensional tolerance of each part of the sealed battery 120 or between the sealed batteries 120, 120. This is larger than the maximum possible value of the distance Lt between the terminal welding surfaces in consideration of the tolerance of the arrangement position of the terminal.

Thereby, even if the size of the sealed battery 120 and the positions of the external positive electrode terminal 131 and the external negative electrode terminal 151 vary, the positions of the first fixed portion 161 and the second fixed portion 162 are always changed to the external positive terminal 131 and It can be adapted to the position of the external negative terminal 151, respectively.
Accordingly, the bus bar 160 is connected to the external positive terminal 131 and the external negative terminal 151 in a state where the first fixed part 161 is disposed at the external positive terminal 131 and the second fixed part 162 is disposed at the appropriate position. It becomes possible to fix.

In the plastic deformation step, the plastic deformation planned portion 164 of the bus bar 160 is plastically deformed.
Accordingly, in the embodiment, after the assembled battery 100 or the battery module 101 is completed, the first fixing portion 162 and the external positive terminal 131 are separated from each other, or the second fixing portion 162 and the external negative terminal 151 are separated from each other. It is possible to suppress the directional stress (elastic force) from remaining on the bus bar 160.
Even if residual stress remains, the magnitude of the residual stress can be reduced by elastic deformation of the plastic deformation scheduled portion.
Accordingly, the stress that separates the bus bar 160 from the external positive terminal 131 and the external negative terminal 151 is prevented from being generated in the bus bar 160, and the residual stress continues to be applied to the external positive terminal 131 and the external negative terminal 151. These deformations and damages do not occur. Therefore, it is possible to obtain the assembled battery 100 in which the sealed batteries 120 and 120 are fixedly connected to the bus bar 160 with high reliability.

In addition, since the connecting portion 163 of the bus bar 160 is a flat plate having a predetermined thickness and a predetermined width, there is no significant difference in the cross-sectional area of the bus bar 160 itself in the entire connecting portion 163 including the plastic deformation portion 165.
Accordingly, the connection portion 163 can prevent an increase in conduction resistance and local heat generation due to the fact that the cross-sectional area of the connection portion 163 is particularly small as compared with other portions. It is also possible to prevent the deterioration of characteristics at.

(Modification)
Next, a modification will be described with reference to FIG.
The assembled battery 300 according to this modification is different from the assembled battery 100 according to the above-described embodiment only in the shape of the inter-terminal connection member used for this, and the other parts are the same. Therefore, description of the same part as an Example is abbreviate | omitted or simplified, and will explain centering on a different part.

  In the assembled battery 300 according to this modification, the bus bar 360 is made of copper, and is made of an S-shaped flat plate as shown in FIG. The bus bar 360 includes a first fixing portion 361 located at both ends, a second fixing portion 362 parallel to the first fixing portion 361, and a connecting portion 363 that connects the first fixing portion 361 and the second fixing portion 362. Of the bus bar 160, the connecting portion 363 includes a first connecting portion 363A that connects the first fixing portion 361, a second connecting portion 363B that connects the second fixing portion 362, and the first fixing portion 361 and the second fixing portion 362. And an intermediate connecting portion 363C that connects the first connecting portion 363A and the second connecting portion 363B. The first connecting portion 363A and the second connecting portion 363B are located on the opposite sides in the plate width (upper left and lower right in FIG. 6) direction of the external positive electrode terminal 131 and the external negative electrode terminal 151, and are parallel to each other.

  In the bus bar 160, the first plastic deformation planned portion 364A that connects the first connecting portion 363A and the intermediate connecting portion 363C is plastically deformed in the plastic deformation step as in the above-described embodiment, and the first plastic deforming portion 365A. Become. In addition, the second plastic deformation planned portion 364B connecting the second connection portion 363B and the intermediate connection portion 363C is plastically deformed to become the second plastic deformation portion 365B in the plastic deformation step.

Of the bus bar 360, the first fixing portion 361 includes a bus bar first welding surface 361a on the intermediate coupling portion 363C side, and a bus bar first pressing surface 361b on the opposite side. The bus bar first welding surface 361 a is in contact with the terminal first welding surface 131 a or the terminal second welding surface 131 b of the external positive electrode terminal 131.
On the other hand, the 2nd adhering part 362 has the bus-bar 1st welding surface 362a in the intermediate | middle connection part 363C side, and the bus-bar 2nd press surface 362b which is the surface of the other side. The bus bar second welding surface 362a is in contact with the terminal first welding surface 151a or the terminal second welding surface 151b of the external negative electrode terminal 151.

In this modification, in the plastic deformation step, the bus bar 360 plastically deforms the first plastic deformation planned portion 365A and the second plastic deformation planned portion 365B, respectively.
Thus, after the assembled battery 300 or the battery module 101 is completed, the stress (in the direction in which the first fixing portion 362 and the external positive electrode terminal 131 are separated from each other, or the second fixing portion 362 and the external negative electrode terminal 151 are separated from each other ( (Elastic force) can be suppressed from remaining on the bus bar 360.
Therefore, the stress that separates the bus bar 360 from the external positive terminal 131 and the external negative terminal 151 is prevented from being generated in the bus bar 360, and the residual stress continues to be applied to the external positive terminal 131 and the external negative terminal 151, thereby These deformations and damages do not occur. Therefore, it is possible to obtain the assembled battery 100 in which the sealed batteries 120 and 120 are fixedly connected to the bus bar 360 with high reliability.

In the above, the present invention has been described with reference to the embodiments and the modified examples. However, the present invention is not limited to the above-described embodiments and the like, and it can be applied as appropriate without departing from the gist thereof. Not too long.
For example, in the example and the modification, ten sealed batteries 120 are arranged in series. However, the number of the sealed batteries connected by the inter-terminal connecting member and the connection form of the sealed batteries can be appropriately changed.
In the embodiment, the sealed batteries 120 and 120 belonging to the battery modules 101 </ b> A and 101 </ b> B are connected by the flat connection member 170. However, the connection form of the first electrode terminal and the second electrode terminal between the battery modules is not limited to the illustrated connection member 170 and can be changed as appropriate.

Further, in the embodiment, after the first fixing portion 161 of the bus bar 160 is fixed to the external positive electrode terminal 131, the plastic deformation scheduled portion 164 is plastically deformed in the plastic deformation step so that the second fixing portion 162 becomes the external negative electrode terminal 151. Stuck. However, after the electrode terminal on the negative electrode side is fixed to the inter-terminal connecting member, in the plastic deformation step, the plastic deformation scheduled portion may be plastically deformed to fix the positive electrode terminal.
Further, the dimensions between the external positive terminal 131 and the external negative terminal 151 are individually measured, and the connecting portion 163 of the bus bar 160 is deformed according to the dimensions, and then the bus bar 160 is connected to the external positive terminal 131 and the external negative terminal 151. It may be fixed to.
In the example, the bus bar 160 was fixed to the external positive terminal 131 and the external negative terminal 151 by ultrasonic welding. However, if the inter-terminal connecting member and the electrode terminal can be fixed to each other by welding means such as laser welding or resistance welding, the inter-terminal connecting member and the electrode terminal may be fixed other than by ultrasonic welding.

It is a perspective view which shows a part of assembled battery which concerns on an Example. It is a perspective view which shows a part of battery module which comprises the assembled battery which concerns on an Example. It is a figure which shows the sealed type cell which concerns on an Example, (a) is a top view, (b) is a front view. It is a perspective view which shows the bus bar used for the battery module which concerns on an Example. It is a figure which shows each process until it connects a sealed cell with a bus bar about the battery module which concerns on an Example, (a) is a bus-bar arrangement | positioning process, (b) is a 1st adhering process, (c) is plasticity. Deformation step (d) is the second fixing step. It is a perspective view which shows the state which connected the external positive electrode terminal and external negative electrode terminal of sealed type cells with the bus-bar which concerns on a modification.

Explanation of symbols

100,300 battery pack 120 sealed cell (unit battery)
120Aa sealed battery (first unit battery)
120Ab sealed battery (second unit battery)
131 External positive terminal (first electrode terminal)
131 Pa External positive terminal (first unit cell) 151 External negative terminal (second electrode terminal)
160, 360 Bus bar (inter-terminal connecting member)
161, 361 First fixing portion (on the positive terminal side) 162, 362 Second fixing portion (on the negative terminal side) 163, 363 Connection portion 164 Plastic deformation planned portion 165 Plastic deformation portion Lb (Bus bar first welding surface and bus bar first Distance between bus bar welding surfaces (with 2 welding surfaces) Lt Distance between terminal welding surfaces (with terminal first welding surface and terminal second welding surface)

Claims (5)

A plurality of unit cells having electrode terminals;
Among the plurality of unit cells, a first electrode terminal of the first unit cell and the second unit cell in a first unit cell and a second unit cell in which a relative position to the first unit cell is fixed. An inter-terminal connecting member that is electrically connected to the second electrode terminal,
A first fixing portion fixed to the first electrode terminal;
A second fixing portion fixed to the second electrode terminal; and
An inter-terminal connecting member having a connecting portion connecting the first fixing portion and the second fixing portion, and a manufacturing method of an assembled battery comprising:
The plastic deformation planned portion that is at least a part of the connection portion of the inter-terminal connection member is plastically deformed to form a plastic deformation portion, and the inter-terminal connection member is positioned at the positions of the first fixing portion and the second fixing portion. A method for manufacturing an assembled battery, comprising a plastic deformation step in which each of the first electrode terminal and the second electrode terminal is adapted to the position. It is a manufacturing method of the assembled battery according to claim 1,
The inter-terminal connecting member is
Before the plastic deformation step, an interval between the first fixing portion and the second fixing portion is made larger than an interval between the first electrode terminal and the second electrode terminal,
A first fixing step of fixing the first fixing portion to the first electrode terminal in a state where the second fixing portion is brought close to the second electrode terminal;
A plastic deformation step in which the second fixing portion is disposed at a position where the second fixing portion can be fixed to the second electrode terminal;
A method for manufacturing an assembled battery, comprising: a second fixing step of fixing the second fixing portion to the second electrode terminal after the plastic deformation step. A method for producing an assembled battery according to any one of claims 1 and 2,
The plastic deformation portion is
A method for producing an assembled battery, which is a bent portion formed by bending a part of the flat plate-like connecting portion having a predetermined thickness and a predetermined width. A plurality of unit cells having electrode terminals;
Among the plurality of unit cells, a first electrode terminal of the first unit cell and the second unit cell in a first unit cell and a second unit cell in which a relative position to the first unit cell is fixed. An inter-terminal connecting member that is electrically connected to the second electrode terminal,
A first fixing portion fixed to the first electrode terminal;
A second fixing portion fixed to the second electrode terminal; and
An inter-terminal connecting member having a connecting portion connecting the first fixing portion and the second fixing portion,
In fixing the inter-terminal connecting member to the first electrode terminal and the second electrode terminal, at least a part of the connecting portion of the inter-terminal connecting member, the positions of the first fixing portion and the second fixing portion are An assembled battery having a plastically deformed portion that is plastically deformed so as to conform to the positions of the first electrode terminal and the second electrode terminal, respectively. The assembled battery according to claim 4,
The plastic deformation portion is
A part of the flat plate-like connecting portion having a predetermined thickness and a predetermined width is bent, and is further plastically deformed when the inter-terminal connecting member is fixed to the first electrode terminal and the second electrode terminal. An assembled battery that is a bent portion.

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