JP5151027B2 - Assembled battery - Google Patents

Description

  The present invention relates to an assembled battery including a plurality of battery modules including a single battery, and more particularly, to an assembled battery in which a positive electrode part and a negative electrode part of battery modules arranged adjacent to each other are electrically connected.

Conventionally, a battery pack in which a plurality of battery modules including a plurality of single cells are arranged adjacent to each other and the positive electrode portion and the negative electrode portion of these battery modules are electrically connected is known.
For example, the assembled battery 900 shown in FIG. 8 is mentioned. The assembled battery 900 includes a plurality of battery modules 920 in which a plurality of sealed batteries (unit cells) 910 are connected in series. The sealed battery 910 has a rectangular parallelepiped shape and includes a battery container 911 that is a negative electrode as a whole. An external positive terminal 913 serving as a positive electrode is fixed to the battery container 911 while maintaining electrical insulation from the battery container 910. The battery module 920 is electrically connected in series and in a row by connecting the external positive electrode terminal 913 of one sealed battery 910 to the end surface 911b of the battery container 911 of another sealed battery 910 adjacent thereto. It is lined up. The battery modules 920 are arranged in parallel with each other, and the positive electrode (external positive terminal 913) and the negative electrode (end surface 911b of the battery container 911) of the adjacent battery modules 920 are arranged in opposite directions.

  Among the sealed batteries 910 belonging to each battery module 920, a positive electrode pole member 950 is welded to the external positive terminal 913 of the sealed battery 910 having the highest potential. In addition, among the sealed batteries 910 belonging to each battery module 920, the negative electrode pole member 960 is welded to the end surface 911b of the sealed battery 910 having the lowest potential. The positive electrode pole member 950 and the negative electrode pole member 960 that are adjacent to each other in a state where the assembled battery 900 is configured are provided with an insulating case 973 that houses a plurality of bus bars 971 together with the bus bars 971, and these are nuts 975. It is concluded by

Thus, in the conventional assembled battery 900, the positive electrode pole member 950 is provided on the external positive electrode terminal 913 of the battery module 920, the negative electrode pole member 960 is provided on the end surface 911b forming the negative electrode of the entire battery module, and these are further connected to the bus bar 971. The insulation case 973 and the nut 975 were used for electrical connection.
In addition, patent document 1 is mentioned as a prior | preceding literature relevant to another prior art.

JP 2001-57196 A

  However, in the assembled battery 900 as shown in FIG. 8, it is necessary to provide a pole member (positive pole member 950, negative pole member 960) for each battery module 920, and a bus bar 971, an insulating case 973, Since the nut 975 is also required, the parts cost and the assembling cost are increased in the connection between the battery modules 920. As a result, the cost of the assembled battery 900 is increased.

  The present invention has been made in view of such a current situation, and in an assembled battery in which battery modules arranged adjacent to each other are electrically connected to each other, the connection reliability is ensured while being cheaper than before. An object of the present invention is to provide an assembled battery that can be used.

Its resolution means is a battery pack including a plurality of battery modules including a single cell of multiple, the single cell is a power generating element comprising a positive electrode and a negative electrode made of a conductive material a rectangular parallelepiped shape, electrically connected to the negative electrode A battery container, a first container surface, a second container surface parallel to the first container surface, a third container surface connecting the first container surface and the second container surface, a fourth container surface parallel to the third container surface, A battery container including an upper surface of the container and a lower surface of the container parallel to the container, and electrically connected to the positive electrode and electrically insulated from the first container surface. A portion of the external positive electrode terminal exposed to the outside of the battery container, the external positive electrode terminal including an extended weld portion extending perpendicularly to the first container surface; The first container surface of the unit cell and the second container surface of the other unit cell; The external positive terminal of the one unit cell is brought into contact with the second container surface of the other unit cell, and the extended welded portion of the external positive terminal of the one unit cell is the other unit. A plurality of the single cells constituting the battery module are electrically connected in series and arranged in a row by welding in a form that overlaps at least one of the third container surface and the fourth container surface of the unit cells from the outside. The plurality of battery modules include a first battery module and a second battery module arranged adjacent to each other, and the single battery belonging to the first battery module is the second battery. A first connection unit cell connected to the module, wherein the unit cell belonging to the second battery module includes a second connection unit cell connected to the first connection unit cell of the first battery module; Single connection When the second connecting unit cells will be arranged next to one another, said first connection unit cell has the extended welded portion of the external positive terminal is a positive portion electrically connected to the positive electrode, the first 2 connecting the single cells have the second container surface of the battery case is a negative electrode portion electrically connected to the negative electrode, the first of the second connecting unit cells and the extending welded portion of the first connecting unit cells The two-vessel surface refers to a positive electrode welded portion welded to the extended welded portion of the first connection unit cell and a negative-electrode welded portion welded to the second container surface of the second connection unit cell. It is an assembled battery that is electrically connected via a connecting member.

According to the present invention, in the first battery module and the second battery module arranged adjacent to each other, the positive electrode portion (extended weld portion of the external positive electrode terminal) of the first connection cell belonging to the first battery module; The negative electrode part (second container surface of the battery container) of the second connection unit cell belonging to the second battery module is welded to the positive electrode part (extended weld part of the external positive electrode terminal ) and the negative electrode It is electrically connected via a connecting member integrally having a negative electrode welded portion welded to a site (second container surface of the battery container) . In such an assembled battery, since the battery modules are electrically connected to each other by the connecting member, it is not necessary to provide the pole column member and fasten it with the bus bar, the insulating case, and the nut unlike the conventional assembled battery. For this reason, component cost and assembly cost can be reduced in the connection between battery modules. Therefore, the assembled battery can be made inexpensive while securing the connection reliability between the battery modules.

As described above, the “connecting member” includes the positive electrode welded portion welded to the positive electrode portion of the first connection unit cell ( extended weld portion of the external positive terminal) and the negative electrode portion of the second connection unit cell (of the battery container). A negative electrode welded portion that is integrally welded to the second container surface) may be used as long as it integrally connects the positive electrode portion and the negative electrode portion, and the shape and material thereof can be changed as appropriate. However, in order to reduce the cost of the assembled battery, it is preferable to use a connection member that is integrally formed of a conductive material and has a simple shape.

Furthermore, a battery pack of the previous SL battery module together are Retsu置in parallel to each other, the first connecting unit cells, among the unit cells belonging to the first battery module, having the highest potential The second connected single cell is a single cell having the lowest potential among the single cells belonging to the second battery module, and the extended welded portion of the first connected single cell is: said first connecting a first container surface of the cell, located within the external positive electrode terminal formed in the first vessel surface a row location direction of the end of the unit cells of the first battery module, wherein The second container surface of the second connection unit cell is a second container surface forming an end of the unit cells in the arrangement direction of the second battery module , and the first container surface of the first connection unit cell. And the second container surface of the second connection unit cell are the same virtual May the battery pack are arranged in a plane.

According to the present invention, the battery modules are formed by arranging the rectangular parallelepiped cells, and the battery modules are also arranged. And a positive electrode site | part (extension welding part of a 1st connection single cell ) is located in the external positive electrode terminal formed in the 1st container surface among the 1st connection single cells, and a negative electrode site | part (2nd connection cell single cell). The second container surface) is located within the second container surface of the second connected single cells, and the first container surface and the second container surface are flush with each other, that is, on the same virtual plane. Yes. Because of these have a relationship, a positive electrode site located within the external positive electrode terminal (extended welds), sufficient connection member is also simple shape for connecting the negative electrode portion (second container surface). Also, the welding of the negative electrode weld external positive terminal cathode site (extended welds) located in a child and welding the positive electrode weld connecting member is also connected to the negative electrode portion (second container surface) member, It can be done easily.

Furthermore, it is an assembled battery according to any one of the above, wherein the connection member is provided between the positive electrode welded portion and the negative electrode welded portion, the extended welded portion of the first connected single cell and the second electrode. It is preferable that the assembled battery includes a fluctuation absorbing portion having a structure that maintains the connection by absorbing the fluctuation of the connection distance between the connected unit cells and the second container surface .

If there is a dimensional variation between the battery modules arranged adjacent to each other when the battery modules are arranged in a row, there is a possibility that the connection member cannot be welded to a predetermined position of the battery module when welding the connection member. In addition, if the battery case of a single cell is deformed due to thermal expansion during use of the assembled battery, the distance between the battery modules will fluctuate, placing a burden on the connection member connecting the battery modules, and damaging the connection member itself. Or the welded portion between the connecting member and the battery module may be damaged.
On the other hand, in this invention, a connection member is equipped with the fluctuation | variation absorption part which has a structure which absorbs the fluctuation | variation of the connection distance between a positive electrode welding part and a negative electrode welding part, and maintains a connection. By providing such a fluctuation absorbing part, even if the dimensional variation of the connection distance at the time of manufacture and the fluctuation of the connection distance at the time of use occur, these fluctuations are absorbed by the fluctuation absorbing part, Can be connected. Therefore, the connection reliability between battery modules can be further improved.

  Further, in the above assembled battery, the connection member is made of a metal plate material, and the fluctuation absorbing portion is a bent battery having a bent fluctuation absorbing portion formed by bending the metal plate material into a U shape or a waveform. good.

As described above, the connecting member is welded to the positive electrode welded portion (extended weld portion) of the first connected single cell and the negative electrode welded to the negative electrode portion (second container surface) of the second connected single cell. The shape and the like can be changed as appropriate if the positive electrode portion and the negative electrode portion are electrically connected. However, the more complicated the shape, the more difficult it is to manufacture and the higher the cost.
On the other hand, in the present invention, the connecting member is made of a metal plate material, and the fluctuation absorbing portion is formed by bending the metal plate material into a U shape or a waveform. By doing in this way, a connection member can be formed easily and cheaply. As a result, the assembled battery can be made inexpensive.

  Furthermore, it is an assembled battery according to any one of the above, and it is preferable that all the battery modules belonging to the assembled battery are electrically connected to each other by the connecting member.

  Thus, if all the battery modules belonging to the assembled battery are electrically connected to each other by the connecting member, the assembled battery can be made cheaper.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows a part of an assembled battery 100 according to this embodiment. 2 shows a view from the positive electrode side of the battery module 120 constituting the assembled battery 100, and FIG. 3 shows a view from the negative electrode side. Further, FIG. 4 shows a sealed battery (unit cell) 110 constituting the battery module 120.

The assembled battery 100 is a secondary battery such as a nickel hydride storage battery or a lithium ion battery that is used as a power source for an electric vehicle or a hybrid car.
As shown in FIG. 4, the sealed battery 110 included in the assembled battery 100 is a rectangular battery having a substantially rectangular parallelepiped shape. The sealed battery 110 includes a battery container 111 having a rectangular parallelepiped shape, a power generation element (not shown) housed in the battery container 111, an external positive terminal 113 fixed to the battery container 111, and the like. The electrolyte is injected.

  The battery container 111 is made of a conductive material (nickel-plated steel plate), and is positioned in parallel with a flat and rectangular first container side surface (first container surface) 111a (a surface facing the lower left in FIG. 4). The second container side surface (second container surface) 111b (the surface facing the upper right not shown in FIG. 4) having the same shape as the first container side surface 111a, the long side of the first container side surface 111a, and the length of the second container side surface 111b A flat and rectangular container that connects the rectangular and rectangular third container side surface 111c and the fourth container side surface 111d, and the short side of the first container side surface 111a and the short side of the second container side surface 111b. It has an upper surface 111e and a container lower surface 111f. The battery container 111 is electrically connected to the negative electrode of the power generation element, and the whole is a negative electrode.

  Two through holes are formed in the first container side surface 111a at predetermined intervals in the longitudinal direction, and the external positive electrode terminal 113 is fixedly provided. Each external positive electrode terminal 113 is fixedly installed in a state of being electrically insulated from the first container side surface 111 a forming a negative electrode via a seal member 115. The external positive terminal 113 is electrically connected to the positive electrode of the power generation element via a positive current collector plate (not shown), and serves as a positive electrode in each sealed battery 110. The container upper surface 111e is formed with a through hole at substantially the center thereof, and a safety valve 115 is fixed.

  The external positive electrode terminal 113 is parallel to the first container side surface 111a of the battery container 111 from the other end (battery outside side) of the pole column part 113a having a hollow cylindrical shape with one end (battery inner side) closed. A terminal flange 113b extending to the first container side, and four extending welds 113c extending vertically from the terminal flange 113b to the first container side surface 111a of the battery container 111.

  Each extending weld 113c has the first container side surface 111a of the sealed battery 110 opposed to the second container side surface 111b of the other sealed battery 110, and the external positive electrode terminal 113 of the sealed battery 110 is connected to the other When brought into contact with the second container surface 111b of the sealed battery 110, the third container side face 110c and the fourth container side face 110d of the other sealed battery 110 are welded and overlapped from the outside (see FIG. 1 to FIG. 3). Specifically, of the four extended welds 113 c included in one external positive electrode terminal 113, the two extended welds 113 c positioned on the third container side surface 111 c side are the third of the other sealed batteries 110. Of the container side surface 111c, it overlaps from the outside so that it can be welded to the vicinity of the boundary with the second container side surface 111b. Further, the other two extending welds 113c overlap from the outside so as to be weldable to a portion in the vicinity of the boundary with the second container side surface 111b among the fourth container side surface 111d of the other sealed battery 110.

  Next, the battery module 120 constituted by the sealed battery 110 will be described (see FIGS. 2 and 3). In the present embodiment, the battery module 120 includes ten sealed batteries 110 (110A to 110J) arranged in a row. The battery module 120 is electrically connected in series by connecting the external positive terminal 113 of one sealed battery 110 to the second container side surface 111b of the battery container 111 of another sealed battery 110 adjacent thereto. It is arranged in a line. Specifically, the pole portion 113 a of the external positive terminal 113 of one sealed battery 110 is in contact with the second container surface 111 b of another sealed battery 110. Of the four extended welds 113 c of the external positive terminal 113 of one sealed battery 110, the two extended welds 113 c located on the third container side surface 111 c side are the second extended welds 113 c of the other sealed battery 110. Of the three container side surfaces 111c, welding is performed in a state of overlapping from the outside to the vicinity of the boundary with the second container side surface 111b (the welded portion is indicated by a black circle in the figure). Further, the other two extended welds 113c are welded in a state where they overlap from the outside in the vicinity of the boundary with the second container side surface 111b in the fourth container side surface 111d of the other sealed battery 110 ( Similarly, the welded part is indicated by a black circle in the figure).

Of the sealed batteries 110 (110A to 110J) belonging to the battery module 120, a sealed battery 110A (a sealed battery located on the lower left side in FIG. 2) having the highest potential (on the positive potential side) is This corresponds to the “first connected unit cell” of the present invention. Of the sealed battery 110A, a total of eight extended welds 113c of the external positive electrode terminal 113 correspond to the “positive electrode portion” of the present invention.
Further, among the sealed batteries 110 (110A to 110J) belonging to the battery module 120, a sealed battery 110J having the lowest potential (the highest potential on the negative potential side) (a sealed battery located on the lower left side in FIG. 3). ) Corresponds to the “second connected cell” of the present invention. Of the sealed battery 110J, the second container side surface 111b corresponds to the “negative electrode part” of the present invention.

Next, the assembled battery 100 including the battery module 120 will be described (see FIG. 1). In the present embodiment, the assembled battery 100 is formed by stacking six battery modules 120 (120A to 120F). In the battery modules 120, the positive electrode (positive electrode external terminal 113) and the negative electrode (second container side surface 111 b of the battery container 111) of each sealed battery 110 included in the adjacent battery modules 120 are adjacent to each other. , Alternately oriented in opposite directions and parallel to each other.
Of the sealed batteries 110 (110A to 110J) belonging to one battery module 120, the sealed battery (first connected single battery) 110A having the highest potential, and another battery module adjacent to the battery module 120. Among the sealed batteries 110 (110A to 110J) belonging to 120, the sealed battery (second connected single battery) 110J having the lowest potential is arranged adjacent to each other. Further, the first container side surface 111a of the sealed battery (first connected single cell) 110A and the second container side surface 111b of the sealed battery (second connected single battery) 110J are flush with each other, that is, the same virtual plane. Is placed inside.

Of the battery modules 120 (120A to 120F) constituting the assembled battery 100, the positive electrode pole member 150 or the negative electrode pole member 160 is welded to the battery modules 120A and 120F located on both sides.
Specifically, the battery module 120A is located at one end side (left side in FIG. 1) of the assembled battery 100 and has the highest potential among the battery modules 120A having the highest potential (on the positive potential side) in the assembled battery 100. A positive electrode pole member 150 shown in FIG. 5 is welded to the external positive electrode terminal 113 of the sealed battery 110A having a potential (front in FIG. 1). The positive electrode pole member 150 serves as a positive electrode of the assembled battery 100 and is used for connection to the outside of the assembled battery.

  The positive electrode pole member 150 includes a positive electrode main body portion 151 that forms a skeleton of the positive electrode pole column member 150, a positive electrode pole column portion 153 that protrudes from the positive electrode main body portion 151 and is directly used for connection to the assembled battery 100 from the outside, The positive electrode main body portion 151 includes a total of eight positive electrode extension portions 155 extending in the same direction as the positive electrode pole column portion 153. Among these, for the positive electrode main body portion 151, four positive electrode extension portions 155 are provided, and two plate-like positive electrode first seat portions 151 a that are in contact with the external positive electrode terminals 113 of the sealed battery 110, respectively, A plate-like positive second seat 151b provided with the positive pole post 153, located on the positive pole post 153 side of the positive first seat 151a, and the positive first seat 151a and the positive second It consists of two substantially plate-like positive electrode walls 151c that connect the seat 151b.

  The positive electrode pole member 150 and the external positive electrode terminal 113 of the sealed battery 110A contact the two positive electrode first seat portions 151a of the positive electrode pole member 150 with the electrode column portion 113a of the external positive electrode terminal 113, respectively. In addition, the positive electrode extension members 155 of the positive electrode pole member 150 are joined to each other by welding them in a state of being overlapped on the inner side of the extension welding portions 113 c of the external positive electrode terminals 113.

  On the other hand, the lowest potential among the battery modules 120F located on the other end side (right side in FIG. 1) of the assembled battery 100 and having the lowest potential (highest potential on the negative potential side) in the assembled battery 100. A negative electrode pole member 160 shown in FIG. 6 is welded to the second container side surface 111b of the sealed battery 110J (front in FIG. 1). The negative electrode pole member 160 becomes a negative electrode of the assembled battery 100 and is used for connection to the outside of the assembled battery.

  The negative electrode pole member 160 includes a negative electrode main body portion 161 that forms a skeleton of the negative electrode polar column member 160, and a negative electrode pole column portion 163 that protrudes from the negative electrode main body portion 161 and is directly used for connection to the assembled battery 100 from the outside. It is configured. Among these, the negative electrode main body 161 is welded to the second container side surface 111b of the sealed battery 110, and is divided into two substantially plate-like negative electrode first seats 161a, and the negative electrode first seats. The plate-shaped negative electrode second seat portion 161b, which is located on the negative electrode pole column portion 163 side with respect to 161a and provided with the negative electrode pole column portion 163, is connected to the negative electrode first seat portion 161a and the negative electrode second seat portion 161b. It consists of two substantially plate-shaped negative electrode walls 161c.

  The negative electrode pole member 160 and the second container surface 111b of the sealed battery 110J contact the two negative electrode first seats 161a of the negative electrode pole member 160 with the second container side surface 111b of the sealed other battery 110J, respectively. In such a state, they are joined together by welding.

Next, connection between battery modules 120 (120A to 120F) constituting the assembled battery 100 will be described (see FIG. 1).
All the battery modules 120 (120A to 120F) belonging to the assembled battery 100 are electrically connected to each other by a connection member 170 shown in FIG. Specifically, among the battery modules 120 arranged adjacent to each other, a sealed battery (first connected single battery) having the highest potential among one of the battery modules 120 (corresponding to the first battery module of the present invention). ) 110A external positive terminal 113 and the second container side surface 111b of the sealed battery (second connected cell) 110J having the lowest potential among the other battery modules 120 (corresponding to the second battery module of the present invention). Are connected in series via the connecting member 170.
Although FIG. 1 shows only one end side of the assembled battery 100, the battery modules 120 (120 </ b> A to 120 </ b> F) are also electrically connected to each other via the connection member 170 on the other end side. All battery modules 120 (120A to 120F) constituting the battery 100 are connected in series.

  As shown in FIG. 7, the connection member 170 is integrally formed of a metal plate material. The connection member 170 includes a connection main body portion 171, two connection extension portions 173 (corresponding to the positive electrode welded portion of the present invention), a connection plate-shaped portion 175 (corresponding to the negative electrode welded portion of the present invention), And a fluctuation absorbing portion 177. The connection main body 171 has a plate shape with the tip side divided into two. The connection extension portion (positive electrode welding portion) 173 extends perpendicularly to the connection main body portion 171 from the tip of the connection main body portion 171 which is divided into two. The connection plate portion (negative electrode welded portion) 175 is located on the same virtual plane as the connection main body portion 171 and has a plate shape in which the tip side is divided into two. The bending fluctuation absorbing portion 177 is interposed between the connection main body portion 171 and the connection plate-like portion 175, and is formed by bending a metal plate material into a U shape. Since such a connection member 170 is made of a metal plate material, and the bending fluctuation absorbing portion 177 is formed by bending the metal plate material into a U shape, the connecting member 170 including the bending fluctuation absorbing portion 177 can be easily and inexpensively formed. .

The positive external terminal 113 and the connection member 170 of the sealed battery (first connection unit cell) 110 </ b> A are connected to the connection extension portions (positive electrode welded portions) 173 of the connection member 170. These are joined to each other by welding them in a state of being overlapped on the outside of the extended welded portion (positive electrode portion) 113c.
On the other hand, the second container side surface 111b of the sealed battery (second connected single cell) 110J and the connecting member 170 are connected to the connecting plate-like portion (negative electrode welded portion) 175 of the connecting member 170 and the second of the sealed other battery 110J. These are welded to each other in a state where they are in contact with the container side surface (negative electrode portion) 111b.

  Although omitted in FIG. 1, in the assembled battery 100, an insulating sheet is disposed between the battery modules 120, and the battery modules 120 are insulated from each other. Further, end plates are disposed on both sides of the assembled battery 100, and the entire assembled battery is restrained by restraining bands.

  As described above, such an assembled battery 100 belongs to one battery module (first battery module) 120 among the battery modules 120 arranged adjacent to each other, and is a sealed battery (first battery) having the highest potential. 1 connection cell) 110A and the sealed battery (second connection cell) 110J belonging to the other battery module (second battery module) 120 and having the lowest potential are electrically connected via the connection member 170. It is connected to the. Specifically, the extended welded portion (positive electrode portion) 113c of the external positive electrode terminal 113 of the first connection unit cell 110A and the second container side surface (negative electrode portion) 111b of the second connection unit cell 110J are extended. Via a connection member 170 integrally having a connection extension portion (positive electrode weld portion) 173 welded to the weld portion 113c and a connection plate-like portion (negative electrode weld portion) 175 welded to the second container side surface 111b. Are electrically connected.

  Thus, if the battery modules 120 adjacent to each other are connected by the connecting member 170, the pole column members 950 and 960 are provided as in the conventional assembled battery 900 (see FIG. 8), and the bus bar 971, the insulating case 973, and the nut 975 are provided. There is no need to fasten and connect. For this reason, component cost and assembly cost can be reduced. Therefore, the assembled battery 100 can be made inexpensive while ensuring the connection reliability between the battery modules 120. In particular, in this embodiment, since all the battery modules 120 (120A to 120F) included in the assembled battery 100 are electrically connected to each other by the connecting member 170, the assembled battery 100 can be made the cheapest.

  Furthermore, in this embodiment, the battery modules 120 are arranged in parallel. The extended welded portion (positive electrode portion) 113c is located in the external positive electrode terminal 113 formed on the first container side surface 111a of the sealed battery (first connection unit cell) 110, and the negative electrode portion is sealed. It is the 2nd container side 111b of a type | mold battery (2nd connection single battery) 110, and the 1st container side 111a and the 2nd container side 111b are located on the same virtual plane. For this reason, the connection member 170 which connects the extended welding part (positive electrode part) 113c and the 2nd container side surface (negative electrode part) 111b can be made into the simple shape formed by processing a metal plate material as mentioned above. In addition, welding of the extended welded portion (positive electrode portion) 113c and the connected extended portion (positive electrode welded portion) 173 of the connecting member 170 is also performed by connecting the second container side surface (negative electrode portion) 111b and the connecting plate-like portion (connecting member 170). There is an advantage that welding with the negative electrode welded portion 175 can be easily performed.

  Moreover, in this embodiment, the connection member 170 absorbs the fluctuation | variation of the connection distance between the connection extension part 173 (positive electrode welding part) and the connection plate-shaped part 175 (negative electrode welding part) as mentioned above. A bending fluctuation absorbing portion 177 having a U-shaped cross-section for maintaining connection is provided. For this reason, when the battery modules 120 are stacked, even if there is a dimensional variation in the connection distance between the battery modules 120, the dimensional variation can be absorbed by the bending fluctuation absorbing portion 177 being bent. Can be reliably welded. Further, even when the battery container 111 of the sealed battery 110 is deformed due to thermal expansion or the like when the assembled battery 100 is used, even if the connection distance between the battery modules 120 varies, the bending fluctuation absorbing portion 177 bends. Therefore, the connection between the battery modules 120 can be reliably maintained. Therefore, the connection reliability between the battery modules 120 is increased by providing the connection member 170 with the bending fluctuation absorbing portion 177.

Next, a method for manufacturing the assembled battery 100 will be described.
First, the sealed battery 110 shown in FIG. 4 is manufactured by a known method.
Next, the sealed batteries 110 are connected in series to manufacture the battery module 120. Specifically, the first container side surface 111a of one sealed battery 110 and the second container side surface 111b of another sealed battery 110 are opposed to each other, and the external positive electrode terminal 113 of the one sealed battery 110 is sealed to the other. The battery is brought into contact with the second container surface 111b of the battery 110. At this time, of the extended welded portion 113c of the external positive electrode terminal 113 of one sealed battery 110, the extended welded portion 113c located on the third container side surface 111c side is the third container side surface of the other sealed battery 110. Of 111c, it overlaps from the outside in the vicinity of the boundary with the second container side surface 111b. Further, the other extended welded portion 113c overlaps from the outside in the vicinity of the boundary with the second container side surface 111b in the fourth container side surface 111d of the other sealed battery 110.

  Thereafter, laser irradiation is performed from the outside of each extended welded portion 113c, and the extended welded portion 113c of one sealed battery 110, the third container side surface 111c or the fourth container side surface 111d of the other sealed battery 110, Are sealed, and the sealed batteries 110 are connected in series. Then, the battery module 120 shown in FIGS. 2 and 3 is formed. Note that resistance welding may be used instead of laser welding for joining the sealed batteries 110 to each other.

Next, the battery modules 120 are arranged in parallel with each other with an insulating sheet (not shown) interposed therebetween. Thereafter, the battery modules 120 arranged in a row are restrained by an end plate and a restraining band (not shown).
Next, the positive electrode column member 150 shown in FIG. 5 is added to the sealed battery 110A having the highest potential among the battery modules 120A (left side in FIG. 1) having the highest potential among the assembled batteries 100. Welded together. Specifically, the two positive first seat portions 151a of the positive electrode pole member 150 are brought into contact with the electrode pillar portions 113a of the positive electrode external terminal 113 of the sealed battery 110A, respectively. The positive electrode extension portions 155 are respectively overlapped with the corresponding extension weld portions 113 c of the positive electrode external terminal 113. Thereafter, laser is irradiated from the outside of the extended welded portion 113c of the positive electrode external terminal 113, and the extended welded portion 113c of the positive electrode external terminal 113 and the positive electrode extended portion 155 of the positive electrode pole member 150 are respectively welded. The polar pole member 150 is fixed to the positive external terminal 113. This welding can also be performed by resistance welding.

  Further, the negative electrode column member 160 shown in FIG. 6 is attached to the sealed battery 110J having the lowest potential among the battery modules 120F having the lowest potential in the assembled battery 100 (right side in FIG. 1). Join by welding. Specifically, the two negative electrode first seats 161a of the negative electrode pole member 160 are brought into contact with predetermined positions on the second container side surface 111b of the sealed battery 110J, respectively. After that, laser irradiation is performed from the outside of the two negative electrode first seat portions 161a of the negative electrode pole member 160, respectively, and the second container side surface 111b and the negative electrode first seat portion 161a of the negative electrode pole member 160 are welded. The pole column member 160 is fixed to the second container side surface 111b. This welding can also be performed by resistance welding.

Further, the battery modules 120 are directly connected by the connection member 170. Specifically, the connection extension part (positive electrode welding part) 173 of the connection member 170 is used as a sealed battery (first connection single cell) having the highest potential among the one battery module (first battery module) 120. It overlaps with the outside of the extended welded part (positive electrode part) 113c of the positive external terminal 113 of 110A. At the same time, the connection plate 170 175 (negative electrode welded portion) of the connection member 170 is the sealed battery (second connected single cell) having the lowest potential among the other adjacent battery modules (second battery modules) 120. 110J is brought into contact with a predetermined position of the second container side surface (negative electrode portion) 111b. Thereafter, a laser is applied to the connection extension portion (positive electrode welding portion) 173 of the connection member 170, and the connection extension portion (positive electrode welding portion) 173 of the connection member 170 and the extension welding portion (positive electrode portion) of the external positive electrode terminal 113. ) 113c is welded, and the connecting member 170 is fixed to the external positive electrode terminal 113. Further, the connecting plate 170 (negative electrode welded portion) 175 of the connecting member 170 is irradiated with laser to weld the connecting plate 170 (negative electrode welded portion) 175 of the connecting member 170 and the second container side surface (negative electrode portion) 111b. The connecting member 170 is fixed to the second container side surface 111b. This welding can also be performed by resistance welding.
Thus, the assembled battery 100 is completed.

In the above, the present invention has been described with reference to the embodiment. However, the present invention is not limited to the above-described embodiment, and it is needless to say that the present invention can be appropriately modified and applied without departing from the gist thereof. .

It is a perspective view which shows a part of assembled battery which concerns on embodiment. It is a perspective view which shows a part of positive electrode side of the battery module which comprises the assembled battery which concerns on embodiment. It is a perspective view which shows a part of negative electrode side of the battery module which comprises the assembled battery which concerns on embodiment. It is a perspective view which shows the sealed battery which comprises the assembled battery which concerns on embodiment. It is a perspective view which shows a positive electrode pole member regarding the assembled battery which concerns on embodiment. It is a perspective view which shows a negative electrode pole column member regarding the assembled battery which concerns on embodiment. It is a perspective view which shows a connection member regarding the assembled battery which concerns on embodiment. It is a perspective view which shows a part of assembled battery which concerns on a prior art.

100 battery pack 110 sealed battery (single cell)
111a 1st container side surface (1st container surface)
111b Second container side surface (second container surface (negative electrode part))
113 External positive terminal 113c (external positive terminal) extended weld (positive electrode part)
120 battery module 150 positive electrode pole member 160 negative electrode pole member 170 connection member 173 connection extension part (positive electrode welding part)
175 Connection plate (negative electrode weld)
177 Bending fluctuation absorbing part

Claims (5)

A battery pack including a plurality of battery modules including a single cell of multiple,
The unit cell is
A power generation element including a positive electrode and a negative electrode,
A battery container having a rectangular parallelepiped shape and made of a conductive material and conducting to the negative electrode, the first container surface, a second container surface parallel to the first container surface, and connecting the first container surface and the second container surface. A battery container including a third container surface, a fourth container surface parallel to the third container surface, a container upper surface, and a container lower surface parallel thereto; and
An external positive terminal that is electrically connected to the positive electrode and electrically insulated from the first container surface and is fixed to the first container surface and a part of itself is exposed to the outside of the battery container, An external positive terminal including an extended weld extending vertically to the first container surface;
The battery module is
The first container surface of one unit cell and the second container surface of another unit cell are opposed to each other;
Contacting the external positive terminal of the one unit cell with the second container surface of the other unit cell;
Welding the extended welded portion of the external positive electrode terminal of the one unit cell to overlap with at least one of the third container surface and the fourth container surface of the other unit cell from the outside;
A plurality of the single cells constituting the battery module are electrically connected in series and arranged in a row,
The plurality of battery modules include a first battery module and a second battery module disposed adjacent to each other,
The cell belonging to the first battery module includes a first connection cell connected to the second battery module,
The cell belonging to the second battery module includes a second connection cell connected to the first connection cell of the first battery module,
The first connection unit cell and the second connection unit cell are arranged next to each other,
Said first connecting unit cell has the extended welded portion of the external positive terminal is a positive portion electrically connected to said positive electrode,
Said second connecting unit cells has a second container surface of the battery case is a negative electrode portion electrically connected to the negative electrode,
The extended welded portion of the first connected single cell and the second container surface of the second connected single cell are connected to the positive electrode welded portion welded to the extended welded portion of the first connected single cell and the second An assembled battery that is electrically connected via a connecting member that integrally has a negative electrode welded portion welded to the second container surface of a two- connection cell. The assembled battery according to claim 1,
Before SL battery module together are Retsu置parallel to each other,
The first connection unit cell is a unit cell having the highest potential among the unit cells belonging to the first battery module,
The second connection unit cell is a unit cell having the lowest potential among the unit cells belonging to the second battery module,
The extended welding part of the first connection unit cell is a first container surface of the first connection unit cell, and is a first container that forms an end of the unit cells in the arrangement direction of the first battery module. Located in the external positive terminal formed on the surface,
The second container surface of the second connection unit cell is a second container surface forming an end of the unit cell in the arrangement direction of the second battery module ,
The assembled battery in which the first container surface of the first connection unit cell and the second container surface of the second connection unit cell are arranged in the same virtual plane. The assembled battery according to claim 1 or 2,
The connection member has a connection distance between the positive electrode welded portion and the negative electrode welded portion between the extended welded portion of the first connected unit cell and the second container surface of the second connected unit cell. An assembled battery including a fluctuation absorbing portion having a structure that absorbs fluctuations and maintains a connection. The assembled battery according to claim 3,
The connection member is made of a metal plate material,
The variation absorbing portion is a battery pack that is a bending variation absorbing portion formed by bending the metal plate material into a U shape or a waveform. It is an assembled battery as described in any one of Claims 1-4, Comprising:
An assembled battery in which all the battery modules belonging to the assembled battery are electrically connected to each other by the connecting member.

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