JP6414478B2 - Assembled battery and method of manufacturing the assembled battery - Google Patents

Description

  The present invention relates to an assembled battery mounted on a vehicle such as an automobile and a method for manufacturing the same.

  Patent Document 1 discloses an assembled battery in which a plurality of laminated single cells are stacked in the thickness direction. That is, in the assembled battery of Patent Document 1, each single cell has a pair of electrode tabs (a positive electrode tab and a negative electrode tab) drawn outward from the battery body. Each unit cell is arranged so that the positive electrode tab and the negative electrode tab are alternate between adjacent unit cells. In this case, the positive electrode tab and the negative electrode tab of the adjacent unit cells are formed so as to be bent toward each other, whereby the tabs are overlapped and joined to each other.

JP2015-002141A

  By the way, in the assembled battery of patent document 1 mentioned above, the positive electrode tab of the single cell arrange | positioned in the uppermost part and the positive electrode tab of the single cell arrange | positioned in the intermediate part are mutually different among each unit cell laminated | stacked up and down. It is bent in shape. Moreover, the negative electrode tab of the unit cell arranged at the lowermost part and the negative electrode tab of the unit cell arranged at the middle part are bent and formed in different shapes. For this reason, when bending these positive electrode tabs and negative electrode tabs, it is necessary to use different bending jigs for each tab having a different shape, which may complicate the processing work.

  Moreover, about each single cell arrange | positioned in the intermediate part, since the positive electrode tab and the negative electrode tab have the same shape, there exists a possibility that a single cell may be assembled | attached by making a positive electrode tab and a negative electrode tab reverse. That is, there is a risk that a unit cell will be mistaken.

  The present invention has been made in view of the above circumstances, and provides an assembled battery and a method of manufacturing the assembled battery that can suppress a mistake in assembling of unit cells while simplifying the bending process of the electrode tab. It is in.

  Hereinafter, means for solving the above-described problems and the effects thereof will be described.

  The assembled battery (11) of the present invention includes a plate-shaped battery main body (34), a positive electrode tab (35) and a negative electrode tab (36) which are a pair of electrode tabs extending from the battery main body to opposite sides. A plurality of single cells stacked, the plurality of single cells being adjacent to each other, the positive electrode tab and the negative electrode tab being At least one of the positive electrode tab and the negative electrode tab facing each other in each adjacent unit cell is bent toward the other side, and the tabs are bent by the bending. Are overlapped with each other and joined at the overlapped portion, and all of the plurality of single cells have the same shape in each positive electrode tab and the same shape in each negative electrode tab. And which is characterized in that it differs from each other and the shapes of and the negative electrode tab of the positive electrode tab.

  According to the above configuration, the shape of each positive electrode tab is the same in each of the plurality of single cells, and the shape of each negative electrode tab is the same. Simplification can be achieved. In addition, since the shape of the positive electrode tab and the shape of the negative electrode tab in the unit cell are different from each other, it is possible to suppress a mistake in assembling the unit cells by reversing the positive electrode tab and the negative electrode tab. Thereby, it is possible to suppress mistakes in the unit cells while simplifying the bending process of the electrode tabs.

The perspective view which shows the whole structure of a battery unit. The disassembled perspective view which decomposes | disassembles and shows the main structures of a battery unit. The perspective view of an assembled battery module. The disassembled perspective view which decomposes | disassembles and shows each component of an assembled battery module. The disassembled perspective view which decomposes | disassembles and shows each component of an assembled battery module. The figure which shows the state by which the battery assembly was mounted on the base. The figure which shows a mode that a positive electrode tab and a negative electrode tab are joined using an ultrasonic metal joining apparatus. The figure which shows the modification of a positive electrode tab and a negative electrode tab.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, an embodiment of the invention will be described with reference to the drawings. In the present embodiment, it is assumed that the power supply system is embodied in a vehicle, and this power supply system is charged and discharged in a power storage unit (power supply unit) for supplying electric power to various on-vehicle electric loads. Are sequentially controlled. The vehicle includes an engine that is an internal combustion engine, an in-vehicle ECU that controls the engine and other units, a generator (alternator) that is driven by the engine to generate power, and a power storage unit that is charged by the power generated by the generator. In particular, a lead storage battery and a lithium ion storage battery are used as the power storage unit. And in this embodiment, the assembled battery of this invention is applied to Li battery unit (henceforth a battery unit only) which functions as a lithium ion storage battery, and the structure of this battery unit is demonstrated below.

  1 is a perspective view showing the overall configuration of the battery unit, and FIG. 2 is an exploded perspective view showing the main configuration of the battery unit. In the following description, for the sake of convenience, the vertical direction of the battery unit 10 is defined based on FIG. 1 in which the battery unit 10 is installed on a horizontal plane.

  As shown in FIGS. 1 and 2, the battery unit 10 includes, as main components, an assembled battery module 11 having a plurality of laminated unit cells, and control for performing charge / discharge control and the like in the assembled battery module 11. A substrate 12 and a housing case 13 for housing the assembled battery module 11 and the control substrate 12 are provided. The housing case 13 includes a base 14 that is fixed to the mounting location of the battery unit 10, a cover 15 that is attached above the base 14, and an intermediate case 16 that is provided between the base 14 and the cover 15. The assembled battery module 11 and the control board 12 are arranged opposite to each other so that the assembled battery module 11 is on the bottom and the control board 12 is on the top, and are fixed to the base 14. Similarly, the cover 15 and the intermediate case 16 are respectively fixed to the base 14.

  Next, the configuration of each part of the battery unit 10 will be described.

  In the housing case 13, the base 14 is formed of a metal material such as aluminum. The base 14 has a bottom plate portion 21 formed in a substantially quadrangular shape, and a standing wall portion 22 provided upright from the peripheral edge portion or the substantially peripheral edge portion of the bottom plate portion 21. The bottom plate portion 21 is a placement portion on which the assembled battery module 11 is placed. In a state where the assembled battery module 11 is placed on the bottom plate portion 21, the assembled battery module 11 is surrounded by the standing wall portion 22. The top surface of the bottom plate portion 21 corresponds to the inner bottom surface. A heat sink 23 is attached to the base 14 for radiating heat generated in the assembled battery module 11 and the control board 12 to the outside.

  Similar to the base 14, the cover 15 is formed of a metal material such as aluminum. The cover 15 has a substantially rectangular shape and has substantially the same size as the base 14 in plan view.

  The intermediate case 16 is made of a synthetic resin material. The intermediate case 16 has an intermediate wall portion 25 that forms a substantially quadrangular ring shape in plan view. The lower end portion of the intermediate wall portion 25 is assembled to the upper end portion of the standing wall portion 22 of the base 14, and the intermediate wall portion 25 continuously extends upward from the standing wall portion 22 in the assembled state.

  Next, the assembled battery module 11 will be described. FIG. 3 is a perspective view of the assembled battery module 11, and FIGS. 4 and 5 are exploded perspective views showing the components of the assembled battery module 11 in an exploded manner.

  As shown in FIGS. 3 to 5, the assembled battery module 11 includes a battery assembly 31 having a plurality of (four in this embodiment) unit cells 33 and a battery holder to be assembled to the battery assembly 31. 32. The battery assembly 31 includes a plurality of unit cells 33 made of a laminate type battery, and the unit cells 33 are stacked one above the other.

  Each cell 33 has a square plate-shaped battery body 34 (see FIG. 6) and a pair of plate-like electrode tabs 35 and 36 connected to the battery body 34. The battery body 34 is accommodated in a flat container 37 made of a laminate film, and the peripheral portion (film peripheral portion 37a) of the flat container 37 is sealed in the container 37. The battery body 34 of each unit cell 33 is provided in a state where it is stacked one above the other.

  The pair of electrode tabs 35 and 36 are respectively provided on the two opposite sides of the battery body 34. Each of these electrode tabs 35 and 36 is drawn out (extends) from the battery main body 34 toward the opposite side. Specifically, the thickness direction of the battery main body 34 (battery stacking direction in which the individual cells 33 are stacked) ) In a direction orthogonal to (hereinafter also referred to as a tab pulling direction). One of the electrode tabs 35, 36 is a positive electrode tab 35, and the other is a negative electrode tab 36. The positive electrode tab 35 and the negative electrode tab 36 are made of different metal materials. In the present embodiment, the positive electrode tab 35 is made of aluminum, and the negative electrode tab 36 is made of copper.

  The unit cells 33 stacked one above the other are arranged so that the positive electrode tabs 35 and the negative electrode tabs 36 are alternately arranged between the unit cells 33 adjacent to each other in the vertical direction. In this case, in each unit cell 33 adjacent in the vertical direction, the positive electrode tab 35 of one unit cell 33 and the negative electrode tab 36 of the other unit cell 33 face each other vertically and overlap each other, and are joined to each other at the overlapping portion. ing. Thereby, each cell 33 is connected in series.

  In each unit cell 33, each positive electrode tab 35 has the same shape. In each unit cell 33, each negative electrode tab 36 has the same shape. That is, all the positive electrode tabs 35 of each unit cell 33 have the same configuration, and all the negative electrode tabs 36 of each unit cell 33 have the same configuration. On the other hand, the positive electrode tab 35 and the negative electrode tab 36 have different shapes (configurations). Therefore, in the following, the configuration of the positive electrode tab 35 and the negative electrode tab 36 will be described with reference to FIG. FIG. 6 is a view showing a state where the battery assembly 31 is placed on the base 14.

  As shown in FIG. 6, the positive electrode tab 35 is bent toward the upper side. The positive electrode tab 35 includes a first plate portion 35a connected to the battery body 34, a second plate portion 35b bent upward with respect to the first plate portion 35a, and a battery body 34 with respect to the second plate portion 35b. And a third plate portion 35c bent to the side away from the first plate portion 35c. Both the first plate portion 35a and the third plate portion 35c extend in the tab pull-out direction, and the second plate portion 35b is the battery stacking direction in which the individual cells 33 are stacked, in other words, the vertical direction (specifically, the plate portion 35a). , 35c). The tab pull-out direction and the battery stacking direction are orthogonal to each other.

  The negative electrode tab 36 is formed in a flat plate shape, and extends from the battery main body 34 in the tab drawing direction. The length of the negative electrode tab 36 in the tab drawing direction is the same as the length of the positive electrode tab 35 in the same direction. Therefore, the negative electrode tab 36 and the positive electrode tab 35 arranged on the same side in the tab pull-out direction have the same tip position in the same direction.

  In each adjacent unit cell 33, the positive electrode tab 35 and the negative electrode tab 36 are joined to each other with the positive electrode tab 35 on the lower side and the negative electrode tab 36 on the upper side. In this case, of the positive electrode tab 35 and the negative electrode tab 36, the positive electrode tab 35 is bent toward the negative electrode tab 36 (upper side), so that both the electrode tabs 35 and 36 are overlapped and joined to each other. Specifically, the third plate portion 35c of the positive electrode tab 35 and the negative electrode tab 36 are superposed on each other and ultrasonically bonded. In such a configuration, the joint location of the positive electrode tab 35 (third plate portion 35 c) and the negative electrode tab 36 of the adjacent unit cells 33 is positioned above the center position between the battery bodies 34 of the adjacent unit cells 33. Will do.

  Further, in such a joined state of the positive electrode tab 35 and the negative electrode tab 36, the second plate portion 35 b of the positive electrode tab 35 extends vertically across the first plate portion 35 a and the negative electrode tab 36. Therefore, the vertical length of the second plate portion 35b is the same as the arrangement pitch L of the battery main bodies 34 of the unit cells 33 arranged in the vertical direction (in other words, the distance between the central positions of the battery main bodies 34 adjacent in the vertical direction). It is set to length.

  Moreover, in the above-described configuration in which the positive electrode tab 35 is bent toward the negative electrode tab 36 among the positive electrode tab 35 and the negative electrode tab 36 of the adjacent unit cell 33, the tabs 35 and 36 are joined. An interval W between the positive electrode tab 35 and the negative electrode tab 36 that are not joined to each other is larger than the arrangement pitch L of the battery main body 34. Specifically, the interval W is twice as large as the arrangement pitch L of the battery main bodies 34. More specifically, there are a plurality of sets (specifically, three sets) of positive electrode tabs 35 and negative electrode tabs 36 that are not joined to each other in the adjacent unit cells 33, but the tabs 35 in each of these sets. , 36 is twice as large as the arrangement pitch L.

  Thus, in this battery assembly 31, the space | interval W between the tabs 35 and 36 is the same magnitude | size in each said group. As described above, in the battery assembly 31, the shape of the positive electrode tab 35 of each unit cell 33 is the same, and the shape of the negative electrode tab 36 of each unit cell 33 is the same. Because.

  Among the unit cells 33 that are stacked one above the other, in the unit cell 33 arranged at the top, the positive electrode tab 35 (hereinafter referred to as “A”) is connected to the negative electrode tab 36 of the other unit cell 33. Not. Further, in the unit cell 33 arranged at the lowermost part, the negative electrode tab 36 (hereinafter referred to as “A”) is not connected to the positive electrode tab 35 of the other unit cell 33. The positive electrode tab 35A and the negative electrode tab 36A constitute the positive electrode and the negative electrode of the plurality of unit cells 33 connected in series, respectively. Among these tabs 35A and 36A, the positive electrode tab 35A is bent upward and a part thereof protrudes upward from the uppermost battery body 34. On the other hand, since the negative electrode tab 36 </ b> A is formed in a flat plate shape, it does not protrude downward from the lowermost battery body 34. Therefore, the negative electrode tab 36 </ b> A does not interfere with the bottom plate portion 21 in a state where the unit cells 33 (battery assemblies 31) stacked one above the other are placed on the bottom plate portion 21 of the base 14. ing.

  As a precaution, in the battery assembly 31, all the positive electrode tabs 35 including the positive electrode tab 35A have the same shape, and all the negative electrode tabs 36 including the negative electrode tab 36A have the same shape. ing.

  A double-sided adhesive type adhesive tape 38 is interposed between each unit cell 33 (specifically, each battery body 34). The unit cells 33 are integrated by the adhesion of the adhesive tape 38. A rigid plate 39 made of an iron plate is attached to the uppermost unit cell 33 among the unit cells 33 by an adhesive tape 38.

  The battery holder 32 is attached to the first holding portion 41 that is assembled to the electrode tabs 35 and 36 on one side of the two opposite sides of each unit cell 33 and the electrode tabs 35 and 36 on the other side. It has the 2nd holding | maintenance part 42 assembled | attached and the connection part 43 which connects each these holding | maintenance parts 41 and 42 mutually. These parts are integrally formed of, for example, a synthetic resin material.

  The first holding portion 41 includes a plurality (three) of bus bars 44 that are electrically connected to the electrode tabs 35 and 36 on one side of both sides of the battery assembly 31 (two opposing sides of the unit cell 33). Have. These bus bars 44 are arranged in the battery stacking direction and are provided in a cantilever state with the plate surfaces facing up and down. Each bus bar 44 is joined to each electrode tab 35, 36 with its plate surface in contact with the electrode tabs 35, 36.

  The second holding part 42 has a plurality (two) of bus bars 44 that are electrically connected to the electrode tabs 35, 36 on the other side of both sides of the battery assembly 31. These bus bars 44 are also arranged in the battery stacking direction and are provided in a cantilever state so that the plate surface faces up and down. Each bus bar 44 is joined to each electrode tab 35, 36 with its plate surface abutted against each electrode tab 35, 36.

  The first holding part 41 is provided with three voltage detection terminals 46 connected to the respective bus bars 44, and the second holding part 42 is provided with two voltage detection terminals 46 connected to the respective bus bars 44 respectively. It has been. The tips of these voltage detection terminals 46 are connected to the control board 12. In this case, the terminal voltage of each unit cell 33 can be detected via these voltage detection terminals 46 (and the bus bar 44).

  The connection part 43 has two upper and lower connection bars 43a. Each of these connecting bars 43a enters a gap between the film peripheral edge portion 37a (film sealing portion) of each unit cell 33 adjacent vertically, and the battery holder 32 is assembled to the battery assembly 31 in the inserted state. Yes (installed).

  Then, the manufacturing procedure at the time of manufacturing the assembled battery module 11 is demonstrated.

  When manufacturing the assembled battery module 11, first, a bending process for forming the positive electrode tab 35 by bending the tab base material constituting the positive electrode tab 35 of the unit cell 33 is performed. In this step, the positive electrode tab 35 is formed by bending a tabular tab substrate made of aluminum using a dedicated bending jig. In addition, about the negative electrode tab 36, since the tabular tab base material which consists of copper is used as the negative electrode tab 36 as it is, this bending process is unnecessary.

  Next, an integration step is performed in which the unit cells 33 are integrated with the adhesive tape 38 in a state where (all) the cells 33 are stacked. Thereby, the battery assembly 31 is formed. This integration process corresponds to a fixing process.

  Next, a holder mounting process for mounting the battery holder 32 on the battery assembly 31 is performed. In this step, each connection bar 43a of the connection portion 43 of the battery holder 32 is inserted into the gap between the film peripheral portions 37a of the adjacent unit cells 33, whereby the battery holder 32 is attached to the battery assembly 31. .

  Next, a tab joining process for joining the positive electrode tab 35 and the negative electrode tab 36 of each adjacent unit cell 33 by ultrasonic bonding is performed. FIG. 7 is a view showing a state in which these tabs 35 and 36 are joined together using an ultrasonic metal joining apparatus. As shown in FIG. 7, the ultrasonic metal bonding apparatus 50 includes an anvil 51 and a horn 52. The anvil 51 and the horn 52 are provided with processed surfaces 51a and 52a on which fine irregularities are formed, respectively.

  When joining the positive electrode tab 35 and the negative electrode tab 36, the tabs 35 and 36 that are overlapped with each other are sandwiched between the processed surfaces 51 a and 52 a of the anvil 51 and the horn 52, and the tabs 35 and 36 are sandwiched between the tabs 35 and 36. 36 is ultrasonically bonded by an ultrasonic metal bonding apparatus 50. Thereby, the positive electrode tab 35 and the negative electrode tab 36 are joined. In the present embodiment, the bus bar 44 is joined together with the positive electrode tab 35 and the negative electrode tab 36. Therefore, in the joining operation, ultrasonic joining is performed on the three members 35, 36, and 44 in a state where the positive electrode tab 35, the negative electrode tab 36, and the bus bar 44 are overlapped. Thereby, the positive electrode tab 35, the negative electrode tab 36, and the bus bar 44 are integrally joined.

  In the tab joining step, the battery assembly 31 to which the battery holder 32 is mounted is fixed to a movable jig, and the battery assembly 31 is fixed to the ultrasonic metal joining apparatus 50 together with the jig in the fixed state. Then, the positive electrode tab 35 and the negative electrode tab 36 of the battery assembly 31 are sequentially joined by the same device 50.

  By the way, in the above-described joining operation, the anvil 51 and the horn 52 of the ultrasonic metal joining apparatus 50 are respectively inserted between the positive electrode tab 35 and the negative electrode tab 36 that are not joined to each other in the adjacent unit cell 33, and in this state, these The tabs 35 and 36 are sandwiched between the anvil 51 and the horn 52 to perform solid phase bonding. Here, as described above, in the battery assembly 31, there are a plurality of sets of the positive electrode tab 35 and the negative electrode tab 36 that are not joined to each other in the adjacent unit cell 33, and the interval W between the tabs 35 and 36 in each of these sets. Are all the same size. In this case, since it is possible to ensure a relatively large gap W between the tabs 35 and 36 in each of the respective groups, even when all the unit cells 33 are stacked, the tabs 35, The anvil 51 and the horn 52 can be relatively easily inserted between the 36. Therefore, the joining work of the positive electrode tab 35 and the negative electrode tab 36 can be performed relatively easily.

  Moreover, in order to perform the above-described joining work firmly, it is desirable that the anvil 51 and the horn 52 have high rigidity. In that case, it is desirable to use a material having a large thickness (vertical length) as the anvil 51 and the horn 52. In that respect, according to the above configuration in which the interval W between the positive electrode tab 35 and the negative electrode tab 36 that are not joined to each other is relatively large, even between the anvil 51 and the horn 52 having a large thickness, it is between the positive electrode tab 35 and the negative electrode tab 36. As a result, the tabs 35 and 36 can be firmly joined to each other.

  As mentioned above, according to the structure of this embodiment explained in full detail, the following outstanding effects are acquired.

  In each of the plurality of unit cells 33, each of the positive electrode tabs 35 has the same shape, and each of the negative electrode tabs 36 has the same shape, so that the bending of the electrode tab can be simplified. In addition, since the shape of the positive electrode tab 35 and the shape of the negative electrode tab 36 are different from each other, it is possible to suppress a mistake in assembling the unit cells 33 with the positive electrode tab 35 and the negative electrode tab 36 reversed. Thereby, it is possible to suppress mistakes in the unit cell 33 while simplifying the bending process of the electrode tab.

  The joining location of the positive electrode tab 35 and the negative electrode tab 36 of the adjacent unit cells 33 was positioned above the center position between the battery bodies 34 of the adjacent unit cells 33. Thereby, since it becomes impossible to assemble the cells 33 with the positive electrode tab 35 and the negative electrode tab 36 reversed, it is possible to prevent the unit cells 33 from being mistakenly assembled.

  Of the positive electrode tab 35 and the negative electrode tab 36, only the positive electrode tab 35 was bent, and the negative electrode tab 36 was formed in a flat plate shape. Thereby, only the positive electrode tab 35 should be bent among the positive electrode tab 35 and the negative electrode tab 36, and the negative electrode tab 36 may not be bent. Therefore, it is possible to further simplify the bending process of the electrode tab.

  The negative electrode tab 36A of the unit cell 33 arranged at the lowermost part (bottom plate portion 21 side) among the plurality of unit cells 33, that is, the electrode tab on the side not connected to the electrode tabs of the other unit cells 33 was formed in a flat plate shape. In this case, since the negative electrode tab 36A can be prevented from projecting downward from the battery body 34 of the unit cell 33 disposed at the lowermost portion, the assembled battery module 11 (battery assembly 31) is mounted on the base 14 (mounting). When placing on the portion 21), the negative electrode tab 36A does not get in the way and is convenient.

  When the assembled battery module 11 is manufactured, first, a plurality of unit cells 33 are integrated (fixed) with the adhesive tape 38 in a state where all the unit cells 33 are laminated, and then the positive electrode tab 35 and the negative electrode tab 36 of the adjacent unit cells 33 are sequentially joined. I did it. In this case, it becomes possible to manufacture the assembled battery module 11 efficiently. Further, since the interval W between the positive electrode tab 35 and the negative electrode tab 36 that are not joined to each other in the adjacent unit cells 33 is the same between the tabs 35, 36, the interval W can be secured relatively large. Therefore, in the configuration in which the anvil 51 and the horn 52 of the ultrasonic metal bonding apparatus 50 are inserted between the tabs 35 and 36 and the tabs 35 and 36 are ultrasonically bonded, the bonding operation can be performed relatively easily. .

  The present invention is not limited to the above embodiment, and may be implemented as follows, for example.

  (1) In the above embodiment, the positive electrode tab 35 is formed by bending and the negative electrode tab 36 is formed in a flat plate shape. However, this may be reversed to form the positive electrode tab in a flat plate shape and bending the negative electrode tab. Good. In this case, as shown in FIG. 8A, it is conceivable that the tabs 61 and 62 are overlapped and joined to each other by bending the negative electrode tab 62 toward the positive electrode tab 61 (lower side). . Further, in this configuration, the positive electrode tab 61 of the unit cell 33 arranged at the top, that is, the electrode tab that is not connected to the other unit cell 33 has a flat plate shape. It does not protrude upward from the main body 34. Therefore, when another member is installed in the housing case 13 in the vicinity of the upper part of the battery assembly 31, it is possible to obtain an advantage that interference with the member can be suppressed.

  (2) Both the positive electrode tab and the negative electrode tab may be bent. For example, in FIG. 8B, the positive electrode tab 64 and the negative electrode tab 65 of each adjacent unit cell 33 are formed to be bent toward each other, and the tabs 64 and 65 (specifically, the third plate are described in detail). Parts 64c and 65c) are overlapped and joined to each other. In each unit cell 33, each positive electrode tab 64 has the same shape, and each negative electrode tab 65 has the same shape. For this reason, also in such a configuration, it is possible to simplify the bending process of the electrode tab.

  Further, in the example of FIG. 8B, the shape of the positive electrode tab 64 and the shape of the negative electrode tab 65 are different from each other. Specifically, the positive electrode tab 64 and the negative electrode tab 65 are different in the lengths of the second plate portions 64b and 65b. Therefore, the joining location of the positive electrode tab 64 and the negative electrode tab 65 that are joined to each other in the adjacent unit cells 33 is set to a position different from the central position between the battery bodies 34 of the adjacent unit cells 33. For this reason, also in this case, it becomes impossible to assemble the cells 33 with the positive electrode tab 64 and the negative electrode tab 65 reversed, so that it is possible to prevent the unit cells 33 from being mistakenly assembled.

  (3) FIG. 8C shows a configuration in which both the positive electrode tab and the negative electrode tab are bent as in FIG. 8B. However, in FIG. 8C, unlike FIG. 8B, the joint position of the positive electrode tab 67 and the negative electrode tab 68 of the adjacent unit cell 33 is the center position between the battery main bodies 34 of the adjacent unit cell 33. Is set at the same position. That is, the second plate portions 67b and 68b of the positive electrode tab 67 and the negative electrode tab 68 are all set to the same length.

  In such a configuration, the second plate portion 67b of the positive electrode tab 67 and the second plate portion 68b of the negative electrode tab 68 are formed at different positions in the tab pull-out direction. That is, the positive electrode tab 67 and the negative electrode tab 68 are different from each other in this point. Therefore, also in this case, due to the difference in shape between the tabs 67 and 68, it is possible to suppress a mistake in assembling the unit cells 33 with the positive electrode tab 67 and the negative electrode tab 68 reversed.

  Further, in such a configuration, the battery body 34 of the uppermost unit cell 33 has the positive electrode tab 67 (that is, the electrode tab on the side not connected to the electrode tabs of the other unit cells 33) of the unit cell 33 arranged at the uppermost part. And the negative electrode tab 68 of the unit cell 33 arranged at the lowermost portion (that is, the electrode tab on the side not connected to the electrode tabs of the other unit cells 33) can be prevented from protruding upward. It can suppress protruding below the battery main body 34 of 33. Therefore, when installing the assembled battery module 11 in the housing case 13, it is possible to prevent the positive electrode tab 64 and the negative electrode tab 65 at both the upper and lower ends from interfering with each other.

  (4) The bending shape of the positive electrode tab 35 (electrode tab) is not necessarily limited to the shape of the above embodiment. For example, in the above embodiment, the positive electrode tab 35 is bent at a right angle, but instead of this, an oblique bend may be used. In other words, the positive electrode tab 35 may be bent so that the second plate portion 35b of the positive electrode tab 35 extends obliquely with respect to the vertical direction (vertical direction).

  Moreover, in the said embodiment, although the positive electrode tab 35 was bent-formed, this may be changed and the positive electrode tab 35 may be curvedly formed. For example, in the positive electrode tab 35, it is conceivable that the second plate portion 35b that connects the first plate portion 35a and the third plate portion 35c is curvedly formed in an S shape.

  (5) In the above embodiment, the positive electrode tab 35 and the negative electrode tab 36 of the adjacent unit cells 33 are joined with the positive electrode tab 35 as the upper side and the negative electrode tab 36 as the lower side. The lower side and the negative electrode tab 36 may be joined as the upper side.

  (6) In the above embodiment, the positive electrode tab 35 and the negative electrode tab 36 of each unit cell 33 are ultrasonically bonded. However, this may be changed and bonded by another welding technique. For example, it is conceivable to apply vibration welding in which welding is performed using vibration at a relatively low frequency of about several hundred Hz, or heat welding in which welding is performed by heat conduction from a heat source (heater).

  (7) In the above embodiment, the lithium ion storage battery is used as the single battery. However, this may be changed and another secondary battery such as a nickel-cadmium storage battery or a plurality of nickel hydrogen storage batteries may be used as the single battery. .

  (8) The battery unit 10 of the above embodiment may be applied to a hybrid vehicle that uses both the internal combustion engine and the motor as driving sources for vehicle travel, or does not have an internal combustion engine and drives only the motor for vehicle travel. You may apply to the electric vehicle used as a source.

  DESCRIPTION OF SYMBOLS 10 ... Battery unit, 11 ... Assembly battery module, 12 ... Control board, 13 ... Housing case, 33 ... Single cell, 35 ... Positive electrode tab, 36 ... Negative electrode tab.

Claims (1)

A battery (33) having a plate-shaped battery body (34) and a positive electrode tab (35) and a negative electrode tab (36) which are a pair of electrode tabs extending from the battery body to opposite sides; An assembled battery (11) configured by stacking a plurality of the unit cells,
The plurality of single cells are arranged so that the positive electrode tabs and the negative electrode tabs are staggered between adjacent single cells,
The positive electrode tab and the negative electrode tab facing each other in each of the adjacent unit cells are formed to be bent toward each other , and the tabs are overlapped with each other by the bending, and are joined at the overlapping portion,
All of the plurality of unit cells, each positive electrode tab is the same shape, and each negative electrode tab is the same shape,
The positive electrode tab and the negative electrode tab have different bending dimensions in the stacking direction of the single cells or different bending positions in the tab pulling direction, so that the shape of the positive electrode tab and the negative electrode are different. An assembled battery, wherein the shape of the tab is different from each other.