JP4829587B2 - Electrical device assembly and manufacturing method thereof - Google Patents

Description

  The present invention relates to an electric device assembly in which a plurality of electric devices (for example, batteries or capacitors) having electric device elements for storing and outputting electric energy are collected, and in particular, electrode tabs drawn from each electric device are welded to each other. The present invention relates to an electrical device assembly that is electrically connected to each other and a method for manufacturing the same.

  In recent years, for example, as a driving power source for an electric vehicle, an assembled battery configured by interconnecting a plurality of battery cells in series and / or in parallel has been developed. The configuration of such an assembled battery will be briefly described with reference to FIG. 11. The assembled battery 150 is a collection of a plurality of battery cells 120, and a sheet-like electrode tab 125 a is formed from each battery cell 120. , 125b are pulled out. The drawn electrode tabs 125a and 125b are joined to each other by, for example, laser welding or ultrasonic welding. It is also disclosed in Patent Document 1 that the electrode tabs are joined together by laser welding or the like.

In the configuration of FIG. 11, the bus bar 131 is connected to the connection portion between the electrode tabs. The bus bar 131 is a plate-like member made of a conductive material, and is attached, for example, in such a form as to support the electrode tab over its entire width. By using such a bus bar 131, for example, the assembled batteries 150 can be electrically connected to each other, or a voltage detection unit corresponding to each connection part of the electrode tabs can be configured. Yes.
JP 2003-338275 A

  By the way, when manufacturing an assembled battery having the above-described configuration, specifically, when welding electrode tabs drawn from each battery cell, a jig 170 as shown in FIG. It is necessary to sandwich the electrode tabs. On the other hand, depending on the type, the thickness of the battery cell 120 may be about 5 mm. Of course, in the case of such a thin battery cell, the interval between the electrode tabs is narrow. Therefore, in such a configuration, it is necessary to prepare a jig 170 having a complicated configuration, which is disadvantageous in terms of manufacturing cost and work efficiency.

  In the case of the configuration as shown in FIG. 11, it is generally necessary to irradiate the laser beam LB in the vertical direction as indicated by an arrow in the figure, and such irradiation is performed for each connection portion. It is very complicated.

  Although the battery cell 120 has been described above as an example, the above-described problem is not limited to the battery, and may occur in common when it is necessary to join sheet-like electrode tabs. That is, for example, even when an electric device other than the battery cell 120 containing an electric device element such as a capacitor (capacitor) inside is welded to electrode tabs drawn from the electric device as described above, Problems can arise.

  The present invention has been made in view of the above-described problems, and the object thereof is to perform welding between electrode tabs without using a jig having a complicated configuration when manufacturing an electric device assembly. An object of the present invention is to provide an electrical device assembly manufacturing method and an electrical device assembly.

  In order to achieve the above object, the method for manufacturing an electrical device assembly according to the present invention connects a plurality of electrical devices in series and / or in parallel by connecting sheet-like electrode tabs drawn from the electrical devices. A method of manufacturing an electrically connected electrical device assembly, the step of inserting the tip side of the electrode tabs connected to each other into a slit formed in a support member made of a conductive material, Irradiating the electrode tab that has passed through the slit to the surface side of the support member with an energy beam, and welding the electrode tab and the support member.

  In the manufacturing method of the present invention, the electrode tab inserted into the slit is irradiated with an energy beam to perform welding. At this time, for example, a support member that can be used as a bus bar functions as a holding jig for the electrode tabs, so there is no need to prepare a dedicated jig for clamping the electrode tabs during welding.

  In the present invention, in the welding step, the two electrode tabs are inserted into the slits, and the protruding amounts of the two electrode tabs from the surface of the support member are the same. May be. On the contrary, the protruding amount of one of the two electrode tabs may be relatively small. In this case, the energy beam is an electrode having a relatively small protruding amount. It may be irradiated toward the tab.

  The irradiation direction of the energy beam is not particularly limited. For example, the energy beam may be irradiated from above the support member in a posture in which the tip sides of the electrode tabs are all directed vertically upward.

  Further, the electric device may be one in which the electrode tabs are drawn out from two opposite sides. In this case, the manufacturing method of the present invention further repeats the step of bending only one of the electrode tabs in advance by pressing and the step of bending in advance so that only the one electrode tab is present. Preparing a plurality of the electric devices that are bent and the other electrode tab remains in a straight state, the one electrode tab of the one electric device, and the other adjacent to the one electric device A step of stacking the plurality of electrical devices so that the other electrode tab of the electrical device is in proximity to or in contact with the other electrode tab.

The electrical device assembly of the present invention is an electrical device assembly in which a plurality of the electrical devices are electrically connected in series and / or in parallel by connecting sheet-like electrode tabs drawn from each electrical device. The electrode tabs connected to each other and the support members are inserted into slits formed in a support member made of a conductive material, and the electrode tabs and the support members are positioned in the vicinity of the openings on the surface side of the slits. Are electrically connected to each other by welding by irradiation with an energy beam .

  According to the present invention, as described above, since a dedicated jig for sandwiching the electrode tabs is not required when welding is performed, the electrode tabs can be welded without preparing a jig having a complicated configuration. Is possible.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a perspective view of an assembled battery which is an example of the electric device assembly of the present invention. 2 is a perspective view showing a single bus bar used for the assembled battery of FIG. 1, and FIG. 3 is a perspective view showing a single battery cell similarly used for the assembled battery of FIG.

  As shown in FIG. 1, the assembled battery 50 according to the present embodiment is formed by stacking a plurality of battery cells 20 in the thickness direction (the vertical direction in the drawing), and the electrode tab 25 drawn from each battery cell 20. The bus bar 30 is arranged in each of the connecting portions. In addition, the electrical connection between the battery cells 20 is not limited to a series connection, and may be a parallel connection or a combination of parallel and series.

  As the battery cell 20 itself, a conventional one can be used, but in the present embodiment, a battery cell having a configuration as shown in FIG. 3 is used. Specifically, as shown in FIG. 3, the battery cell 20 includes a thin battery element 22 (electric device) that outputs a predetermined electromotive force (for example, 3.6 V) in a sealed space formed by the exterior film 24. Element) is housed together with the electrolyte. The exterior film 24 has a structure in which two upper and lower films are bonded to each other, and a sealing portion 23 in which the films are heat-sealed is formed on the outer peripheral portion of the exterior film 24. The exterior film 24 has a rectangular outline shape, and a positive electrode tab 25a and a negative electrode tab 25b are drawn out from two sides on the short side.

  The battery element 22 is formed by laminating a plurality of sheet-like positive electrodes whose surfaces are coated with a positive electrode active material and sheet-like negative electrodes whose surfaces are coated with a negative electrode active material via separators. The thickness is, for example, about several mm.

  Although it does not specifically limit as the exterior film 24, For example, 3 layers by which the inner surface layer provided with heat sealing property, the intermediate | middle layer which consists of metal foil films | membranes, and the outer surface layer which functions as a protective layer were laminated | stacked in order. It may be of a structure. The inner surface layer may be made of a thermoplastic resin excellent in electric field liquid resistance and heat sealing properties such as polyethylene, polypropylene, polyethylene terephthalate (PET), polyamide, ionomer, and the like. The intermediate layer may be made of a flexible material having excellent strength, such as an aluminum foil or a SUS foil film. The outer surface layer may be made of a thermoplastic resin excellent in insulation, such as a polyamide resin or a polyester resin.

  The electrode tabs 25a and 25b (hereinafter also referred to as electrode tabs 25 without being distinguished from each other) are sheet-like conductive members having a thickness of, for example, 50 μm to 300 μm. The material of the electrode tab 25a for the positive electrode is, for example, aluminum or an aluminum alloy. The material of the electrode tab 25b for the negative electrode is, for example, copper or an alloy.

  Although not particularly limited, each battery cell 120 is housed in a resin case 29 (see FIG. 1), and the assembled battery 50 has a configuration in which the battery cells in the case are stacked in the thickness direction. It has become. A part of the case 29 is provided with a protrusion 29 a for supporting the bus bar 30. Specifically, both end portions (held portion 33) of the bus bar 30 are sandwiched between the protruding portion 29a of one case and the protruding portion 29a of the other case adjacent thereto.

  As shown in FIG. 2, the bus bar 30 includes a plate-shaped central portion 35 formed slightly longer than the width dimension of the electrode tab, and sandwiched portions 33 formed on both sides thereof. A slit 35a is formed in the central portion 35, and two electrode tabs 25 are inserted into the slit 35a as described later. Each of the sandwiched portions 33 is formed as a flat surface orthogonal to the central portion 35, and this portion is sandwiched between the protruding portions 29a of the case.

  In addition, the bus bar 30 in FIG. 2 is formed with an engaging portion 34 provided with an engaging hole 34 a continuously to one of the sandwiched portions 33. This engaging part 34 should just be provided only in the bus bar located in the up-and-down both ends of the lamination direction among some bus bars 30 shown in FIG. This is because the engaging portion 34 is a structural portion for fixing the bus bars 30 at both the upper and lower ends to the case of the assembled battery.

  The connection part of the bus bar 30 and each electrode tab 25a, 25b has a form as shown in FIG. 4 (b). That is, a welded portion 28 is formed on the tip side of the two electrode tabs inserted into the slit 35a (near the opening on the surface side of the slit 35a), and the two electrode tabs and the bus bar are formed by the welded portion 28. 30 are in a state of being energized with each other.

  Various methods of using the bus bar 30 thus provided are conceivable. For example, the bus bar 30 can be connected to a predetermined electric circuit and used as a terminal for voltage extraction. When used as a terminal for voltage extraction, it is preferable that the bus bar 30 is arranged for each connection portion between the electrode tabs as in this embodiment. With such a configuration, the voltage for each battery cell 20 can be detected. For example, a copper material can be used for the bus bar 30, but the present invention is not limited to this, and various materials can be used as long as the conductive material can be welded to the electrode tab.

  Moreover, in this embodiment, as shown in FIG. 1, one to-be-clamped part 33 of each bus-bar 30 is in the state which protruded along the X direction shown in figure from the projection part 29a. Then, the connecting member 40 is connected to the protruding sandwiched portions 33, and each sandwiched portion 33 is inserted into each insertion portion 43 so that the sandwiched portion 33 and the electric circuit are connected. It has become. In other words, the connection between the plurality of sandwiched portions 33 and the plurality of insertion portions 43 corresponding thereto is performed only by connecting one connection member 40. Therefore, compared with a configuration in which connectors or the like (not shown) are connected to each of the sandwiched portions 33 one by one, the labor of connection work is greatly reduced. Further, if the connection member 40 is configured to be attachable to the side surface of the case 29, for example, the connection member 40 also functions as a member that fixes the cases 29 to each other. Therefore, it is advantageous in that it is not necessary to prepare a member for fixing the cases 29 to each other, or the rigidity of the case of the assembled battery can be improved.

  Next, the manufacturing method of the assembled battery 50 of this embodiment is demonstrated centering on the process of connecting electrode tabs with reference to FIG. 4, FIG. In FIG. 5, only the central portion 35 of the bus bar 30 is schematically shown, and a part of the bus bar 30 is drawn.

  The connection between the electrode tabs is performed as follows in a state where the plurality of battery cells 20 are overlapped. First, as shown in FIGS. 4A and 5, the tip ends of the electrode tabs 25 a and 25 b respectively drawn out from the battery cells 20 adjacent to each other are inserted into the slits 35 a of the bus bar 30. The distal ends of the inserted electrode tabs 25a and 25b slightly protrude from the upper surface of the bus bar 30, and the positions of the distal ends of the electrode tabs 25a and 25b are aligned. The two electrode tabs 25a and 25b are sandwiched by being inserted into the slit 35a.

  The electrode tab does not necessarily protrude from the bus bar surface, and the end surface of each electrode tab and the bus bar surface may be flush with each other.

  Next, an energy beam is irradiated from above in the figure onto the electrode tabs 25a and 25b inserted into the slit and exiting on the surface side of the bus bar by the above process. As a result, as shown in FIG. 4B, the tip sides of the electrode tabs 25a and 25b are melted, and the vicinity of the slit 35a on the upper surface of the bus bar 30 is also melted to form a weld 28 that is substantially flush with the upper surface of the bus bar. Is done. As a result, the two electrode tabs and the bus bar 30 are energized with each other.

  For example, a laser beam or an electron beam can be used as the energy beam. Also, as shown in FIG. 4, if the tips of the electrode tabs 25a and 25b are aligned in the same plane and the energy beam is irradiated toward the close contact surface between the electrode tabs, The electrode tabs 25a and 25b are irradiated with substantially the same amount of energy beam. However, the irradiation position of the energy beam is not limited to the above and can be variously changed.

  As shown in FIG. 5, by moving the irradiation position along the extending direction of the slit 35 a, the streaky welded portion 28 is formed. However, the present invention is not limited to this, and it is also possible to form a plurality of spot-like welded portions 28 by irradiating only some of the electrode tab tips with an energy beam.

  All the battery cells 20 are electrically connected by repeatedly performing the said welding process with respect to each connection part of electrode tabs. Then, the final assembled battery 50 is completed by fixing the cases 29 or attaching the connection member 40.

  In the manufacturing method according to this embodiment, as described above, welding is performed by irradiating the electrode tab inserted into the slit 35a with an energy beam. That is, since welding is performed using the bus bar 30 as one member constituting the assembled battery 50 as a pressing jig for the electrode tab, it is not necessary to prepare a dedicated pressing jig. Conventionally, when an assembled battery is configured by using relatively thin battery cells 20, there is a problem that the configuration of the jig is complicated because the distance between the electrode tabs is narrowed. Such a problem does not occur because no holding jig is required.

  Further, in the manufacturing method of the present embodiment, the irradiation direction of the energy beam is the drawing direction of the electrode tab, and in this respect, the conventional manufacturing method in which the energy beam is irradiated perpendicularly to the electrode tab (FIG. 11). In the conventional manufacturing method, as described above, it is difficult to perform welding one after another in a state where the battery cells 120 are stacked. On the other hand, in the manufacturing method of the present embodiment, for example, it is possible to successively weld each connection portion in a state where battery cells are stacked as shown in FIG. preferable.

  Although one embodiment of the present invention has been described above, the present invention is not limited to the above and can be variously modified.

  First, regarding the irradiation of the energy beam, the irradiation direction may be inclined with respect to the drawing-out direction (the vertical direction in the drawing) of the electrode tab as shown in FIG. In FIG. 6A, the energy beam is irradiated in an oblique direction toward one of the electrode tabs 25a and 25b protruding from the bus bar surface. Even if irradiation is performed in this manner, the two electrode tabs and a part of the bus bar 30 adjacent thereto are melted as in the above-described embodiment, and the welded portion 28 that interconnects the members 25a, 25b, and 30 is formed. The

  Moreover, although the said embodiment demonstrated the form with which the front-end | tip of electrode tab 25a, 25b irradiated with an energy beam was arrange | equalized, the front-end | tip of electrode tab 25a, 25b has become uneven as shown in FIG. Also good. In FIG. 7, the tip surface of one of the two electrode tabs (for example, the electrode tab 25b) is relatively low. In the case of such a configuration, for example, the energy beam may be irradiated to the tip of the lower electrode tab 25b. Here, the irradiation direction of the energy beam may be either a vertical direction as shown in FIG. 7 or an oblique direction as shown in FIG. This irradiation heats and melts the portion of the electrode tab 25b irradiated with the energy beam, and also melts a portion of the electrode tab 25a and the bus bar 30 adjacent thereto, thereby interconnecting the members 25a, 25b, and 30. A weld 28 is formed.

  Moreover, in the said embodiment and FIG.6, FIG.7, the structure which an energy beam is irradiated from the perpendicular | vertical upper direction (In other words, the structure which all become the attitude | positions in which the front end side of an electrode tab faces vertically upward) is shown. However, the present invention is not limited to this. For example, as shown in FIG. 1, the bus bar 30 may be positioned on the side surface of the assembled battery, and the tip side of the electrode tab may be in the horizontal direction. Even in such a posture, the electrode tab and the bus bar can be welded by irradiating the energy beam from the horizontal direction (or oblique direction). The number of electrode tabs inserted into the slit is not limited to two, and for example, three or more electrode tabs may be inserted into the slit.

  Next, the bus bar is not limited to the one having the sandwiched portion 33 or the like as shown in FIG. 2, but is made of a simple flat member like the bus bars 30A and 30B in FIG. Also good. Furthermore, the slit formed in the bus bar may also be a slit 35 ′ with one end in the longitudinal direction being an open end, as shown in FIG. In this case, since the two electrode tabs can be inserted from the open end in the extending direction of the slit, the process of inserting the electrode tab into the slit can be easily performed. In order to facilitate the insertion into the slit, it is also possible to form a notch introducing portion 36 by notching the corner portion on the open end side, like the slit 35 ″ in FIG. 8B. .

  Moreover, in the said embodiment, as shown in FIG. 4, although both electrode tab 25a, 25b was bent, the front end side was the structure inserted in a slit, it is not restricted to this, It shows in FIG. Such a configuration may be adopted. In the battery cell 20 of FIG. 9A, one electrode tab 25a remains in a straight state, and only the other electrode tab 25b is pre-pressed and bent. A predetermined number of such battery cells 20 are prepared, and then, as shown in FIG. 9B, the electrode tab 25a of one battery cell and the electrode tab 25b of the battery cell adjacent thereto are close (or in contact). Thus, the predetermined number of battery cells are overlapped. Then, a bus bar (not shown) is attached so that the tip ends of the two electrode tabs 25a and 25b adjacent to each other are inserted into the slit.

  As shown in FIG. 4, when both of the electrode tabs 25a and 25b are bent in advance by, for example, press working or the like, a shape error due to the press working is equivalent to two electrode tabs 25a and 25b. On the other hand, as shown in FIG. 9, when only one electrode tab 25b is pressed, the shape error due to the pressing is one electrode tab. Therefore, as shown in FIG. 9B, when the battery cells are overlapped with each other, the variation of the tip positions of the electrode tabs 25a and 25b is reduced, and as a result, the process of inserting the electrode tabs into the slits can be performed more easily. It becomes.

  The configuration of the assembled battery 50 as a whole is not particularly limited, but may be, for example, as shown in FIG. An assembled battery 50A shown in FIG. 10 includes two modules M each having a plurality of battery cells 20 (cases 29) overlapped, and an upper plate 48 and a lower plate 49 that sandwich the modules M from the upper surface side and the lower surface side. Have. Although not shown, each case 29 is formed with convex portions (or concave portions) for engagement on the upper and lower surfaces thereof, so that the upper and lower cases 29 are positioned relative to each other.

  Each case 29 is formed with a through hole (not shown) extending in the thickness direction, and a fixing through bolt 47a is passed through the through hole. A recess 49a is formed in a portion to which the nut 47b is attached so that the nut 47b attached to the end of the through bolt 47a does not protrude from the surfaces of the upper plate and the lower plate (FIG. 10B). The assembled battery 50A is completed by fixing the upper plate 48 and the lower plate 49 with through bolts and nuts.

  When this type of assembled battery is configured, generally, the configuration is not as described above, and each module M is sandwiched between an upper plate and a lower plate (separate members from the upper plate 48 and the lower plate 49 in FIG. 10). In many cases, the module M is further sandwiched between the upper plate 48 and the lower plate 49. In FIG. 10A, for example, another upper plate for fixing the module M itself is arranged between the upper surface of the module M and the upper plate 48. However, in the case of such a configuration, the number of parts becomes relatively large, and the number of assembling steps increases accordingly. On the other hand, in the configuration of FIG. 10, since the assembled battery is configured by the module M and the upper plate 48 and the lower plate 49 arranged on the upper and lower surfaces thereof, the number of parts is reduced and the assembly process is simplified. Is also realized. The reduction in the number of parts is also preferable from the viewpoint of reducing the weight and size of the assembled battery.

  Although the battery cell 20 and the assembled battery 50 in which the battery cell 20 is assembled have been described above as examples, the present invention joins electrode tabs drawn from electric device elements such as capacitors in addition to the battery. It can be suitably used for this. Specifically, the electric device element may be an electric double layer capacitor or an electrolytic capacitor.

  In FIG. 3, the member that houses the battery element 22 is not limited to the exterior film 24, and may be a rigid member such as a can. In addition to the laminated type in which the positive electrode and the negative electrode are laminated via the separator as described above, the battery element 22 is laminated with a strip-like positive electrode and a negative electrode via the separator, It may be of a wound type that is thinned by being compressed into a flat shape after being wound. The battery element 22 may be, for example, a lithium ion secondary battery, a nickel metal hydride battery, a nickel cadmium battery, a lithium metal primary / secondary battery, or a lithium polymer battery.

It is a perspective view of the assembled battery which is an example of the electric device aggregate | assembly of this invention. It is a perspective view which shows the bus bar single-piece | unit used for the assembled battery of FIG. It is a perspective view which shows the battery cell single-piece | unit used for the assembled battery of FIG. It is a figure for demonstrating the welding process of the electrode tabs by one Embodiment of this invention. It is a perspective view for demonstrating the welding process of the electrode tabs by one Embodiment of this invention. It is a figure for demonstrating the other example of a welding process. It is a figure for demonstrating the further another example of a welding process. It is a perspective view which shows the other structural example of a bus bar. It is a figure for demonstrating the process of bending the electrode tab of each battery cell, and the process of superimposing the battery cell obtained in that way. It is a figure which shows an example of a structure of the whole assembled battery. It is a side view for demonstrating one structural example of the conventional assembled battery.

Explanation of symbols

20 battery cell 22 battery element 23 sealing part 24 exterior film 25, 25a, 25b electrode tab 28 welded part 29 case 29a protrusion part 30, 30A, 30B bus bar 33 clamped part 34 engaging part 34a engaging hole 35 central part 35a , 35a ', 35a''slit 36 introduction part 40 connection member 43 insertion part 47a through bolt 47b nut 48 upper plate 49 lower plate 49a recess 50, 50A battery pack EB energy beam M module

Claims (6)

A method of manufacturing an electrical device assembly in which a plurality of electrical devices are electrically connected in series and / or in parallel by connecting sheet-like electrode tabs drawn from each electrical device,
Inserting the tip sides of the electrode tabs connected to each other into a slit formed in a support member made of a conductive material;
Irradiating an energy beam to the electrode tab coming out to the surface side of the support member through the slit, and welding the electrode tab and the support member.   The said welding process WHEREIN: Two said electrode tabs are inserted in the said slit, and the protrusion amount from the surface of the said supporting member of the said two electrode tabs is all the same. A method for manufacturing an electrical device assembly.   In the welding step, the two electrode tabs are inserted into the slit, and the protruding amount of one of the electrode tabs from the surface of the support member is relatively small, and the energy beam protrudes. The manufacturing method of the electric device assembly according to claim 1, wherein the irradiation is performed toward the electrode tab having a relatively small amount.   4. The electrical device according to claim 1, wherein the welding step irradiates the energy beam from above the support member with a posture in which a tip side of each electrode tab is vertically upward. 5. A method for manufacturing an assembly. The electric device is one in which the electrode tabs are drawn out from two sides facing each other,
A step of bending only one of the electrode tabs by press working in advance;
Repeating the pre-bending step, preparing a plurality of the electrical devices in which only the one electrode tab is bent and the other electrode tab remains in a straight state;
The plurality of electrical devices are stacked such that the one electrode tab of one electrical device and the other electrode tab of another electrical device adjacent to the one electrical device are close to or in contact with each other. The method for producing an electrical device assembly according to claim 1, further comprising: a step. By connecting the sheet-like electrode tabs drawn from each electrical device, a plurality of the electrical devices are electrically connected in series and / or in parallel,
The tip sides of the electrode tabs connected to each other are inserted into a slit formed in a support member made of a conductive material, and in the vicinity of the opening on the surface side of the slit, the electrode tab and the support member Are electrically connected to each other by welding by irradiation of an energy beam .

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