WO2007032273A1

WO2007032273A1 - Electric device module and production method therefor

Info

Publication number: WO2007032273A1
Application number: PCT/JP2006/317850
Authority: WO
Inventors: Hisako Nakano; Takeshi Kanai
Original assignee: Nec Corporation; Fuji Jukogyo Kabushiki Kaisha
Priority date: 2005-09-13
Filing date: 2006-09-08
Publication date: 2007-03-22

Abstract

A method or the like of producing a cell module capable of downsizing the entire cell module in a constitution in which electrode tabs led out from cells are joined by welding. The cell module (50) has cells (20) having sheet-form electrode tabs (25a, 25b) led out from film packages, and cases housing the cells therein. The method of producing the cell module (50) comprises the step of disposing each cell (20) in each case to partially allow electrode tabs (25a, 25b) to overlap each other, and the step of welding electrode tabs to each other while cooling the electrode tabs by supplying cool air to the electrode tabs.

Description

Specification

Electrical device module and manufacturing method thereof

Technical field

TECHNICAL FIELD [0001] The present invention relates to an electric device module in which a predetermined number of electric devices such as film-clad batteries are housed in a case and a method for manufacturing the same.

Background art

[0002] In recent years, for example, a lightweight and small battery has been developed as a power source for driving a motor of an electric vehicle. One of them is an assembled battery in which a plurality of thin film-clad batteries (also called “battery cells”) are assembled. Hereinafter, an example of the configuration of the assembled battery will be described with reference to FIGS. FIG. 1 is an exploded perspective view of a battery module constituting the assembled battery. FIG. 2 is a perspective view showing an entire assembled battery constructed by stacking the battery modules of FIG. FIG. 3 is a cross-sectional view showing a connection portion between electrode tabs drawn from each battery cell.

[0003] As shown in FIG. 2, the assembled battery 180 includes a plurality of battery modules 150 assembled in a stacked state. Each battery module 150 contains two battery cells 120 each.

[0004] Each battery cell 120 includes, for example, a lithium secondary battery. Although not shown in detail, a battery element and an electrolytic solution are accommodated in a package that also has a laminating film force. A sheet-like electrode tab 125 extends from the outer peripheral portion of the film package so that a voltage can be taken out from the electrode tab 125. In FIG. 1, the two electrode tabs 125 are shown with no particular distinction. One is a positive electrode tab, and the other is a negative electrode tab.

[0005] The two battery snares 120 are accommodated in a case 130 constituted by a lower case 135 and two lid members 136A and 136B. A bus bar 115 is disposed between the two battery cells 120. The electrode tabs 125 extending from each battery cell force are connected to each other on the bus bar 115 as shown in FIG. For example, laser welding or ultrasonic welding can be used for the connection between the two electrode tabs 125 and the bus bar 115.

[0006] According to the battery module 150 having such a configuration, the two battery cells 120 are arranged in the lower case. Since it is possible to weld the electrode tabs in a state of being arranged in a plane on 135, the workability of welding can be improved. A technique for arranging a plurality of battery cells in a plane to constitute one module is also disclosed in, for example, Japanese Patent Application Laid-Open No. 2005-116456.

Disclosure of the invention

[0007] By the way, when electrode tabs are joined together by ultrasonic welding or laser welding, the temperature of the electrode tabs rises due to heat during welding. On the other hand, the part where the electrode tab is pulled out (the base part of the electrode tab) is a laminate film. For this reason, if the temperature of the electrode tab rises too much, the laminate film may melt. If the film melts, the airtightness of the film package may be impaired.

[0008] Therefore, in order to prevent the above-described adverse effects, in the conventional configuration, the length Lt (see FIG. 3) of the electrode tab 125 has been set to be long. In other words, by increasing the distance between the position where welding is performed (welded part) and the base of the tab, the temperature rise at the base of the tab is suppressed to prevent melting of the laminate film.

However, when the electrode tabs are lengthened in this way, the problem of film melting can be solved, but the distance between the battery cells 120 becomes wide. For this reason, there was a problem that the battery module and the assembled battery as a whole were enlarged.

[0010] As described above, the power for explaining the problems of the prior art using the battery cell and the battery module using the battery cell as an example. The above problems do not occur only in the battery. For example, the same problem may occur in an electric device having a capacitor or the like instead of a battery element.

[0011] The present invention has been made in view of the above-described problems, and an object of the present invention is to provide an electrical connection in a configuration in which electrode tabs from which a film-clad electrical device force is also drawn are joined by welding. An object of the present invention is to provide an electric device module and a method for manufacturing the same that can reduce the size of the entire device module.

[0012] In order to achieve the above object, the method for producing an electric device module of the present invention comprises a film packaging body strength sheet-shaped electrode tab having two or more film-clad electrical devices with bow I cut out, and the film-clad packaging. A case for accommodating an electrical device, and adjacent to each other A method of manufacturing an electrical device module in which the electrode tabs of a film-clad electrical device are joined together by welding, wherein each of the film-clad electrical devices is disposed in the case, and the electrode tabs are partially connected to each other. A step of superimposing, and a step of welding the electrode tabs while cooling the electrode tabs by supplying cooling air to the electrode tabs.

[0013] In the manufacturing method of the present invention, welding is performed while the electrode tab is cooled. Therefore, the temperature rise at the base portion of the electrode tab is suppressed, and the film is melted. Therefore, according to the present invention, it is possible to reduce the size of the battery module and the assembled battery as a whole without requiring a long electrode tab as in the prior art.

In the present invention, the cooling air supply position may be a region between the base portion of the electrode tab and the welded portion. Further, in the case where the overlapping portion of the electrode tabs is welded to a nos bar having a metal material force, the welding step may include supplying cooling air to the bus bar.ヽ. When laser welding is used as welding, the cooling air may be simple air, but is preferably an inert gas.

[0015] The electrical device module of the present invention has two or more film-clad electrical devices in which sheet-like electrode tabs are drawn out from the film package, and a case that accommodates the film-clad electrical device, An electric device module in which the electrode tabs of the film-covered electrical devices adjacent to each other are joined by welding, and the case is cooled to a position between the film-covered electrical devices adjacent to each other. The cooling structure portion is provided with a hole for supplying cooling air to the vicinity of the overlapping portion of the electrode tabs. With such a configuration, the production method of the present invention can be favorably performed.

[0016] In the electrical device module according to the present invention, in the case where the overlapping portion of the electrode tabs is disposed on the upper surface of the cooling structure portion, the cooling structure portion has one opening. It is preferable that a through hole is formed in the upper surface and the other opening is located on the back side of the case, and cooling air is sent to the hole through the through hole. Further, a bus bar made of a metal material force may be arranged between the overlapping portion of the electrode tabs and the upper surface of the cooling structure portion. Cold The rejection structure portion may be a member having a metallic material force provided separately from the case.

[0017] As described above, according to the present invention, since welding is performed while the electrode tab is cooled, it is difficult for the film to melt at the base of the electrode tab, and the electrode tab is lengthened. Since it is not necessary, the battery module and the like can be downsized. Brief Description of Drawings

FIG. 1 is an exploded perspective view showing a configuration example of a conventional battery module.

FIG. 2 is a perspective view showing an entire assembled battery formed by stacking battery modules.

FIG. 3 is a cross-sectional view showing a connection portion between electrode tabs drawn from each battery cell.

FIG. 4 is an exploded perspective view of a battery module according to an embodiment of the present invention.

FIG. 5 is a perspective view showing a battery cell in a single state.

FIG. 6 is a perspective view showing a configuration of a cooling structure provided in a part of the case.

FIG. 7 is a cross-sectional view showing a configuration around a cooling structure when welding is performed.

FIG. 8 is a perspective view showing only the through hole of the cooling structure portion of FIG.

FIG. 9A is a perspective view showing another form of the cooling structure.

FIG. 9B is a perspective view showing another form of the cooling structure.

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, embodiments of the present invention will be described with reference to the drawings, taking a battery cell and a battery module using the battery cell as examples. FIG. 4 is an exploded perspective view of the battery module of the present embodiment. FIG. 5 is a perspective view showing the battery cell in a single state. In FIG. 4, the illustration of the lid member (corresponding to the lid members 136A and 136B in FIG. 1) is omitted.

As shown in FIG. 4, the battery module 50 of the present embodiment is mainly characterized in that a cooling structure 31 is provided at the center of the lower case 35, and other structural parts. Is configured in the same manner as the conventional battery module shown in FIG. Therefore, structural parts having the same function are indicated by reference numerals corresponding to those in FIGS.

[0021] The battery cell 20 is a conventional general film-clad battery. As shown in FIG. 5, a thin battery element 22 that outputs a predetermined electromotive force (eg, 3.6 V) is sealed by a film package 24. It is sealed. Laminate films are fused to the outer periphery of film packaging 24 A sealed portion 23 is formed. From each short side of the sealing portion 23, a sheet-like electrode tab 25a for a positive electrode and an electrode tab 25b for a negative electrode both extend.

[0022] The electrode tabs 25a and 25b will be described in more detail. Each electrode tab has a thickness of, for example, about πι to 300 / ζ m and is electrically connected to the internal battery element 22 respectively. . As the material of the electrode tab 25a for the positive electrode, either aluminum, an aluminum alloy, or an anodized or resin-coated material (referred to as “aluminum-based material”) is selected. On the other hand, the electrode tab 25b for the negative electrode may be made of copper, a copper alloy, or a metal plating (for example, nickel plating) applied to them. ) Is selected.

As shown in FIG. 4, the battery module 50 of the present embodiment is configured to accommodate two battery cells 20 in one case 30 (only the lower case 35 is shown in FIG. 4). . In addition, the battery modules 50 thus modularized are stacked in a plurality of stages, and the modules are electrically connected to form a final assembled battery.

[0024] Both the lower case 35 and the lid member are made of a resin material. The lower case 35 has two accommodating portions 39A and 39B in which one battery cell 20 is disposed, and one groove 37 is formed between the accommodating portions 39A and 39B. The cooling structure 31 is formed in the groove 37. The bus bar 15 is arranged on the upper surface of the cooling structure 31 as described later.

The nose bar 15 is made of a conductive material (metal material), and functions as a voltage extraction terminal corresponding to each battery cell 20 by connecting the electrode tabs 25a and 25b. That is, although not shown in the figure, by connecting a predetermined electric circuit to the bus bar 15, the voltage of each battery cell 20 is managed, or when an abnormality occurs in one battery cell 20. It is possible to install a fuse so that the circuit of the entire assembled battery is not damaged.

[0026] Although not particularly limited, in order to satisfactorily fix the battery cell 20 disposed in the space formed by the accommodating portions 39A, 39B and the lid member, for example, around the battery cell 20 Even if you put urethane foam.

[0027] As shown in FIG. 4, the cooling structure 31 is a structure that protrudes upward from the bottom surface of the groove 37. More specifically, the cooling structure 31 has a structure as shown in FIGS. ing. That is, the cooling structure Two inclined surfaces 32 (see FIG. 6) are formed on the outer peripheral surface of the structure portion 31, and each of the inclined surfaces 32 has a plurality of holes 32. The hole 33 functions as an outlet for cooling air, as will be described later. On the upper surface of the cooling structure 31, there are 34 long openings.

As shown in FIG. 7, both the hole 32 and the opening 34 communicate with a through hole 38 formed inside the cooling structure 31. In other words, as shown in FIG. 8, the through hole 38 is a through hole whose upper side opens as an opening 34 and whose lower side opens as an opening 38a. By forming the through hole 38 in such a shape, as shown by the arrow in FIG.

Cooling air can be introduced uniformly from 38a, and as a result, variation in the amount of cooling air delivered from each hole 33 is reduced. However, the cooling structure 31 has a force S that can be variously changed in addition to such a structure, which will be described later with reference to other drawings.

[0029] The cooling structure 31 may be configured as a separate member from the lower case 35, or may be configured as an integral member. When configured as a separate member, the cooling structure 31 can be made of a metal material, for example. In order to attach such a cooling structure 31 to the case, for example, an opening (not shown) is provided in the groove 37 of the lower case 35, and the cooling structure 31 is attached to this opening. Good.

[0030] Next, a method for manufacturing the battery module 50 will be described below with a focus on the laser welding process.

[0031] First, after the bus bar 15 is arranged on the upper surface of the cooling structure 31, the battery cells 20 are accommodated in the housing portions 39A, 39B of the lower case 35 so that the tip sides of the electrode tabs 25a, 25b overlap each other. Place each of them. Further, by using the holding jig 90 to hold the electrode tab 25a from the upper surface side, the two electrode tabs and the bus bar can be in good contact with each other. As a means for fixing the bus bar 15 to the cooling structure 31, for example, an adhesive may be used, or a screw may be used.

[0032] The holding jig 90 is not particularly limited, but is preferably made of a good heat conductor. As a result, the heat applied to the electrode tab during welding is satisfactorily absorbed by the holding jig 90, and as a result, the temperature rise of the electrode tab is suppressed.

[0033] Next, the laser beam is irradiated from the upper surface side of the electrode tabs, and the electrode tabs and the electrodes Join the tab and busbar. In this welding process, cooling air is sent into the through-hole 38, and a part of the air is passed through the hole 33 to the lower surfaces of the electrode tabs 25a and 25b (specifically, the region between the welded portion and the base portion). Being able to be sprayed. As a result, the electrode tab is cooled, and the temperature rise at the base of the electrode tabs 25a and 25b is suppressed. Further, the remaining part of the cooling air is blown to the lower surface of the bus bar 15 exposed at the opening 34, so that the bus bar 15 and the electrode tab arranged thereon are also the same. It will be P

[0034] The cooling air may be mere air, but inert gas (for example, helium gas, neon gas, argon gas, krypton gas, xenon) so as not to affect the focusing of the laser beam. Gas or radon gas). Further, the timing for starting the supply of the cooling air may be simultaneous with the irradiation of the laser beam, but is not limited thereto. Even after the start of irradiation, if the temperature of the electrode tab does not rise that much, it is considered that the problem of melting the laminate film does not occur.Therefore, supply of cooling air is started after a predetermined time has elapsed from the start of irradiation. You can do it!

Through the above steps, the electrode tabs 25a and 25b are electrically connected to each other, and the electrode tab and the bus bar 15 are electrically connected to each other. Further, the subsequent steps until the battery module 50 is completed (for example, the lid member attaching step) can be performed in the same manner as before.

As described above, according to the configuration of the present embodiment, laser welding is performed while supplying cooling air and cooling the electrode tab. For this reason, the temperature rise at the base of the electrode tab is suppressed, and the laminate film is hardly melted. Therefore, it is possible to reduce the size of the battery module 50 and the assembled battery as a whole without the need to increase the length Lt of the electrode tab as in the prior art.

[0037] The above embodiment is merely an example of the present invention, and the present invention can be variously modified in addition to the above. For example, in the above description, the electrode tabs are connected to each other using laser welding. However, the present invention is not limited to laser welding, but a welding method (accurately) that raises the temperature of the electrode tabs during welding. This also covers welding methods in which the temperature of the electrode tab rises to such an extent that a problem of melting of the laminate film can occur. [0038] Next, in addition to the above, the cooling structure may be configured as shown in FIGS. 9A and 9B, for example. The cooling structure 31A shown in FIG. 9A is formed with an introduction hole 38A extending in the lateral direction instead of the through hole 38 (see FIG. 7). The introduction hole 38A is opened only on one of the side surfaces of the cooling structure 31A, and this opening force cooling air is sent. The sent cooling air is blown out through the holes 33 as described above.

A cooling structure 31B shown in FIG. 9B is formed by forming a single elongated hole 33A in place of the plurality of holes 33 (see FIG. 6). Even if the cooling structures 31 A and 3 IB are configured in this way, it is possible to cool the electrode tabs by sending cooling air from the holes 33 and 33 A during welding. The same effect as the form can be obtained.

In the above embodiment, the cooling air is supplied from the cooling structure 31 provided in the case. However, the present invention is not limited to this, and for example, the cooling air supply mechanism is provided on the holding jig 90 side. May be provided to cool the electrode tab during welding.

[0041] Although not described in detail in the above description, the battery element 22 used in the battery cell 20 is

Lithium-ion secondary batteries, and more specifically, lithium 'positive electrode plates with positive electrode active materials such as manganese composite oxide and lithium cobaltate coated on both sides of aluminum foil, etc .; and lithium-doped' undoped ' A negative electrode plate coated with a possible carbon material on both sides, such as copper foil, may be opposed to each other through a separator and impregnated with an electrolyte containing a lithium salt. However, in addition to lithium ion secondary batteries, battery elements are battery elements of other types of chemical batteries such as nickel metal hydride batteries, nickel cadmium batteries, lithium metal primary batteries or secondary batteries, and lithium polymer batteries. Also good. Further, the battery element is not limited to a laminated type, and a positive electrode side active electrode is obtained by stacking a belt-like positive electrode side active electrode and a negative electrode side active electrode through a separator, and then compressing the same into a flat shape. And a negative electrode having a structure in which the negative electrode side active electrode is laminated alternately. Furthermore, as an electric device element, an element that stores and outputs (charges and discharges) electric energy, such as a capacitor element exemplified by a capacitor such as an electric double layer capacitor or an electrolytic capacitor, is used. Also good.

Claims

The scope of the claims

[1] Strength of film packaging body There are two or more film-covered electrical devices in which a sheet-like electrode tab is cut out of a bow I, and a case for housing the film-wrapped electrical device, and adjacent to each other. A method of manufacturing an electrical device module in which the electrode tabs are joined together by welding,

Arranging each of the film-covered electrical devices in the case, and partially overlapping the electrode tabs;

A step of welding the electrode tabs while cooling the electrode tabs by supplying cooling air to the electrode tabs.

[2] The method for manufacturing an electrical device module according to claim 1, wherein the cooling air is supplied to a region between a welded portion where the electrode tabs are joined to each other and a base portion of the electrode tab.

[3] In the configuration in which the overlapping portion of the electrode tabs is welded to a bus bar made of a metal material, the welding step includes supplying cooling air to the bus bar. The manufacturing method of the electrical device module of Claim 1 or 2.

[4] The welding step is laser welding, and the cooling air is an inert gas.

The method for producing an electric device module according to claim 1, wherein the displacement force is 1.

[5] The film-wrapped electrical device has two or more film-covered electrical devices in which a sheet-like electrode tab has a bow I cut out and a case that accommodates the film-wrapped electrical device, and is adjacent to each other. An electrode device module in which the electrode tabs are joined together by welding,

The case has a cooling structure portion between the film-covered electrical devices adjacent to each other, and a hole portion for supplying cooling air to the electrode tab in the cooling structure portion. An electrical device module is formed.

[6] In the configuration in which the overlapping portion of the electrode tabs is disposed on the upper surface of the cooling structure portion, the cooling structure portion has one opening located on the upper surface and the other opening. 6. The electric device module according to claim 5, wherein a through-hole located on the back side of the case is formed, and cooling air is sent to the hole through the through-hole.

[7] The electric device module according to claim 5 or 6, wherein a bus bar made of a metal material is disposed between the overlapping portion of the electrode tabs and the upper surface of the cooling structure portion.

[8] The electric device module according to any one of [5] to [7], wherein the cooling structure is a member made of a metal material provided separately from the case.

[9] The electrical device module force according to any one of claims 5 to 8, wherein a plurality of electrical device assemblies are assembled in a state of being electrically connected to each other.