JP2005116457A - Battery pack and manufacturing method of the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a battery pack which can be used as ones for vehicles advantageous in welding operation, and a manufacturing method of the same. <P>SOLUTION: A welding part of the battery pack can be welded in flexible stage when forming the battery pack by pressing a lamination body formed by laminating a plurality of layers formed by elastically holding a unit batteries B between a rigid first frame F<SB>1</SB>and a second frame F<SB>2</SB>made of an elastic material. Vibration at welding is not transmitted to battery parts, previously welded parts or the like, and the welding is surely made without generating any stress strain or welding exfoliation. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an assembled battery that is optimal as a power source that supplies large energy with high energy density, small size, and light weight.

  In recent years, in response to growing environmental awareness, there is a movement to shift the power source of automobiles from an engine using fossil fuel to a motor using electric energy. For this reason, the technology of the battery that serves as a power source for the motor is also rapidly developing.

  An automobile is desired to be equipped with a battery that is small and light and can be charged and discharged with a large amount of electric power and has excellent vibration resistance and heat dissipation. As an assembled battery excellent in heat dissipation capable of supplying large electric power, there is a battery as shown in Patent Document 1 below.

  The assembled battery disclosed in Patent Document 1 includes a plurality of flat unit cells that are electrically connected in series, in parallel, or in series-parallel at predetermined intervals in the thickness direction of the unit cells, A pressing member that presses the unit cells on both sides is arranged on the side, and a plurality of unit cells are fixed by an exterior member. By adopting such a structure, the heat dissipation characteristics of the single battery are improved, and the cycle characteristics and rate characteristics of the assembled battery are improved.

In such an assembled battery, after fixing a cell to an exterior member and laminating | stacking up and down, the electrode tabs protruded from each cell are connected by the connection member (refer the following patent document 2).
Japanese Unexamined Patent Publication No. 2000-195480 (see paragraph number “0014” to paragraph number “0029”, paragraph number “0040”, paragraph number “0041” and the descriptions in FIGS. 1, 2, and 4) Japanese Patent Laid-Open No. 7-183022 (see paragraph number “0008”, paragraph number “0019” and the description of FIGS. 1, 2, 4, and 5)

  Since the assembled battery of Patent Document 1 uses a flat battery as a single battery, the battery has the same energy capacity and higher energy density than a conventional assembled battery configured using a battery other than the flat battery. If so, downsizing is possible. For this reason, the assembled battery comprised with the flat battery is suitable as a vehicle-mounted battery in terms of small size and high energy density.

  However, since this assembled battery is an assembled battery developed for an electricity storage system, its structure is required to be used as an assembled battery for vehicles that require production efficiency, small size and light weight, vibration resistance, and high reliability. It is necessary to add a big improvement to.

  Specifically, it should have a structure with high production efficiency. In addition, a single cell that can achieve a reduction in size and weight, a reduction in the number of components, and an increase in volumetric efficiency is arranged, and charging and discharging are repeated frequently. Even if it is carried out, it has a structure that does not cause a decrease in battery capacity and life due to gas generated inside the unit cell, and a structure with vibration resistance, and even if it is arranged at high density, heat dissipation is efficient It is necessary to add various improvements that are made automatically.

  Further, in the battery of Patent Document 2, when the cell tabs are stacked on top and bottom and the electrode tabs of each cell are welded together with a connection member, the electrode tabs are constrained in the surface direction, and the connection members are also predetermined. Since the two are welded in a state of being restrained at a fixed position, it is difficult to perform the welding operation.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide an assembled battery that can be used as an assembled battery for a vehicle and is advantageous in terms of welding workability, and a manufacturing method thereof.

  In order to achieve such an object, a method of manufacturing an assembled battery according to the present invention includes a step of placing a plurality of flat unit cells on a first frame, and an electrode tab protruding from each unit cell adjacent to the unit cell. A step of placing a connection member for joining to the electrode tab on a placement portion provided on the first frame; and placing a second frame made of an elastic body on the first frame to place the first member on the first frame. A step of elastically holding and temporarily holding each unit cell and the connection member between the frame and the second frame, and joining the connection member temporarily held by the first frame and the second frame to the electrode tab; Connecting the unit cells, and forming a laminate by laminating a plurality of the first frame and the second frame that elastically sandwich the unit cells.

  Further, the assembled battery of the present invention holds the first frame on which the plurality of flat unit cells are placed and the plurality of unit cells placed on the first frame by being sandwiched between the first frame. A plurality of the first frame and the second frame that elastically sandwich the unit cell to form a laminate, and the plurality of unit cells in the laminate are connected. It is characterized by that.

  In the assembled battery manufacturing method of the present invention, a plurality of flat unit cells are mounted on the first frame, the electrode tab protruding from each unit cell is joined, and the connection member for connecting the unit cells is connected to the first frame. Place the second frame made of an elastic body on the first frame, place the single cell elastically between each cell, and temporarily hold it. In this temporarily held state, the connection member and the electrode Since the tab is joined, even if vibration is generated during this joining, the vibration of the connecting member does not reach other parts, and the peeling of the welded part and the adverse effect on the weak part can be suppressed as much as possible.

  In the assembled battery of the present invention, a single battery is elastically sandwiched by a first frame and a second frame made of an elastic body, and a plurality of layers are stacked to form a stacked body, and the plurality of single cells in the stacked body are connected. Therefore, it is possible to weld the welded part at a flexible stage, and vibration during this welding is not transmitted to the battery part or the already welded part or is difficult to transmit, and stress distortion is applied to the connection part between the electrode tab and the battery body. In this case, reliable welding can be performed without causing poor welding connection or peeling of the weld, which is advantageous in terms of workability.

  Hereinafter, an embodiment of an assembled battery according to the present invention will be described with reference to the drawings. First, a single cell used in the assembled battery will be described, and the structure of the assembled battery and a method for manufacturing the assembled battery will be described.

<Single cell>
FIG. 1 is a perspective view showing a unit cell. As shown in FIG. 1, the unit cell B used in this embodiment is a rectangular flat secondary battery, and a power generation element (not shown) in which a positive electrode plate, a negative electrode plate, and a separator are sequentially stacked is an exterior material. 1 has a plurality. This power generation element is, for example, a lithium ion secondary battery.

  The exterior material 1 used here is, for example, a laminate film having a three-layer structure in which an aluminum foil is sandwiched between resin films such as polyamide resin. In forming the cell B, this laminate film is used. Two sheets are prepared, one is formed into a flat bowl shape by pressing, the other is used as a sheet, the power generation element is installed between both laminated films, and the periphery is heat sealed and sealed. It has stopped. Hereinafter, such a flat cell is simply referred to as a cell.

  From the packaged unit cell B, for example, a positive electrode tab Ta made of a thin aluminum plate having a thickness of about 0.2 mm and a negative electrode made of a copper thin plate having a thickness of about 0.2 mm, for example. Although the electrode tab Tb is drawn out to the outside, in this embodiment, a single cell of a type in which electrode tabs T (electrode tabs Ta and Tb) having different polarities are drawn from two opposite sides is used. The assembled battery 10 is configured.

<Structure of assembled battery>
2 is a schematic perspective view of the assembled battery according to the present embodiment, FIG. 3 is a schematic perspective view showing a state in which the unit cell is provided on the frame, FIG. 4 is an enlarged perspective view of the main part of FIG. 3, and FIG. It is sectional drawing of a connection member periphery of the state which accumulated the 2nd frame.

  2 and 3, as shown in FIGS. 2 and 3, four unit cells B are arranged in a plane direction on a flat frame F, and a plurality of these unit cells B connected in series are stacked. In addition, the holding means 18 (see FIG. 6) pressurizes from both sides in the stacking direction and integrally holds them.

  As shown in FIG. 3, the frame F according to the present embodiment includes a rigid first frame F1 made of a synthetic resin such as PPS (polyphenylene sulfide) and an elastic material such as a vibration-proof rubber. 2 frames F2.

  The first frame F1 is a substantially rectangular plate body on which the four unit cells B are installed, and is formed of a rigid synthetic resin, so that it can be molded with high dimensional accuracy. A voltage detection line 11 for detecting the voltage of each cell B is molded on the upper surface of the first frame F1, and a thermistor 12 is molded on the lower surface. If the first frame F1 is made of synthetic resin in this way, the voltage detection line 11 and the thermistor 12 can be molded and integrated, and the subsequent battery assembly operation becomes extremely easy. However, when the first frame F1 is formed, only the groove in which the voltage detection line 11 and the thermistor 12 are provided may be formed, and the voltage detection line 11 and the thermistor 12 may be incorporated in the groove later. In any case, the voltage detection line 11 can be directly connected to the electrode tabs Ta and Tb by being disposed on the upper surface of the first frame F1, and the thermistor 12 is simply disposed by being disposed on the lower surface of the first frame F1. The surface temperature of the battery B can be accurately detected.

  The second frame F2 includes a positioning unit 13 that positions and holds the plurality of single cells B placed on the first frame F1, and each single cell B is connected to the outer peripheral frame 15 of the positioning unit 13 and the second frame F2. Elastically supported from the periphery. In the second frame F2, the positioning protrusion 13 having a predetermined length L protrudes inward from the outer peripheral frame 15, and an opening O is provided inside.

  In the four single cells B installed on the first frame F1, the electrode tabs Ta and Tb protrude above the cutout recess 16 of the first frame F1, but do not protrude from the periphery of the first frame F1. Absent.

  In the four unit cells B, the electrode tab Ta of the + electrode and the electrode tab Tb of the − electrode of each unit cell B adjacent to each other are connected in series by a connection member 30 (commonly called a bus bar). These electrode tabs Ta and Tb and the connection member 30 are joined by ultrasonic welding.

  Ultrasonic welding is used for the following two reasons.

  The first reason is that ultrasonic welding performs mechanical joining by diffusing and recrystallizing metal atoms by applying high-frequency vibrations to the parts to be joined. Very effective against. In the unit cell of the present embodiment, the electrode tab Ta of the + electrode is an aluminum thin plate, the electrode tab Tb of the − electrode is a copper thin plate, and the connection member 30 is made of copper.

  The second reason is that ultrasonic welding does not reach a high temperature during joining, and the maximum temperature of the joining surface can be suppressed to about 35 to 50% of the melting point. No melting or brittle cast structure is formed. The unit cell used in the present embodiment is made of a very thin metal without exposing the unit cell B to a high temperature state because the exterior material is a laminate material and the electrode tab T cannot be raised to a very high temperature. It is most suitable for joining the electrode tabs T.

  When the electrode tab T and the connection member 30 are welded by ultrasonic welding, when vibration generated during welding is transmitted to the electrode tab T having low rigidity, stress strain is generated at the base of the electrode tab T on the battery body side. Therefore, it is preferable to avoid transmission of vibration to the electrode tab T as much as possible because various problems such as poor connection and peeling of welding may occur.

For this reason, in this embodiment,
(1) The second frame F2 is made of an elastic material such as an anti-vibration rubber, and the unit cell itself is elastically held.
(2) The electrode tab T and the connection member 30 to be ultrasonically welded are flexibly supported during welding.
(3) The connection member 30 is elastically supported by the temporary holding portion 17 provided in the second frame F2.
(4) The positioning portion 13 is also formed of an elastic body integrally with the second frame F2, and has a high vibration proofing property so as to avoid transmission of the vibration as much as possible.
(5) The form of the connection member 30 itself is also improved, and the connection member 30 itself is also highly vibration proof.

  These points will be described in further detail.

  First, as shown in FIGS. 4 and 5, the temporary holding portion 17 is formed at the left and right end portions of the notch recess 16 formed in the first frame F <b> 1 and the second frame F <b> 2. The temporary holding portion 17 includes a concave portion 17a formed on the second frame F2 made of an elastic material and a base portion 17b formed on the rigid first frame F1, and connects the interval between the concave portions 17a. The connection member 30 can be temporarily held between the recesses 17a by using the elasticity of the second frame F2 slightly shorter than the entire length of the member 30. Assembling of the connection member 30 will be described in detail later, but the connection member 30 placed on the table-like portion 17b of the first frame F1 is received and held on both concave portions 17a, and then welded.

  Since the connection member 30 supported by the temporary holding portion 17 is disposed on the electrode tab T and is supported softly and flexibly by the second frame F2 even if some vibration is applied during ultrasonic welding, the connection member 30 is restrained. Therefore, it is possible to prevent the situation in which welding is smoothly performed and vibration during welding is transmitted to the base of the electrode tab T via the electrode tab T.

  Next, as shown in FIGS. 4 and 5, the positioning portion 13 is formed of an elastic body integrally with the second frame F <b> 2, has a certain length L, and protrudes into the opening O. Therefore, the unit cell B can be slightly displaced by the elastic deformation of the positioning portion 13, and this also absorbs vibration during welding and enhances vibration isolation.

  As shown in FIG. 5, the connecting member 30 itself has a deformed portion 30 a between both joint end portions. In ultrasonic welding, when one end is welded and then the other end is ultrasonic welded, if there is a deformed portion 30a in the middle, vibration generated during welding at the other end will be absorbed. Since the transmission to one end portion that has already been welded is prevented, the vibration isolation is further enhanced.

  Further, if the angles β and γ between the inclined portions 32a and 32b of the connecting member 30 and the flat portion 31 are not equal and are not symmetrical with respect to the axis perpendicular to the plane passing through the center between the joint portions, welding is performed. Sometimes the resonance point between the one end of the connecting member 30 and the other end will be shifted, thereby preventing large vibrations. Note that the width and thickness of the intermediate portion of the connection member 30 may be changed as appropriate, or the material of the connection member 30 may be a softer material than the electrode tab material.

  When the assembled battery 10 is configured using such a connection member 30, the strength against shaking is improved, and the practical assembled battery 10 for a vehicle having excellent vibration resistance is obtained.

  The assembled battery 10 of the present embodiment is configured by stacking 24 layers of frames F1 and F2 in which four unit cells B are arranged in parallel in a plane direction, and connecting a total of 96 unit cells in series. The cells B need to be connected in series to each other in a direction perpendicular to the surface.

  6 is a cross-sectional view taken along line AA or A′-A ′ in FIG. 2. In FIG. 2, for convenience of explanation, the holding means 18 shown in FIG. 6 is not shown, but a holding means 18 described later is provided at this portion.

  There are various methods for the series connection in the direction perpendicular to the plane, but the assembled battery 10 of this example has three notch recesses 16 in which the connection members 30 are provided, and the notch recesses 16 from which the electrode tabs T protrude. Since there are two places, the electrode tabs T projecting from the two notch recesses 16 are connected in series.

  Specifically, as shown in FIG. 6, the first frame F1 is electrically connected to the first frame F1a in which the conductive washer Wa is embedded at the right end and the insulating washer Wb is embedded at the left end, the insulating washer Wb at the right end, and the left end. Two types of first frames F1b in which washers Wa are embedded are prepared. Similarly, the second frame F2 has a second frame F2a in which a conductive washer Wa is embedded at the right end, an insulating washer Wb is embedded at the left end, and a second frame in which an insulating washer Wb is embedded at the right end and a conductive washer Wa is embedded at the left end. Two types of F2b are prepared.

  The conductive washer Wa of the first frame F1a and the conductive washer Wa of the second frame F2a are stacked so as to sandwich the electrode tab Ta of the + electrode, and at the opposite end of the frame, the insulating washer Wb of the first frame F1a is stacked. And the insulating washer Wb of the second frame F2a is laminated. The conductive washers Wa of the first frame F1a and the second frame F2a of the first layer are in contact with the conductive washers Wa of the first frame F1a and the second frame F2a of the second layer, and at the end on the opposite side, The insulating washers Wb of the layer and the second layer are placed in contact with each other. The third layer and the fourth layer are laminated so that the insulating washer Wb is positioned on the conductive washer Wa of the first layer and the second layer. In FIG. 6, only three layers are stacked, but actually six layers are stacked, the intermediate heat sink H3 is placed, and the same operation is repeated.

  As described above, when the first frame F1 and the second frame F2 are laminated so that the portion where the conductive washer Wa contacts and the portion where the insulating washer Wb contacts are alternately formed on the left and right, the four single units of each layer are stacked. The battery B is electrically connected in series via the conductive washer Wa and the electrode tab T.

  As shown in FIG. 6, the holding means 18 includes a through bolt 19, a nut 20, and heat sinks H1 and H2 at the upper and lower ends. The lower end of the through bolt 19 is fixed to the heat sink H2 at the lower end side. Yes. A conducting member 21 is provided in the through hole of the upper end heat sink H1 through which the through bolt 19 is inserted.

  The heat sinks H1 and H2 at the upper and lower ends are hard and are made of a porous material or a metal plate having a passage inside so as to exhibit heat dissipation, so that a predetermined surface pressure is applied to each unit cell B. I have to. This is because, when a predetermined surface pressure is applied to the unit cell B, it is possible to prevent a decrease in battery capacity and a decrease in service life due to gas generated inside the unit cell even if charging and discharging are frequently repeated.

  In applying this surface pressure, the laminated unit cell B as a whole is usually provided directly below the heat sink H1 at the upper end with an elastic body made of a material that is easily deformed by compression, such as cardboard, rubber, resin, etc. However, in this embodiment, since the second frame F2 is formed of an elastic body, such an elastic body for adjusting the surface pressure is not necessary.

  FIG. 7 is a cross-sectional view of the frame end in a state where the first frame and the second frame are overlapped. In the present embodiment, as shown in FIGS. 3, 4, and 7, the second frame F <b> 2 has a surface pressure adjusting portion 22 that contacts the first frame F <b> 1 at both side ends, and is added by the holding means 18. When the pressure is applied, the surface pressure applied to the unit cell B is adjusted by the surface pressure adjusting unit 22.

  The surface pressure adjusting portion 22 includes a surface pressure adjusting protrusion 23 formed on the second frame F2 and a groove portion 24 formed at a position corresponding to the surface pressure adjusting protrusion 23 on the back surface of the first frame F1. When the frames F1, F2 are overlapped and pressurized, the groove portion 24 deforms the surface pressure adjusting projection 23, adjusts the crushing margin of the projection 23, and adjusts the surface pressure. This surface pressure adjustment can be further finely adjusted by finely adjusting the pitch a of the protrusions 23 shown in FIG.

  In adjusting the surface pressure, the surface pressure adjusting protrusion 23 formed on the second frame F2 may be simply pressed on the lower surface of the first frame F1, but in this way, the two frames overlapped with each other. Since F1 and F2 may be displaced and volume loss may occur due to deformation of the protrusion 23, the surface pressure adjusting protrusion 23 is deformed by the groove 24 to prevent volume loss.

  When the protrusion 23 was pressed by the groove 24, the pressure margin and the surface pressure were verified. Here, the height of the protrusion 23 is h, and the depth of the groove 24 is d. As described above, the protrusion 23 is made of a rubber material. The protrusion 23 is used within 20% so that a predetermined surface pressure can be given to the unit cell B over a long period of time. The hardness (Hs) is about 50.

  The amount of crushing of the protrusion 23 is | h−d |, and is used within 20% of the height h of the protrusion 23, so the following expression (1) is satisfied.

| H−d | /h×100≦0.2h (1)
Solving equation (1) with the depth d of the groove 24,
^{d ≧ h-h 2/500} ... (2)
An experiment was conducted to pressurize the unit cell within the range where the above formulas (1) and (2) are satisfied. As a result, the pressurization allowance of the unit cell and the surface pressure range are as shown in FIG.

  The surface pressure range shown in FIG. 8 is experimentally within the surface pressure range (0.05 Mpa to 0.4 Mpa) effective in improving the battery life, and the effect of improving the life is recognized.

  Production of the assembled battery using the first frame F1, the second frame F2, the connection member 30 and the like formed as described above is as follows.

<Method for producing assembled battery>
In order to manufacture the assembled battery 10, first, the first frame F 1 and the second frame F 2, the single battery B, or the like is previously formed and prepared. The first frame F1 can be easily processed by injection molding or the like, and the second frame F2 can be processed by injection compression, injection press, press molding, or the like.

<First step>
In order of assembly, first, four unit cells B are placed in a plane direction on a rigid first frame F1. The tabs T of the four unit cells B protrude into the notch recess 16.

<Second step>
A connection member 30 that joins the electrode tab Ta protruding from each unit cell B to the electrode tab Tb of the adjacent unit cell B is installed on the platform 17b provided on the first frame F1.

<Third step>
A second frame F2 made of an elastic body is placed on the first frame F1, and each cell B is elastically held by the positioning unit 13. In this case, the second frame F2 is slightly pressurized to the first frame F1, and the connection member 30 on the base portion 17b is fitted into the concave portion 17a of the second frame F2, temporarily held, and positioned.

<4th process>
The connection member 30 temporarily held by the first frame F1 and the second frame F2 is joined to the electrode tabs Ta and Tb, and the unit cells B are connected in series. The electrode tabs Ta and Tb of each unit cell B are located on the frame F, and the connection member 30 is placed on the electrode tabs Ta and Tb, and is temporarily held by the second frame F2. The connection member 30 and the electrode tabs Ta and Tb of the unit cell B are sandwiched by a jig, and ultrasonic welding is performed by applying ultrasonic vibration. However, you may laminate | stack the 1st flame | frame F1 and the 2nd flame | frame F2 only in the range which can be welded with the jig of an ultrasonic welding apparatus.

  At the time of this welding, in the present embodiment, the connection member 30 is ultrasonically welded in a state where it is temporarily held both in the surface direction and in a direction perpendicular to the surface, that is, in a state where it is elastically supported. Even when one end of the connection member 30 is welded, and also when the other end is welded after welding one end of the connection member 30, the vibration is generated by the deformed portion 30 a of the connection member 30 or the battery. Due to the temporary holding state by the second frame F2 or the slip on the first frame F1, it is not transmitted to the part where the welding is completed, or even if it is transmitted, it becomes extremely small. There is no risk of adversely affecting the base of T.

  Further, the connection member 30 after the welding is completed cannot move in the surface direction of the unit cell B, but has a flexible structure in the direction perpendicular to the surface. Therefore, the assembled battery after being assembled is extremely preferable as a battery for a vehicle to which vibration is applied.

<5th process>
In this way, a battery unit in which the four cells B are combined in the first frame F1 and the second frame F2 is repeated a plurality of times to form a plurality of battery units. Then, the cells F1 and F2 are stacked while being passed through the through bolts 19 so that the cells are connected in series to form a stacked body of a plurality of battery units. Since the through bolt 19 is erected on the heat sink H2 on the lower end side of the holding means 18, the battery units are placed on the upper surface of the heat sink H2 on the lower end side and are stacked one after another.

  When six layers of battery units are stacked in this way, an intermediate heat sink H3 is installed. This operation is repeated to stack 24 battery units.

<6th process>
When 24 battery units are stacked, the upper end heat sink H <b> 1 is placed thereon and tightened by the holding means 18. This tightening is performed by screwing the nut 20 into the through bolt 19. By this tightening, a predetermined surface pressure is applied to each cell B via the heat sinks H1 and H2 at the upper and lower ends. This surface pressure is adjusted by deformation of the surface pressure adjusting projection 23 by the groove 24. It has been done.

  Further, the tightening by the holding means 18 pressurizes the electrode tabs Ta and Tb and the washers Wa and Wb located at the end portions, thereby forming an electrical connection state so that the cells are connected in series. .

  In this way, the assembled battery 10 in which all the predetermined number of single cells B are connected in series is constructed.

  The present invention is not limited to the above-described embodiments, and various modifications can be used within the scope of the claims. For example, although the connection member of the embodiment is deformed, it is not limited to this, and may be a straight one.

  In the present invention, a rigid first frame on which a plurality of single cells are placed and a second frame made of an elastic body are stacked and pressed from both sides in the stacking direction. Become.

It is a perspective view which shows a cell. It is a schematic perspective view of the assembled battery which concerns on embodiment of this invention. It is a schematic perspective view which shows the state which provides a cell in a flame | frame. It is a principal part expansion perspective view of FIG. It is sectional drawing of the periphery of a connection member of the state which accumulated the 1st frame and the 2nd frame. It is sectional drawing which follows the AA or A'-A 'line | wire in FIG. It is sectional drawing of the frame edge part of the state which accumulated the 1st frame and the 2nd frame. It is a figure which shows a pressurization allowance and a surface pressure range.

Explanation of symbols

10 ... assembled battery,
11 ... Voltage detection line,
12 ... Thermistor,
13 ... positioning part,
15 ... peripheral part,
17 ... Temporary holding part,
18 ... holding means,
22 ... Surface pressure adjusting unit,
23: Surface pressure adjustment protrusion,
24 ... groove,
30: Connecting member,
F1 ... 1st frame,
F2 ... the second frame,
B ... Single cell,
Ta, Tb ... electrode tab.

Claims (8)

Placing a plurality of flat cells on the first frame;
Placing a connection member for joining an electrode tab protruding from each unit cell with an electrode tab of an adjacent unit cell on a placement unit provided in the first frame;
Placing a second frame made of an elastic body on the first frame, elastically sandwiching and temporarily holding the unit cells and the connection member between the first frame and the second frame;
Connecting a connection member temporarily held by the first frame and the second frame to the electrode tab and connecting the unit cell,
A method for manufacturing an assembled battery, in which a plurality of the first and second frames that elastically sandwich the unit cell are stacked to form a stacked body. A first frame on which a plurality of flat cells are placed;
A second frame made of an elastic body that holds and holds the plurality of single cells placed on the first frame with the first frame;
A battery pack, wherein a plurality of the first and second frames sandwiching the unit cells are stacked to form a stack, and the plurality of unit cells in the stack are connected.   The assembled battery according to claim 2, wherein the second frame has a positioning portion that positions the single cells.   The first frame and the second frame have temporary holding portions that elastically temporarily hold the electrode tabs protruding from the unit cells and sandwich the connection member connecting the unit cells between the frames. The assembled battery according to claim 2 or 3.   The assembled battery according to claim 4, wherein the connection member is joined to the electrode tab while being held by the temporary holding portion.   The assembled battery according to any one of claims 2 to 5, wherein the first frame is formed of a synthetic resin, and a voltage detection line and a thermistor are molded.   The stack includes a holding unit that pressurizes the stacked body from both sides in the stacking direction to apply a surface pressure to the single cells on the stacked body and holds the stacked body, and abuts the second frame with the first frame Protrusions that are integral with the second frame are provided on the surface, and grooves that adjust the collapse allowance of the protrusions are provided at positions corresponding to the protrusions of the first frame, whereby the surface pressure is a predetermined surface pressure. The assembled battery according to any one of claims 2 to 6, wherein the assembled battery is adjusted.   The assembled battery according to claim 5, wherein the joining is performed by ultrasonic welding.

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