JP2005267880A - Battery pack - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a battery pack for eliminating the uselessness of space for passing lead wires 8, 9, by extracting the lead wires 8, 9 along junction sections 3a, 3b of a battery container 3. <P>SOLUTION: In the battery pack in which a plurality of flat nonaqueous electrolyte secondary batteries 1 using the battery container 3 made of aluminum laminate films 31, 32 are connected, the lead wires 8, 9 for connecting electrode lead pieces 4, 5 of the nonaqueous electrolyte secondary batteries 1 and an assembly battery terminal 6a are arranged along the junction sections 3a, 3b of the aluminum laminate films 31, 32 at the periphery end of the battery container 3 of the nonaqueous electrolyte secondary battery 1. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an assembled battery in which a plurality of batteries using a battery container made of a flexible film such as an aluminum laminate film are combined.

  In a flat battery, a flexible aluminum laminate film may be used for a battery container that is a battery outer body for housing a power generation element (battery element) (see, for example, Patent Document 1). A conventional configuration example of a non-aqueous electrolyte secondary battery using a battery container made of an aluminum laminate film is shown in FIGS. As shown in FIG. 2, in the non-aqueous electrolyte secondary battery 1, a battery container 3 that houses a power generation element 2 is composed of two rectangular aluminum laminate films 31 and 32.

  In this example, the power generating element 2 is formed by winding a belt-like positive electrode 2a and a negative electrode 2b through a separator 2c, and crushing this from the side surface to form a flat shape, and from one end surface to the side of the positive electrode 2a Aluminum (foil or thin plate) exposed at the end is projected, and copper (foil or thin plate) exposed at the side end of the negative electrode 2b is projected from the other end surface. A positive electrode lead piece 4 made of strip-shaped aluminum (foil shape or plate shape) is connected to the aluminum of the positive electrode 2a protruding from one end face of the power generating element 2, and the negative electrode 2b protruding from the other end face. A negative electrode lead piece 5 made of strip-shaped copper or nickel (foil shape or plate shape) is connected to the copper.

  The aluminum laminate films 31 and 32 constituting the battery container 3 are flexible films in which a base film layer made of nylon resin or the like, a metal layer made of aluminum foil, and a sealant layer made of a thermoplastic resin such as polypropylene are laminated in a laminate. . And these two aluminum laminate films 31 and 32 are overlapped with the sealant layer facing each other and sandwiching the power generating element 2, and as shown in FIG. The battery container 3 is sealed inside. Further, the electrode lead pieces 4 and 5 projecting from both end faces of the power generation element 2 project between the aluminum laminate films 31 and 32 heat-welded at the peripheral edge of the battery case 3 and projecting to the outside. In the non-aqueous electrolyte secondary battery 1 shown in this example, the electrolytic solution is injected and the preliminary charging is performed before the inside of the battery container 3 is completely sealed.

  The battery container 3 composed of the two aluminum laminate films 31 and 32 has the joint portions 3a to 3d in which the aluminum laminate films 31 and 32 are overlapped and closely adhered to each other by heat-sealing the four peripheral edges. Since these are formed, these joints 3 a to 3 d protrude to the periphery of the power generation element 2 and occupy a space. Therefore, in the nonaqueous electrolyte secondary battery 1 shown in this example, as shown in FIG. 3, the joint portions 3 c, in which the electrode lead pieces 4, 5 in the four joint portions 3 a to 3 d of the battery container 3 do not protrude. 3d is bent at a right angle so that it does not protrude too much to the side.

  As shown in FIG. 4, the non-aqueous electrolyte secondary battery 1 is a plurality of (here, four) stacked in the front-rear direction, arranged in series, and housed in an assembled battery case 6 to be used as an assembled battery. There is. In this assembled battery, L-shaped connection fittings 7 are connected and fixed to electrode lead pieces 4 and 5 protruding from the joint portions 3a and 3b of the battery container 3 in each non-aqueous electrolyte secondary battery 1, respectively. Then, the positive electrode lead piece 4 is bent forward together with the connection fitting 7 and folded back toward the joint portion 3a, and the negative electrode lead piece 5 is folded backward together with the connection fitting 7 and folded back toward the joint portion 3b, thereby these electrode leads. The pieces 4 and 5 and the connection fitting 7 are prevented from protruding in the vertical direction of the assembled battery. Further, by connecting and fixing the connection fittings 7 and 7 to each other in the portions where the connection fittings 7 and 7 of the adjacent nonaqueous electrolyte secondary batteries 1 and 1 are bent in an L shape, All the nonaqueous electrolyte secondary batteries 1 are connected in series.

  The assembled battery includes a positive electrode lead piece 4 of the non-aqueous electrolyte secondary battery 1 disposed at the front end and a connection fitting 7 of the negative electrode lead piece 5 of the non-aqueous electrolyte secondary battery 1 disposed at the rear end. Current lead wires 8 and 8 are drawn out from 7 and connected to an assembled battery terminal 6 a provided in the assembled battery case 6. The current lead wires 8 and 8 are for discharging discharge current from the plurality of nonaqueous electrolyte secondary batteries 1 through the assembled battery terminal 6a and charging current from the outside. In addition, the voltage lead wire 9 is pulled out from any one of the connection fittings 7 and 7 connected and fixed between the adjacent nonaqueous electrolyte secondary batteries 1 and 1 and connected to the assembled battery terminal 6a. doing. The voltage lead wire 9 is combined with the current lead wire 8 to select a pair of lead wires 8 and 9 connected to the positive electrode lead piece 4 and the negative electrode lead piece 5 of any nonaqueous electrolyte secondary battery 1, The cell voltage of each non-aqueous electrolyte secondary battery 1 can be detected. The assembled battery terminal 6a is a connector for connecting the current lead wire 8 and the voltage lead wire 9 to an external circuit.

  However, in the conventional assembled battery, the lead wires 8 and 9 are passed through the upper and lower joints 3a and 3b of the battery container 3 of each non-aqueous electrolyte secondary battery 1 and the front end portion in the assembled battery case 6 It was connected to the assembled battery terminal 6a by being pulled out. For this reason, conventionally, a space for passing these lead wires 8 and 9 above and below the assembled battery case 6 is required, which causes a problem that the assembled battery becomes too large. That is, when the aluminum laminate films 31 and 32 are used for the battery container 3, at least the electrode lead pieces 4 and 5 are projected to the outside, and the aluminum laminate films 31 and 32 are overlapped and heat-welded to join the joint portions 3 a and Since 3b has to be formed, these joints 3a and 3b protrude around the power generation element 2, and space is likely to be wasted. For example, in the above conventional example, the side joint portions 3c and 3d where the electrode lead pieces 4 and 5 of the battery case 3 do not protrude are bent at right angles so as not to be unnecessarily protruded in the left-right direction shown in FIG. Yes. In addition, in the case of the battery described in Patent Document 1, the aluminum laminate film is first formed into a cylindrical shape to eliminate side protrusions, but at least the bonding in the direction in which the positive and negative electrode lead pieces protrude. The part has a useless protrusion. Conventionally, since the lead wires 8 and 9 are passed above and below the joint portions 3a and 3b, this further contributes to waste of space.

Further, the assembled battery needs to be pulled out by bending the lead wires 8 and 9 soldered to the connection fitting 7 immediately at substantially right angles. However, end portions of the soldered lead wires 8 and 9 are often difficult to bend due to solder, and a large force is applied to the connection fitting 7 and the electrode lead pieces 4 and 5 when bending. There has also been a problem that the soldering itself may be peeled off.
JP 2001-351492 A

  The present invention is intended to solve the problem that the space for passing these lead wires is wasted by pulling out the lead wires along the joint portion of the battery container.

  The invention of claim 1 is a battery pack in which a plurality of flat batteries using a battery container made of a flexible film are arranged and connected, and the lead wire that connects between the battery electrode lead piece and the battery pack terminal It is arranged along the joint part of the flexible film in the peripheral part of the battery container of a battery.

  According to the first aspect of the present invention, since the lead wire connected to the electrode lead piece is drawn out along the joint portion of the battery container and connected to the assembled battery terminal, the gap along the joint portion is utilized. Wiring can be performed without wasting space, and the assembled battery can be prevented from becoming too large. That is, the battery container made of a flexible film is thicker at the portion covering the power generation element, but the flexible film is bonded and thinned at the joint portion at the peripheral portion, so when arranging a plurality of batteries, In this junction, a gap is formed between adjacent batteries. Therefore, if the lead wire is passed through the gap between the joints at the peripheral edge of the battery container, the lead wire will not protrude to the periphery. Also, since the electrode lead piece protrudes from the joint portion, if the lead wire connected to the electrode lead piece directly or indirectly through the connector is wired along the joint portion, the lead wire is connected. It is not necessary to bend it near the portion, and it is possible to prevent a large burden from being applied to the connecting portion. In addition, the lead wire should just have the part pulled out from this electrode lead piece along a junction part, and the part connected to an assembled battery terminal does not necessarily follow a junction part completely by the structure of this assembled battery terminal. There is no need to be. For example, when the battery container of a battery is a square flat shape, the lead wire should just follow the junction part in the edge | side of the battery container from which an electrode lead piece protrudes.

  Hereinafter, the best embodiment of the present invention will be described with reference to FIG. In FIG. 1 as well, the same reference numerals are given to constituent members having the same functions as those of the conventional example shown in FIGS.

  In the present embodiment, an assembled battery in which a plurality of nonaqueous electrolyte secondary batteries 1 using a battery container 3 composed of two aluminum laminate films 31 and 32 are connected in series will be described as in the conventional example. The assembled battery is further used in combination with a plurality of electric vehicles, hybrid vehicles, and the like. For this reason, each non-aqueous electrolyte secondary battery is managed so as to maintain an optimal state by monitoring a cell voltage, a cell temperature, and the like together with a charge / discharge current by a battery management device (not shown).

  As shown in FIG. 1, the assembled battery includes a plurality (four in this case) of rectangular flat nonaqueous electrolyte secondary batteries 1 that are stacked in the front-rear direction so that the flat surfaces of the battery containers 3 overlap. . The configuration of each non-aqueous electrolyte secondary battery 1 is exactly the same as the conventional example shown in FIGS. 2 to 4, and aluminum laminate films 31 and 32 are overlapped on the upper and lower and left and right peripheral portions of the battery container 3. Heat-welded joints 3a to 3d are formed. The electrode lead pieces 4 and 5 protrude from the upper and lower joint portions 3a and 3b, and the left and right joint portions 3c and 3d are bent rearward at a right angle so as not to protrude so much in the left-right direction. The electrode lead pieces 4 and 5 are each connected and fixed to the connection fitting 7 by resistance welding or the like, and are bent forward or backward to be turned back to the joint portions 3a and 3b.

  The conductor at one end of the current lead wire 8 on the positive electrode side is soldered to the connection fitting 7 connected and fixed to the positive electrode lead piece 4 of the nonaqueous electrolyte secondary battery 1 disposed at the front end. At the same time, the conductor at one end of the current lead wire 8 on the negative electrode side is soldered to the connection fitting 7 connected and fixed to the negative electrode lead piece 5 of the nonaqueous electrolyte secondary battery 1 disposed at the rear end. ing. Further, the connection is fixed to the electrode lead pieces 4 and 5 of the two adjacent non-aqueous electrolyte secondary batteries 1 and 1, and the L-shaped bent portions overlap each other and are connected and fixed by resistance welding or the like. The conductors at one end of the voltage lead wire 9 are soldered to either one of the fittings 7 and 7 respectively. In addition, since these lead wires 8 and 9 are both soldered to the connection fitting 7 with the conductor at one end facing leftward, the lead wires 8 and 9 themselves Is pulled out substantially straight from the connection fitting 7 in the right direction and wired along the joint portions 3a and 3b.

  Here, for example, that the lead wires 8 and 9 are along the joint portion 3a at the upper peripheral edge of the battery case 3 means that the wiring is slightly below the upper end side of the joint portion 3a in the left-right direction. That is, the joint portion 3a is formed above a portion where the battery container 3 swells so as to cover the power generation element 2, and the joint portion 3a extends in the upward width direction, which is a direction that protrudes away from the power generation element 2. Since the length in the left-right direction along the upper end surface of the power generation element 2 is longer than the length, it means that wiring is performed along this longitudinal direction. This also means that when the voltage lead wire 9 is along the joint portion 3b at the lower peripheral edge, the voltage lead wire 9 is similarly wired in the left-right direction only upside down. When a plurality of non-aqueous electrolyte secondary batteries 1 are stacked and arranged, the battery container 3 covers the power generating element 2 and comes into close contact, but the aluminum laminate films 31 and 32 are in close contact with each other. In this portion, a gap is formed between the adjacent nonaqueous electrolyte secondary batteries 1, 1, so that the lead wires 8, 9 are wired in this gap space. Moreover, since these lead wires 8 and 9 are drawn rightward from one end portion soldered to the connection fitting 7, there is no need to bend and pull out the vicinity of the soldered end portion.

  The other end of each of the lead wires 8 and 9 is pulled out to the right end in the assembled battery case 6 and connected to the assembled battery terminal 6a. The assembled battery terminal 6a is a connector that allows a charging / discharging current to flow through the contacts to which the lead wires 8 and 9 are connected, respectively, and that the cell voltage of each non-aqueous electrolyte secondary battery 1 can be detected. Although not shown here, for example, a contact point connected to a lead wire from a temperature detecting element arranged in the vicinity of each non-aqueous electrolyte secondary battery 1 in the assembled battery case 6 is provided to each non-aqueous electrolyte. The temperature of the secondary battery 1 may be detected.

  According to the above configuration, since the lead wires 8 and 9 are wired along the joint portions 3a and 3b of the battery container 3 of the nonaqueous electrolyte secondary battery 1, a plurality of nonaqueous electrolyte secondary batteries 1 are arranged. These lead wires 8 and 9 pass through the gaps between the joint portions 3a and 3b generated between the adjacent nonaqueous electrolyte secondary batteries 1 and 1. Accordingly, it is not necessary to pass the lead wires 8 and 9 through the upper and lower sides of the nonaqueous electrolyte secondary battery 1, so that space is not wasted and the assembled battery can be prevented from becoming unnecessarily large. In addition, in the case of the present embodiment, the lead wires 8 and 9 are drawn almost straight out from one end portion soldered to the connection fitting 7 to the other side, so that these lead wires 8 and 9 are soldered. There is no need to forcefully bend it at the end, and a large burden is not applied to the connection fitting 7 and the electrode lead pieces 4 and 5, and soldering is not peeled off.

  In the above embodiment, the connection fitting 7 is connected and fixed to the electrode lead pieces 4 and 5, and the lead wires 8 and 9 are indirectly drawn out through the connection fitting 7. However, the connection fitting 7 May not necessarily be used, and the lead wires 8 and 9 may be directly drawn out from the electrode lead pieces 4 and 5. The connection between the non-aqueous electrolyte secondary batteries 1 when the connection fitting 7 is not used may use an inter-battery connection wire different from the lead wires 8 and 9, or other connection such as a connection rod or a connection plate. A member can also be used.

  Moreover, although the case where the current lead wire 8 and the voltage lead wire 9 are used as the lead wires has been described in the above embodiment, only one of these may be used as the lead wire along the joint portions 3a and 3b. it can. For example, as the conductive material for passing the charge / discharge current of the non-aqueous electrolyte secondary battery 1, a bowl-like or plate-like material is used, and only the voltage lead wire 9 is drawn from between the non-aqueous electrolyte secondary batteries 1. You can also Further, instead of these lead wires 8 and 9, or in addition to these lead wires 8 and 9, the above-mentioned lead wire for temperature detection and other lead wires can be used. Furthermore, these lead wires can be wired not only along the joint portions 3a and 3b from which the electrode lead pieces 4 and 5 protrude, but also along the side joint portions 3c and 3d. In the assembled battery shown in FIG. 4, the lead wires 8 and 9 are wired not only along the joints 3 a and 3 b but also along the joint 3 d, but in particular, the current lead wires 8 and 8 at both ends. The other end connected to the assembled battery terminal 6a is wired through the outer side in the right direction from the joint 3d. However, in this assembled battery, since the protrusions in the left and right directions are reduced by bending the joint portions 3c and 3d rearward, even if the current lead wires 8 and 8 pass slightly outside, there is almost no trouble. . In addition, since the electrode lead pieces 4 and 5 do not protrude from the joint portions 3c and 3d, the portion where the current lead wires 8 and 8 are wired can be further recessed or provided with a hole or a notch. It can also be prevented from protruding. Further, if the assembled battery terminal 6a is long in the front-rear direction, the current lead wires 8, 8 are connected to the assembled battery terminal 6a while being wired along the joint 3a and the joint 3d. You can also.

  Moreover, in the said embodiment, although the case where the two aluminum laminate films 31 and 32 were piled up and it was set as the battery container 3 was shown, the structure of this aluminum laminate film is arbitrary, for example, one sheet of aluminum laminate film is used. The battery container 3 can also be formed by folding it in half, and it is optional whether or not to form a recess for fitting the power generating element 2 in this aluminum laminate film in advance. Furthermore, although the case where an aluminum laminate film was used for the battery case was shown in the above embodiment, a metal / resin laminate film using a metal layer having another barrier property instead of the aluminum foil can also be used. Furthermore, any material can be used as long as it is a flexible film that ensures sufficient strength and barrier properties and can be surely sealed. For example, a film material that is not a laminate film made only of a resin can be used. Further, the overlapping portions of such flexible films can be joined by other methods such as adhesion instead of heat welding.

  Moreover, although the case where the electrode lead pieces 4 and 5 consist of strip-shaped aluminum, copper, or nickel was shown in the said embodiment, the shape and the kind of metal of these electrode lead pieces 4 and 5 are arbitrary. Furthermore, although the case where the electrode lead pieces 4 and 5 protrude from the joint portions 3a and 3b at both end portions of the battery container 3 is shown in the above embodiment, the positive and negative electrode lead pieces are formed only from the joint portion at one end portion. Even in the case of protruding, the same can be implemented. Here, the electrode lead piece is a lead material that is connected to the electrode of the power generation element inside the battery container and partially protrudes from the joint portion of the flexible film in the battery container for connection to the outside. Say.

  Moreover, in the said embodiment, although the assembled battery which connected the some nonaqueous electrolyte secondary battery 1 in series was demonstrated, it is not necessary to connect all the nonaqueous electrolyte secondary batteries 1 in series, and one part They can be connected in parallel or all in parallel, and the series-parallel connection can be switched by the assembled battery terminal 6a or an external circuit. Furthermore, in the above-described embodiment, the case where a plurality of nonaqueous electrolyte secondary batteries 1 are arranged in a row is shown, but a plurality of such rows of nonaqueous electrolyte secondary batteries 1 can also be arranged. Furthermore, in the said embodiment, although the case where each nonaqueous electrolyte secondary battery 1 was comprised with the cell was shown, if the battery container made from a flexible film is used, the structure of an internal battery is arbitrary. There may be a combination of a plurality of single cells.

  Moreover, although the said embodiment demonstrated the assembled battery which accommodated the some nonaqueous electrolyte secondary battery 1 in the assembled battery case 6, it does not necessarily need to use the box-shaped or container-shaped assembled battery case 6, for example, It may be surrounded by a frame or the like. Furthermore, although the case where the connector-like assembled battery terminal 6a is used has been described in the above embodiment, the configuration of the assembled battery terminal 6a is also arbitrary. For example, a positive / negative terminal or a cell voltage detection terminal on the terminal block It is also possible to use an assembled battery terminal with only protruding.

  Moreover, in the said embodiment, although the winding-type electric power generation element 2 shape | molded in flat shape was shown, the method of making this electric power generation element 2 flat is arbitrary, and it winds from the beginning to a long cylindrical shape or an ellipse shape. You may use what you did. Furthermore, the power generation element 2 does not need to be a winding type, and a stacked type power generation element can also be used. Furthermore, in the said embodiment, although the case where the nonaqueous electrolyte secondary battery 1 was used was shown, the kind of this battery is arbitrary and another secondary battery and a primary battery can also be used.

1 is a perspective view illustrating an internal structure of an assembled battery according to an embodiment of the present invention. It is an assembly perspective view which shows the structure of a nonaqueous electrolyte secondary battery. It is a perspective view of a nonaqueous electrolyte secondary battery. It is a perspective view which shows a prior art example and shows the internal structure of an assembled battery.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Nonaqueous electrolyte secondary battery 3 Battery container 3a Joining part 3b Joining part 31 Aluminum laminated film 32 Aluminum laminated film 4 Positive electrode lead piece (electrode lead piece)
5 Negative lead piece (electrode lead piece)
6a Battery pack terminal 8 Current lead wire (lead wire)
9 Voltage lead wire (lead wire)

Claims (1)

In an assembled battery in which a plurality of flat batteries using a battery container made of a flexible film are arranged and connected,
An assembled battery, wherein a lead wire connecting between an electrode lead piece of a battery and an assembled battery terminal is arranged along a joint portion of a flexible film at a peripheral edge portion of the battery container of the battery.

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