WO2014010395A1

WO2014010395A1 - Cell structure

Info

Publication number: WO2014010395A1
Application number: PCT/JP2013/067249
Authority: WO
Inventors: 洋介空; 和幸坂本; 小比賀　基治; 智明吉川
Original assignee: 日産自動車株式会社
Priority date: 2012-07-13
Filing date: 2013-06-24
Publication date: 2014-01-16
Also published as: JP5871067B2; JPWO2014010395A1

Abstract

This invention is provided with: a plurality of flat secondary cells in which power-generating elements obtained by stacking electrode plates and separators are sealed using exterior members; metal parts in contact, between the flat secondary cells, with at least a part of the side surfaces of the flat secondary cells oriented along the direction perpendicular to the stacking direction of the electrode plates and the separators, the metal parts having surfaces oriented along the side surfaces; air layers that cover the side surfaces between the flat secondary cells, with the metal parts disposed therebetween; and a fixing part for fixing the metal parts. The fixing part is a case that houses the flat secondary cells.

Description

Battery structure

The present invention relates to a battery structure.

This application claims priority based on Japanese Patent Application No. 2012-157176 filed on Jul. 13, 2012. For designated countries that are allowed to be incorporated by reference, The contents described in the application are incorporated into the present application by reference and made a part of the description of the present application.

A plurality of prismatic batteries are stacked and integrated through a heat insulating member, and the heat insulating member is sized to cover substantially the entire end face of the prismatic battery, and the heat insulating member is composed of polypropylene, polyurethane, or the like having sufficiently low thermal conductivity. An assembled battery using a resin is known (Patent Document 1).

JP 2004-362879 A

However, since the heat insulating effect of the synthetic resin heat insulating member is not sufficient, there is a problem that when heat is generated in the rectangular battery, heat conduction to the adjacent rectangular battery cannot be suppressed.

The problem to be solved by the present invention is to provide a battery structure that suppresses heat conduction between a plurality of secondary batteries.

The present invention is a surface that is in contact with at least a part of a side surface of a flat secondary battery along a direction perpendicular to the stacking direction of an electrode plate and a separator between a plurality of flat secondary batteries and along the side surface. A plurality of flat secondary batteries, an air layer that covers the side surface via the metal part, and a fixing part that fixes the metal part. The above-described problem is solved by using a case that houses a secondary battery.

In the present invention, the thermal expansion of the secondary battery is suppressed by the metal plate, and an air layer having a low thermal conductivity is secured. Therefore, the conduction of heat generated from the secondary battery can be suppressed by the air layer, As a result, heat conduction between the plurality of secondary batteries can be suppressed.

It is a top view of the battery contained in the battery structure which concerns on embodiment of this invention. FIG. 2 is a cross-sectional view taken along the line II-II in FIG. 1 is a perspective view of a battery structure according to an embodiment of the present invention. It is a perspective view of the single cell contained in the battery structure concerning other embodiments of the present invention. It is a disassembled perspective view of the battery module comprised by laminating | stacking the cell of FIG. It is a perspective view of the battery structure concerning other embodiments of the present invention. It is a top view of the battery structure of FIG. FIG. 7 is a cross-sectional view taken along line VIII-VIII in FIG. 6. It is a perspective view of the battery structure concerning other embodiments of the present invention. It is a perspective view of the battery structure concerning other embodiments of the present invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

<< First Embodiment >>
First, the configuration of the battery 10 included in the battery structure 1 of this example will be described. In addition, the structure of the battery of the battery structure 1 is not limited to the following structure, and a battery having another structure may be applied to the battery structure 1 of the present example. 1 is a plan view of the battery 10, and FIG. 2 is a cross-sectional view taken along the line II-II of FIG. The X, Y, and Z axis displays in FIGS. 1 and 2 correspond to the axis displays in FIG.

The battery 10 is a lithium-based, flat plate, and laminated type flat (thin) secondary battery. As shown in FIGS. 1 and 2, the three positive plates 11, five

separators

12, 3 The negative electrode plate 13, the positive electrode terminal 14, the negative electrode terminal 15, the upper exterior member 16, the lower exterior member 17, and an electrolyte (not particularly illustrated) are configured.

Of these, the positive electrode plate 11, the separator 12, the negative electrode plate 13, and the electrolyte constitute a power generation element 18, the positive electrode plate 11 and the negative electrode plate 13 constitute an electrode plate, and the upper exterior member 16 and the lower exterior member 17 are a pair. The exterior member is configured.

The positive electrode plate 11 constituting the power generation element 18 includes a positive electrode side current collector 11a extending to the positive electrode terminal 14, and

positive electrode layers

11b and 11c formed on both main surfaces of a part of the positive electrode side current collector 11a, respectively. Have In addition, the

positive electrode layers

11b and 11c of the positive electrode plate 11 are not formed over both main surfaces of the entire positive electrode side current collector 11a, but as shown in FIG. When the power generation element 18 is configured by laminating the negative electrode plate 13, the

positive electrode layers

11 b and 11 c are formed only on the portion of the positive electrode plate 11 that substantially overlaps the separator 12. Further, in this example, the positive electrode plate 11 and the positive electrode side current collector 11a are formed of a single conductor. However, the positive electrode plate 11 and the positive electrode side current collector 11a are formed separately and joined together. May be.

The positive electrode side current collector 11a of the positive electrode plate 11 is made of an electrochemically stable metal foil such as an aluminum foil, an aluminum alloy foil, a copper foil, or a nickel foil. Moreover, the

positive electrode layers

11b and 11c of the positive electrode plate 11 are formed of, for example, lithium composite oxides such as lithium nickelate (LiNiO ₂ ), lithium manganate (LiMnO ₂ ), or lithium cobaltate (LiCoO ₂ ), chalcogen ( S, Se, Te) A positive electrode side current collector obtained by mixing a positive electrode active material such as a compound, a conductive agent such as carbon black, an adhesive such as an aqueous dispersion of polytetrafluoroethylene, and a solvent. It is formed by applying to both main surfaces of a part of 11a, drying and rolling.

The negative electrode plate 13 constituting the power generation element 18 includes a negative electrode side current collector 13a extending to the negative electrode terminal 15 and negative electrode layers 13b and 13c formed on both main surfaces of a part of the negative electrode side current collector 13a, respectively. And have. The negative electrode layers 13b and 13c of the negative electrode plate 13 are not formed over both main surfaces of the entire negative electrode current collector 13a. As shown in FIG. When the power generation element 18 is configured by laminating the negative electrode plate 13, the negative electrode layers 13 b and 13 c are formed only on the portion of the negative electrode plate 13 that substantially overlaps the separator 12. Further, in this example, the negative electrode plate 13 and the negative electrode side current collector 13a are formed of a single conductor. However, the negative electrode plate 13 and the negative electrode side current collector 13a are formed as separate bodies and are joined together. May be.

The negative electrode side current collector 13a of the negative electrode plate 13 is composed of an electrochemically stable metal foil such as nickel foil, copper foil, stainless steel foil, or iron foil. Further, the negative electrode layers 13b and 13c of the negative electrode plate 13 are formed of styrene as a negative electrode active material that occludes and releases lithium ions, such as amorphous carbon, non-graphitizable carbon, graphitizable carbon, or graphite. An aqueous dispersion of butadiene rubber resin powder is mixed, dried and then pulverized, so that the main material is carbonized styrene butadiene rubber supported on the surface of the carbon particles, and a binder such as an acrylic resin emulsion. Are further mixed, this mixture is applied to both main surfaces of a part of the negative electrode side current collector 13a, dried and rolled.

When amorphous carbon or non-graphitizable carbon is used as the negative electrode active material, the flatness of the potential during charging and discharging is poor, and the output voltage decreases with the amount of discharge, so it is not suitable for the power supply of communication equipment and office equipment. However, it is advantageous when used as a power source for an electric vehicle because there is no sudden drop in output.

The separator 12 of the power generation element 18 prevents a short circuit between the positive electrode plate 11 and the negative electrode plate 13 described above, and may have a function of holding an electrolyte. The separator 12 is a microporous film made of polyolefin such as polyethylene (PE) or polypropylene (PP), for example. When an overcurrent flows, the pores of the layer are blocked by the heat generation and the current is cut off. It also has a function.

The separator 12 according to this example is not limited to a single-layer film such as polyolefin, but a three-layer structure in which a polypropylene film is sandwiched with a polyethylene film or a laminate of a polyolefin microporous film and an organic nonwoven fabric may be used. it can. Thus, by making the separator 12 into multiple layers, various functions such as an overcurrent prevention function, an electrolyte holding function, and a separator shape maintenance (stiffness improvement) function can be provided.

The power generation element 18 is formed by alternately stacking the positive electrode plates 11 and the negative electrode plates 13 with the separators 12 interposed therebetween. The three positive plates 11 are respectively connected to the positive terminal 14 made of metal foil through the positive current collector 11a, while the three negative plates 13 are connected to the negative current collector 13a. In the same manner, each is connected to a negative electrode terminal 15 made of metal foil.

In addition, the positive electrode plate 11, the separator 12, and the negative electrode plate 13 of the power generation element 18 are not limited to the above number, and for example, one positive plate 11, three separators 12, and one negative plate 13 are also included. The power generation element 18 can be configured, and the number of the positive electrode plate 11, the separator 12, and the negative electrode plate 13 can be selected and configured as necessary.

The positive electrode terminal 14 and the negative electrode terminal 15 are not particularly limited as long as they are electrochemically stable metal materials. As the positive electrode terminal 14, for example, a thickness of about 0.2 mm is used, as in the positive electrode side current collector 11 a described above. An aluminum foil, an aluminum alloy foil, a copper foil, a nickel foil, or the like can be given. Moreover, as the negative electrode terminal 15, like the above-mentioned negative electrode side collector 13a, nickel foil, copper foil, stainless steel foil, iron foil, etc. of thickness about 0.2 mm can be mentioned, for example.

As described above, in the configuration of the battery 10 shown in FIG. 2, the metal foil itself constituting the

current collectors

11 a and 13 a of the

electrode plates

11 and 13 is extended to the

electrode terminals

14 and 15. An electrode layer (

positive electrode layer

11b, 11c or negative electrode layer 13b, 13c) is formed on a part of the sheet of

metal foil

11a, 13a, and the remaining end portion is used as a connecting member to the electrode terminal. Although it was set as the structure connected to the

electrode terminals

14 and 15, the metal foil which comprises the

collectors

11a and 13a located between a positive electrode layer and a negative electrode layer, and the metal foil which comprises a connection member by different materials and components You may connect.

The power generation element 18 described above is housed and sealed in the upper exterior member 16 and the lower exterior member 17. Although not specifically illustrated, the upper exterior member 16 and the lower exterior member 17 of this example are both resistant from the inner side to the outer side of the thin battery 1, such as polyethylene, modified polyethylene, polypropylene, modified polypropylene, or ionomer. An inner layer composed of a resin film excellent in electrolytic solution and heat-fusibility, an intermediate layer composed of a metal foil such as aluminum, and an electrical insulating property such as a polyamide resin or a polyester resin And an outer layer made of an excellent resin film.

Therefore, both the upper exterior member 16 and the lower exterior member 17 are made of a resin such as polyethylene, modified polyethylene, polypropylene, modified polypropylene, or ionomer on one surface of the metal foil such as aluminum foil (inner surface of the thin battery 1). It is made of a flexible material such as a resin-metal thin film laminate material in which the other surface (the outer surface of the thin battery 1) is laminated with a polyamide resin or a polyester resin.

Thus, by providing the

exterior members

16 and 17 with the metal layer in addition to the resin layer, it is possible to improve the strength of the exterior member itself. Further, the inner layers of the

exterior members

16 and 17 are made of, for example, a resin such as polyethylene, modified polyethylene, polypropylene, modified polypropylene, or ionomer, so that good fusion properties with the

metal electrode terminals

14 and 15 can be obtained. It can be secured.

As shown in FIGS. 1 and 2, the positive terminal 14 is led out from one end of the sealed

exterior members

16 and 17, and the negative terminal 15 is led out from the other end. Since a gap is formed in the fused portion between the upper exterior member 16 and the lower exterior member 17 by the thickness of the

electrode terminals

14 and 15, the

electrode terminals

14 and 15 are maintained in order to maintain the sealing performance inside the thin battery 1. For example, a seal film made of polyethylene, polypropylene, or the like may be interposed in a portion where the

exterior members

16 and 17 are in contact with each other. It is preferable from the viewpoint of heat-fusibility that the seal film is made of a resin of the same system as the resin constituting the

exterior members

16 and 17 in both the positive electrode terminal 14 and the negative electrode terminal 15.

These

exterior members

16, 17 enclose the power generation element 18, part of the positive electrode terminal 14 and part of the negative electrode terminal 15, so that the internal liquid space formed by the

exterior members

16, 17 contains an organic liquid solvent. While injecting a liquid electrolyte having a lithium salt such as lithium chlorate, lithium borofluoride or lithium hexafluorophosphate as a solute, the space formed by the

exterior members

16 and 17 is sucked into a vacuum state, The outer peripheral edges of the

members

16 and 17 are heat-sealed by hot pressing and sealed.

Examples of the organic liquid solvent include ester solvents such as propylene carbonate (PC), ethylene carbonate (EC), dimethyl carbonate (DMC), and methyl ethyl carbonate, but the organic liquid solvent in this example is limited to this. Alternatively, an organic liquid solvent prepared by mixing and preparing an ether solvent such as γ-butylactone (γ-BL) or dietoxyethane (DEE) in the ester solvent can also be used.

Next, the configuration of the battery structure 1 of this example will be described with reference to FIG. FIG. 3 is a perspective view of the battery structure 1. The battery structure 1 includes a plurality of batteries 10,

metal plates

21 and 22, an air layer 30, and a lower case 40.

The plurality of batteries 10 are arranged in a line with the stacking direction (corresponding to the Y direction in FIGS. 2 and 3) of the positive electrode plate 11, the negative electrode plate 13, and the separator 12 included in each battery 10 being the same direction. . The battery 10a and the battery 10b are arranged in pairs, and the battery 10c and the battery 10d are arranged in pairs. Of the side surfaces of the battery 10a and the battery 10b, side surfaces (surfaces in the XZ direction) that are perpendicular to the stacking direction of the positive electrode plate 11, the negative electrode plate 13, and the separator 12, and so that the side surfaces facing each other overlap. A battery 10a and a battery 10b are arranged. Similarly to the

batteries

10a and 10b, the battery 10c and the battery 10d are also arranged so that the side surfaces facing each other overlap each other. Moreover, the battery 10 is arrange | positioned so that a clearance gap may be formed between the battery 10b and the battery 10c.

Metal plates

21 and 22 are members formed in a plate shape from metal. The

metal plates

21 and 22 are provided in a gap between the battery 10b and the battery 10c, and the metal plate 21 and the metal plate 22 are disposed so as to be in contact with the side surface of the battery 10b and the side surface of the battery 10c, respectively.

In other words, in the stacking direction of the positive electrode plate 11, the negative electrode plate 13, and the separator 12, one side surface is in contact with the side surface of the battery 10 a and the other side surface is in contact with the side surface of the metal part 21. Yes. Further, of the both side surfaces of the metal plate 21, one side surface is in contact with the side surface of the battery 10 b and the other side surface faces the air layer 30.

Similarly, in the stacking direction of the positive electrode plate 11, the negative electrode plate 13, and the separator 12, one of the side surfaces of the battery 10 c is in contact with the side surface of the battery 10 d and the other side surface is in contact with the side surface of the metal portion 22. Yes. Further, of the both side surfaces of the metal plate 22, one side surface is in contact with the side surface of the battery 10 c, and the other side surface faces the air layer 30.

The area of the side surfaces of the

metal plates

21 and 22 is formed to be equal to or greater than the area of the side surfaces of the

batteries

10b and 10 cm in contact with the side surfaces. Moreover, the thickness of the

metal plates

21 and 22 is thinner than the thickness of the battery 10 in the stacking direction. Thereby, the side surfaces of the

batteries

10 b and 10 c are covered with the side surfaces of the

metal plates

21 and 22.

The

metal plates

21 and 22 are provided to dissipate the heat by conducting heat generated from the

batteries

10b and 10c. The

metal plates

21 and 22 are provided to prevent the battery 10 from bulging (swelling in the stacking direction of the

batteries

10b and 10c) when the battery 10 expands due to an abnormal short circuit or the like. Therefore, a metal material with high thermal conductivity is used for the

metal plates

21 and 22, and a metal material that maintains the shape of the

metal plates

21 and 22 against the swelling of the battery 10 is used. Further, the thickness of the metal plates 21 and 22 (thickness in the Y direction in FIG. 3) is regulated to a thickness that maintains high rigidity so as not to be easily deformed by the swelling of the battery 10. That is, in the Y direction in FIG. 3, the

metal plates

21 and 22 are formed so that the rigidity is at least higher than the rigidity of the

exterior members

16 and 17.

An air layer 30 is provided in the normal direction of the side surfaces of the metal plate 21 and the metal plate 22 (which is the same direction as the above-described stacking direction and corresponds to the Y direction in FIG. 3). The air layer 30 is a space formed by arranging the

metal plates

21 and 22 with a gap therebetween. The air layer 30 is provided to suppress heat conduction between the

adjacent batteries

10b and 10c. Therefore, the width of the air layer 30 (the width in the Y direction of FIG. 3) is large in the Y direction of the battery structure 1 in FIG. 3 while ensuring a space so that heat is not transmitted between the

metal plates

21 and 22. The length is specified so as to suppress this.

The air layer 30 is formed so as to cover the side surfaces of the

batteries

10b and 10c via the

metal plates

21 and 22, in other words, between the air layer 30 and the

batteries

10b and 10c. Is pinched.

The lower case 40 is a plate-like case for housing a plurality of batteries 10 and is made of metal. The lower case 40 has a plane along the stacking direction of the batteries 10, and the plurality of batteries 10 are placed on the plane. The contact portions of the plurality of batteries 10 and the lower case 40 are bonded with an adhesive or the like.

The

metal plates

21 and 22 are arranged on the lower case so as to be perpendicular to the plane portion of the lower case 40, and the contact portion between the one end of the

metal portions

21 and 22 and the lower case 40 is fixed by welding or the like. Thereby, the lower case 40 fixes the

metal plates

21 and 22.

Here, the connection part between the

metal parts

21 and 22 and the lower case 40 will be described. As described above, when the battery 10 expands, stress due to expansion (stress in the Y direction in FIG. 3) is received by the side surfaces of the

metal plates

21 and 22. Then, the stress applied to the

metal plates

21 and 22 is caused by one end of the metal plates 21 and 22 (one end on the lower case 40 side of both ends in the Z direction in FIG. 3 on the side surfaces of the metal plates 21 and 22) and the lower case 40. Concentrate on the connecting part. Therefore, when the stress due to the expansion of the battery 10 is applied to the connection portion, the strength (adhesion strength) of the connection portion is high enough that the

metal plates

21 and 22 are not detached from the lower case 40. On the other hand, since the adhesion part between the battery 10 and the lower case 40 is provided for positioning the battery 10 on the lower case 40, the adhesion strength of the adhesion part between the battery 10 and the lower case 40 is a metal plate. It may be lower than the strength of the connecting portion between 21 and 22 and the lower case 40.

The lower case 40 is formed of metal in the same manner as the

metal plates

21 and 22. The preferable thermal conductivity of the lower case 40 may be 10 W / mK or more. Thereby, since the lower case 40 is excellent in the heat dissipation effect, the heat generated from the battery 10 is radiated from the lower case 40 through the

metal plates

21 and 22.

As described above, in this example, the

metal plates

21 and 22 having the surfaces along the side surfaces are in contact with the side surfaces along the vertical direction with respect to the stacking direction of the batteries 10 between the plurality of batteries 10. Between the plurality of batteries 10, an air layer 30 that covers the side surface of the battery 10 via the

metal plates

21 and 22 and a lower case 40 that fixes the

metal parts

21 and 22 are provided. Thereby, since the air layer 30 exists between the adjacent batteries 10, it can suppress that the heat emitted from the battery 10 is transmitted to the other adjacent batteries 10. Moreover, since the

metal plates

21 and 22 are provided, the heat of the battery 10 can be absorbed and the heat dissipation effect can be enhanced.

In addition, by fixing the highly

rigid metal plates

21 and 22 to the lower case 40, when the battery 10 expands due to an internal short circuit or the like, deformation in the stacking direction of the battery 10 is suppressed, so the air layer 30 is maintained. can do. Unlike this example, when the metal layers 21 and 22 are not provided between the plurality of batteries 10, the air layer 30 is narrowed due to the expansion of the battery. The heat conduction to the battery 10 cannot be suppressed. Also, unlike this example, when a resin material is provided instead of the air layer 30, the resin material becomes hot and can be melted by the heat from the battery 10 being transmitted through the

metal plates

21 and 22. There is sex. On the other hand, by maintaining the air layer 30, the present invention can enhance the heat dissipation effect while suppressing the heat conduction to the other battery 10 against the heat generation of the battery 10.

In this example, the lower case 40 is made of metal. Thereby, since the heat absorbed by the

metal plates

21 and 22 can be radiated from the lower case 40, the heat radiation effect can be enhanced.

In this example, the two

metal plates

21 and 22 are provided between the battery 10b and the battery 10c, but only one of the

metal plates

21 and 22 may be provided. Moreover, you may fasten the connection part of the

metal plates

21 and 22 and the lower case 40 with a screw | thread etc. As shown in FIG. Further, the battery 10a and the battery 10b, and the battery 10c and the battery 10d do not necessarily have to be paired. Moreover, you may provide the

metal plates

21 and 22 and the air layer 30 between the battery 10a and the battery 10b, or between the battery 10c and the battery 10d. Moreover, the

metal parts

21 and 22 should just contact at least one part of the side surface of the

batteries

10b and 10c. Further, the

metal portions

21 and 22 and the lower case 40 may be integrated.

The battery 10 corresponds to the “flat secondary battery” of the present invention, the

metal plates

21 and 22 correspond to the “metal part” of the present invention, and the lower case 40 corresponds to the “fixing part” of the present invention.

<< Second Embodiment >>
The battery structure according to another embodiment of the invention differs from the first embodiment described above in that the function of the

metal plates

21 and 22 is provided in a part of the configuration of the battery module 50. Other configurations are the same as those in the first embodiment described above, and the description thereof is incorporated as appropriate.

First, the configuration of the battery module 50 will be described. The configuration of the battery of the battery structure is not limited to the configuration described below, and a module having another configuration may be applied to the battery structure 1 of this example. FIG. 4 is a perspective view of a single battery constituting the battery module 50. FIG. 5 shows a battery module configured by stacking a plurality of flat and thin single cells. The X, Y, and Z axis displays in FIGS. 4 and 5 correspond to the axis displays in FIGS.

The cell 510 shown in FIG. 1 has a plate-like electrode terminal 511 at the end, and a plate-like electrode terminal 512 is provided at the opposite end of the electrode terminal 511 toward the outside of the battery. ing. The electrode terminal 511 has an anode polarity, and the electrode terminal 512 has a cathode polarity. The unit cell 510 is formed by sealing a power generation element in which an electrode plate and a separator are stacked with an exterior member.

The spacer 513 and the spacer 514 sandwich the electrode terminal 511, and the spacer 515 and the spacer 516 sandwich the electrode terminal 512. The spacer has an insulating property, and maintains the insulating property between the single electrode 510 and the unit cell 520 stacked. The output terminal 517 is electrically connected to the electrode terminal 511 and becomes the output terminal 517 of the battery module shown in FIG.

The unit cell 520 is stacked on the upper surface of the unit cell 510. The spacer 523 is a lower spacer among the spacers that sandwich the electrode terminal 521 of the unit cell 520 from above and below. The spacer 525 similarly indicates the lower spacer among the spacers that sandwich the electrode terminal 522 of the unit cell 520 from above and below. The electrode terminal 521 has a cathode polarity, and the electrode terminal 522 has an anode polarity. When the single battery 510 and the single battery 520 are stacked, the electrode terminal 511 and the electrode terminal 521 are electrically connected. Thereby, the unit cell 510 and the unit cell 520 are connected in series and stacked.

Note that FIG. 4 shows only the state in which two

unit cells

510 and 520 are stacked. However, when three or more unit cells are stacked as in the battery module shown in FIG. The positive electrode terminal of another unit cell is connected to the electrode terminal 522 by being stacked from the upper surface of the unit cell. Thereby, three unit cells are stacked in series connection.

The single cell 530 of the battery module 50 shown in FIG. 5 is a battery stack in which eight

single cells

510 and 520 shown in FIG. 4 are stacked (hereinafter, the eight single cells are collectively referred to as a single cell 530).

The

output terminals

531 and 532 of the anode and the cathode are connected to one end of the unit cell 530, respectively. The sleeve 533 is inserted into a hole provided in each of the stacked spacers, and is fastened with a bolt or the like to fix the unit cell 530 and the spacer 534. The insulating cover 535 is attached to the end face side of the unit cell 530 to which the

output terminals

531 and 532 are connected, covers the electrode terminal, and maintains insulation between the electrode terminal and the outside of the unit cell. Similarly, the insulating cover 535 is attached to the side opposite to the connection surface of the

output terminals

531 and 532 and covers the electrode terminals. A buffer material 536 is inserted between the spacer 534 and the upper case 361. The shock absorbing material 536 controls the function of preventing the influence of the vibration of the vehicle on the single cell when the battery module is mounted on the vehicle or the like.

The case 540 includes an upper case 541 and a lower case 542. As shown in the drawing, an assembly such as a single cell 530 is inserted into the lower case 542, and the end portion of the upper case 541 and the lower case 542 are crimped to form the single cell 530. And a spacer 534 and the like are accommodated. Case 540 is formed of a thin steel plate.

Also, a bulging portion 543 is formed on the surface of the upper case 541 so as to face the inside of the case 540. The bulging portion 543 is formed in an embossed shape by press-molding the central portion of the upper case 541. The bulging portion 543 is provided to prevent the unit cell 530 from expanding when the unit cell 530 expands due to a short circuit abnormality of the unit cell 530 or the like.

In particular, in this example, a thin steel plate is used for the case 540, and a bulging portion 543 is provided in order to increase rigidity against stress (stress in the Y direction in FIG. 5) generated when the single cell 530 expands. Yes. In addition, when the side surface of the case 540 has sufficient rigidity in a flat surface portion like the

metal plates

21 and 22 of the first embodiment, the bulging portion 543 is not provided in the case 540. Also good.

The insertion port 537 is provided in the insulating cover 535 and is fitted with a connector (not shown). When the connector is fitted into the insertion port 537, the voltage detection terminals of the unit cells constituting the unit cell 530 are electrically connected to the terminals of the connector.

The battery module 50 according to this example is a stack of eight unit cells, but is not necessarily limited to eight, and the number of unit cells that are appropriately configured in each battery module is set. can do.

Next, the configuration of the battery structure 1 of this example will be described with reference to FIGS. 6 is a perspective view of the battery structure 1, FIG. 7 is a plan view of the battery structure 1, and FIG. 8 is a cross-sectional view taken along line VIII-VIII in FIG.

The battery structure 1 includes a plurality of battery modules 50, an air layer 30, and a lower case 40. The plurality of battery modules 50 are twelve battery modules in this example, but are not necessarily twelve, and may be ten, for example. The twelve battery modules 50 are arranged in two rows in the lower case 40 in the same number of six, and in each row, two battery modules 50 have a gap corresponding to the air layer 30. It is arranged in the state. The battery modules 50 arranged in two rows are provided with an air layer 30 between the rows.

The six battery modules 50 arranged in a line are stacked in the stacking direction of the cells 530 included in each battery module 50 (the Y direction in FIGS. 6 to 8), similarly to the plurality of batteries 10 according to the first embodiment. Are aligned in the same direction. A gap is provided between the battery module 50b and the battery module 50c in order to form the air layer 30. In addition, a gap is provided between the battery module 50d and the battery module 50e in order to form the air layer 30. In FIG. 8, the battery module 50 is illustrated with the configurations of the

output terminals

531 and 532 omitted, and the internal configuration of the unit cell 530 is also simplified.

The case 540 of the battery module 50 has the same function as the

metal plates

21 and 22 according to the first embodiment. In other words, the case 540 corresponds to the

metal plates

21 and 22 according to the first embodiment. A member is formed by the case 540. That is, in this example, the case 540 that is the housing of the battery module 50 is formed of metal, and thus fixing the case 540 to the lower case 40 has a heat dissipation function and a function of suppressing the expansion of the unit cell 530. ing.

The air layer 30 is formed so as to cover the side surface (side surface along the Z direction in FIGS. 6 and 8) of the unit cell 530 through the case 540. The width of the air layer 30 (the width in the Y direction in FIG. 8) is such that a space is secured between the

metal plates

21 and 22 so that heat based on the heat generated by the unit cells 530 is not transmitted, while FIG. The length is defined so as to suppress the size in the Y direction.

The lower case 40 is a case for accommodating twelve battery modules as shown in FIG. 6, and is formed to be a rectangular parallelepiped casing. The contact portions between the plurality of battery modules 50 and the lower case 40 are fixed by welding or the like. As a result, the lower case 40 fixes the cases 540 of the plurality of battery modules 50.

As described above, the present example has a surface along the side surface in contact with the side surface perpendicular to the stacking direction of the unit cells 530 between the plurality of unit cells (battery stacks) 530. Between the case 540 and the plurality of unit cells 530, the air layer 30 that covers the side surface of the unit cell 530 and the lower case 40 that fixes the case 540 are provided via the case 540. Thereby, since the air layer 30 exists between the plurality of unit cells 530, it is possible to suppress the heat generated from the unit cells 530 from being transmitted to other adjacent unit cells 530. In addition, since the case 540 is provided, the heat of the unit cell 530 can be absorbed, and the heat dissipation effect can be enhanced. Further, by fixing the rigid case 540 to the lower case 40, the deformation of the single cells 530 in the stacking direction is suppressed when the single cells 530 expand due to an internal short circuit or the like, so that the air layer 30 is maintained. be able to. As a result, the heat dissipation effect can be enhanced while suppressing the heat conduction to the other battery modules 50 against the heat generation of the unit cell 530.

The unit cell 530 corresponds to the “flat secondary battery” of the present invention, and the case 540 corresponds to the “metal part” of the present invention.

<< Third Embodiment >>
FIG. 9 is a perspective view of a battery structure according to another embodiment of the present invention. This example differs from the above-described first embodiment in the configuration of the lower case 40. Other configurations are the same as those in the first embodiment described above, and the description thereof is incorporated as appropriate.

The battery structure 1 of the present example includes a plurality of batteries 10, an air layer 30, and a lower case 40. The lower case 40 includes a first case portion 41 serving as a plate for placing the pair of

batteries

10a and 10b, a second case portion 42 serving as a plate for placing the pair of

batteries

10c and 10d, and a third case portion. 43, a fourth case portion 44, and a fifth case portion 45.

The first case part 41 and the second case part 42 are plate-like metal members. The

batteries

10a and 10b and the

batteries

10c and 10d are arranged on the main surfaces of the first case part 41 and the second case part 42, respectively. The third case 43 is a plate-like metal member that extends from one end of the planar portion of the first case 41 in a direction perpendicular to the stacking direction of the batteries 10 (the Z direction in FIG. 9). The fourth case 44 is a plate-like metal member that extends from one end of the planar portion of the second case 42 in a direction perpendicular to the stacking direction of the batteries 10.

The fifth case portion 45 has one end of the third case portion 43 (the other end is fixed to the first case portion 41) to one end of the fourth case portion 44 (the other end is fixed to the second case portion 42). It is a plate-shaped metal member that is formed so as to extend to connect the one end of the third case portion 43 and the one end of the fourth case portion 44. Of the both side surfaces (XZ plane in FIG. 9) of the third case portion 43, the facing surface facing the fourth case portion 44 faces the air layer 30, and the side surface opposite to the facing surface is the side surface of the battery 10b. In contact. Of both side surfaces (XZ surface in FIG. 9) of the fourth case portion 44, the facing surface facing the third case portion 43 faces the air layer 30, and the side surface opposite to the facing surface is the side surface of the battery 10c. In contact.

Further, the first case portion 41 to the fifth case portion 45 are made of the same metal material and are integrated, and are formed by bending a single plate-like metal member. Thereby, the space between the first case portion 41 and the third case portion 43 is fixed, and the space between the second case portion 42 and the fourth case portion 44 is fixed.

The air layer 30 is formed so as to be sandwiched between the third case portion 43 and the fourth case portion 44. The width of the air layer 30 (the length in the Y direction in FIG. 9) is secured by the fifth case portion 45. That is, in the Y direction of FIG. 9, the length of the fifth case portion 45 is formed to be longer than the length of the third case portion 43 plus the thickness of the fourth case portion 44.

Of the side surface of the air layer 30 (here, the air layer is regarded as a rectangular parallelepiped space), the side surface located between the third case portion 43 and the fourth case portion 44 has the battery stack 1. The air layer 30 is formed by the pair of openings 31 so that the wind passes through in the X direction of FIG. 9.

Although not shown in detail, the battery structure 1 is provided in the vehicle so that the opening 31 is opposed to the traveling direction of the vehicle, and wind during vehicle travel enters from the opening 31. Then, it passes through the air layer 30 and exits from the opening 31 on the opposite side.

As described above, in the present example, the air layer 30 has the vent hole 31 through which air from the outside passes while being held between the third case portion 43 and the fourth case portion 44. Thereby, since the temperature of the air layer 30 can be lowered, the heat of the case 40 in contact with the air layer 30 can be radiated.

In this example, the first case portion 41 to the fifth case portion 45 are formed from a single plate, but may be formed by connecting a plurality of plates by welding or screwing.

The third case portion 43 and the fourth case portion 44 described above correspond to the “metal portion” of the present invention.

<< 4th Embodiment >>
FIG. 10 is a perspective view of a battery structure according to another embodiment of the present invention. This example is different from the above-described first embodiment in that the configuration of the lower case 40 and the reinforcing

portions

61 and 62 are provided. Other configurations are the same as those of the first embodiment described above, and the descriptions of the first and third embodiments are incorporated as appropriate.

The battery structure 1 includes a plurality of batteries 10,

metal plates

21 and 22, an air layer 30, a lower case 40, and reinforcing

portions

61 and 62. The lower case 40 includes a first case portion 41 and a second case portion 42. Since the structure of the 1st case part 41 and the 2nd case part 42 is the same as the structure which concerns on 3rd Embodiment, description is abbreviate | omitted. The

metal plates

21 and 22 are fixed to the end portions of the first case portion 41 and the second case portion 42, respectively.

The reinforcing

portions

61 and 62 are members for reinforcing the

metal plates

21 and 22 and are formed in a prismatic shape. The reinforcing

portions

61 and 62 are bonded to the side surface of the

metal plates

21 and 22 facing the air layer 30 with an adhesive or the like. The reinforcing

portions

61 and 62 are provided on the side surfaces of the

metal plates

21 and 22 so that the longitudinal direction of the reinforcing

portions

61 and 62 is perpendicular to the stacking direction of the battery 10.

Moreover, since the

reinforcement parts

61 and 62 are provided in the air layer 30, they are formed of resin so as not to hinder the heat transfer preventing action of the air layer 30. When the battery 10 generates heat with respect to the side surfaces of the

metal plates

21 and 22, the central portion of the side surfaces becomes higher in temperature. Therefore, the

reinforcement parts

61 and 62 are provided in parts other than the center part of the side surface of the

metal plates

21 and 22, thereby preventing deformation of the

reinforcement parts

61 and 62 due to heat. In addition, the preferable thermal conductivity of the

reinforcement parts

61 and 62 should just be 0.5 W / mK or less.

The battery 10 tends to expand due to the abnormal short circuit of the battery 10, and the

metal plates

21 and 22 are subjected to stress in the Y direction in FIG. In this example, since the

reinforcement parts

61 and 62 which make the X direction of FIG. 10 a longitudinal direction are provided, rigidity can be improved with respect to the bending which makes the Z direction of FIG. 10 a crease | fold. Thereby, the air layer 30 can be maintained while suppressing the expansion of the battery 10.

As described above, in this example, the reinforcing

portions

61 and 62 for reinforcing the rigidity of the

metal plates

21 and 22 are provided on the side surfaces of the

metal plates

21 and 22 facing the air layer 30. Thereby, since the rigidity of the

metal plates

21 and 22 increases, the suppression effect of expansion of the battery 10 can be enhanced.

In this example, a plurality of reinforcing

portions

61 and 62 are provided, but a single reinforcing portion may be provided. Moreover, although the

reinforcement parts

61 and 62 were provided so that it might become parallel on the side surface of the

metal plates

21 and 22, you may provide so that it may become a cross shape on the said side surface.

DESCRIPTION OF SYMBOLS 1 ... Battery structure 10 ... Battery 11 ... Positive electrode plate 11a ... Positive

electrode side collector

11b, 11c ... Positive electrode layer 12 ... Separator 13 ... Negative electrode plate 13a ... Negative electrode side collector 13b, 13c ... Negative electrode layer 14 ... Positive electrode terminal ( Electrode terminal)
15 ... Negative terminal (electrode terminal)
DESCRIPTION OF SYMBOLS 16 ... Upper exterior member 17 ... Lower exterior member 18 ... Electric

power generation element

21,22 ... Metal plate 30 ... Air layer 31 ... Opening part 40 ... Lower case 41 ... 1st case part 42 ... 2nd case part 43 ... 3rd case part 44 ... 4th case part 45 ... 5th case part 50 ...

Battery module

510, 520, 530 ...

Single cells

511, 512, 521, 522 ... Electrode terminals 513 to 516, 523, 525, 534 ...

Spacers

517, 531, 532 ... Output terminal 533, sleeve 535, insulating cover 536, cushioning material 537, insertion port 540, case 541, upper case 542, lower case 543, bulging

portions

61, 62, reinforcing portion

Claims

A plurality of flat secondary batteries in which a power generation element in which an electrode plate and a separator are stacked is sealed with an exterior member;
A surface that is in contact with at least a part of a side surface of the flat secondary battery along a direction perpendicular to the stacking direction of the electrode plate and the separator between the plurality of flat secondary batteries and extends along the side surface A metal part having
Between the plurality of flat secondary batteries, an air layer covering the side surface via the metal part,
A fixing part for fixing the metal part,
The fixing part is
A battery structure which is a case for accommodating the plurality of flat secondary batteries.
The battery structure according to claim 1, wherein the fixing portion is made of metal.
A case for accommodating the plurality of flat secondary batteries;
The battery structure according to claim 1, wherein the metal part is formed by the case.
The battery structure according to any one of claims 1 to 3, wherein the air layer is sandwiched between a pair of the metal portions and has a vent hole through which air from the outside passes.
The battery structure according to any one of claims 1 to 4, further comprising a reinforcing portion that reinforces rigidity of the metal portion on a side surface of the metal portion facing the air layer. .