WO2014010414A1 - Cell structure - Google Patents

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 by exterior members; and holding parts provided between the flat secondary cells to the side surfaces of the flat secondary cell oriented along the direction perpendicular to the direction in which the electrode plates and the separators are stacked, the holding parts holding the shape of the flat secondary cells. The middles of the holding parts on the principal surfaces opposite the side surfaces have higher stiffness than do the outer peripheries of the holding parts.

Description

Battery structure

The present invention relates to a battery structure.

This application claims priority based on Japanese Patent Application No. 2012-157177 filed on July 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 laminated body in which a plurality of positive electrodes and negative electrodes are alternately stacked via separators is accommodated in a flat rectangular battery case, and three pieces are extended laterally at equal intervals outside the side surface of the battery case body. An assembled battery structure in which a metal rod on a beam having a thickness of 2 to 4 mm and a predetermined width is fixed is known (Patent Document 1).

JP-A-8-212986

However, when a plurality of the above conventional flat rectangular batteries are arranged, the strength of the central part of the side surface of the battery is insufficient, so that there is a problem that the battery is in contact with an adjacent battery due to expansion of the battery. It was.

The problem to be solved by the present invention is to provide a battery structure that suppresses deformation of a battery due to expansion of the battery and prevents contact with an adjacent battery.

The present invention includes a holding unit that holds a shape of a flat secondary battery provided on a side surface of the flat secondary battery along a direction perpendicular to the stacking direction among a plurality of flat secondary batteries. The above-mentioned problem is solved by making the rigidity of the central part higher than the rigidity of the outer peripheral part on the main surface of the holding part facing the side surface and along the vertical direction.

According to the present invention, when the battery expands, the rigidity of the central portion to which high stress is applied is increased on the side surface of the battery, so that deformation of the battery can be suppressed, and as a result, contact between adjacent batteries can be suppressed. 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 top view of the battery structure of FIG. It is a perspective view of the battery structure which concerns on the modification of this invention. It is a disassembled perspective view of the battery module of the battery structure which concerns on the modification of this invention. It is a perspective view of the battery structure concerning other embodiments of the present invention. It is a side view of the battery structure of FIG. It is a figure which shows the battery structure which concerns on other embodiment of this invention, (a) is a side view of a battery structure, (b) is a top view of a battery structure. FIG. 10 is a cross-sectional view taken along line XX in FIG. 9. FIG. 10 is a sectional view taken along line XI-XI in FIG. 9. It is a figure which shows the battery structure which concerns on the modification of this example, (a) is a side view of a battery structure, (b) is a top view of a battery structure. It is a top view of the battery structure concerning other embodiments of the present invention. It is a top 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 FIGS.

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, an air layer 30, and a shape holding unit 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. 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 that are opposite to each other. A battery 10a and a battery 10b are arranged. Moreover, the battery 10 is arrange | positioned so that a clearance gap may be formed between the battery 10a and the battery 10b.

The air layer 30 is formed so as to cover the side surfaces of the batteries 10a and 10b via the shape holding member 40. In other words, the shape member 40 is sandwiched between the air layer 30 and the batteries 10b and 10c. ing. The air layer 30 is a space formed by providing a gap between the side surface of the battery 10a and the side surface of the battery 10b, and the heat generated by the abnormal short circuit of the batteries 10a and 10b is adjacent (adjacent). It is formed to prevent it from being transmitted to. Since the thermal conductivity of the air contained in the air layer 30 is lower than that of resin or metal, the air layer 30 is a part that prevents heat conduction. For example, when an abnormal short circuit occurs in the battery 10a, the heat generated in the battery 10a is difficult to be transmitted to the battery 10b by the air layer 30, so heat transfer to the battery 10b is prevented.

The shape retaining member 40 is provided between the pair of batteries 10a and 10b on the side surfaces facing each other with the batteries 10a and 10b. The shape holding member 40 is bonded to the side surface of the battery 10 with an adhesive or the like. The shape holding member 40 is provided to prevent deformation of the battery 10 due to expansion of the battery 10a, and is provided to increase the rigidity of the exterior members 16 and 17 of the battery 10a.

Hereinafter, a detailed configuration of the shape holding member 40 will be described with reference to FIGS. FIG. 4 is a plan view of the battery 10a and the shape holding member 40 provided on the side surface of the battery 10a. In addition, since the shape holding member 40 provided in the battery 10b is provided similarly to FIG. 4, description is abbreviate | omitted.

The shape holding member 40 has a pair of holding members 41 and 42. The holding member 41 and the holding member 42 are three rectangular parallelepiped rod-shaped members, and are formed of metal. The holding member 41 is disposed on the same surface so that the three members are parallel to each other and along the side surface of the battery 10a. Similar to the holding member 41, the holding member 42 is arranged on the same plane so that the three members are parallel to each other and along the side surface of the battery 10a. Moreover, the surface which contacts the side surface of the battery 10a among the side surfaces of the holding member 41 and the surface which contacts the side surface of the battery 10a among the side surfaces of the holding member 42 are on the same plane. Thereby, the shape holding member 40 is provided in the battery 10a so that the main surface of the shape holding member 40 (the surface in contact with the side surface of the battery 10a and the XZ surface in FIGS. 3 and 4) is along the side surface of the battery 10a. It is done.

The shape holding member 40 is connected to the battery 10a so that the longitudinal direction of each member of the holding member 41 and the longitudinal direction of each member of the holding member 42 are perpendicular to the side surface of the battery 10a (on the main surface of the shape holding member 40). Is provided. In FIG. 4, the longitudinal direction of each member of the holding member 41 is the X direction, and the longitudinal direction of each member of the holding member 42 is the Z direction. Moreover, each member of the holding members 41 and 42 is provided in the center part of the side surface of the battery 10a. In other words, each member of the holding member 41 is provided near the center from both ends of the battery 10a in the Z direction of FIG. 4, and each member of the holding member 42 is formed from both ends of the battery 10a in the X direction of FIG. It is provided near the center.

The members of the holding member 41 and the members of the holding member 42 are arranged so as to intersect at the center of the battery 10a. On the other hand, the members of the holding member 41 and the members of the holding member 42 do not intersect with each other on the outer peripheral portion of the battery 10a located on the outer side on the side surface with respect to the central portion on the side surface of the battery 10a.

Here, in the main surface of the shape retaining member 40, the central portion of the shape retaining member 40 corresponds to the central portion of the side surface of the battery 10a, and the outer peripheral portion of the shape retaining member 40 corresponds to the outer peripheral portion of the side surface of the battery 10a. To do. As described above, the outer peripheral edges of the exterior members 16 and 17 are heat-sealed by hot pressing. Therefore, the adhesive strength of the outer edge portion is sufficiently high with respect to the expansion of the battery 10. On the other hand, the rigidity of the exterior members 16 and 17 in the portions that are not heat-sealed decreases as the distance from the outer peripheral edge increases. Therefore, the rigidity of the central portion of the side surface of the battery 10a (stiffness against stress in the stacking direction) is lower than the rigidity of the outer peripheral portion, and the central portion of the side surface of the battery 10a is easily deformed as the battery 10 expands. Become.

In this example, the shape holding member 40 is provided on the side surface of the battery 10a to increase the rigidity of the battery 10a so as to hold the shape of the battery 10a. And the rigidity of the center part in the main surface of the shape holding member 40 is made higher than the rigidity of an outer peripheral part by crossing each member of the shape members 41 and 42 in the part corresponded to the center part of the battery 10a. Therefore, the rigidity of the portion that is easily deformed by the expansion of the battery 10a becomes higher, and the deformation of the battery 10a can be suppressed. Further, when deformation of the battery 10a in the stacking direction is suppressed, the shape of the air layer 30 is also maintained, so that heat conduction to the other battery 10b can be prevented.

As described above, in this example, the shape holding member 40 is provided on the side surfaces of the batteries 10a and 10b, and the rigidity of the central portion of the shape holding member 40 is determined on the main surface of the shape holding member 40 facing the side surface. Make it higher than the rigidity of the outer periphery. Thereby, when the battery 10 expand | swells, a deformation | transformation of the battery 10 can be suppressed. As a result, contact with other adjacent batteries 10 can be prevented.

Also, in this example, the shape holding member 40 is made of metal. Thereby, the heat | fever generate | occur | produced by the abnormal short circuit of the battery 10 is transmitted to the shape holding member 40 which is a metal, and it thermally radiates outside, Therefore The battery 10 can be cooled.

Further, in this example, a plurality of rod-shaped members of the shape members 41 and 42 are crossed at the central portion of the shape holding member 40. Thereby, among the side surfaces of the battery 10, the rigidity of the central portion can be particularly increased, so that deformation of the battery 10 can be suppressed. As a result, contact with other adjacent batteries 10 can be prevented.

In this example, the shape prevention member 40 is provided on each of the side surface of the battery 10a and the side surface of the battery 10b. However, the shape prevention member 40 is provided on either the side surface of the battery 10a or the side surface of the battery 10b. May be. Further, the rod-shaped members of the holding members 41 and 42 may be one, two, or four or more, and may have a shape other than a rectangular parallelepiped.

In this example, the shape retaining member 40 is made of metal, but may be made of resin as shown in FIG. FIG. 5 is a perspective view of a battery structure 1 according to a modification of the present invention. The battery structure 1 includes a battery 10 and a shape holding member 40. The difference from the battery structure 1 shown in FIG. 4 is that the air layer 30 is not provided.

The shape holding member 40 is made of resin. The preferable thermal conductivity of the shape holding member 40 may be 0.5 W / mK or less. In the modification according to the present invention, the shape-retaining member 40 is made of a resin having low thermal conductivity to prevent heat conduction to the other battery 10. Accordingly, in the modification, the air layer 30 can be omitted, and the battery 10 a and the battery 10 b are adjacent to each other via the shape holding member 40. Since each member of the holding members 41 and 42 is bonded to the side surface of the battery 10a and the side surface of the battery 10b, the respective members increase the rigidity of the battery 10b while increasing the rigidity of the battery 10a.

As described above, in the modification of the present invention, the shape holding member 40 is formed of resin. Thereby, the heat conduction to the adjacent battery can be suppressed while preventing the battery 10 from being deformed.

Further, in this example, the shape holding member 40 is provided on the exterior members 16 and 17 of the flat battery 10, but the shape holding member 40 may be provided on the case 540 of the battery module 50 shown in FIG.

A configuration of a battery module 50 of a battery stack according to a modification of the present invention will be described with reference to FIG. FIG. 6 is an exploded perspective view of the battery module 50. The X, Y, and Z axis displays in FIG. 6 correspond to the axis displays in FIGS.

The single cell 530 of the battery module 50 shown in FIG. 5 is a battery stack in which eight single cells are stacked. One unit cell is formed by sealing a power generation element in which an electrode plate and a separator are stacked with an exterior member. Further, terminals (tabs) connected to the electrode plates are led out from the end portions of the unit cells. And the cell 530 of FIG. 5 is comprised by laminating | stacking via a spacer, connecting the terminals between the laminated | stacked batteries.

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.

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.

Then, the shape holding member 40 is provided on the side surface of the upper case 541 or the side surface of the lower case 542 in the same manner as in FIGS. Thereby, the rigidity of the center part of the side surface of the upper case 40 can be made higher than the rigidity of the outer peripheral part, or the rigidity of the center part of the lower case 41 can be made higher than the rigidity of the outer peripheral part. As a result, it is possible to prevent heat conduction to other battery modules 50 while suppressing deformation of the battery modules 50 in the stacking direction.

The battery 10 and the battery module 50 correspond to the “flat secondary battery” of the present invention, and the shape holding member 40 corresponds to the “holding portion” of the present invention.

<< Second Embodiment >>
FIG. 7 is a perspective view of a battery structure according to another embodiment of the present invention. FIG. 8 is a side view of the battery structure of FIG. This example differs from the first embodiment described above in that the metal plates 21 and 22 are provided. 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 this example includes a plurality of batteries 10, metal plates 21 and 22, an air layer 30, and a shape holding member 40.

The metal plates 21 and 22 are high heat conductive members formed in a plate shape from metal. The metal plates 21 and 22 are provided in a gap between the battery 10a and the battery 10b, and the metal plate 21 and the metal plate 22 are in close contact with the side surface of the battery 10a and the side surface of the battery 10b, respectively, and cover each side surface. Is provided. The metal plates 21 and 22 are provided in order to dissipate the heat by conducting heat generated from the batteries 10a and 10b. The preferable thermal conductivity of the metal plates 21 and 22 may be 1.0 W / mK or more.

The shape holding member 40 is provided on the side surface of the battery 10 a via the metal plate 21 and on the side surface of the battery 10 b via the metal plate 22.

As described above, in this example, the metal plates 21 and 22 formed in a plate shape are provided so as to cover the side surfaces of the batteries 10 a and 10 b, and the shape holding member 40 is connected to the battery 10 a via the metal plates 21 and 22. 10b. Thereby, since the heat generated from the battery 10 can be absorbed by the metal plates 21 and 22, the battery 10 can be cooled.

In this example, the two metal plates 21 and 22 are provided between the battery 10a and the battery 10b. However, only one of the metal plates 21 and 22 may be provided.

The metal plates 21 and 22 correspond to the “metal part” of the present invention.

<< Third Embodiment >>
FIG. 9 is a diagram for explaining a battery structure according to another embodiment of the present invention, in which (a) shows a side view of the battery structure and (b) shows a plan view of the battery structure. 10 is a cross-sectional view taken along line XX in FIG. 9, and FIG. 11 is a cross-sectional view taken along line XI-XI in FIG. In this example, the shape holding member 40 is different from the first embodiment described above. Other configurations are the same as those of the first embodiment described above, and the descriptions of the first and second embodiments are incorporated as appropriate.

The holding member 41 has members 41a and 41b, and the holding member 42 has members 42a and 42b. The member 41a is a rod-shaped member having two rectangular parallelepipeds, and has a height (a length in the Y direction in FIG. 9) and a width (a length in the Z direction in FIG. 9) perpendicular to the longitudinal direction. Each is formed to be the same in the direction. The member 41b is a single rod-like member, and is formed such that the height in the direction perpendicular to the longitudinal direction is high at the center in the longitudinal direction and is low at both ends in the longitudinal direction. With respect to the height in the Y direction of FIG. 9 of the members 41a and 41b (the height in the stacking direction of the battery 10 and the height relative to the side surfaces of the batteries 10a and 10b), the height of both ends of the member 41a The holding member 41 is formed so that the height of the central portion of the member 41a is the same as the height of the central portion of the member 41b, and is provided on the side surfaces of the batteries 10a and 10b.

The member 42a is a rod-shaped member having two rectangular parallelepipeds, and has a height (a length in the Y direction in FIG. 9) and a width (a length in the Z direction in FIG. 9) perpendicular to the longitudinal direction. Each is formed to be the same in the direction. The member 42b is a single bar-like member, and is formed such that the height in the direction perpendicular to the longitudinal direction is high at the center in the longitudinal direction and is low at both ends in the longitudinal direction. Regarding the heights of the members 42a and 42b in the Y direction in FIG. 9 (the height in the stacking direction of the batteries 10 and the height relative to the side surfaces of the batteries 10a and 10b), the heights of both ends of the member 42a The holding member 42 is formed and provided on the side surfaces of the batteries 10a and 10b such that the height of the central portion of the member 42a is the same as the height of the central portion of the member 42b. The member 41a and the member 42a have the same shape, and the member 41b and the member 42b have the same shape.

Thereby, the shape maintaining member 40 is configured such that the height of the central portion of the main surface is higher than the height of the outer peripheral portion of the main surface in the stacking direction of the battery 10 with respect to the main surface. As the battery 10 expands, the direction of the stress applied to the shape retaining member 40 is the stacking direction of the battery 10, and the rigidity against the stress is reduced at the center. In this example, by increasing the height in the stacking direction at the central portion, the rigidity of the central portion of the main surface of the shape maintaining member 40 is made higher than the rigidity of the outer peripheral portion. Therefore, in this example, the deformation of the battery 10a in the stacking direction can be suppressed, and the shape of the air layer 30 is also maintained, so that heat conduction to the other battery 10b can also be prevented.

As described above, the shape holding member 40 of this example is formed such that the height of the central portion in the stacking direction of the batteries 10 is higher than the height of the outer peripheral portion. Thereby, when the battery 10 expand | swells, a deformation | transformation of the battery 10 can be suppressed. As a result, contact with other adjacent batteries 10 can be prevented.

In this example, as shown in FIG. 12, the ratio of the area of the holding members 41 and 42 per unit area on the main surface of the shape holding member 40 is increased in the center portion than the outer peripheral portion. The rigidity of the central portion of the holding member 40 may be increased. 12A and 12B are diagrams for explaining a battery structure according to a modification of the present invention. FIG. 12A is a side view of the battery structure, and FIG. 12B is a plan view of the battery structure.

Each of the holding members 41 and 42 is a rod-shaped member having three rectangular parallelepipeds, and has a height (a length in the Y direction in FIG. 9) and a width (a length in the Z direction in FIG. 9) perpendicular to the longitudinal direction. ) Are formed to be the same in the longitudinal direction. Then, on the main surface of the shape holding member 40, the holding members 41 and 42 intersect at the center. As a result, the ratio of the area of the holding members 41 and 42 in the central part is larger than the ratio of the area of the holding members 41 and 42 in the outer peripheral part. Therefore, the rigidity of the central portion of the main surface of the shape maintaining member 40 is higher than the rigidity of the outer peripheral portion.

As described above, in the modification of the present invention, the shape holding member 40 is formed such that the density of the area of the holding members 41 and 42 per unit area on the main surface is larger than the outer peripheral portion. Thereby, when the battery 10 expand | swells, a deformation | transformation of the battery 10 can be suppressed. As a result, contact with other adjacent batteries 10 can be prevented.

<< 4th Embodiment >>
FIG. 13 is a plan view of a battery structure according to another embodiment of the present invention. In this example, the shape holding member 40 is different from the first embodiment described above. Other configurations are the same as those of the first embodiment described above, and the description of the first embodiment is incorporated as appropriate.

The shape holding member 40 has holding members 43a and 43b. The holding member 43a is formed in a plurality of honeycomb shapes by a metal frame. The holding member 43 a is provided in the central portion on the main surface of the shape holding member 40. The holding member 43b is formed in a plurality of honeycomb shapes by a metal frame. The holding member 43 b is provided on the outer peripheral portion on the main surface of the shape holding member 40.

The honeycomb shape of the holding member 43a is smaller than the honeycomb shape of the holding member 43b. That is, in this example, a plurality of honeycomb-shaped frames are arranged on the main surface of the shape holding member 40, and the size of the honeycomb shape at the center is smaller than the honeycomb shape at the outer periphery. Is formed so as to be higher than the rigidity of the outer peripheral portion.

As described above, in this example, the central portion is formed on the main surface of the shape holding member 40 in a honeycomb shape along the main surface. Thereby, since the rigidity in a center part can be improved, when the battery 10 expand | swells, a deformation | transformation of the battery 10 can be suppressed. As a result, contact with other adjacent batteries 10 can be prevented. Moreover, since rigidity becomes high even if the density of a member is low, the quantity of a member can be reduced.

In this example, the outer peripheral portion of the shape holding member 40 is not necessarily formed in a honeycomb shape, and may have another shape.

<< 5th Embodiment >>
FIG. 14 is a plan view of a battery structure according to another embodiment of the present invention. In this example, the shape and material of the shape holding member 40 are different from those of the first embodiment described above. Other configurations are the same as those of the first embodiment described above, and the description of the first embodiment is incorporated as appropriate.

The shape holding member 40 has holding members 44 and 45. The holding member 44 is formed of a plurality of rod-like members and is arranged so as to intersect at the center on the main surface. The holding member 45 is formed of a plurality of rod-shaped members, and is arranged so as to form a lattice at the outer peripheral portion on the main surface. The holding member 44 is formed of stainless steel (SUS),
The holding member 45 is made of aluminum. Thereby, the shape holding member 40 is formed so that the rigidity of the central member on the main surface is higher than the rigidity of the outer peripheral member.

As described above, in this example, the shape maintaining member 40 is formed such that the rigidity of the material in the central portion is higher than the rigidity of the material in the outer peripheral portion. Thereby, when the battery 10 expand | swells, a deformation | transformation of the battery 10 can be suppressed. As a result, contact with other adjacent batteries 10 can be prevented.

DESCRIPTION OF SYMBOLS 1 ... Battery structure 10 ... Battery 11 ... Positive electrode plate 11a ... Positive electrode side collector 11b, 101c ... 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 ... Shape holding member 41, 42, 43a, 43b, 44, 45 ... Holding member 50 ... Battery Module 530 ... Single cell 531,532 ... Output terminal 533 ... Sleeve 534 ... Spacer 535 ... Insulating cover 536 ... Buffer material 537 ... Insertion port 540 ... Case 541 ... Upper case 542 ... Lower case

Claims (8)

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;
Between the plurality of flat secondary batteries, provided on the side surface of the flat secondary battery along the direction perpendicular to the stacking direction of the electrode plate and the separator, and maintains the shape of the flat secondary battery And a holding part that
In the main surface of the holding part facing the side surface, the battery structure is characterized in that the rigidity of the central part of the holding part is higher than the rigidity of the outer peripheral part of the holding part. An air layer that covers the side surface through the holding portion between the plurality of flat secondary batteries,
The battery structure according to claim 1, wherein the holding portion is made of metal. The holding part has a plurality of rod-shaped members,
The battery structure according to claim 1, wherein the plurality of rod-shaped members intersect at the central portion. Between the plurality of flat secondary batteries, further comprising a metal part that covers the side surface and is formed in a plate shape,
The battery structure according to any one of claims 1 to 3, wherein the holding portion is provided on the side surface via the metal portion. 5. The holding portion is formed such that a height of the central portion in the stacking direction is higher than a height of the outer peripheral portion in the stacking direction. Battery structure. The holding part is
The battery structure according to any one of claims 1 to 5, wherein a density of an area of a member per unit area on the main surface is formed so that the central portion is larger than the outer peripheral portion. . The battery structure according to any one of claims 1 to 6, wherein the holding portion is formed in a honeycomb shape with the central portion along the main surface. The battery structure according to any one of claims 1 to 7, wherein the holding portion is formed so that a rigidity of a material of the central portion is higher than a rigidity of a material of the outer peripheral portion.

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