JP2017004655A - Laminate pack type battery unit, and battery pack module - Google Patents

Abstract

PROBLEM TO BE SOLVED: To take measures to cope with swelling deformation of a laminate pack type battery even when providing a cover over the laminate pack type battery.SOLUTION: A laminate pack type battery unit 40 comprises: a flat laminate pack type battery 10 accommodating a power generation element 13 in a battery sheath 12 that is formed from laminate films 11A and 11B; and a battery case 41 in which the laminate pack type battery 10 is accommodated. The battery case 41 includes: a first cover 48 that opposes a flat top face 10A of the laminate pack type battery; and a second cover 49 that opposes a bottom face 10B. The first cover 48 has such rigidity that the first cover deforms with swelling of the laminate type battery 10, and the second cover 49 has such rigidity that the second cover is unlikely to deform in relative to the first cover 48.SELECTED DRAWING: Figure 5

Description

  The present invention relates to a laminate pack type battery unit in which a battery outer body covering a power generation element is formed of a laminate film, and an assembled battery module.

  As a battery such as a lithium ion secondary battery, a flat laminate pack type battery is known in which a battery exterior covering a power generation element is formed of an aluminum laminate film using an aluminum alloy as a base material. Thin and light weight can be achieved by using a flat laminate pack type battery. Further, a structure in which this flat laminate pack type battery is sandwiched and fixed between an upper cover and a lower cover is also known (see, for example, Patent Document 1).

Japanese Patent No. 4186500

By the way, it is known that the laminate pack type battery is deformed so as to bulge out by repeating charging and discharging.
However, in the conventional structure in which a flat laminated pack battery is provided with a cover, it cannot be said that the countermeasure against the bulging deformation of the laminated pack battery is sufficient.

  The present invention has been made in view of the above-described circumstances, and even when a cover is provided on a laminate pack type battery, a laminate pack type battery unit and an assembled battery module that prevent bulging deformation of the laminate pack type battery are provided. The purpose is to provide.

  In order to achieve the above object, the present invention comprises a flat laminate pack type battery in which a power generation element is housed in a battery outer body formed of a laminate film, and a battery case in which the laminate pack battery is housed. The battery case includes a first cover facing one of a flat upper surface and a lower surface of the laminated pack battery, and a second cover facing the other, and the first cover is formed of the laminate pack type. Provided is a laminate pack type battery unit characterized in that it has rigidity that deforms as the battery expands, and the second cover has rigidity that is harder to deform than the first cover.

  In the laminate pack battery unit according to the present invention, a predetermined expansion of the laminate pack battery is added to the thickness of the laminate pack battery between the first cover and the second cover. A thickness space is provided.

  In the laminate pack battery unit, the battery case may be provided between the space between the first cover and the second cover and the upper surface and / or the lower surface of the laminate pack battery. It is provided with a cushioning material that fills the gap generated in

  According to the present invention, in the laminate pack battery unit, at least the laminate pack battery and the second cover are bonded, and the laminate pack battery is fixed in the battery case.

  The present invention further includes a plurality of laminate pack battery units according to any one of the above and a module case formed by laminating the plurality of laminate pack battery units, and the module case includes a plurality of the laminate laminates. Provided is an assembled battery module in which pack-type battery units are supported so as not to interfere with adjacent second covers even when the first cover is expanded and deformed.

  In the assembled battery module according to the present invention, the module case is supported by sandwiching edges of the plurality of laminated pack battery units.

In the present invention, the first cover provided in the battery case containing the laminate pack type battery has rigidity that deforms as the laminate pack type battery expands, and the second cover is less likely to be deformed than the first cover. It was set as the structure which has rigidity.
Thereby, when the laminate pack type battery expands, the first cover is deformed along with the expansion, so that the expansion is not hindered. Moreover, since the deformation | transformation accompanying the said expansion is mainly induced by the 1st cover, a deformation | transformation does not arise in the unexpected location of a battery case.

1 is a perspective view of a laminated pack battery according to a first embodiment of the present invention. It is the figure which showed the II-II cross section of FIG. 1 typically. It is the top view which looked at the lamination pack type battery from the upper part. It is a perspective view of a laminate pack type battery unit. It is a disassembled perspective view of a laminate pack type battery unit. It is a figure which shows typically the cross-sectional structure of a laminate pack type battery unit. It is explanatory drawing of the modification of a laminate pack type battery unit. It is a perspective view of an assembled battery module. It is a figure which shows the structure of the inner surface of a side frame, (A) is a top view which shows the inner surface of a side frame, (B) is the side view which looked at the side from the front end side of the side frame. It is a figure which shows the rear end side of the XX cross section of FIG.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a perspective view of a flat laminate pack battery 10 according to the present embodiment. FIG. 2 is a view schematically showing a II-II section of FIG. FIG. 3 is a plan view of the laminated pack battery 10.
As shown in FIGS. 1 and 2, this laminate pack type battery (also referred to as a laminate cell) 10 accommodates a power generation element 13 in a battery outer package 12 made of laminate films 11A and 11B. The negative electrode current collector tab portion 20 and the positive electrode current collector tab portion 23 are extended to the outside from between the laminate films 11A and 11B to form a lithium ion secondary battery which is an embodiment of the nonaqueous electrolyte secondary battery. A battery is constructed. In addition, electrolyte solution is also injected into the battery outer package 12. The flat laminate pack type battery 10 can be used as a single unit, but in this embodiment, it is housed in a battery case 41 (see FIG. 4) described later and used as a laminate pack type battery unit 40.

  As shown in FIG. 2, the power generation element 13 is a group of electrode plates in which negative plates 15 and positive plates 16 are alternately stacked one above the other. The negative electrode plate 15 has a structure in which a negative electrode coating portion 18 is provided on both surfaces of a rectangular plate-shaped negative electrode current collector 17. One end side of the battery exterior body 12 from the negative electrode current collector 17 (in FIGS. 1 and 2). Each has a negative terminal 17A extending toward the left side. Each negative electrode terminal 17 </ b> A is electrically connected to the current collecting tab portion 20 on the negative electrode side, and the current collecting tab portion 20 is exposed to the outside of the battery outer package 12.

  The positive electrode plate 16 has a structure in which a positive electrode coating portion 22 is provided on both surfaces of a rectangular plate-shaped positive electrode current collector 21, and the one end side of the battery exterior body 12 from the positive electrode current collector 21 (FIGS. 1 and 2). A positive electrode terminal 21 </ b> A extending toward the middle left side is provided. Each positive electrode terminal 21 </ b> A is electrically connected to the current collecting tab portion 23 on the positive electrode side, and the current collecting tab portion 23 is exposed to the outside of the battery outer package 12.

  A separator 24 is disposed between the negative electrode plate 15 and the positive electrode plate 16, and the negative electrode coating film portion 18 of the negative electrode plate 15 faces the positive electrode coating film portion 22 of the positive electrode plate 16 adjacent thereto via the separator 24. Thus, the negative electrode plate 15, the separator 24, and the positive electrode plate 16 are laminated in this order.

  In FIG. 2, the negative electrode current collector 17 is disposed on both outermost layers of the power generation element 13, and the negative electrode current collector portion 18 is provided on only one side of the negative electrode current collector 17 facing the positive electrode current collector 21. It is the structure which was made. However, the present invention is not limited to this, and negative electrode coating film portions 18 may be provided on both surfaces of the negative electrode current collector 17. Further, the arrangement of the negative electrode plate 15 and the positive electrode plate 16 is reversed from that in FIG. 2, so that the positive electrode current collector 21 is positioned in both outermost layers of the power generation element 13, and the positive electrode current collector 21 of the outermost layer is formed. The positive electrode coating film portion 22 may be provided only on one surface facing the negative electrode current collector 17. Further, the number of stacked negative electrode plates 15 and positive electrode plates 16 is not limited to the illustrated example and can be changed as appropriate.

  The battery exterior body 12 has a bag shape in which the edge portions 32 of the entire circumference of the two rectangular laminate films 11A and 11B are joined and the power generation element 13 is contained inside. That is, one laminate film 11A covers the power generation element 13 from one side in the stacking direction of the negative electrode plate 15 and the positive electrode plate 16 (upper side in FIG. 2), and the other laminate film 11B includes the negative electrode plate 15 and the positive electrode plate. The power generation element 13 is covered from the other side of the stacking direction 16 (lower side in FIG. 2), that is, from the opposite side of the laminate film 11A. The edge portions 32 of these laminate films 11A and 11B are overlapped with each other and bonded (for example, heat welding).

  As each of the laminate films 11A and 11B, a known aluminum laminate film (hereinafter simply referred to as “laminate film”) can be used. For example, a laminate of austenitic stainless steel foil can be used. is there.

  Each of the laminate films 11A and 11B includes a resin layer at least at the innermost layer, and can be thermally welded by the resin layer. This resin layer also functions as an insulating layer by being formed of PP (polypropylene) which is an example of an insulating thermoplastic resin. By this insulating layer, it is possible to insulate between the power generation element 13 (including the current collecting tab portions 20 and 23) and the base material of each of the laminate films 11A and 11B.

The current collecting tab portions 20 and 23 are formed of a thin plate metal material such as copper or aluminum, and are exposed to the outside of the laminate films 11A and 11B through between the two laminate films 11A and 11B.
In each of the laminate films 11A and 11B, recesses 31A and 31B for receiving the power generation elements 13 are formed, which are recessed on the opposite side of the other laminate films 11B and 11A (that is, bulge outward). More specifically, an accommodation recess 31A having a depth f1 deeper than that of the other laminate film 11B is formed in one laminate film 11A, and most of the power generating element 13 is accommodated in the accommodation recess 31A. The other laminate film 11B is formed with an accommodation recess 31B having a shallow depth f2 (<f1) that is substantially flat.
An amount obtained by adding the thicknesses of the laminate films 11A and 11B to the depths f1 and f2 of the housing recesses 31A and 31B is roughly equivalent to the thickness D1 of the laminate pack type battery 10.

  In addition, at least the laminate films 11A and 11B are used for the metal material of the current collecting tab portions 20 and 23 for the purpose of an insulating layer that more reliably welds the laminate films 11A and 11B and more reliably prevents short circuit. A resin layer (not shown) for the current collecting tab portion is provided in a portion to be heat sealed. By providing the resin layer for the current collecting tab portion, it is possible to maintain the airtightness in the vicinity of the current collecting tab portions 20 and 23.

  As shown in FIG. 2 and FIG. 3, the laminate film 11 </ b> A is accommodated to be recessed upward on one side in the laminating direction by drawing the central portion in advance with respect to the laminate film formed in a rectangular sheet. The recess 31A and the frame-shaped edge 32 surrounding the housing recess 31A are integrally formed. The edge portion 32 is a region where the laminate films 11A and 11B are joined together by heat welding.

  The housing recess 31A is integrally provided with a rectangular frame-shaped wall portion 31K extending upward in FIG. 2 from the inner peripheral edge of the edge portion 32 and a rectangular cover portion 31T that closes between the upper edges of the wall portion 31K. . As shown in FIG. 2, the power generation element 13 abuts on the inner surface of the cover portion 31 </ b> T, and the displacement of the power generation element 13 is suppressed. Thus, the power generating element 13 is sandwiched between the cover portions 31T of the laminate films 11A and 11B. Further, a space for accommodating the positive electrode terminal 21 </ b> A, the negative electrode terminal 17 </ b> A, and the electrolytic solution is secured between the wall portion 31 </ b> K and the power generation element 13.

  As shown in FIG. 3, the edge portion 32 (32L, 32S) is formed in a rectangular frame shape, and integrally includes a pair of opposed long side portions 32L and a pair of opposed short side portions 32S. Then, the negative electrode side current collecting tab portion 20 and the positive electrode side current collecting tab portion 23 extend between the laminate films 11A and 11B and extend from the inside of the battery exterior body 12 to the outside from one short side portion 32S. .

4 is a perspective view of the laminate pack type battery unit 40, and FIG. 5 is an exploded perspective view of the laminate pack type battery unit 40. As shown in FIG. FIG. 6 is a diagram schematically showing a cross-sectional structure of the laminate pack type battery unit 40. In FIG. 6, the dimensions of each member are different from the actual dimensions in order to facilitate understanding of the cross-sectional structure.
As shown in FIG. 6, the laminate pack type battery unit 40 is unitized by storing one of the above laminate pack type batteries 10 (so-called single cells) in a battery case 41.
As shown in FIG. 4, the laminate pack type battery unit 40 has a flat plate shape having a rectangular shape in plan view. On one side surface, positive and negative terminal portions 43 and 44 sandwich an insulating portion 45. It is arranged.

As shown in FIG. 5, the battery case 41 includes a first cover 48 and a second cover 49, a terminal portion forming bar member 50, and a rear end closing bar member 51.
The first cover 48 and the second cover 49 face the flat upper surface 10A (FIGS. 2 and 6) and the lower surface 10B (FIGS. 2 and 6) of the laminate pack battery 10 and the long side portions 32L on both sides. And it is the member which covers these. Specifically, each of the first cover 48 and the second cover 49 is formed in a U-shaped cross section in which both edges of the rectangular plate are bent in an L shape and bent pieces 48A and 49A are provided on both edges. It is formed and combined so that the respective bent pieces 48A and 49A are overlapped to form a flat box having both ends opened.

  Each of the terminal portion forming bar member 50 and the rear end closing bar member 51 is a bar-shaped member having a rectangular section that closes the front end side and the rear end side of the battery case 41 to form a side surface. For example, it is formed of a thermoplastic resin such as PP which is excellent in properties and easy to mold. In the battery case 41, the first cover 48 and the second cover 49 are assembled to the terminal portion forming bar member 50 and the rear end closing bar member 51.

  Specifically, as shown in FIG. 5, each of the terminal portion forming bar member 50 and the rear end closing bar member 51 has convex protrusions 53, 54 at the left and right ends of the upper surface and the lower surface thereof. Is provided. On the other hand, engagement holes 55 are formed in the four corners of each of the first cover 48 and the second cover 49. Then, the projections 53 and 54 of the terminal portion forming bar member 50 and the rear end closing bar member 51 are inserted into the engagement holes 55, and the first cover 48 and the second cover 49 are assembled and fixed. Thus, the battery case 41 having a space for enclosing the laminate pack battery 10 therein is formed.

  The laminated pack battery 10 is housed in a battery case 41, and as shown in FIG. 5, the tip portions 20A, 23A of the current collecting tab portions 20, 23 pass below the terminal portion forming bar member 50. The terminal portion forming bar member 50 is pulled out to the front surface 50A. Tab receiving recesses 56 are formed on the front surface 50 </ b> A at positions separated from each other in the left and right directions, and the respective front end portions 20 </ b> A and 23 </ b> A of the current collecting tab portions 20 and 23 are bent in an L shape to form tab receiving recesses 56. The positive electrode of the laminate pack battery unit 40 and the negative electrode terminal portions 43 and 44 are formed on the front surface 50A. Further, the terminal portion forming bar member 50 has a convex portion formed between the two tab accommodating concave portions 56, and this convex portion functions as the insulating portion 45 that electrically insulates the terminal portions 43 and 44. .

An insulating plate 57 is disposed between the lower surface of the terminal portion forming bar member 50 and the second cover 49. The insulating plate 57 is formed of, for example, a material having excellent electrical insulation, and electrically insulates the current collecting tab portions 20 and 23 passing through the lower side of the terminal portion forming bar member 50 and the second cover 49.
Furthermore, the first cover 48 and the second cover 49 are subjected to a surface treatment that enhances electrical insulation at least at a location facing the laminate pack battery 10. Examples of the surface treatment include hard alumite processing.

  By the way, the laminate pack type battery 10 generates internal gas by repeating charging and discharging, whereby the flat upper surface and the lower surface bulge and deform. Such bulging deformation can be suppressed to some extent by using an electrolytic solution (for example, vinylene carbonate, vinyl ethylene carbonate, butane sultone, 1,3-propane sultone, etc.) that suppresses the generation of internal gas. Swelling deformation due to gas accumulation is inevitable.

  Therefore, in this laminate pack type battery unit 40, as shown in FIG. 6, the battery case 41 for housing the laminate pack type battery 10 is arranged so that the battery case 41 does not hinder the bulging deformation of the laminate pack type battery 10. The thickness D2 of the inner space is set to a thickness obtained by adding an expansion amount (for example, 1 mm to 2 mm) to the thickness D1 of the laminate pack battery 10. In this laminate pack type battery unit 40, the thickness D2 of the space in which the laminate pack type battery 10 is accommodated corresponds to the thickness of the terminal portion forming bar member 50 and the rear end closing bar member 51, and these members have the above thickness. D2 is accurately molded.

In the present embodiment, this corresponds to the thickness of the space inside the battery case 41 and the amount of expansion due to gas generation or the like added between the upper surface 10A and the lower surface 10B of the laminate pack battery 10. A gap is formed, and deformation of the battery case 41 itself can be suppressed by forming the gap. The gap is preferably filled in consideration of vibration, impact, etc., as shown in FIG. 6, between the space in the battery case 41 and the upper surface 10A and the lower surface 10B of the laminate pack type battery 10. Inserts a cushioning material 60. The buffer material 60 has a weak elasticity so as not to inhibit the expansion of the laminate pack type battery 10. As a material of the buffer material 60, foamed rubber, foamed PP, foamed PE (polyethylene), silicone rubber, polymer gel, or the like can be suitably used.
In the present embodiment, a gap is formed between the space inside the battery case 41 and the upper surface 10A and the lower surface 10B of the laminated pack battery 10, but at least the first cover 48 having rigidity that deforms with expansion. What is necessary is just to form a clearance gap between 10A of upper surfaces.

This buffer material 60 is fixed in the battery case 41 by adhesion. Specifically, the cushioning material 60 is applied to the surface of the cushioning material 60, or a double-sided tape is attached, and is adhered to at least the second cover 49, thereby being adhered to the cushioning material 60. The laminated pack battery 10 is also fixed in the battery case 41.
In the fixing structure, the expansion of the upper surface 10A and the lower surface 10B is not hindered compared to the structure in which the upper surface 10A and the lower surface 10B of the laminate pack battery 10 are sandwiched and pressed by a cover or the like.

By the way, the laminate pack type battery 10 may expand beyond the margin provided in the battery case 41 during long-term use. In the battery case 41, in order not to suppress this expansion, either the first cover 48 or the second cover 49 (in this embodiment, the upper surface 10A of the laminated pack battery 10 is faced). The first cover 48) has a rigidity that is weak enough to bend and deform so as to bulge with the expansion of the laminate pack type battery 10.
On the other hand, the other (in this embodiment, the second cover 49 facing the lower surface 10B of the laminated pack battery 10) is the first cover 48 or the second cover 49 (in the present embodiment, the first cover 49). It has rigidity (that is, high rigidity) that is hard to be deformed as compared with one cover 48). In the present embodiment, the second cover 49 is not deformed against the expansion of the laminate pack type battery 10, and has sufficient rigidity to ensure the shape of the battery case 41 itself.

Thereby, even when the laminate pack type battery 10 expands beyond the margin provided in the battery case 41, this expansion is absorbed by the bulging deformation of the first cover 48.
Further, the second cover 49 secures the strong rigidity of the battery case 41 itself, and the second cover 49 is not deformed even when the laminate pack battery 10 is expanded. In other words, in this battery case 41, deformation accompanying expansion of the laminate pack type battery 10 is exclusively induced in the first cover 48, so that deformation does not occur in unexpected locations of the battery case 41. .

The rigidity of the first cover 48 and the second cover 49 can be made different from each other, for example, as follows.
That is, when the first cover 48 and the second cover 49 are formed of materials having different rigidity, or are formed of the same material, the thickness of the plates is varied or unevenness is provided in the cross section. The rigidity can be varied.
As materials for the first cover 48 and the second cover 49, metals such as aluminum, stainless steel, nickel-plated iron, and magnesium alloys, or resins such as PP, PE, and bakelite can be preferably used.
In the battery case 41 in the present embodiment, the same aluminum is used as the material of the first cover 48 and the second cover 49, and the thickness g1 of the first cover 48 is set to the second thickness as shown in FIG. By making it thinner than the plate thickness g2 of the cover 49, the first cover 48 and the second cover 49 have different rigidity.

Here, the current collecting tab portions 20 and 23 of the laminate pack type battery 10 are, as shown in FIG. 2, the upper surface 10A or the lower surface 10B (in the illustrated example) from the center in the thickness direction (the stacking direction of the power generating elements 13). It extends from a position close to the lower surface 10B).
When the laminate pack type battery 10 is housed in the battery case 41, the flat surface (the lower surface 10B in the illustrated example) on the side where the current collecting tab portions 20 and 23 are brought into contact with the second cover 49 having high rigidity. It is stored in the posture to do.
In this way, when the laminate pack type battery 10 expands greatly beyond the margin of the battery case 41 during long-term use, the first cover 48 swells in the direction opposite to the second cover 49 due to the bending of the first cover 48. Therefore, the stress due to the expansion to the current collecting tab portions 20 and 23 arranged closer to the second cover 49 side is relieved.

In the laminated pack battery unit 40, the cushioning material 60 covers the entire upper surface 10A and lower surface 10B of the laminated pack battery 10. However, the arrangement of the cushioning material 60 can be changed as appropriate. For example, the cushioning material 60 may cover only a part of the upper surface 10A and the lower surface 10B of the laminated pack battery 10.
Further, on the upper surface 10A and the lower surface 10B of the laminate pack type battery 10, as shown in FIG. 7, strip-shaped buffer materials 61 extending in one direction are provided side by side, and the laminate is formed by the separated portions of the buffer materials 61. A ventilation path may be formed between the upper surface 10 </ b> A and the lower surface 10 </ b> B of the battery pack 10 and the first cover 48 and the second cover 49.
Moreover, it can replace with the shock absorbing material 60 and can also use the double-sided tape which has sufficient elasticity.

FIG. 8 is a perspective view of the assembled battery module 70.
The assembled battery module 70 is an assembled battery module including a plurality of the laminated pack type battery units 40 and a module case 71 in which the laminated pack type battery units 40 are stacked.
The module case 71 is made of a resin material such as PP, for example, and includes a pair of side frames 72 that constitute both sides of the module case 71, a front frame 73 that constitutes the front surface, and a back frame 74 that constitutes the back surface. These are fastened together with screws or the like.
The front frame 73 is provided with positive and negative terminals 80, 81, respectively. The terminals 80, 81 are electrically connected to the terminal portions 43, 44 of each built-in laminate pack battery unit 40. It is connected to the.

9 is a diagram showing the structure of the inner surface of the side frame 72, FIG. 9A is a plan view showing the inner surface of the side frame 72, and FIG. 9B is a side view of the side frame 72 from the front end side. It is a side view.
On the inner surface of the side frame 72 (opposite surfaces of the pair of side frames 72), a plurality of support pieces 77 that sandwich and support the edge of the laminate pack battery unit 40 extend from the front end to the rear end of the side frame 72. It is provided to extend intermittently or continuously. These support pieces 77 are arranged vertically (in a so-called comb shape) at a predetermined interval T. The size of the interval T is such that even when the first cover 48 of the laminate pack type battery unit 40 bulges and deforms, a gap is formed so that the laminate pack type battery units 40 do not contact each other. This gap also functions as a ventilation path, and heat buildup in the assembled battery module 70 is suppressed.

  Further, the protrusion amount (height) H of the support piece 77 from the side frame 72 is long enough to support the edge of the laminate pack battery unit 40 without entering the bulging deformation portion of the upper surface or the lower surface. Is suppressed. Thereby, with the incorporation of the laminate pack type battery unit 40 into the module case 71, the upper and lower surfaces of the laminate pack type battery unit 40 are not pressed and the expansion deformation is not hindered.

10 is a view showing the rear end side of the XX cross section of FIG.
Positioning of the laminate pack battery unit 40 in the front-rear direction with respect to the support piece 77 of the side frame 72 is performed using the projections 53 and 54 protruding from the upper surface and the lower surface of the laminate pack battery unit 40. That is, as shown in FIG. 10, positioning holes 75 are formed in each of the support pieces 77, and the protrusions 53 and 54 enter the positioning holes 75 to position the laminate pack battery unit 40. .
Thus, by using the protrusions 53 and 54 for positioning the laminate pack battery unit 40 in the module case 71, the flat upper surface and lower surface of the laminate pack battery unit 40 are pressed for positioning. The expansion deformation of the first cover 48 and the second cover 49 having the lower rigidity is not hindered.

As described above, according to the present embodiment, the first cover 48 included in the battery case 41 in which the laminate pack type battery 10 is housed has rigidity that deforms as the laminate pack type battery expands, and the second cover 49 Has a structure that does not deform against expansion.
Thereby, when the flat surface of the laminate pack type battery 10 expand | swells, since the 1st cover 48 deform | transforms with the said expansion | swelling, the said expansion | swelling is not inhibited.
In addition, since the deformation accompanying the expansion is induced only in the first cover 48, the deformation of the battery case 41 does not occur at an unexpected location, and the strength design and the structural design of the battery case 41 considering the expansion can be performed. It becomes easy.

Further, according to the present embodiment, the thickness between the first cover 48 and the second cover 49 is the thickness D1 of the laminate pack battery 10 plus an expansion amount of the laminate pack battery 10. D2 space was provided.
Thereby, some expansion of the laminate pack type battery 10 can be absorbed by the margin.

Further, in the present embodiment, the battery case 41 includes a cushioning material 60 that fills a gap generated between the space between the first cover 48 and the second cover 49 and the upper surface 10A and the lower surface 10B of the laminate pack battery 10. It was set as the structure provided with.
Thereby, a gap formed around the laminate pack type battery 10 in the battery case 41 is filled. Further, since the gap is filled with the buffer material 60, the expansion of the laminate pack type battery 10 is not hindered.

In this embodiment, the laminate pack type battery 10 is bonded to the buffer material 60, the buffer material 60 is bonded to the space in the battery case 41, and the laminate pack type battery 10 is fixed in the battery case 41. .
Accordingly, the expansion of the upper surface 10A and the lower surface 10B is not hindered compared to the structure in which the upper surface 10A and the lower surface 10B of the laminate pack battery 10 are sandwiched and pressed by a cover or the like.

In the present embodiment, the laminate pack type battery 10 includes current collecting tab portions 20 and 23 that extend from the position closer to the lower surface 10B than the center in the thickness direction of the battery outer package 12, and the battery case 41 includes: The laminated pack battery 10 is housed in a posture in which the lower surface 10B on the side where the current collecting tab portions 20 and 23 are opposed faces the second cover 49 that is not easily deformed as compared to the first cover 48.
As a result, when the laminate pack type battery 10 expands greatly beyond the margin of the battery case 41 during long-term use, the first cover 48 bulges in the direction opposite to the second cover 49 due to the bending of the first cover 48. Therefore, the stress due to the expansion to the current collecting tab portions 20 and 23 arranged closer to the second cover 49 side is relieved. Thereby, destruction of the current collection tab parts 20 and 23 is prevented, and the fall of the characteristic of the battery by the said destruction is suppressed.

Further, in the present embodiment, a module case 71 is provided in which a plurality of laminate pack type battery units 40 are vertically arranged, and the first cover 48 is inflated and deformed between the plurality of laminate pack type battery units 40. In this case, the assembled battery module 70 is configured to be supported so as not to interfere with each other.
Thereby, even when the laminate pack battery 10 expands greatly during long-term use, the expansion is not hindered by interference between the laminate pack battery units 40.

In the present embodiment, the module case 71 is configured to be supported with the edge portions of the plurality of laminate pack battery units 40 sandwiched therebetween.
Thereby, with the incorporation of the laminate pack type battery unit 40 into the module case 71, the flat upper surface and the lower surface of the laminate pack type battery unit 40 are not pressed, and the bulging deformation of the upper surface or the lower surface is inhibited. It will not be done.

  The above-described embodiments merely show one aspect of the present invention, and it is needless to say that modifications and applications can be arbitrarily made without departing from the gist of the present invention.

DESCRIPTION OF SYMBOLS 10 Laminated pack type battery 11A, 11B Laminated film 12 Battery exterior body 13 Electric power generation element 20, 23 Current collection tab part 40 Laminate pack type battery unit 41 Battery case 43 Terminal part 45 Insulating part 48 1st cover 49 2nd cover 53, 54 Projection 55 Engagement hole 60, 61 Buffer material 70 Battery module 71 Module case 72 Side frame 75 Positioning hole 77 Supporting piece T Interval D1 Thickness of laminate pack type battery D2 Thickness of space inside battery case

Claims (6)

A flat laminate pack type battery in which a power generation element is housed in a battery outer body formed of a laminate film;
A battery case containing the laminate pack type battery,
The battery case is
A first cover facing one of the flat upper surface and the lower surface of the laminate pack type battery, and a second cover facing the other,
The first cover has a rigidity that deforms as the laminate pack type battery expands, and the second cover has a rigidity that hardly deforms compared to the first cover. Battery unit. A space having a thickness obtained by adding a predetermined expansion of the laminate pack type battery to the thickness of the laminate pack type battery is provided between the first cover and the second cover. The laminate pack type battery unit according to claim 1. The battery case is
A cushioning material is provided to fill a gap formed between the space between the first cover and the second cover and the upper surface and / or the lower surface of the laminate pack type battery. The laminated pack battery unit described.   The laminate pack type battery according to any one of claims 1 to 3, wherein at least the laminate pack type battery and the second cover are adhered to each other, and the laminate pack type battery is fixed in the battery case. unit. A plurality of laminate pack type battery units according to any one of claims 1 to 4,
A module case formed by laminating a plurality of the laminated pack battery units,
The module case is
The assembled battery module, wherein a plurality of the laminated pack battery units are supported so as not to interfere with an adjacent second cover even when the first cover is expanded and deformed. The module case is
The assembled battery module according to claim 5, wherein the battery pack module is supported by sandwiching edges of the plurality of laminate pack battery units.

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