JP2011243385A - Laminate battery pack and laminate exterior material for battery pack - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a laminate battery pack which prevents itself from swelling or deforming by external pressure without requiring any additional component and provides excellent heat dissipation and emits heat in a battery to the outside.SOLUTION: The laminate battery pack 1 includes a battery pack body portion 2 comprising a plurality of batteries, a first exterior material 10 including at least a soft aluminum foil and a thermoplastic resin film as constituent layers, and a second exterior material 20 including at least a hard metal foil and a thermoplastic resin film as constituent layers. The first exterior material 10 is molded in a solid shape having a storage case 17, which stores the battery pack body portion and a peripheral edge portion 18 for sealing which extends outward from a peripheral edge of an upper-surface opening of the storage case 17. The second exterior material 20 is in a plane shape, wherein the battery pack body portion 2 is stored in the storage case 17 of the first exterior material 10, and the second exterior material 20 is arranged on the body portion 2, and a peripheral edge 28 of the second exterior material and a peripheral edge 18 of the first exterior material are bonded together and sealed.

Description

  The present invention relates to a laminate exterior material that wraps a main body of an assembled battery used for a power source of a hybrid vehicle, an electric vehicle or the like, or an assembled battery used for wind power generation, solar power generation, or night electricity storage, and the laminate The present invention relates to a laminated battery pack using an exterior material.

  In this specification and claims, the term “aluminum” is used to include both aluminum and aluminum alloys.

  In recent years, with the miniaturization and weight reduction of mobile electrical devices, as an exterior material for lithium ion batteries and lithium polymer batteries mounted on them, aluminum foil having a thickness of about 20 to 100 μm is used instead of conventional metal cans. The weight reduction is achieved by using a laminate exterior material in which a plastic film is bonded to both sides. In addition, as an application thereof, it has been studied to coat a power source for electric vehicles, a large battery for power storage, a capacitor, and the like with a laminate sheath material having such a configuration.

  The large battery has a large capacity, is often used for a long period of time, and has a high frequency of repeated charge and discharge, so internal pressure is likely to occur.For this reason, especially when a configuration in which batteries are stacked by modularization is adopted However, the entire module is likely to be greatly deformed.

  Therefore, a configuration in which a pressing plate and a rubber sheet are arranged between the cover of the module and the flat secondary battery in order to prevent deformation of the module in which the batteries are stacked even if internal pressure is generated (Patent Document) 1), and a configuration in which a belt-like annular frame is attached to the central portion of the module laminated battery (see Patent Document 2).

JP 2003-203615 A JP 2009-259581 A

  However, the configurations described in Patent Documents 1 and 2 have a problem that the number of parts is increased, and there is a problem that a sufficient weight reduction cannot be achieved as a result of an increase in the number of parts.

  In addition, when adopting a configuration in which batteries are stacked by modularization, heat is generated inside the battery due to repeated charging and discharging, and the battery performance is likely to deteriorate due to such heat generation. It has been demanded to improve the heat dissipation performance.

  The present invention has been made in view of such a technical background, and can prevent swelling and deformation due to internal pressure inside the battery without requiring additional parts such as a pressing plate and an annular frame, It is an object of the present invention to provide a laminated battery pack and a laminated outer packaging material for a battery pack, which are excellent in heat dissipation to release the heat inside the battery to the outside.

  In order to achieve the above object, the present invention provides the following means.

[1] an assembled battery main body composed of a plurality of batteries;
A first exterior material comprising at least a soft aluminum foil and a thermoplastic resin film as constituent layers;
A second exterior material comprising at least a hard metal foil and a thermoplastic resin film as constituent layers,
The first exterior material includes a housing case that can house the assembled battery main body portion, and a sealing peripheral portion that extends outward in a substantially horizontal direction from the peripheral edge of the upper surface opening of the housing case. Molded into a three-dimensional shape,
The second exterior material is planar,
The assembled battery body is housed in the housing case of the first exterior material, the second exterior material is disposed on the assembled battery body, and the peripheral portion of the second exterior material and the first exterior material A laminated battery pack characterized by being sealed by being joined to a sealing peripheral portion.

  [2] The laminated assembled battery according to item 1 above, wherein the thickness of the soft aluminum foil is 15 to 120 μm and the thickness of the hard metal foil is 30 to 300 μm.

  [3] The laminated battery assembly according to item 1 or 2, wherein a stainless steel foil, an iron foil, a copper foil, a nickel foil or a hard aluminum foil is used as the hard metal foil.

  [4] The method according to any one of items 1 to 3, wherein the width of the sealing portion in which the peripheral edge portion of the second exterior material and the sealing peripheral edge portion of the first external material are joined is 1 mm or more. Laminated battery.

[5] An exterior material used to externally surround the assembled battery main body composed of a plurality of batteries, and a first exterior material formed into a three-dimensional shape and used in a planar shape. With two exterior materials,
The first exterior material comprises a laminate including at least a soft aluminum foil and a thermoplastic resin film,
Said 2nd exterior material consists of a laminated body containing a hard metal foil and a thermoplastic resin film at least, The laminated exterior material for assembled batteries characterized by the above-mentioned.

  [6] The laminate outer packaging material for an assembled battery according to item 5 above, wherein the thickness of the soft aluminum foil is 15 to 120 μm and the thickness of the hard metal foil is 30 to 300 μm.

  [7] The laminate outer packaging material for an assembled battery according to [5] or [6], wherein a stainless steel foil, an iron foil, a copper foil, a nickel foil or a hard aluminum foil is used as the hard metal foil.

  In the invention of [1], since the second exterior material disposed on the assembled battery main body portion includes a hard metal foil, it is possible to prevent swelling and deformation due to internal pressure inside the battery, and heat dissipation. The heat inside the battery can be efficiently released to the outside. Thereby, the lifetime improvement of a laminated assembled battery can be achieved. In addition, since the first exterior material molded into a three-dimensional shape can accommodate the assembled battery main body in the accommodation case, the second exterior material is difficult to be molded such as press molding by including a hard metal foil. There is an advantage that can be used for sealing in a flat state.

  In the invention of [2], since the thickness of the soft aluminum foil is 15 to 120 μm, the first exterior material is three-dimensionally molded in a good state without pinholes or the like. In addition, since the thickness of the hard metal foil is 30 to 300 μm, it is possible to sufficiently prevent swelling and deformation due to internal pressure inside the battery and to efficiently release the heat inside the battery to the outside (further improving heat dissipation performance). Can be made).

  In the invention of [3], stainless steel foil, iron foil, copper foil, nickel foil or hard aluminum foil is used as the hard metal foil. Since these hard metal foils have higher strength, they depend on the internal pressure inside the battery. Swelling and deformation can be prevented more sufficiently. Among these, stainless steel foil, iron foil, copper foil, and nickel foil have higher material strength than hard aluminum foil, so that the second exterior material can be used with a thinner thickness.

  In invention of [4], since the width | variety of the sealing part where the peripheral part of the 2nd exterior material and the peripheral part for sealing of the said 1st exterior material were joined is 1 mm or more, sealing joining is more reliable. In addition to this, the heat dissipation performance can be further improved.

  In the invention of [5], since the second exterior material used in a planar shape to enclose the periphery of the assembled battery main body portion includes the hard metal foil, the battery is prevented from being swelled or deformed due to internal pressure. In addition, the heat dissipation is excellent and the heat inside the battery can be efficiently released to the outside. Thereby, the lifetime improvement of a laminated assembled battery can be achieved. In addition, since the first exterior material molded into a three-dimensional shape can accommodate the assembled battery main body within the three-dimensional shape, it is difficult to form such as press molding by including a hard metal foil. A certain 2nd exterior material can be used for sealing joining with planar shape.

  In the invention of [6], since the thickness of the soft aluminum foil is 15 to 120 μm, the first exterior material can be three-dimensionally molded in a good state with no pinholes or the like. In addition, since the thickness of the hard metal foil is 30 to 300 μm, it is possible to sufficiently prevent swelling and deformation due to internal pressure inside the battery and to efficiently release the heat inside the battery to the outside (further improving heat dissipation performance). Can be made).

  In the invention of [7], stainless steel foil, iron foil, copper foil, nickel foil or hard aluminum foil is used as the hard metal foil. Since these hard metal foils have higher strength, they depend on the internal pressure inside the battery. Swelling and deformation can be prevented more sufficiently. Among these, stainless steel foil, iron foil, copper foil, and nickel foil have higher material strength than hard aluminum foil, so that the second exterior material can be used with a thinner thickness.

It is sectional drawing (equivalent to sectional drawing of the XX line in FIG.2 (D)) which shows one Embodiment of the laminated assembled battery which concerns on this invention. It is a perspective view which shows an example of the manufacturing process of the laminated battery assembly which concerns on this invention, Comprising: (A) is the 1st exterior material before shaping | molding, (B) is the three-dimensional molded object which consists of 1st exterior materials, (C) is A state in which the assembled battery main body is housed in the housing case of the first exterior material, and (D) shows a state in which the second exterior material is further overlapped and sealed. It is sectional drawing which shows a 1st exterior material. It is sectional drawing which shows a 2nd exterior material. It is explanatory drawing of the test method of a deformation | transformation prevention performance evaluation test.

  One embodiment of a laminated battery pack 1 according to the present invention is shown in FIG. 1 and FIG. The laminated battery assembly 1 includes an assembled battery body 2, a three-dimensional molded body 10 </ b> A composed of a first exterior material 10, and a second exterior material 20.

  The assembled battery main body 2 is configured by laminating and arranging a plurality of batteries (unit cells), and in the present embodiment, the unit cell body unit 2 is composed of two unit cells (see FIG. 1). That is, in the present embodiment, the assembled battery body 2 includes the separator 42A disposed on the second exterior member 20 side and the negative electrode disposed on the lower surface (surface on the first exterior member 10 side) of the separator 42A. 41, a separator 42B disposed on the lower surface side of the negative electrode 41, a positive electrode 43 disposed on the lower surface side of the separator 42B, a separator 42C disposed on the lower surface side of the positive electrode 43, and a lower surface of the separator 42C A negative electrode 41 disposed on the lower side, a separator 42D disposed on the lower surface side of the negative electrode 41, a positive electrode 43 disposed on the lower surface side of the separator 42D, and a separator 42E disposed on the lower surface side of the positive electrode 43 (See FIG. 1).

  The said 1st exterior material 10 consists of a laminated body which contains the soft aluminum foil 11 and the thermoplastic resin film 12 as a structural layer at least (refer FIG. 3). In the present embodiment, as the first exterior material 10, as shown in FIG. 3, an unstretched resin film 13 (12) is laminated on one surface of the soft aluminum foil 11 via the first adhesive layer 15, A laminate in which the stretched resin film 14 (12) is laminated on the other surface of the soft aluminum foil 11 with the second adhesive layer 16 interposed therebetween is used.

  Thus, the first exterior member 10 includes a housing case 17 having a housing recess 17a capable of housing the assembled battery main body 2 by press molding such as cold press molding, and an upper surface side of the housing case 17. It is formed in a three-dimensional molded body 10 </ b> A including a sealing peripheral edge 18 that extends outward from the peripheral edge of the opening in a substantially horizontal direction (see FIG. 2B). The storage case 17 has side walls 17Y erected from each of the four sides of the bottom wall 17X having a substantially rectangular shape in plan view, and has an upper surface opened. The inner surface of the housing case 17 of the three-dimensional molded body 10A (exposed to the inner space of the housing case 17) is the unstretched resin film 13 and the outer surface of the housing case 17. What is exposed to the outside is the stretched resin film 14 (see FIGS. 1 and 2B).

  The second exterior material 20 is composed of a laminate including at least a hard metal foil 21 and a thermoplastic resin film 22 as constituent layers (see FIG. 4). The second exterior member 20 is used in a planar state (without being three-dimensionally molded or the like). In this embodiment, as said 2nd exterior material 20, as shown in FIG. 4, the unstretched resin film 23 (22) is laminated | stacked through the 1st adhesive bond layer 25 on the one surface of the hard metal foil 21, A laminate in which the stretched resin film 24 (22) is laminated on the other surface of the hard metal foil 21 with the second adhesive layer 26 interposed therebetween is used.

  As shown in FIGS. 1 and 2, the assembled battery body 2 is housed in a housing case 17 of a three-dimensional molded body 10 </ b> A made of the first exterior material 10, and the planar battery body 2 is placed on the assembled battery body 2. The second exterior material 20 is disposed, and the peripheral edge 28 of the second exterior material 20 and the sealing peripheral edge 18 of the first exterior material 10 (three-dimensional molded body 10A) are joined and sealed. The laminated battery pack 1 of the present invention is configured.

  1 and 2, 31 is a negative electrode tab, 32 is a negative electrode tab film, 33 is a positive electrode tab, and 34 is a positive electrode tab film. Reference numeral 51 denotes a negative electrode lead portion, which electrically connects the negative electrode tab 31 and the negative electrode 41. Reference numeral 53 denotes a positive electrode lead portion, which electrically connects the positive electrode tab 33 and the positive electrode 43.

  The width W of the sealing portion where the peripheral edge portion 28 of the second exterior material 20 and the peripheral edge portion 18 for sealing of the first exterior material 10 are joined is preferably 1 mm or more (see FIG. 1). When it is 1 mm or more, there is an advantage that sealing joining can be performed more reliably and the heat dissipation performance can be further improved. Especially, it is especially preferable that the width W of the sealing portion is 3 to 15 mm.

  In the present invention, the first exterior material 10 is composed of a laminate including at least a soft aluminum foil 11 and a thermoplastic resin film 12 as constituent layers. Especially, as said 1st exterior material 10, unstretched resin film 13 (12) is laminated | stacked through the 1st adhesive bond layer 15 on one side of the soft aluminum foil 11, and the other side of the said soft aluminum foil 11 It is preferable to use a laminate (see FIG. 3) in which the stretched resin film 14 (12) is laminated on the second adhesive layer 16.

  The said soft aluminum foil 11 means aluminum foil other than the hard aluminum foil mentioned later, for example, the foil of the state softened by complete annealing, etc. are mentioned, and is generally called O material by JIS standard (JIS H0001). What is being done is mentioned.

  The material of the soft aluminum foil 11 is not particularly limited, but JIS H4160-A8021H-O, JIS H4160-A8079H-O, JIS H4160-A3003H-O, JIS H4160-A3004H-O, etc. are preferably used. It is done.

  The thickness of the soft aluminum foil 11 is preferably 15 to 120 μm. By being 15 μm or more, the three-dimensional molded body 10A made of the first exterior material is three-dimensionally molded in a good state with no pinholes or the like. Moreover, shaping | molding, such as cold press molding, can be easily performed because it is 120 micrometers or less. Especially, it is especially preferable that the thickness of the said soft aluminum foil 11 is 30-80 micrometers.

  The unstretched resin film 13 constituting the first exterior material 10 is not particularly limited, but is unstretched polypropylene film, unstretched acid-modified polypropylene film, unstretched polyethylene film, unstretched acid-modified polyethylene film, An ionomer resin film or the like is preferably used. It is good also as a structure which laminated | stacked 2 or more types of these unstretched films. The unstretched resin film 13 preferably has a thickness of 20 to 100 μm.

  Although it does not specifically limit as the stretched resin film 14 which comprises said 1st exterior material 10, A stretched nylon film, a stretched polyester film, a stretched polyethylene naphthalate film, a stretched polypropylene film, etc. are used preferably. In automotive applications, it is preferable to use a stretched polyester film that hardly undergoes a chemical change even when a coolant liquid or gasoline used in an automobile adheres. It is good also as a structure which laminated | stacked 2 or more types of these stretched films. The stretched resin film 14 preferably has a thickness of 5 to 40 μm.

  The adhesive constituting the first adhesive layer 15 and the second adhesive layer 16 is not particularly limited, and examples thereof include polyether-urethane adhesives, polyester-urethane adhesives, Examples include acrylic-urethane adhesives, polyamide-urethane adhesives, polyimide-urethane adhesives, and epoxy-urethane adhesives.

  In the present invention, the second exterior material 20 is composed of a laminate including at least a hard metal foil 21 and a thermoplastic resin film 22 as constituent layers. Among them, as the second exterior material 20, an unstretched resin film 23 (22) is laminated on one surface of the hard metal foil 21 via the first adhesive layer 25, and the other surface of the hard metal foil 21. It is preferable to use a laminate (see FIG. 4) in which the stretched resin film 24 (22) is laminated via the second adhesive layer 26.

  Although it does not specifically limit as said hard metal foil 21, It is preferable to use the thing of the structure in any one of the following 1) -3).

1) Stainless steel foil, iron foil, copper foil, nickel foil or hard aluminum foil Since the hard metal foil of 1) has higher strength, it can more fully prevent swelling and deformation due to internal pressure inside the battery.

2) A foil made of a clad material in which at least one metal material selected from the group consisting of copper and hard aluminum and at least one metal material selected from the group consisting of stainless steel, iron and nickel are combined. In the configuration using the foil made of the clad material, a material in which at least one of high strength stainless steel, iron, and nickel is combined with at least one of copper and hard aluminum having good thermal conductivity is used. Thus, the thermal conductivity and strength of the second exterior material can be further improved.

3) A foil in which a nickel plating layer, a tin plating layer or a chrome plating layer is provided on the surface of one type of foil selected from the group consisting of iron foil, copper foil and hard aluminum foil. Copper foil and hard aluminum foil have high strength, and nickel plated layer, tin plated layer or chrome plated layer plated thereon has good thermal conductivity and is easy to oxidize the surface of iron foil or copper foil. Since it plays a role of improving the corrosion resistance, the thermal conductivity, strength and long-term durability of the second exterior material can be further improved.

  The hard aluminum foil 21 means an aluminum foil that has been processed (rolled) and work hardened, for example, a foil that has been hardened by work, a foil that has undergone an appropriate heat treatment after work hardening, and the like. Examples of the classification symbols HX1, HX2, HX3, HX4, HX5, HX6, HX7, HX8, and HX9 generally used in the JIS standard (JIS H0001) (where X is 1 to 3).

  The material of the hard aluminum foil 21 is not particularly limited, but JIS H4160-A3003H-H18, JIS H4160-A3004H-H18, JIS H4160-A8021H-H18, JIS H4160-A8079H-H18, etc. are preferably used. It is done. Further, JIS H4000 2000 series, 5000 series, and 6000 series aluminum foils having high thermal conductivity may be used.

  The thickness of the hard metal foil 21 is preferably 30 to 300 μm. When the thickness is 30 μm or more, swelling and deformation due to internal pressure inside the battery can be sufficiently prevented, and heat inside the battery can be efficiently released to the outside. Further, by being 300 μm or less, lamination processing such as bonding of the hard metal foil 21 to the unstretched resin film 23 and the stretched resin film 24 becomes easy, and heat sealing for forming a sealing portion is also possible. Facilitated. Especially, it is especially preferable that the thickness of the said hard metal foil 21 is 50-200 micrometers.

  The unstretched resin film 23 constituting the second exterior material 20 is not particularly limited, but is unstretched polypropylene film, unstretched acid-modified polypropylene film, unstretched polyethylene film, unstretched acid-modified polyethylene film, An ionomer resin film or the like is preferably used. It is good also as a structure which laminated | stacked 2 or more types of these unstretched films. The unstretched resin film 23 preferably has a thickness of 20 to 100 μm.

  The stretched resin film 24 constituting the second exterior material 20 is not particularly limited, but a stretched nylon film, a stretched polyester film, a stretched polyethylene naphthalate film, a stretched polypropylene film, and the like are preferably used. In automotive applications, it is preferable to use a stretched polyester film that hardly undergoes a chemical change even when a coolant liquid or gasoline used in an automobile adheres. It is good also as a structure which laminated | stacked 2 or more types of these stretched films. The stretched resin film 24 preferably has a thickness of 5 to 40 μm.

  Although it does not specifically limit as an adhesive agent which comprises said 1st adhesive bond layer 25 and said 2nd adhesive bond layer 26, For example, polyether-urethane type adhesive, polyester-urethane type adhesive, poly Examples include acrylic-urethane adhesives, polyamide-urethane adhesives, polyimide-urethane adhesives, and epoxy-urethane adhesives.

  Next, specific examples of the present invention will be described, but the present invention is not particularly limited to these examples.

<Example 1>
A stretched nylon film having a thickness of 15 μm is bonded to one surface of a 40 μm-thick soft aluminum foil (JIS H4160-A8079H-O) via a polyester-urethane adhesive, and a polyester-urethane system is further formed thereon. After pasting a stretched polyester film having a thickness of 12 μm via an adhesive, an unstretched polypropylene film having a thickness of 80 μm is pasted on the other surface of the soft aluminum foil via a polyacrylic adhesive, The 1st exterior material 10 was obtained (refer FIG. 2 (A)).

  After a stretched polyester film having a thickness of 12 μm is bonded to one surface of a hard aluminum foil having a thickness of 150 μm (JIS H4160-A3004H-H18) via a polyester-urethane adhesive, the other of the hard aluminum foil is bonded. A second exterior material 20 was obtained by bonding an unstretched polypropylene film having a thickness of 80 μm to the surface via a polyacrylic adhesive.

  Next, the flat first exterior material 10 is hot press-molded using a mold, whereby a housing case 17 having a length of 145 mm, a width of 130 mm, and a depth of 5 mm, and a peripheral edge of the upper surface opening of the housing case 17 A solid molded body 10A having a sealing peripheral edge 18 having a width of 10 mm extended outward in a substantially horizontal direction was obtained (see FIG. 2B).

  On the other hand, an aluminum foil having a length of 144 mm, a width of 129 mm, a thickness of 30 μm, a cellulose separator having a length of 144 mm, a width of 129 mm, and a thickness of 250 μm, and a copper foil having a length of 144 mm, a width of 129 mm, and a thickness of 20 μm stacked in this order. As a set, a set of 15 sets was created, and an assembled battery body (simulated product) 2 was obtained.

  The assembled battery body 2 is accommodated in the accommodating case 17 of the three-dimensional molded body 10A (see FIG. 2C), and 20 g of electrolytic solution and 20 mg of pure water are introduced into the accommodating case 17, and then the assembled battery The second exterior member 20 is placed on the main body 2 so that the unstretched polypropylene film 23 becomes the inner surface, and the upper surface of the second exterior member 20 is 3 with a hot plate at 200 ° C. under a reduced pressure of 0.086 MPa. The laminate assembled battery 1 was produced by pressing for 2 seconds and sealingly joining the peripheral edge portion 28 of the second exterior material and the peripheral edge portion 18 for sealing of the first exterior material.

  In the laminated battery assembly 1 obtained, the width W of the sealing portion in which the peripheral edge portion 28 of the second exterior material and the peripheral edge portion 18 for sealing of the first exterior material were joined was 10 mm.

The electrolytic solution is a solution in which LiPF ₆ is adjusted to 1 mol / L with a mixed solution (a solution in which ethylene carbonate / dimethylene carbonate / dimethyl carbonate is mixed at a volume ratio of 1: 1: 1).

<Example 2>
A laminated battery assembly 1 was produced in the same manner as in Example 1 except that a hard aluminum foil having a thickness of 100 μm (JIS H4160-A3004H-H18) was used instead of the hard aluminum foil having a thickness of 150 μm.

<Example 3>
Except that the design was changed so that the width W of the sealing portion where the peripheral edge portion 28 of the second exterior material and the peripheral edge portion 18 for sealing of the first external material were joined was 2 mm, the same as in Example 1. A laminated battery pack 1 was produced.

<Example 4>
A laminated battery assembly 1 was produced in the same manner as in Example 1 except that a stainless steel foil (JIS304-H) having a thickness of 80 μm was used instead of the hard aluminum foil having a thickness of 150 μm.

<Example 5>
A laminated battery assembly 1 was produced in the same manner as in Example 1 except that an iron foil having a thickness of 80 μm was used instead of the hard aluminum foil having a thickness of 150 μm.

<Example 6>
A laminated battery assembly 1 was produced in the same manner as in Example 1 except that a copper foil having a thickness of 100 μm was used instead of the hard aluminum foil having a thickness of 150 μm.

<Example 7>
A laminated battery assembly 1 was produced in the same manner as in Example 1 except that a nickel foil having a thickness of 100 μm was used instead of the hard aluminum foil having a thickness of 150 μm.

<Comparative Example 1>
As a second exterior material, a stretched nylon film having a thickness of 15 μm is bonded to one surface of a 40 μm-thick soft aluminum foil (JIS H4160-A8079H-O) via a polyester-urethane adhesive, and this After bonding a stretched polyester film having a thickness of 12 μm via a polyester-urethane adhesive on the other surface, an unstretched polypropylene film having a thickness of 80 μm via a polyacrylic adhesive on the other surface of the soft aluminum foil. A laminated battery assembly 1 was produced in the same manner as in Example 1 except that the laminate (having the same configuration as the first exterior material used in Example 1) obtained by bonding was used.

<Comparative example 2>
After bonding a stretched polyester film having a thickness of 12 μm on one surface of a soft aluminum foil having a thickness of 80 μm (JIS H4160-A8079H-O) as a second exterior material via a polyester-urethane adhesive, A laminated assembled battery in the same manner as in Example 1 except that a laminate obtained by bonding an unstretched polypropylene film having a thickness of 80 μm to the other surface of the soft aluminum foil via a polyacrylic adhesive was used. 1 was produced.

  The deformation prevention performance and heat dissipation performance of the laminate battery obtained as described above were evaluated based on the following evaluation methods. These evaluation results are shown in Table 1.

<Deformation prevention performance evaluation method>
Five laminated battery packs of Example 1 were prepared, and as shown in FIG. 5, the five laminated battery packs 1 were overlapped so that the second exterior member 20 of each battery pack was on the lower surface side. Is placed in a transparent case 61 made of polyacryl with an open upper surface portion, and hard aluminum having a thickness of 150 μm is attached to the upper surface of the laminated battery pack 1 at the top of the five stacked layers via a double-sided adhesive tape 62. A foil 63 was attached. In this state, the height Ha from the lower surface of the lowermost laminated battery assembly 1 to the uppermost hard aluminum foil 63 (height before the cooling test) was measured (see FIG. 5).

  Next, the transparent case containing the five laminated battery packs stacked was placed in a thermostat set at 80 ° C. and allowed to stand for 8 hours, and then placed in a freezer at −30 ° C. for 8 hours. After repeating such a cooling cycle 50 times (50 cycles), the height Hb from the lower surface of the laminated battery pack 1 at the lowest position to the hard aluminum foil 63 at the highest position (the height Hb after the cooling test) is repeated as described above. ) Was measured (see FIG. 5). The amount of change in height (Hb-Ha) was calculated, and the deformation prevention property was evaluated from this.

  The deformation prevention performance was evaluated in the same manner as above for the laminated batteries of Examples 2 to 7 and Comparative Examples 1 and 2.

<Heat dissipation performance evaluation method>
The laminated battery is placed in a thermostat set at 80 ° C. so that the second exterior material is on the lower surface side, and left to stand for 24 hours. Then, the laminated battery is taken out and allowed to stand under normal temperature conditions. Time required for the temperature of the inner central portion to decrease to 50 ° C. (time from the start of standing until 50 ° C.) and time required for the temperature to decrease to 30 ° C. (time from the start of leaving to 30 ° C.) ) Was measured, and the heat dissipation performance was evaluated from this.

  As is clear from Table 1, the laminated battery packs of Examples 1 to 7 of the present invention have a small amount of change in height before and after the cooling test, and the swelling of the battery pack due to the gas generated by the decomposition of the electrolyte is sufficient. It can be suppressed and is excellent in deformation prevention. Moreover, the laminated battery packs of Examples 1 to 7 of the present invention have a rapid decrease in the temperature of the battery pack body and are excellent in heat dissipation.

  On the other hand, the laminated batteries of Comparative Examples 1 and 2 using a soft aluminum foil as a metal foil that is one of the constituent layers of the second exterior material are inferior in deformation prevention and also have insufficient heat dissipation. there were.

  The laminated assembled battery according to the present invention is suitably used as a power source for a hybrid vehicle, an electric vehicle or the like, or for storing wind power, solar power, or night electricity. Moreover, the laminated outer packaging material for the assembled battery of the present invention is an assembled material for an assembled battery used for a power source of a hybrid vehicle, an electric vehicle or the like, or an assembled battery used for wind power generation, solar power generation, night electricity storage. It is suitably used as an exterior material.

DESCRIPTION OF SYMBOLS 1 ... Laminate assembled battery 2 ... Assembly battery main-body part 10 ... 1st exterior material 10A ... 3D molded object 11 ... Soft aluminum foil 12 ... Thermoplastic resin film 17 ... Housing case 18 ... Peripheral part 20 for sealing ... 2nd exterior material 21 ... Hard metal foil 22 ... Thermoplastic resin film 28 ... Peripheral part

Claims (7)

An assembled battery body comprising a plurality of batteries;
A first exterior material comprising at least a soft aluminum foil and a thermoplastic resin film as constituent layers;
A second exterior material comprising at least a hard metal foil and a thermoplastic resin film as constituent layers,
The first exterior material includes a housing case that can house the assembled battery main body portion, and a sealing peripheral portion that extends outward in a substantially horizontal direction from the peripheral edge of the upper surface opening of the housing case. Molded into a three-dimensional shape,
The second exterior material is planar,
The assembled battery body is housed in the housing case of the first exterior material, the second exterior material is disposed on the assembled battery body, and the peripheral portion of the second exterior material and the first exterior material A laminated battery pack characterized by being sealed by being joined to a sealing peripheral portion.   The laminated battery assembly according to claim 1, wherein the thickness of the soft aluminum foil is 15 to 120 µm, and the thickness of the hard metal foil is 30 to 300 µm.   The laminated battery assembly according to claim 1 or 2, wherein a stainless steel foil, an iron foil, a copper foil, a nickel foil or a hard aluminum foil is used as the hard metal foil.   The laminate battery according to any one of claims 1 to 3, wherein a width of a sealing portion in which a peripheral edge portion of the second exterior material and a sealing peripheral edge portion of the first external material are joined is 1 mm or more. . A packaging material used for packaging the periphery of an assembled battery main body composed of a plurality of batteries, the first packaging material used by being molded into a three-dimensional shape, and the second packaging material used in a planar shape And
The first exterior material comprises a laminate including at least a soft aluminum foil and a thermoplastic resin film,
Said 2nd exterior material consists of a laminated body containing a hard metal foil and a thermoplastic resin film at least, The laminated exterior material for assembled batteries characterized by the above-mentioned.   The laminate outer packaging material for an assembled battery according to claim 5, wherein the thickness of the soft aluminum foil is 15 to 120 µm, and the thickness of the hard metal foil is 30 to 300 µm.   The laminated outer packaging material for an assembled battery according to claim 5 or 6, wherein a stainless steel foil, an iron foil, a copper foil, a nickel foil or a hard aluminum foil is used as the hard metal foil.

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