JP2015088409A - Electrochemical device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrochemical device capable of sufficiently preventing warp deformation of a sheath material sheathing a device main body part or swelling of the sheath material caused by inner pressure rising without reducing a weight energy density even if the electrochemical device (such as a battery) is large-sized and thin.SOLUTION: The electrochemical device includes a first sheath material 1, a second sheath material 41 and an electrochemical device main body part 10. One or more lines of ribs 5 are protrusively provided on a surface of the first sheath material closer to an outer layer 2. The second sheath material is formed in a three-dimensional shape including an accommodation case 42 and a sealing edge part 43 extending from an edge of an opening of a top face of the accommodation case towards the outside in a substantially horizontal direction. The electrochemical device main body part 10 is accommodated within the accommodation case 42 of the second sheath material. On the main body part 10, the first sheath material 1 is disposed while turning the side of an inner layer 3 inside, and an edge part of the inner layer 3 of the first sheath material 1 and the inner layer 3 of the sealing edge part 43 of the second sheath material 41 are joined.

Description

  The present invention relates to an electrochemical device such as a battery or a capacitor used for a portable device such as a smartphone or a tablet, a hybrid vehicle, an electric vehicle, wind power generation, solar power generation, or a battery or capacitor used for power storage for night electricity. .

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

  In recent years, with the reduction in thickness and weight of mobile electrical devices such as smartphones and tablet terminals, the exterior materials of lithium ion batteries and lithium polymer batteries mounted thereon are replaced with conventional metal cans with a thickness of 20 to A laminate exterior material in which a plastic film is bonded to both surfaces of an aluminum foil of about 100 μm is used to reduce the weight. In addition, as an application, packaging of a power source for an electric vehicle or the like, a large-scale power source for power storage, a capacitor, or the like with the laminate exterior material having the above-described configuration has been studied.

  In general, in lithium ion batteries that use metal cans as exterior materials, aluminum materials, iron materials, and stainless steel materials with a thickness of 0.2 mm or more are used as materials for metal cans, and these metal materials have high material strength. Therefore, warpage deformation of the can due to the residual stress of the electrode, and swelling of the can due to an increase in internal pressure caused by gas generated by decomposition of the electrolytic solution or the like can be suppressed.

  On the other hand, lithium-ion batteries and lithium-polymer batteries that use laminated exterior materials in which a plastic film is bonded to both surfaces of an aluminum foil as exterior materials, especially large-sized thin lithium-ion batteries and lithium used for smartphones and automobiles. In polymer batteries, the strength of the outer packaging material is not sufficient, so it suppresses the warpage deformation of the laminated outer packaging material due to the residual stress of the electrode and the swelling of the laminated outer packaging material due to the increase in internal pressure caused by the gas generated by the decomposition of the electrolyte etc. I couldn't.

  Patent Document 1 discloses an assembled battery main body composed of a plurality of batteries, at least a thermoplastic resin film, and a first soft material having a thickness of 15 to 120 μm. A first exterior material comprising an aluminum foil as a constituent layer, and a second exterior material comprising at least a thermoplastic resin film and a second soft aluminum foil having a thickness of 150 to 400 μm as a constituent layer, the first exterior material comprising: A housing case that can house the assembled battery body portion, and a sealing peripheral portion that extends outward from the periphery of the upper surface opening of the housing case in a substantially horizontal direction; The second exterior material has a planar shape, the assembled battery main body is accommodated in a housing case of the first exterior material, the second exterior material is disposed on the assembled battery main body, The outer periphery of the two exterior materials and the A laminated battery pack is described in which the peripheral edge for sealing of the first exterior material is bonded and sealed. In this battery, since the second exterior material disposed on the assembled battery main body includes a second soft aluminum foil having a thickness of 150 to 400 μm, the exterior material swells due to internal pressure inside the battery. , Deformation can be prevented.

  Patent Document 2 discloses an assembled battery main body composed of a plurality of batteries, a first exterior material including at least a soft aluminum foil and a thermoplastic resin film as constituent layers, and at least a hard metal foil and a thermoplastic resin. A first exterior material comprising a film as a constituent layer, wherein the first exterior material is a housing case that can house the assembled battery main body, and a substantially horizontal outer side from a peripheral edge of the upper surface opening of the housing case. The second outer packaging material is planar, and the assembled battery main body is accommodated in the housing case of the first outer packaging material. And the second exterior material is disposed on the assembled battery main body, and the peripheral edge of the second exterior material and the sealing peripheral edge of the first exterior material are joined and sealed. An assembled battery is described. In this battery, since the 2nd exterior material arrange | positioned on an assembled battery main-body part contains the hard metal foil, the swelling and deformation | transformation of the exterior material by the internal pressure inside a battery can be prevented.

JP 2011-243522 A JP 2011-243385 A

  However, in the technique described in Patent Document 1, it is necessary to increase the thickness of the second soft aluminum foil in order to sufficiently prevent deformation, and as a result, a laminated battery (battery covered with an exterior material) is obtained. ) Has a problem that the weight energy density decreases.

  In addition, in the technique described in Patent Document 2, since the second exterior material includes the hard metal foil, the strength of the exterior material is improved, and there is an effect of preventing the expansion and deformation of the exterior material. In a large-sized laminate battery used for automobiles with a small thickness, it has not been possible to sufficiently prevent warping deformation of the laminate exterior material due to the residual stress of the electrode.

  The present invention has been made in view of such a technical background, and even if the electrochemical device (battery or the like) is large and thin, the device main body portion is reduced without reducing the weight energy density. It is an object of the present invention to provide an electrochemical device capable of sufficiently preventing warpage deformation of an exterior packaging material and swelling of the packaging material due to an increase in internal pressure.

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

[1] A first exterior material comprising a heat-resistant resin stretched film layer as an outer layer, a thermoplastic resin unstretched film layer as an inner layer, and a metal foil layer disposed between these two film layers,
A second exterior material comprising a heat-resistant resin stretched film layer as an outer layer, a thermoplastic resin unstretched film layer as an inner layer, and a metal foil layer disposed between these two film layers;
An electrochemical device body, and
One or more ribs project from the outer layer side surface of the first exterior material,
The second exterior material includes a storage case that can store the electrochemical device main body, and a sealing peripheral edge that extends outward in a substantially horizontal direction from the peripheral edge of the upper surface opening of the storage case. Formed into a three-dimensional shape having
The electrochemical device main body is accommodated in a housing case for the second exterior material, and the first exterior material is disposed on the electrochemical device main body with the inner layer side inward, An electrochemical device, wherein a peripheral portion of an inner layer of the exterior material and an inner layer of a sealing peripheral portion of the second exterior material are bonded and sealed.

  [2] The electrochemical device according to item 1 above, wherein the rib has a height of 0.5 mm to 5 mm.

  [3] The electrochemical device according to 1 or 2 above, wherein a plurality of the ribs are provided in the first exterior material.

[4] The rib is formed by projecting by partially folding a laminated material including the outer layer, the inner layer, and the metal foil layer,
The electrochemical device according to any one of the preceding items 1 to 3, wherein inner layers overlapped by the folding process inside the rib are welded together.

  [5] The electrochemical device according to item 4, wherein the thickness of the first exterior material is 0.05 mm to 0.3 mm.

  [6] The electrochemical device according to item 4 or 5, wherein the thickness of the inner layer of the first exterior material is 0.02 mm to 0.1 mm.

  [7] The electrochemical device according to any one of items 1 to 6, wherein a hard aluminum foil is used as the metal foil layer of the first exterior material.

  In the invention of [1], since one or more ribs protrude from the surface on the outer layer side of the first exterior material, even if the electrochemical device (battery or the like) is large and thin. Without reducing the weight energy density, it is possible to sufficiently prevent warping deformation of the outer packaging material due to the residual stress of the electrode (warping deformation of the electrode) and swelling of the outer packaging material due to an increase in internal pressure generated by the gas generated by the decomposition of the electrolyte etc. can do.

  In the invention of [2], the height of the rib is set to 0.5 mm to 5 mm, and the height is 0.5 mm or more, so that warping deformation and swelling of the exterior material in an electrochemical device (battery etc.) are prevented. While being able to prevent enough, the whole thickness of an electrochemical device (battery etc.) can be suppressed because height is 5 mm or less.

  In the invention of [3], since a plurality of ribs are provided, it is possible to further improve the effect of preventing warpage deformation and swelling of the exterior material in an electrochemical device (battery or the like).

  In the invention of [4], the laminated material including the outer layer, the inner layer, and the metal foil layer is formed by protruding the ribs by being partially folded so that the ribs can be easily formed. . Moreover, since the inner layers overlapped by the folding process inside the ribs are welded and joined, the ribs rising stably can be formed.

  In the invention of [5], the thickness of the exterior material is set to 0.05 mm to 0.3 mm, and when the thickness is 0.05 mm or more, the thickness of the rib can be sufficiently secured, and the electrochemical device (battery Etc.), it is possible to sufficiently prevent warping deformation and swelling of the exterior material, and when it is 0.3 mm or less, formation of a rib by folding is facilitated.

  In the invention of [6], since the thickness of the inner layer is 0.02 mm to 0.1 mm, a gap remains in the heat seal portion when the peripheral portions of the inner layer of the exterior material are heat sealed. This can sufficiently prevent leakage of the electrolyte.

  In the invention of [7], since the hard aluminum foil is used as the metal foil layer, warping deformation and swelling of the exterior material can be more sufficiently suppressed in an electrochemical device (battery or the like).

It is sectional drawing which shows one Embodiment of the 1st exterior material (exterior material with a rib) used by this invention. It is sectional drawing which shows one Embodiment of the 2nd exterior material (thing shape | molded by the solid shape) used by this invention. It is sectional drawing which shows one Embodiment of the electrochemical device which concerns on this invention (sectional drawing of the electrochemical device in the position corresponding to the XX line in FIG. 4). The first exterior material (ribbed exterior material), the electrochemical device main body, and the second exterior material (molded into a three-dimensional shape) constituting the electrochemical device of FIG. 3 are shown in a separated state before heat sealing. It is a perspective view. FIG. 6 is a cross-sectional view (cross-sectional view of the electrochemical device at a position corresponding to the YY line in FIG. 4) showing a state of seal bonding at the heat seal portion at the peripheral edge of the electrochemical device in FIG. 3.

  One embodiment of an electrochemical device 20 according to the present invention is shown in FIG. The electrochemical device 20 includes a first exterior material (exterior material with ribs) 1, a second exterior material 31, and an electrochemical device body 10.

  As shown in FIG. 1, the first exterior material 1 includes a heat-resistant resin stretched film layer 2 as an outer layer, a thermoplastic resin unstretched film layer 3 as an inner layer, and a gap between the two film layers 2 and 3. And a plurality of ribs (protrusions) 5 are provided on the surface of the laminate on the outer layer 2 side. The plurality of ribs 5 are spaced apart from each other (see FIG. 1). In addition, the number of the ribs (protrusions) 5 formed may be one.

  In the present embodiment, the rib 5 is formed in a projecting manner by partially folding a planar laminate including the outer layer 2, the inner layer 3 and the metal foil layer 4. (See FIG. 1). Then, the inner layers 3, 3 overlapped by the folding process inside the rib 5 are welded and integrated by heating to form a welded joint 6, and such welded joints (inner layers) ), The protruding state of the rib 5 is not eliminated (the rib 5 is not lost). Since the rib 5 is formed by partially folding such a planar laminate, the productivity is excellent. In the partial folding process, for example, in a state in which a folded part is partially formed by a human hand, the folded part is subjected to an apparatus (product number: TP-701-B) manufactured by Tester Sangyo Co., Ltd. This can be done by sequentially proceeding with the work of heat sealing and welding and integration using a slab, but this is only an example and is particularly limited to such methods and devices is not.

  In the present invention, the method for forming the rib 5 is not limited to the above-described partial folding process, and other methods may be employed.

  The second exterior material 31 includes a heat-resistant resin stretched film layer 2 as an outer layer, a thermoplastic resin unstretched film layer 3 as an inner layer, and a metal foil layer 4 disposed between these two film layers. It is the structure which contains (refer FIG. 2).

  The second exterior member 41 includes a housing case 42 having a housing recess 42a capable of housing the electrochemical device main body 10 by press molding such as cold press molding, and an opening on the upper surface side of the housing case 42. The three-dimensional molded body 41 </ b> A is provided with a sealing peripheral edge portion 43 extending outward from the peripheral edge in a substantially horizontal direction (see FIGS. 2 and 4).

  The storage case 42 has side walls 42Y erected from each of the four sides of the bottom wall 42X having a substantially rectangular shape in plan view, and the upper surface is opened. The thermoplastic resin unstretched film layer 3 constitutes the inner surface of the housing case 42 of the three-dimensional molded body 41A (exposed to the inner space of the housing case 42), and constitutes the outer surface of the housing case 42. The heat-resistant resin stretched film layer 2 is exposed (exposed to the outside) (see FIG. 2).

  As shown in FIG. 4, a positive electrode tab 31, a positive electrode tab film 32, a negative electrode tab 33, and a negative electrode tab film 34 are attached to the electrochemical device main body 10.

  As shown in FIGS. 3 and 4, the electrochemical device body 10 having a substantially rectangular parallelepiped shape is housed in the housing case 42 of the three-dimensional molded body 41 </ b> A made of the second exterior material 41, and the electrochemical device body The first exterior material (exterior material with ribs) 1 is disposed on the portion 10 with the inner layer 3 side inward (lower side), and the peripheral portion of the inner layer 3 of the first exterior material 1; The electrochemical device 20 of the present invention is configured by sealing and sealing the inner layer 3 of the sealing peripheral edge 43 of the three-dimensional molded body 41A (second exterior material 41) by heat sealing. Yes.

  In FIG. 3, 13 is a heat seal part formed by the peripheral part of the first exterior material 1 and the peripheral part 43 for sealing of the three-dimensional molded body 41A. FIG. 5 is a cross-sectional view showing a seal joining state at the heat seal portion 13. As shown in FIG. 5, in the heat seal part 13, no gap remains between the first exterior material 1 and the second exterior material 41, that is, the welding of the inner layers 3 in the heat seal part 13. There are no gaps in the portion 14, and therefore, leakage of contents such as the electrolyte can be sufficiently prevented.

  In the electrochemical device 20, the ribbed exterior material 1 is used as the exterior material constituting the lid. Therefore, in the electrochemical device (battery or the like) 20, the first exterior material due to the residual stress of the electrodes 31 and 33 is used. 1. Sufficient swelling of the first exterior material 1 and the second exterior material 41 due to warp deformation of the second exterior material 41 (warp deformation of the electrodes 31 and 33) and an increase in internal pressure caused by gas generated by decomposition of the electrolyte or the like Can be prevented.

  In the present invention, the height H of the rib 5 is preferably set to 0.5 mm to 5 mm. When the height of the rib 5 is 0.5 mm or more, warpage deformation of the exterior materials 1 and 41 (the warpage deformation of the electrode due to the residual stress of the electrode) that covers the electrochemical device main body 10, and the exterior materials 1 and 41. Can be sufficiently prevented, and the overall thickness of the electrochemical device (battery or the like) 20 can be suppressed when the height is 5 mm or less. Among them, the height H of the rib 5 is particularly preferably set to 1 mm to 2 mm.

  The rib 5 is preferably provided in a plurality of strips (plural) in the ribbed exterior material (first exterior material) 1. In this case, in the electrochemical device 20, it is possible to further improve the effect of preventing the warping deformation of the outer packaging materials 1 and 41 (the warping deformation of the electrode due to the residual stress of the electrodes) and the swelling of the outer packaging materials 1 and 41.

  Especially, it is more preferable that 2 to 20 (2 to 20) of the ribs 5 are provided in the ribbed exterior material (first exterior material) 1. The complexity of the folding process can be suppressed by setting the number to 20 or less, and the peripheral edge of the inner layer 3 of the first exterior material 1 and the peripheral edge for sealing of the second exterior material 41 (three-dimensional molded body 41A). When the heat-sealing is performed by superimposing the 43 inner layers 3 on each other, a uniform heat-sealing can be realized, and the gaps in the welded joints 14 between the inner layers 3 in the heat-sealing part 13 can be prevented more sufficiently. As a result (see FIG. 5), the effect that the leakage of the content solution such as the electrolytic solution can be more sufficiently prevented can be obtained.

  The thickness of the ribbed exterior material (first exterior material) 1 is preferably set to 0.05 mm to 0.3 mm. When the thickness is 0.05 mm or more, the thickness of the rib 5 can be sufficiently secured to sufficiently prevent the warp deformation and swelling of the exterior material, and when the thickness is 0.3 mm or less, the rib 5 can be formed by folding. It becomes easy.

  In the first exterior material (exterior material with ribs) 1 and the second exterior material 41 (three-dimensional molded body 41A), the laminated structure is preferably as follows. That is, the heat-resistant resin stretched film layer (outer layer) 2 is laminated and integrated on the upper surface of the metal foil layer 4 via a first adhesive layer (not shown), and the second surface on the lower surface of the metal foil layer 4. It is preferable to employ a laminated structure in which the thermoplastic resin unstretched film layer (inner layer) 3 is laminated and integrated through an adhesive layer (not shown) (see FIGS. 1 and 2).

  The heat-resistant resin stretched film layer (outer layer) 2 is not particularly limited, and examples thereof include stretched polyamide films such as stretched nylon films and stretched polyester films. Among them, the heat-resistant resin stretched film layer 2 includes a biaxially stretched polyamide film such as a biaxially stretched nylon film, a biaxially stretched polybutylene terephthalate (PBT) film, a biaxially stretched polyethylene terephthalate (PET) film, or a biaxially stretched film. It is particularly preferable to use a polyethylene naphthalate (PEN) film. The nylon film is not particularly limited, and examples thereof include 6 nylon film, 6,6 nylon film, MXD nylon film, and the like. The heat-resistant resin stretched film layer 2 may be formed as a single layer or, for example, a multilayer composed of a stretched polyester film / stretched polyamide film (a multilayer composed of a stretched PET film / stretched nylon film, etc.) ).

  The heat-resistant resin stretched film layer 2 preferably has a thickness of 9 μm to 50 μm. When using a stretched polyester film, the thickness is preferably 9 μm to 50 μm, and when using a stretched nylon film, the thickness is preferably 15 μm to 50 μm. By setting it above the preferred lower limit value, it is possible to ensure sufficient strength as the exterior materials 1 and 41, and by setting it below the preferred upper limit value, the weight energy density of the electrochemical device (battery etc.) is improved and the cost is reduced. Can be realized.

  The thermoplastic resin unstretched film layer (inner layer) 3 has excellent chemical resistance against a highly corrosive electrolytic solution used in a lithium ion secondary battery or the like, and the exterior materials 1 and 41. It plays a role of imparting heat-sealing properties.

  The thermoplastic resin unstretched film layer 3 is not particularly limited, but is at least one heat selected from the group consisting of polyethylene, polypropylene, olefin copolymers, acid-modified products thereof, and ionomers. It is preferably composed of an unstretched film made of a plastic resin.

  The thickness of the thermoplastic resin unstretched film layer (inner layer) 3 is preferably set to 0.02 mm to 0.1 mm. When the thickness is 0.02 mm or more, the peripheral portion of the inner layer 3 of the first exterior member 1 and the inner layer 3 of the peripheral portion 43 for sealing of the second exterior member 41 (three-dimensional molded body 41A) are combined. When overlapping and heat-sealing, it is possible to sufficiently prevent a gap from remaining in the welded joint portion 14 between the inner layers 3 in the heat-sealed portion 13 and to sufficiently prevent leakage of the content liquid (electrolyte solution or the like). Moreover, it can fully prevent that welding becomes inadequate by heat shortage by the heat insulation at the time of heat sealing because thickness is 0.1 mm or less. The thermoplastic resin unstretched film layer 3 may be a single layer or a multilayer.

  The metal foil layer 4 plays a role of imparting gas barrier properties to the exterior materials 1 and 41 to prevent entry of oxygen and moisture. Although it does not specifically limit as said metal foil layer 4, For example, aluminum foil, copper foil, etc. are mentioned, Aluminum foil is generally used. Among these, it is preferable to use a hard aluminum foil. The thickness of the metal foil layer 4 is preferably 20 μm to 100 μm. When it is 20 μm or more, generation of pinholes during rolling when producing a metal foil can be prevented, and when it is 100 μm or less, the weight energy density of an electrochemical device (battery or the like) can be improved and the cost can be reduced.

The metal foil layer 4 is preferably subjected to chemical conversion treatment on at least the inner surface (the surface on the inner layer 3 side). By performing such a chemical conversion treatment, corrosion of the metal foil surface by the contents (battery electrolyte or the like) can be sufficiently prevented. For example, the metal foil is subjected to chemical conversion treatment by the following treatment. That is, for example, on the surface of the metal foil that has been degreased,
1) Aqueous solution comprising a mixture of phosphoric acid, chromic acid and fluoride metal salt 2) Aqueous solution comprising a mixture of phosphoric acid, chromic acid, fluoride metal salt and non-metal salt 3) Acrylic resin and / or phenolic resin Then, a chemical conversion treatment is performed by applying one of an aqueous solution composed of a mixture of phosphoric acid, chromic acid, and a fluoride metal salt and then drying.

  Although it does not specifically limit as said 1st adhesive bond layer, For example, the adhesive bond layer etc. which were formed with the 2 liquid reaction type adhesive agent are mentioned. Examples of the two-component reactive adhesive include a first liquid composed of one or more polyols selected from the group consisting of polyurethane polyols, polyester polyols and polyether polyols, and a second liquid composed of isocyanate. And a two-component reactive adhesive composed of a liquid (curing agent). That is, when described by the type of adhesive after reaction, the first adhesive layer is not particularly limited. For example, a polyurethane adhesive layer, a polyester polyurethane adhesive layer, a polyether polyurethane adhesive layer, etc. Is mentioned. The first adhesive layer may be, for example, an adhesive such as the two-component reactive adhesive on the upper surface of the metal foil layer 4 and / or the lower surface of the stretched heat-resistant resin film layer 2 by a gravure coating method or the like. It is formed by applying by the above method.

  The second adhesive layer is not particularly limited. For example, a polyurethane adhesive, an acrylic adhesive, an epoxy adhesive, a polyolefin adhesive, an elastomer adhesive, a fluorine adhesive, and the like. The adhesive layer formed by (1) is mentioned. Among them, it is preferable to use an acrylic adhesive or a polyolefin adhesive. In this case, the electrolytic solution resistance and the water vapor barrier property of the exterior materials 1 and 41 can be improved.

  In addition, in the said embodiment, although the structure which provided the 1st adhesive bond layer and the 2nd adhesive bond layer is employ | adopted, neither of these layers is an essential structure layer, and the structure which does not provide these is employ | adopted. You can also

  The electrochemical device body 10 is not particularly limited, and examples thereof include a battery body, a capacitor body, and a capacitor body. As the electrochemical device main body 10, one having a thickness T of 0.5 mm to 10 mm is usually used (see FIG. 4), but is not particularly limited to this thickness.

  The width of the heat seal portion 13 is preferably set to 0.5 mm or more. Sealing can be reliably performed by setting it as 0.5 mm or more. Especially, it is preferable to set the width | variety of the said heat seal part 13 to 3 mm-15 mm.

  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 (outer layer) 2 having a thickness of 25 μm is bonded to one surface of a soft aluminum foil 4 defined by JIS A8079 having a thickness of 40 μm via a polyester-urethane adhesive (two-component curing type). Then, an unstretched polypropylene film (inner layer) 3 having a thickness of 40 μm is bonded to the other surface of the soft aluminum foil 4 via a polyolefin adhesive (two-component curing type), and then placed in a constant temperature bath at 40 ° C. Two laminates obtained by performing curing for 3 days were prepared.

  Next, by embossing one of the laminates, a storage case 42 formed into a three-dimensional shape (a substantially rectangular parallelepiped shape with an open top surface) having a length of 54 mm, a width of 33 mm, and a depth of 4 mm, and an upper surface opening port of the storage case A solid molded body 41A having a sealing peripheral portion 43 with a width of 5 mm extended from the peripheral edge of the outer periphery toward the outer side in a substantially horizontal direction was obtained (see FIGS. 2 and 4).

  Further, after punching out the other laminate to a size of 80 mm in length and 53 mm in width, the laminate is partially folded at intervals of 10 mm in the longitudinal direction, thereby extending along the transverse direction. Three protrusions (scheduled ribs) having a height of 1 mm were formed on the outer layer side, and then both sides of the protrusions were sandwiched by a pair of 200 ° C. hot plates for 3 seconds, The inner layers 3 and 3 overlapped by the folding process inside are welded and joined, and three (three) ribs 5 (height H is 1 mm) are vertically arranged on the surface on the outer layer 2 side. The ribbed exterior material 1 provided in parallel in the lateral direction with a space was obtained (reference diagram: FIGS. 1 and 3) (In FIGS. 1 and 3, the number of ribs formed is 6) However, in Example 1, the number of ribs formed is three).

  Also, by laminating 40 sheets of soft aluminum foil with a thickness of 30 μm, polypropylene film with a thickness of 30 μm, and soft copper foil with a thickness of 30 μm and punched into a size of 52 mm in length and 31 mm in width A simulated product of the battery body 10 having a substantially rectangular parallelepiped shape was created.

As shown in FIGS. 3 and 4, after the battery main body (simulated product) 10 is put in the accommodating recess 42 a of the three-dimensional molded body 41 </ b> A, an electrolytic solution (ethylene carbonate: dimethylene carbonate) is formed on the upper surface of the battery main body 10. : An electrolyte having a LiPF ₆ concentration of 1 mol / L obtained by adding LiPF ₆ to a mixed carbonate in which dimethyl carbonate is mixed at a volume ratio of 1: 1: 1. 5 mL of a liquid added with water at a concentration of 5000 ppm is dropped, and then the outer packaging material 1 with ribs is placed on the battery body 10 with the inner layer 3 side inward (downward) (that is, on the rib forming side). Then, the peripheral portion of the ribbed outer packaging 1 and the sealing peripheral portion 43 of the three-dimensional molded body 41A are placed under a reduced pressure of 0.086 MPa. , Gold heated to 200 ° C A battery (simulated product) having the structure shown in FIG. 3 was obtained by heat sealing for 2 seconds with a heat plate made of a metal.

<Example 2>
A battery (simulated product) was obtained in the same manner as in Example 1 except that the interval between adjacent ribs was 5 mm and the number of ribs formed was 10 (10). The height H of the rib is 1 mm as in the first embodiment.

<Example 3>
The laminated body constituting the ribbed exterior material 1 has a thickness of 12 μm on one surface of a hard aluminum foil 4 defined by JIS A3003 with a thickness of 30 μm via a polyester-urethane adhesive (two-component curing type). The stretched polyethylene terephthalate film (outer layer) 2 is bonded, and the other surface of the hard aluminum foil 4 is unstretched polypropylene film (inner layer) having a thickness of 40 μm via a polyolefin adhesive (two-component curing type). 3) A battery (simulated product) having the structure shown in FIG. 3 was obtained in the same manner as in Example 1 except that the laminate with 3 bonded was used.

<Comparative Example 1>
A battery (simulated product) was obtained in the same manner as in Example 1 except that a ribless exterior material (planar laminate before forming ribs in Example 1) was used instead of the ribbed exterior material 1. It was. Therefore, in the electrochemical device of Comparative Example 1, no rib is provided on the outer package.

  Each battery (simulated product) obtained as described above was evaluated for deformation prevention based on the following test method. The results are shown in Table 1.

<Deformation prevention test method>
Nine samples were prepared for each example and comparative example, and the thickness T of each sample (battery) was measured in advance with a digital caliper. Place three each in a constant temperature bath at 60 ° C., a constant temperature bath at 60 ° C., and a constant temperature bath at 80 ° C., and after 24 hours have passed in this state, take out the samples from the constant temperature bath, Measure the thickness of the sample (battery) with a vernier caliper (the maximum value of the thickness when there is a difference in the thickness at the measurement position).
Deformation rate (%) = {(thickness after test) − (thickness before test)} ÷ (thickness before test) × 100
The deformation rate (%) was obtained from the above formula.

  Note that the amount of gas generated inside the sample (battery) placed in a constant temperature bath having a higher temperature is larger.

  As is clear from Table 1, from the comparison results under the same temperature conditions, in the batteries of Examples 1 to 3 of the present invention in which the ribbed outer packaging material was used as the lid material, the ribless outer packaging material was used as the lid material. Compared with the constructed battery of Comparative Example 1, the deformation rate is suppressed to be sufficiently small, and it can be seen that warpage deformation and swelling of the exterior material can be sufficiently prevented.

  In particular, in the battery of Example 3 having a configuration using a hard aluminum foil as the metal foil layer of the ribbed exterior material, even under high temperature conditions of 60 ° C. and 80 ° C. (even if the amount of gas generated inside increases) Compared with the battery of Comparative Example 1, the deformation rate is remarkably reduced, and it can be seen that the warping deformation and swelling of the exterior material can be more sufficiently suppressed than in Examples 1 and 2.

  The ribbed outer packaging material for electrochemical devices of the present invention is suitably used, for example, as a battery outer packaging material or a capacitor outer packaging material, but is not particularly limited to such applications.

The electrochemical device according to the present invention is, for example,
1) Lithium polymer batteries, lithium ion batteries, lithium ion capacitors, electric double layer capacitors used for mobile devices such as smartphones and tablets 2) Power sources for hybrid cars, electric cars, etc. 3) Wind power generation, solar power generation, nighttime electricity However, it is not particularly limited to such applications.

1 ... 1st exterior material (exterior material with ribs)
2 ... Heat-resistant resin stretched film layer (outer layer)
3 ... Unstretched thermoplastic resin film layer (inner layer)
4 ... Metal foil layer 5 ... Rib (projection)
6 ... welding joint 10 between inner layers in rib ... electrochemical device body 13 ... heat sealing part 14 ... welding joining (joining interface) between inner layers in heat sealing part
DESCRIPTION OF SYMBOLS 20 ... Electrochemical device 41 ... 2nd exterior material 41A ... Three-dimensional molded object 42 ... Housing case 43 ... Peripheral part for sealing

Claims (7)

A first exterior material comprising a heat-resistant resin stretched film layer as an outer layer, a thermoplastic resin unstretched film layer as an inner layer, and a metal foil layer disposed between these two film layers;
A second exterior material comprising a heat-resistant resin stretched film layer as an outer layer, a thermoplastic resin unstretched film layer as an inner layer, and a metal foil layer disposed between these two film layers;
An electrochemical device body, and
One or more ribs project from the outer layer side surface of the first exterior material,
The second exterior material includes a storage case that can store the electrochemical device main body, and a sealing peripheral edge that extends outward in a substantially horizontal direction from the peripheral edge of the upper surface opening of the storage case. Formed into a three-dimensional shape having
The electrochemical device main body is accommodated in a housing case for the second exterior material, and the first exterior material is disposed on the electrochemical device main body with the inner layer side inward, An electrochemical device, wherein a peripheral portion of an inner layer of the exterior material and an inner layer of a sealing peripheral portion of the second exterior material are bonded and sealed.   The electrochemical device according to claim 1, wherein a height of the rib is 0.5 mm to 5 mm.   The electrochemical device according to claim 1, wherein a plurality of the ribs are provided in the first exterior material. The rib is formed by protruding a laminated material including the outer layer, the inner layer and the metal foil layer by being partially folded.
The electrochemical device according to any one of claims 1 to 3, wherein inner layers overlapped by the folding process inside the rib are welded and joined.   The electrochemical device according to claim 4, wherein the first exterior material has a thickness of 0.05 mm to 0.3 mm.   The electrochemical device according to claim 4 or 5, wherein the thickness of the inner layer of the first exterior material is 0.02 mm to 0.1 mm.   The electrochemical device according to any one of claims 1 to 6, wherein a hard aluminum foil is used as the metal foil layer of the first exterior material.

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