JP6697227B2 - Power storage device - Google Patents

Description

  The present invention relates to a power storage device mounted on various devices.

  In the present specification, the term “aluminum” is used to include Al and Al alloys, the term “copper” is used to include Cu and Cu alloys, and the term “nickel” is Ni and It is used to include a Ni alloy, and the term "titanium" is used to include Ti and a Ti alloy. In addition, in the present specification, the term “metal” is used to include simple metals and alloys.

  Lithium ion secondary batteries and lithium polymer secondary batteries used in batteries for hybrid vehicles and electric vehicles, stationary storage batteries for home and industrial use are made of metal, which has been used in the past due to miniaturization and weight reduction. Instead of the above, a laminated exterior material in which a resin film is attached to both surfaces of a metal foil is often used. Further, mounting of an electric double layer capacitor using a laminated exterior material, a lithium ion capacitor, or the like on an automobile or a bus is also being considered (see Patent Document 1).

  The size and capacity of the power storage device are designed by the battery manufacturer for the power storage device alone. For this reason, when designing a device equipped with a power storage device by a device manufacturer, either design it in a dedicated power storage device again in order to efficiently install it in the device or to obtain the capacity required for the device, or adapt it to an existing power storage device. Work is progressing in the process of designing the loading space in the device.

JP, 2013-161674, A

  The above-mentioned device design is wasteful, and efficient design of the device incorporating the power storage device is required.

  The present invention has been made in view of such technical background, and an object of the present invention is to provide an electricity storage device whose size and capacity can be easily changed.

  That is, the present invention has the configurations described in [1] to [6] below.

[1] A first heat resistant resin layer is laminated on one surface of the first metal foil via a first adhesive layer, and a first thermoplastic resin layer is laminated on the other surface via a third adhesive layer. And a first exterior material having a first metal foil inner exposed portion where the first metal foil is exposed on the surface of the first thermoplastic resin layer side,
A second heat resistant resin layer is laminated on one surface of the second metal foil via a second adhesive layer, and a second thermoplastic resin layer is laminated on the other surface via a fourth adhesive layer, A second exterior material having a second metal foil inner exposed portion where the second metal foil is exposed on the surface of the second thermoplastic resin layer side,
A battery element having a positive electrode active material layer laminated on the first metal foil inner exposed portion, a negative electrode active material layer laminated on the second metal foil inner exposed portion, and a separator arranged between them. ,
The first thermoplastic resin layer of the first exterior material and the second thermoplastic resin layer of the second exterior material face each other, and the heat sealing portion in which the first thermoplastic resin layer and the second thermoplastic resin layer are fused to each other. By being surrounded by, the exterior body having a plurality of battery element chambers facing the first metal foil inner exposed portion and the second metal foil inner exposed portion is formed in the room,
The battery element enclosed with the electrolyte in the battery element chamber, the positive electrode active material layer is conducted to the first metal foil inner exposed portion and the negative electrode active material layer is conducted to the second metal foil inner exposed portion,
In the heat-sealed portion between the adjacent battery element chambers, the first exterior material has a first non-adhesive portion in which the first adhesive layer does not exist between the first metal foil and the first heat resistant resin layer, The electricity storage device, wherein the second exterior material has a second non-adhesive portion where the second adhesive layer does not exist between the second metal foil and the second heat resistant resin layer.

  [2] The first exterior material has a first metal foil outer exposed portion where the first metal foil is exposed without the first heat-resistant resin layer facing the first non-adhesive portion, and the second exterior material is 2. The electricity storage device according to item 1 above, which has a second metal foil outer exposed portion where the second metal foil is exposed without the second heat resistant resin layer facing the second non-adhesive portion.

  [3] The electricity storage device according to the above item 2, wherein the first metal foil outer side exposed portion and the second metal foil outer side exposed portion are covered with an insulating sheet.

  [4] The first exterior material has a first metal foil removal portion in which a part of the first metal foil facing the first non-adhesion portion is removed, and the second exterior material is the second non-adhesion portion. Having a second metal foil removing portion in which a part of the second metal foil facing to is removed, and in the stacking direction of the first exterior material and the second exterior material, the first metal foil removing portion and the second metal The electricity storage device according to any one of the preceding items 1 to 3, wherein the foil removal portion is formed at a position where the first metal foil and the second metal foil do not overlap each other.

  [5] The first exterior material has a third non-adhesive portion where the third adhesive layer does not exist at a symmetrical position of the first non-adhesive portion with the first metal foil sandwiched therebetween, and the second exterior material is the second 5. The electricity storage device according to any one of items 1 to 4 above, which has a fourth non-adhesive portion in which the fourth adhesive layer does not exist at a symmetrical position of the second non-adhesive portion with the metal foil interposed therebetween.

  [6] The first paragraph 5 which has an unfused part where the first thermoplastic resin layer and the second thermoplastic resin layer are not fused between the first non-bonded part and the second non-bonded part. The electric storage device according to any one of 1.

Electric storage device according to the above [1], the first metal foil and the second metal foil is connected in all the cell element compartment is an electrode, and since all the batteries element chamber is sealed in each cell element chamber It can be cut at any heat-sealed portion in between and divided into any size. Since the first non-adhesive portion without the first adhesive layer and the second non-adhesive portion without the second adhesive layer are formed in the heat-sealing portion, at the cut end of the divided power storage device, The first heat-resistant resin layer facing the first non-adhesive portion is removed to form the first metal foil outside exposed portion, and the second heat-resistant resin layer facing the second non-adhesive portion is removed to remove the second metal foil. The outer exposed portion is formed, and these can be used as a positive electrode terminal and a negative electrode terminal. Thus, a plurality of power storage devices obtained by division can be used as the dimension and capacity of the devices according to their batteries elements rooms, it is possible to easily produce a different storage device capacity and dimensions. As a result, one power storage device can be supplied as a device to be mounted on a plurality of types of devices having different capacities and storage spaces.

  In the electricity storage device according to the above [2], there is no first heat-resistant resin layer facing the first non-adhesive portion, the first metal foil outer exposed portion where the first metal foil is exposed, and the second non-adhesive portion facing the first non-adhesive portion. (2) Since there is no heat-resistant resin layer and the second metal foil outer exposed portion where the second metal foil is exposed, the divided power storage device has the first metal foil outer exposed portion and the second metal foil outer exposed portion as electrodes. It can be used as it is as a terminal.

  In the electricity storage device according to the above [3], the outer exposed portion of the first metal foil and the outer exposed portion of the second metal foil are covered with an insulating sheet, so that the insulating property is maintained and deterioration due to solvent adhesion or the like is prevented. You can

The electric storage device according to [4], the lamination of the first non-first metal foil removed portion of the adhesive portion and the second metal foil removed portion of the second non-bonded portion, the first exterior member and the second exterior member Since the first metal foil and the second metal foil are formed at positions where they do not overlap each other in the direction, when the power storage device is cut at the heat-sealed portion or at the cut surface, the first metal foil and the second metal foil do not overlap. It is possible to prevent intentional contact and prevent short circuit.

  In the electricity storage device according to the above [5] and [6], at the cut end of the divided electricity storage device, the first metal foil that is the positive electrode terminal and the second metal foil that is the negative electrode terminal are independently set at arbitrary angles. Since it can be bent, there are less restrictions on the posture of loading the device and the posture of connecting to other devices.

It is a top view of the 1st electrical storage device concerning this invention. It is the 1B-1B sectional view taken on the line of FIG. 1A. FIG. 1B is a cross-sectional view of an electricity storage device obtained by dividing the electricity storage device of FIG. 1A. It is a fragmentary sectional view of the 2nd electricity storage device concerning the present invention. It is a partial cross section figure of the 3rd electrical storage device concerning this invention. It is a top view of the 4th electrical storage device concerning this invention. FIG. 5B is a sectional view taken along line 5B-5B of FIG. 5A. It is a partial cross section figure of the 5th electrical storage device concerning this invention. FIG. 7 is a sectional view of an electricity storage device obtained by dividing the electricity storage device of FIG. 6. It is a fragmentary sectional view of the 6th electricity storage device concerning the present invention.

  1A to 2 show a basic form of an electricity storage device of the present invention, and FIGS. 3 to 8 show electricity storage devices of modified examples thereof.

In the following description, the same reference numerals indicate the same things, and duplicate explanations are omitted.
[First power storage device]
In the electricity storage device 1 shown in FIGS. 1A and 1B, the exterior body 30 is composed of the first exterior material 10 and the second exterior material 20, and is divided into 5 × 4 by the heat sealing parts 50 and 51. It has a battery element chamber 40. A battery element 60 and an electrolyte (no reference numeral) are enclosed in each battery element chamber 40. The heat-sealing unit 50 is a heat-sealing unit located on the outer periphery of the electricity storage device 1, and the heat-sealing unit 51 is a heat-sealing unit located between the adjacent battery element chambers 40. The sealing portion 51 is formed in a lattice shape. In addition, the partially enlarged view in FIG. 1B is a diagram showing the heat-sealed portion 51 in an enlarged manner compared to other portions in order to explain the structure of the heat-sealed portion 51, and is a diagram showing at a constant enlargement ratio. is not. The same applies to other cross-sectional views.

  In the first exterior material 10, the first heat-resistant resin layer 12 is laminated on one surface of the first metal foil 11 via the first adhesive layer 15, and the third adhesive layer 16 is laminated on the other surface. Is a laminated material in which the first thermoplastic resin layer 13 is laminated. In the first exterior material 10, the first thermoplastic resin layer 13 is removed and the third adhesive layer 16 is not provided on the first thermoplastic resin layer 13 at a portion corresponding to the battery element chamber 40 on the surface on the first thermoplastic resin layer 13 side. A first metal foil inner exposed portion 14 where the metal foil 11 is exposed is formed. Further, in the portion corresponding to the heat-sealed portion 51, the first adhesive layer 15 does not exist in the middle portion in the width direction of the heat-sealed portion 51, and the first metal foil 11 and the first heat resistant resin layer 12 are formed. A first non-adhesive portion 17a is formed which is not adhered.

  In the second exterior material 20, the second heat resistant resin layer 22 is laminated on one surface of the second metal foil 21 with the second adhesive layer 25 interposed therebetween, and the fourth adhesive layer 26 is interposed on the other surface thereof. The second thermoplastic resin layer 23 is a laminated material. In the second outer packaging material 20, the second thermoplastic resin layer 23 is removed and the fourth adhesive layer 26 is not provided in the second thermoplastic resin layer 23 at a portion corresponding to the battery element chamber 40 on the second thermoplastic resin layer 23 side. A second metal foil inner exposed portion 24 is formed to expose the metal foil 21. Further, in the portion corresponding to the heat sealing portion 51, the second adhesive layer 25 does not exist in the middle portion in the width direction of the heat sealing portion 51, and the second metal foil 21 and the second heat resistant resin layer 22 are formed. The second non-adhesive portion 27a which is not adhered is formed. The first non-adhesive portion 17a and the second non-adhesive portion 27a are formed at the same position in a plan view of the electricity storage device 1.

  The battery element 60 is composed of a positive electrode active material layer 61, a separator 62, a negative electrode active material layer 63 and layers associated therewith. The positive electrode active material layer 61 is laminated on the first metal foil inner exposed portion 14 of the first exterior material 10 via the binder layer 64, and the negative electrode active material layer 63 is the second metal foil inner exposed portion 24 of the second exterior material 20. Is laminated via a binder layer 65.

  The battery element chamber 40 is assembled by facing the first thermoplastic resin layer 13 of the first exterior material 10 and the second thermoplastic resin layer 23 of the second exterior material 20 with the separator 62 in between. 40 is sealed by forming a heat-sealed portion 50, 51 in which the first thermoplastic resin layer 13 and the second thermoplastic resin layer 23 are fused by heat-sealing the periphery in a state where the electrolyte is injected. ing. The battery element chamber 40 is a space occupied by the binder layer 64, the positive electrode active material layer 61, the separator 62, the negative electrode active material layer 63, the binder layer 65, and the electrolyte. The separator 62 needs to have a size that covers at least the first metal foil inner exposed portion 14 and the second metal foil inner exposed portion 24 in order to reliably separate the positive electrode active material layer 61 and the negative electrode active material layer 63, and is preferable. Is preferably enlarged to a size overlapping the heat-sealed portions 50 and 51. Further, in the electricity storage device 1 having the plurality of battery element chambers 40 as in the present embodiment, a plurality of battery elements are provided across the heat sealing parts 50 and 51 instead of using separate separators for each battery element chamber 40. A large size separator 62 that can cover the chamber 40 can be used. The electricity storage device 1 uses one separator 62 for each of the 20 battery element chambers 40, and the separator 62 is also sandwiched between the entire regions of the heat-sealed portions 50 and 51.

  The positive electrode active material layer 61 constituting the battery element 60 is laminated on the first metal foil inner exposed portion 14, and the negative electrode active material layer 63 is laminated on the second metal foil inner exposed portion 24. The outer casing 30 and the battery are assembled by a process of assembling three members, that is, the first outer casing 10 provided with 61, the second outer casing 20 provided with the negative electrode active material layer 63, and the separator 62, and injecting an electrolyte and heat sealing. The electricity storage device 1 is manufactured in a state where the element 60 and the element 60 are integrated.

  In the electricity storage device 1, the first metal foil 11 of the first exterior material 10 serves as a positive electrode and the second metal foil 21 of the second exterior material 20 serves as a negative electrode, which are isolated by the separator 62 in each battery element chamber 40. Has been done.

The electricity storage device 1 is connected first metal foil 11 and the second metal foil 21 is an electrode that in all batteries element chamber 40, and since all the batteries element chamber 40 is sealed in each of any heat It can be cut and divided at the sealing portion 51. Cutting can be easily done with scissors or a cutter.

  As shown in FIG. 2, the divided power storage device 1a forms an electrode terminal by using the first non-adhesive portion 17a and the second non-adhesive portion 27a at the cut ends. Since the first adhesive 15 does not exist in the first non-adhesive portion 17a and the first heat-resistant resin layer 12 and the first metal foil 11 are not joined, the first heat-resistant resin facing the first non-adhesive portion 17a. Layer 12 can be easily excised. By removing the first heat resistant resin layer 12, the first metal foil 11 is exposed to form the first metal foil outer exposed portion 18, and the first metal foil outer exposed portion 18 is used as a positive electrode terminal. Similarly, the second metal foil outer exposed portion 28 formed by removing the second heat resistant resin layer 22 facing the second non-adhesive portion 27a is used as a negative electrode terminal. Since the first non-adhesive portion 17a and the second non-adhesive portion 27a are present at all the cut ends of the electricity storage device 1a, the first metal foil outer exposed portion 18 and the second metal foil are located at any of these positions. The outer exposed portion 28 can be formed. The first metal foil outer side exposed portion 18 and the second metal foil outer side exposed portion 28 can be formed on the same side or on different sides. Since the first non-adhesive portion 17a is covered and protected by the first heat-resistant resin layer 12 unless the first heat-resistant resin layer 12 is removed, insulation is maintained and solvent adhesion and the like are maintained. Is prevented from deterioration. The same applies to the second non-adhesive portion 27a.

As described above, the plurality of power storage devices 1a obtained by division can be used as the dimension and capacity of the device according to the 40 count batteries element chamber thereof. This makes it possible to easily manufacture power storage devices having different capacities and dimensions, and supply one power storage device as a device to be mounted in a plurality of types of devices having different capacities and storage spaces.

  The electricity storage device 2 shown in FIG. 3 does not have the first heat-resistant resin layer 12 facing the first non-adhesive layer 17a, but the first metal foil outer exposed portion 18 is formed. Similarly, the second heat resistant resin layer 22 that faces the second non-adhesive portion 27a is not provided, and the second metal foil outer exposed portion 28 is formed.

Since the electricity storage device 2 has the first metal foil outer exposed portion 18 and the second metal foil outer exposed portion 28 formed before division, it can be used as it is after division, and the work after division is easy. In addition, since electricity can be supplied even before division, it can be used as an electricity storage device having a size before division. In addition, the first metal foil outer exposed portion 18 and the second metal foil outer exposed portion 28 which are not used as the electrode terminals can maintain the insulating property and prevent deterioration by a simple method such as attaching an insulating sheet.
[Third electricity storage device]
The electricity storage device 3 in FIG. 4 is a device in which insulating sheets 70 are attached to both surfaces of the electricity storage device 2 in FIG. The insulating sheet 70 protects the first metal foil outer side exposed portion 18 and the second metal foil outer side exposed portion 28 to maintain insulation and prevent deterioration due to solvent adhesion and the like. After the electric storage device 3 is divided into the required size, the insulating sheet 70 of the portion used as an electrode terminal is peeled off to expose the first metal foil outer side exposed portion 18 and the second metal foil outer side exposed portion 28. By leaving the insulating sheet 70 in the portion not used as the electrode terminal, the insulating property can be maintained and the deterioration can be prevented.

The insulating sheet 70 may be attached only on the first metal foil outer exposed portion 18 and the second metal foil outer exposed portion 28, or may be attached to the entire surface.
[Fourth power storage device]
In the electricity storage device 4 of FIGS. 5A and 5B, the first exterior material 10 has a first metal foil removal portion 19 formed by removing a part of the first metal foil 11 facing the first non-adhesive portion 17a. However, the first metal foil outer exposed portion 18 and the first metal foil removed portion 19 face the first non-bonded portion 17a. Similarly, the second exterior material 20 has a second metal foil removing portion 29 formed by removing a part of the second metal foil 21 facing the second non-adhesive portion 27a, and the second non-adhesive portion 27a. The second metal foil outside exposed portion 28 and the first metal foil removed portion 29 face the above. The first metal foil removing section 19 and the second metal foil removing section 29 are arranged in the stacking direction of the first exterior material 10 and the second exterior material 20 with the first metal foil outside exposed portion 18 (first metal foil 11). The second metal foil outer exposed portion 28 (second metal foil 21) is formed at a position where it does not overlap.

  With the above configuration, when the electricity storage device 4 is cut by the heat-sealed portion 51 or at the cut surface, unintentional contact between the first metal foil 11 and the second metal foil 21 can be prevented, and a short circuit can be prevented.

The removed area of the first metal foil outer exposed portion 18 and the second metal foil outer exposed portion 28 is not limited as long as there remains an area that can be used as an electrode terminal. Therefore, as shown in FIG. 5A and FIG. 5B, the first metal foil removing portion 19 and the second metal foil removing portion 29 are formed at positions where they partially overlap each other, and the first metal foil 11 and the second metal foil 11 are formed. There is no inconvenience even if there is a portion where both of the foils 21 are removed.
[Fifth power storage device]
In the electricity storage device 5 of FIG. 6, the first outer packaging material 10 is disposed between the first metal foil 11 and the first thermoplastic resin layer 13 at a symmetrical position of the first non-adhesive portion 17a with the first metal foil 11 interposed therebetween. Has a third non-adhesive portion 17b where the third adhesive layer 16 does not exist. Similarly, the second exterior material 20 has a fourth adhesive between the second metal foil 21 and the second thermoplastic resin layer 23 at the symmetrical position of the second non-adhesive portion 27a with the second metal foil 21 interposed therebetween. It has a fourth non-adhesive portion 27b where the layer 26 does not exist. The first metal foil 11 and the first thermoplastic resin layer 13 are not bonded to each other in the third non-bonding portion 17b, and the second metal foil 21 and the second thermoplastic resin layer 23 are bonded to each other in the fourth non-bonding portion 27b. And are not dressed on his back.

FIG. 7 shows that, in the electricity storage device 5a obtained by dividing the electricity storage device 5, the first heat resistant resin layer 12 facing the first non-adhesive portion 17a and the second heat resistant resin layer 22 facing the second non-adhesive portion 27a are removed. The first metal foil outer side exposed portion 18 and the second metal foil outer side exposed portion 28 are formed. The first metal foil 11 of the first metal foil outer exposed portion 18 and the second metal foil 21 of the second metal foil outer exposed portion 28 are not bonded to the first thermoplastic resin layer 13 and the second thermoplastic resin layer 23. Therefore, the first metal foil 11 and the second metal foil 21 can be bent at arbitrary angles independent of each other. Therefore, there are less restrictions on the loading posture of the apparatus and the connecting posture with other devices.
[Sixth power storage device]
In the heat storage unit 51 of the electricity storage device 6 of FIG. 8, the first thermoplastic resin layer 13 and the second thermoplastic resin layer 23 between the first non-adhesive portion 17a and the second non-adhesive portion 27a are heat-insulated. It is not fused, and only the portion in contact with the battery element chamber 40 is thermally fused. In FIG. 8, the portion indicated by the thick solid line L1 is the unfused portion, and the portion indicated by the wavy line L2 is the fused portion. In addition, in the electricity storage device 6 of the present embodiment, the spacer 62 is provided over the entire area of the mating surface of the first exterior material 10 and the second exterior material 20, and the first thermoplastic resin layer 13, the second thermoplastic resin layer 23, and the spacer. Two of 62 are heat-sealed.

When the electricity storage device 6 is divided, the first metal foil 11 of the first metal foil outer exposed portion 18 can be bent at an arbitrary angle together with the first heat-fusible resin layer 13, and the second metal foil outer exposed portion 28 can be bent. The second metal foil 21 can be bent at an arbitrary angle together with the second heat-fusible resin layer 23. Since the first metal foil 11 and the second metal foil 21 can be bent independently at arbitrary angles, there are less restrictions on the loading posture in the apparatus and the connection posture with other devices.
[Materials and Fabrication of First Exterior Material and Second Exterior Material]
In the first exterior material 10, the first heat-resistant resin layer 12 is bonded to one surface of the first metal foil 11 via the first adhesive layer 15, and the other surface is bonded to the first adhesive layer 16 via the third adhesive layer 16. The first thermoplastic resin layer 13 is attached. The second heat-resistant resin layer 22 is bonded to one surface of the second metal foil 21 via the second adhesive layer 25, and the second exterior material 20 is bonded to the other surface via the fourth adhesive layer 26. The second thermoplastic resin layer 23 is attached. The preferred materials for each layer are as follows.

  A preferred material for the first metal foil 11 is a soft aluminum foil, and the thickness thereof is preferably 7 to 150 μm. A soft aluminum foil having a thickness of 30 to 80 μm is particularly preferable in terms of formability and cost. On the other hand, preferable materials for the second metal foil 21 are soft or hard aluminum foil, stainless steel foil, nickel foil, copper foil, and titanium foil. The preferable thickness of these foils is 7 to 150 μm, and 15 to 100 μm is preferable in terms of impact resistance, bending resistance and cost.

  Further, as the first metal foil 11 and the second metal foil 21, a plated foil or a clad foil can be used. For example, as the second metal foil 21, a plated foil obtained by plating copper with nickel or a clad foil of stainless steel and nickel can be used.

Further, it is preferable that a chemical conversion film is formed on the first metal foil layer 11 and the second metal foil layer 21. The chemical conversion film is a film formed by subjecting the surface of the metal foil to a chemical conversion treatment, and by performing such a chemical conversion treatment, corrosion of the metal foil surface due to the contents (electrolyte etc.) is sufficient. In addition, even in an exposed portion that serves as an electricity extraction window, discoloration or deterioration does not occur even if an electrolyte is attached when a device is manufactured, and the influence of corrosion due to moisture in the atmosphere can be reduced. The chemical conversion treatment layer itself has almost no conductivity, but since the coating film thickness is extremely small, there is almost no current resistance. For example, the metal foil is subjected to chemical conversion treatment by performing the following treatment. That is, on the surface of the metal foil subjected to degreasing treatment,
1) phosphoric acid,
Chromic acid,
An aqueous solution of a mixture containing at least one compound selected from the group consisting of metal salts of fluorides and non-metal salts of fluorides 2) phosphoric acid;
At least one resin selected from the group consisting of acrylic resins, chitosan derivative resins and phenolic resins;
An aqueous solution of a mixture containing at least one compound selected from the group consisting of chromic acid and chromium (III) salts 3) phosphoric acid;
At least one resin selected from the group consisting of acrylic resins, chitosan derivative resins and phenolic resins;
At least one compound selected from the group consisting of chromic acid and chromium (III) salts;
An aqueous solution of a mixture containing at least one compound selected from the group consisting of metal salts of fluorides and non-metal salts of fluorides, and the aqueous solution of any one of 1) to 3) above is applied to the surface of the metal foil. After working, it is dried to be subjected to chemical conversion treatment.

The conversion coating, chromium coating weight preferably is 0.1mg ^{/ m 2} ~50mg ^/ m 2 as a (per one surface), in particular ^2mg / ^{m 2 ~20mg} / m ² preferred.

  As the heat-resistant resin forming the first heat-resistant resin layer 12 and the second heat-resistant resin layer 22, a heat-resistant resin that does not melt at the heat sealing temperature when heat-sealing the exterior material is used. As the heat resistant resin, it is preferable to use a heat resistant resin having a melting point higher than the melting point of the thermoplastic resin constituting the thermoplastic resin layers 13 and 23 by 10 ° C. or more, and a melting point higher than the melting point of the thermoplastic resin by 20 ° C. or more. It is particularly preferable to use a heat resistant resin having For example, stretched films such as polyethylene naphthalate film, polybutylene naphthalate film, and polycarbonate film are preferable in addition to polyester film and polyamide film. Further, the thickness is preferably in the range of 9 to 50 μm.

  As the first thermoplastic resin layer 13 and the second thermoplastic resin layer 23, at least one thermoplastic resin selected from the group consisting of polyethylene, polypropylene, olefin copolymers, acid modified products thereof and ionomers. Is preferably an unstretched film having a thickness of 20 to 80 μm.

The adhesive constituting the first adhesive layer 15 and the second adhesive layer 25 is preferably a two-component curing type polyester polyurethane-based or polyether polyurethane-based adhesive, and the third adhesive layer 16 and the fourth adhesive. The adhesive forming the layer 26 is preferably a polyolefin-based adhesive in consideration of electrolyte resistance. The preferable coating amount of each adhesive is 1 to 5 g / m ² .

The first outer packaging material 10 and the second outer packaging material 20 form a polar material layer after the exposed portion of the metal foil is formed in the step of laminating each layer, or are extremely active on the metal foil in the step of laminating each layer. It can be manufactured by forming a material layer. Further, the first non-adhesive portion 17a, the second non-adhesive portion 27a, the third non-adhesive portion 17b, and the fourth non-adhesive portion 27b are also formed in the step of laminating. The details are as follows.
(I) A method of forming an exposed portion of the metal foil inside in a laminating step and then forming a polar active material layer. For example, in a step of laminating a metal foil and a resin layer by a dry laminating method, a portion to which an adhesive is not attached is An adhesive is applied using the engraved gravure roll to form a non-adhesive portion, and the metal foil and the resin layer are bonded together.

  The first exterior material 10 is formed by forming the adhesive uncoated portion at a position corresponding to the first metal foil inner exposed portion 14 and, if necessary, the third non-adhesive portion 17b by the above-described method. And the first thermoplastic resin layer 13 are bonded together. The exposed portion 14 of the first inside of the metal foil is formed by cutting off the first thermoplastic resin layer 13 on the adhesive uncoated portion formed at a predetermined position. The third non-adhesive portion 17b is formed by leaving the first thermoplastic resin layer 13 on the adhesive uncoated portion formed at a predetermined position without cutting. The opposite surface of the first metal foil 11 is formed with an adhesive uncoated portion at a position corresponding to the first non-adhesive portion 17a by the above-mentioned method, and the first metal foil 11 and the first heat resistant resin layer 12 are formed. And paste together. The first non-adhesive portion 17a is formed by leaving the first heat resistant resin layer 12 on the adhesive uncoated portion formed at a predetermined position without cutting, and by cutting the first heat resistant resin layer 12 One metal foil outer exposed portion 18 is formed. The first heat resistant resin layer 12 may be cut off at any time.

  The first heat-resistant resin layer 12 and the first thermoplastic resin layer 13 may be attached in any order, regardless of the order of attachment. Further, it is preferable to mark the position of the cuttable first non-adhesive portion 17a on the surface of the first heat-resistant resin layer 12 that has been pasted.

  The periphery of the first metal foil inner exposed portion 14 formed by the above process is masked with an easily peelable adhesive tape or the like, and the composition for the binder layer 64 and the composition for the positive electrode active material layer 61 are sequentially applied and dried. .. After the positive electrode active material layer 61 is completed by drying, the masking is peeled off.

Also for the second exterior material 20, the second metal foil 21, the second heat-resistant resin layer 22, and the second thermoplastic resin layer 23 are bonded together, the second metal foil inner exposed portion 24, and the second metal in the same procedure. The foil outer exposed portion 28, the second non-adhesive portion 27a and the fourth non-adhesive portion 27b are formed, the cuttable position is marked, and the binder layer 65 and the negative electrode active material layer 63 are laminated.
(II) Method of Laminating Each Layer After Coating of Polar Active Material Layer The composition for the binder layer 64 and the composition for the positive electrode active material layer 61 are provided on the portion of the first metal foil 11 that is the exposed portion 14 on the inside of the first metal foil. The binder layer 64 and the positive electrode active material layer 61 are laminated by sequentially applying and drying, and the surface of the positive electrode active material layer 61 is masked with an easily peelable adhesive tape or the like. A third adhesive is used, and if necessary, an adhesive uncoated portion is formed at a position corresponding to the third non-adhesive portion 17b, and the first metal foil 11 and the first thermoplastic resin layer 13 are bonded together. Then, the first thermoplastic resin layer 13 on the positive electrode active material layer 61 is cut off. Since the easily peelable adhesive tape and the first thermoplastic resin layer 13 are strongly adhered to each other with the second adhesive, the easily peelable adhesive tape is removed together with the first thermoplastic resin layer 13, and the positive electrode active material layer 61 is removed. Exposed. The positive electrode active material layer 61 is stacked on the first metal foil inner exposed portion 14.

  Further, an adhesive non-applied portion is formed at a position corresponding to the first non-adhesive portion 17a by the above method, and the first metal foil 11 and the first heat resistant resin layer 12 are attached to each other. The first non-adhesive portion 17a is formed by leaving the first heat resistant resin layer 12 on the adhesive uncoated portion formed at a predetermined position without cutting, and by cutting the first heat resistant resin layer 12 One metal foil outer exposed portion 18 is formed. Further, it is preferable to mark the position of the cuttable first non-adhesive portion 17a on the surface of the bonded first heat resistant resin layer 12.

  Also for the second exterior material 20, the second metal foil 21, the second heat-resistant resin layer 22, and the second thermoplastic resin layer 23 are bonded together, the second metal foil inner exposed portion 24, and the second metal in the same procedure. The foil outer exposed portion 28, the second non-adhesive portion 27a and the fourth non-adhesive portion 27b are formed, the cuttable position is marked, and the binder layer 65 and the negative electrode active material layer 63 are laminated.

When the first metal foil removing portion 19 and the second metal foil removing portion 29 are formed on the first exterior material 10 and the second exterior material 20 produced in the above process, the first metal foil 11 and the second metal foil 21. Can be formed by masking the portions other than the respective portions to be removed with a corrosion resistant film or a print with a resist ink and then etching.
[Battery element structure and materials]
The battery element 60 serving as a battery element includes a positive electrode active material layer 61 laminated on the first metal foil inner exposed portion 14, a separator 62, a negative electrode active material layer 63 laminated on the second metal foil inner exposed portion 24, and these. It is composed of associated layers. Although the binder layers 64 and 65 are not essential layers, it is preferable that they are interposed between the metal foil and the active material layer in order to enhance the adhesion between them. The preferable composition and thickness of each layer of the battery element 60 and the electrolyte to be encapsulated together with the battery element 60 are as follows. The compositions and the like described below are examples, and the present invention is not limited to these.

  The positive electrode active material layer 61 is made of, for example, a binder such as PVDF (polyvinylidene fluoride), SBR (styrene butadiene rubber), CMC (carboxymethyl cellulose sodium salt), PAN (polyacrylonitrile), linear polysaccharide, and lithium salt. (For example, lithium cobalt oxide, lithium nickel oxide, lithium iron phosphate, lithium manganate, etc.) are added to form a mixed composition. The thickness of the positive electrode active material layer 61 is preferably set to 2 μm to 300 μm. The positive electrode active material layer 61 may further contain a conductive auxiliary agent such as carbon black or CNT (carbon nanotube).

  For the negative electrode active material layer 63, for example, an additive (for example, graphite, lithium titanate, Si-based alloy, tin-based alloy, or the like) is added to a binder such as PVDF, SBR, CMC, PAN, or a linear polysaccharide. It is formed of the mixed composition or the like. The thickness of the negative electrode active material layer 63 is preferably set to 1 μm to 300 μm. The negative electrode active material layer 63 may further contain a conductive auxiliary agent such as carbon black or CNT (carbon nanotube).

  The separator 62 is, for example, a polyethylene separator, a polypropylene separator, a separator formed of a multi-layer film composed of a polyethylene film and a polypropylene film, or a wet or dry type in which a heat-resistant inorganic material such as ceramic is applied to the resin separator of the separator. The separator and the like composed of the above porous film can be mentioned. The thickness of the separator 62 is preferably set to 5 μm to 100 μm.

  The separator 62 preferably has a size larger than each side of the battery element chamber 40 by 2 to 5 mm in order to ensure insulation. Further, if the separator is not coated with the heat-resistant inorganic substance, it is fused with the first thermoplastic resin layer 13 and the second thermoplastic resin layer 23 during heat sealing, so that it is a large cover for the plurality of battery element chambers and the heat sealed portion. Size separators can also be used. In the electricity storage device 1 of FIG. 1B, one separator 62 covers all the battery element chambers 60.

  The binder layer 64 may be, for example, a layer formed of PVDF, SBR, CMC, PAN, linear polysaccharide, or the like. In addition, a conductive auxiliary agent such as carbon black or CNT (carbon nanotube) is further added to the binder layer 64 to improve the conductivity between the first metal foil 11 and the positive electrode active material layer 61. Good. The thickness of the binder layer 64 is preferably set to 0.2 μm to 10 μm. By setting the thickness of the binder layer 64 to 10 μm or less, it is possible to suppress the increase in the internal resistance of the core cell 60 due to the binder having no conductivity as much as possible.

  Examples of the binder layer 65 include a layer formed of PVDF, SBR, CMC, and PAN. A conductive auxiliary agent such as carbon black or CNT may be further added to the binder layer 65 in order to improve the conductivity between the second metal foil 21 and the negative electrode active material layer 63. The thickness of the binder layer is preferably set to 0.2 μm to 10 μm. When the binder layer has a thickness of 10 μm or less, it is possible to suppress the increase in the internal resistance of the battery element 60 due to the binder having no conductivity as much as possible.

As the electrolyte, an electrolyte containing a lithium salt and at least one solvent selected from the group consisting of water, ethylene carbonate, propylene carbonate, dimethyl carbonate, ethylmethyl carbonate, diethyl carbonate and dimethoxyethane can be mentioned. The lithium salt is not particularly limited, and examples thereof include lithium hexafluorophosphate, lithium tetrafluoroborate, and quaternary ammonium tetrafluoroborate salt. Examples of the quaternary ammonium salt include tetramethylammonium salt and the like. Further, the above-mentioned electrolyte may be gelled with PVDF, PEO (polyethylene oxide) or the like.
[Method for manufacturing power storage device]
In the electricity storage device 1, the separator 62 is sandwiched in the process of assembling the exterior body 30 with the first exterior material 10 and the second exterior material 20, and the electrolyte is injected and heat sealed. The first exterior material 10 and the second exterior material 20 described here are already laminated with the positive electrode active material layer 61 and the negative electrode active material layer 63.
(1) The first exterior body 10 and the second exterior body 20 face each other. At this time, the separator 62 is sandwiched between the positive electrode active material layer 61 and the negative electrode active material layer 63, and the injection needle is sandwiched so as to reach the positions of the positive electrode active material layer 61 and the negative electrode active material layer 63, and the both are stacked. The exterior body 30 is assembled. The end of the injection needle is pulled out of the exterior body 30.
(2) The periphery of each positive electrode active material layer 61 and negative electrode active material layer 63 is heat-sealed with the injection needle held therebetween to form heat-sealed portions 50 and 51.
(3) Inject an electrolyte through the injection needle, and then seal the injection needle.
(4) Preliminarily charge and put in a constant temperature bath at 100 ° C. for 8 hours to degas.
(5) Remove the injection needle and heat-seal the hole of the removal hole to completely close it. Due to this heat sealing, the battery element 60 and the electrolyte are enclosed in the room.
(6) If necessary, the first heat-resistant resin layer 12 on the first non-adhesive portion 17a is cut off to form the first metal foil outer exposed portion 18, and the second heat-resistant on the second non-adhesive portion 27a is formed. The resin layer 22 is cut off to form the second metal foil outer exposed portion 28. Further, if necessary, the first metal foil removing portion 19 and the second metal foil removing portion are formed.

  The above-mentioned manufacturing method is only one example, and is not particularly limited to such a manufacturing method.

  Although the use of the assembled battery according to the present invention is not limited, it is a power source for automobiles, bicycles, motorcycles, trains, airplanes, ships, etc. that require electricity, specifically, the capacity of hybrid vehicles, electric vehicles, industrial / household storage batteries, etc. Can be used for lithium secondary batteries (lithium ion batteries, lithium polymer batteries, etc.), solid state batteries, lithium ion capacitors for the same purpose, and electric double layer capacitors for the same purpose.

Next, specific examples of the present invention will be described, but the present invention is not particularly limited to these examples.
<Example>
An electricity storage device 1 having the structure shown in FIGS. 1A and 1B was produced.

The first outer packaging material 10 and the second outer packaging material 20 constituting the outer packaging body 30 of the electricity storage module 1 are “(II) a method of laminating the respective layers after coating the active material layer” of the two methods described above. It was produced based on.
(Preparation of first exterior material)
The first metal foil 11 is a soft aluminum foil of A8079 classified according to JIS H4160 and having a thickness of 40 μm, and subjected to chemical conversion treatment on both sides. The first heat resistant resin layer 12 is a 25 μm thick biaxially stretched polyamide film, and the adhesive for the first adhesive layer 15 is a two-component curable polyester polyurethane adhesive. The first thermoplastic resin layer 13 is an unstretched polypropylene film having a thickness of 40 μm, and the adhesive for the third adhesive layer 16 is a two-component curing type olefin adhesive. As a paste for the positive electrode active material layer 61, 100 parts by weight of a positive electrode active material containing lithium cobalt oxide as a main component, 5 parts by weight of acetylene black as a conductive material, and 10 parts by weight of vinylidene fluoride as a binder / electrolyte holding agent. As the paste, a paste kneaded and dispersed in an organic solvent was used. PVDF dissolved in dimethylformamide was used as an adhesive for the binder layer 64.

  The size of the exposed portion 14 of the first metal foil inner side was 45 mm × 81 mm, and 20 pieces of 5 × 4 were formed.

  An adhesive agent for the binder layer 64 was applied to one surface of the first metal foil 11 at 20 locations to be the first metal foil inner exposed portion 14 at intervals of P1: 20 mm, which is the width of the heat sealing portion 51. The one coating portion of the binder layer 64 is 45 mm × 81 mm, and the coating thickness is 0.5 μm. The paste for the positive electrode active material layer 61 was applied onto the binder layer 64 and dried to form the positive electrode active material layer 61 having a thickness of 30 μm. A polyester adhesive tape for masking was attached on the positive electrode active material layer 61.

  On the other surface of the first metal foil 11, an adhesive non-applied portion is formed at a portion corresponding to the first non-adhesive portion 17a, the adhesive for the first adhesive layer 15 is applied, and the first adhesive layer 15 is applied with a dry laminating method. One heat resistant resin layer 12 was attached. The width Q1 of the first non-adhesive portion 17a, that is, the width of the adhesive-unapplied portion is 10 mm, and the width P1 is formed at the center of the portion to be the heat-sealing portion 51 of 20 mm. After pasting, it is aged in a 50 ° C. aging furnace for 3 days, and the thickness of the first adhesive layer 15 after aging is 3 μm. The position corresponding to the center of the first non-adhesive portion 17a on the surface of the bonded first heat resistant resin layer 15 was marked.

  Next, the first thermoplastic resin layer 13 is attached to one surface of the first metal foil 11 by a dry laminating method using the adhesive for the third adhesive layer 16, and the aging furnace at 50 ° C. is used for 3 days. I was cured. After the curing, the first thermoplastic resin layer 13 at the portion where the polyester adhesive tape was attached was cut with a laser sword to expose the positive electrode active material layer 61.

The first exterior material 10 was trimmed and cut to have a plane size of 335 mm × 415 mm.
(Second exterior material)
The second metal foil 21 is a C1100R hard copper foil having a thickness of 15 μm classified by JIS H3100, and both surfaces thereof were subjected to chemical conversion treatment. The second heat resistant resin layer 22 is a biaxially stretched polyester film having a thickness of 12 μm, and the adhesive for the second adhesive 25 layer is a two-component curing type polyester polyurethane adhesive. The second thermoplastic resin layer 23 is an unstretched polypropylene film having a thickness of 40 μm, and the adhesive for the fourth adhesive layer 26 is a two-component curing type olefin adhesive. As the paste for the negative electrode active material layer 63, 57 parts by mass of the negative electrode active material containing carbon powder as a main component, 5 parts by mass of PVDF as a binder / electrolyte holding agent, and 10 parts by mass of a copolymer of hexafluoropropylene and maleic anhydride. Part, acetylene black (conductive material) 3 parts by mass, and N-methyl-2-pyrrolidone (organic solvent) 25 parts by mass were kneaded and dispersed. PVDF dissolved in dimethylformamide was used as an adhesive for the binder layer 65.

  An adhesive agent for the binder layer 65 was applied to one surface of the second metal foil 21 at 20 locations to be the second metal foil inner exposed portion 24 at a P2 (= P1): 20 mm interval. The one coated portion of the binder layer 65 is 45 mm × 81 mm, and the coating thickness is 0.5 μm. In addition, the interval P2 is a dimension that is the width of the heat sealing portion 51. The paste for the negative electrode active material layer 63 was applied on the binder layer 65 and dried to form the negative electrode active material layer 63 having a thickness of 30 μm. A polyester adhesive tape for masking was attached on the positive electrode active material layer 63.

  On the other surface of the second metal foil 21, an adhesive non-applied portion is formed at a portion corresponding to the second non-adhesive portion 27a, the adhesive for the second adhesive layer 25 is applied, and the second adhesive layer 25 is applied with a dry laminating method. The two heat resistant resin layers 22 were attached. The width Q2 of the second non-adhesive portion 27a, that is, the width of the adhesive-unapplied portion is 10 mm, and the width P2 is formed at the center of the portion to be the heat sealing portion 51 having a width of 10 mm. After pasting, the film is aged in an aging furnace at 50 ° C. for 3 days, and the second adhesive layer 25 after aging has a thickness of 3 μm.

  Next, the second thermoplastic resin layer 23 is attached to one surface of the second metal foil 21 by a dry laminating method using an adhesive for the fourth adhesive layer 26, and the aging furnace at 50 ° C. is used for 3 days. I was cured. After curing, the second thermoplastic resin layer 23 at the portion where the polyester adhesive tape was adhered was cut with a laser knife to expose the negative electrode active material layer 61.

The second exterior material 10 was trimmed and cut to have a plane size of 335 mm × 415 mm.
(Production of power storage module)
As the separator 62, a porous wet separator made of polypropylene and having a thickness of 335 mm × 415 mm and a thickness of 8 μm was used. The separator 62 is sized so that the positive electrode active material layers 61 and the negative electrode active material layers 63 of the twenty battery element chambers 40 can be insulated by one separator 62. As an electrolyte, a mixed solvent in which ethylene carbonate (EC), dimethyl carbonate (DMC), and ethyl methyl carbonate (EMC) were mixed in an equal volume ratio, lithium hexafluorophosphate (LiPF ₆ ) at a concentration of 1 mol / L. The dissolved electrolytic solution was used.
(1) The first exterior body 10 and the second exterior body 20 were opposed to each other. At this time, the separator 62 is sandwiched between the positive electrode active material layer 61 and the negative electrode active material layer 63, and the injection needle is sandwiched so as to reach the positions of the positive electrode active material layer 61 and the negative electrode active material layer 63, and the both are stacked. The exterior body 30 was assembled. Further, the end of the injection needle was pulled out of the exterior body 30.
(2) The periphery of each of the positive electrode active material layer 61 and the negative electrode active material layer 63 was heat-sealed to form the heat-sealed parts 50 and 51.
(3) 1 mL of electrolyte was injected through each of the injection needles, and the injection needles were sealed.
(4) The first heat-resistant resin layer 12 is cut off at one place on the first non-adhesive portion 17a to form the first metal foil outer exposed portion 18, which is used as a temporary positive electrode terminal, and the second non-adhesive portion 27a. The second heat-resistant resin layer 22 is cut off at one place above to form a second metal foil outer exposed portion 28, which is used as a temporary negative electrode terminal, and clips are attached to the positive and negative terminals to obtain a battery voltage of 4.2V. The battery element chamber 40 was degassed by placing it in a constant temperature bath at 100 ° C. for 8 hours.
(5) After degassing, remove the injection needle, and pinch the hole at the discharge hole with a hot plate at 200 ° C under a reduced pressure of 0.086 MPa and a pressure of 0.3 MPa for 3 seconds. Sealing was performed. By this heat sealing, the core cell and the electrolyte were enclosed in the battery element chamber 40.
<Evaluation>
The electricity storage device 1 of the example obtained as described above was fully charged to 4.2V. Then, it cut | disconnected so that the number of battery element chambers 40 might be 1, 2, 5, 12, and was divided | segmented into the four electrical storage devices 1a. In the divided power storage device 1a, the first heat-resistant resin layer 12 is cut off at one location of the first non-adhesive portion 17a facing the cut end to form the first metal foil outer exposed portion 18 to form a positive electrode terminal. The second heat-resistant resin layer 22 was cut off at one place of the second non-adhesive portion 27a to form the second metal foil outer exposed portion 28 to form a negative electrode terminal. Vinyl tape was attached to the cut ends other than the positive electrode terminal and the negative electrode terminal to prevent a short circuit.

  Each of the four power storage devices 1a was charged and discharged at 1 C at room temperature of 18 ° C. (charged for 1 hour and discharged for 1 hour) 100 times, and the voltage and the capacity when fully charged again were measured. The measured values are shown in Table 1.

  After the above discharge test, the vinyl tape at the cut end was peeled off and the presence or absence of liquid leakage was visually observed. The observation results are shown in Table 1.

  As shown in Table 1, it was confirmed that the divided power storage device 1a had a battery capacity according to the size and did not cause liquid leakage due to disconnection.

1, 2, 3, 4, 5, 6 ... Electric storage device 1a, 5a ... Divided electric storage device 10 ... First exterior material 11 ... First metal foil 12 ... First heat resistant resin layer 13 ... First thermoplastic resin layer Reference numeral 14 ... First metal foil inner exposed portion 15 ... First adhesive layer 16 ... Third adhesive layer 17a ... First non-adhesive portion 17b ... Third non-adhesive portion 18 ... First metal foil outer exposed portion 19 ... First Metal foil removing portion 20 ... Second exterior material 21 ... Second metal foil 22 ... Second heat resistant resin layer 23 ... Second thermoplastic resin layer 24 ... Second metal foil inner exposed portion 25 ... Second adhesive layer 26 ... Fourth adhesive layer 27a ... Second non-adhesive part 27b ... Fourth non-adhesive part 28 ... Second metal foil outer exposed part 29 ... Second metal foil removing part 30 ... Exterior body 40 ... Battery element chamber 50, 51 ... Heat Sealing portion 60 ... Battery element 61 ... Positive electrode active material layer 62 ... Separator 63 ... Negative electrode active material layer 70 ... Insulating sheet

Claims (6)

The first heat-resistant resin layer is laminated on one surface of the first metal foil via the first adhesive layer, and the first thermoplastic resin layer is laminated on the other surface via the third adhesive layer, A first exterior material having a first metal foil inner exposed portion where the first metal foil is exposed on the surface of the first thermoplastic resin layer side,
A second heat resistant resin layer is laminated on one surface of the second metal foil via a second adhesive layer, and a second thermoplastic resin layer is laminated on the other surface via a fourth adhesive layer, A second exterior material having a second metal foil inner exposed portion where the second metal foil is exposed on the surface of the second thermoplastic resin layer side,
A battery element having a positive electrode active material layer laminated on the first metal foil inner exposed portion, a negative electrode active material layer laminated on the second metal foil inner exposed portion, and a separator arranged between them. ,
The first thermoplastic resin layer of the first exterior material and the second thermoplastic resin layer of the second exterior material face each other, and the heat sealing portion in which the first thermoplastic resin layer and the second thermoplastic resin layer are fused to each other. By being surrounded by, an exterior body having a plurality of battery element chambers facing the first metal foil inner exposed portion and the second metal foil inner exposed portion is formed in the chamber,
The battery element enclosed with the electrolyte in the battery element chamber, the positive electrode active material layer is conducted to the first metal foil inner exposed portion and the negative electrode active material layer is conducted to the second metal foil inner exposed portion,
In the heat-sealed portion between the adjacent battery element chambers, the first exterior material has a first non-adhesive portion in which the first adhesive layer does not exist between the first metal foil and the first heat resistant resin layer, The electricity storage device, wherein the second exterior material has a second non-adhesive portion where the second adhesive layer does not exist between the second metal foil and the second heat resistant resin layer.   The first exterior material has a first metal foil outer exposed portion where the first metal foil is exposed without the first heat-resistant resin layer facing the first non-adhesive portion, and the second exterior material is the second non-adhesive material. The electricity storage device according to claim 1, further comprising a second metal foil outer exposed portion where the second metal foil is exposed without the second heat resistant resin layer facing the adhesive portion.   The electricity storage device according to claim 2, wherein the first metal foil outer side exposed portion and the second metal foil outer side exposed portion are covered with an insulating sheet.   The first exterior material has a first metal foil removal portion where a part of the first metal foil facing the first non-adhesive portion is removed, and the second exterior material faces the second non-adhesion portion. (2) a second metal foil removing section from which a part of the metal foil is removed, and in the stacking direction of the first exterior material and the second exterior material, the first metal foil removing section and the second metal foil removing section The electricity storage device according to claim 1, wherein the first metal foil and the second metal foil are formed at positions where they do not overlap with each other.   The first exterior material has a third non-adhesive portion in which a third adhesive layer does not exist at a symmetrical position of the first non-adhesive portion with the first metal foil interposed therebetween, and the second exterior material is the second metal foil. The electricity storage device according to claim 1, further comprising a fourth non-adhesive portion in which the fourth adhesive layer does not exist at a symmetrical position of the second non-adhesive portion with the fourth non-adhesive portion interposed therebetween. Between the said 1st non-adhesion part and the 2nd non-adhesion part, the 1st thermoplastic resin layer and the 2nd thermoplastic resin layer have the non-fusion part which is not fusion-bonded. The electric storage device according to any one of 1.

Images